Pathopoiesis Mechanism of Smoking and Shared Genes in Pancreatic Cancer
To raise new questions, new possibilities, to regard old problems from a new angle requires creative imagination and marks the real advance in science (Einstein & Infeld, 1938, p. 92).
Pancreatic cancer (PC) at the start of the 21st century continues to be a vital unresolved health problem, remaining as one of the deadliest human cancers. By the year 2030, it is projected that PC will be the second leading cause of cancer death after lung cancer among the major types of cancer (Rahib et al. 2014). The outcome of this study would provide valuable insights into the etiopathogenesis of PC and cancer types with a shared-gene association (CTSG-A), as well as the possible recognition of the probable unique pattern of PC malignancy among defined age groups, between men and women, in correlation to the modification effect of smoking to cancer predisposition genes (CPG), or its combined impact. Additional understanding of the pathopoiesis dynamics of smoking status, gender, and age in individuals with CPG in the induction and promotion of PC could help promote pre- and post behavioral diagnosis change. This study may assist in developing a novel patient management approach to accurately assess the disease burden under the lens of public health and modern epidemiology. Although genetic changes can be either somatic or hereditary, described as de novo (new), PC does not arise de novo (Maitra & Hruban, 2008), but rather initiated by a probable gene mutation such as p16/CDKN2A that results to debilitating metabolic effects of uncontrolled growth. Given the assumption that a disease is caused by a factor that can be controlled, exploring the relationship between modifiable health behaviors such as smoking and family cancer history (FCH), CPG or shared genes was a legitimate endeavor. In this study, genetic syndromes associated with PC were interchangeably referred to as FCH, CPG, or shared genes. Pancreatic cancer and other cancers found to have a shared-gene association (S-GA) were the dependent variables, and smoking status, age, and gender were the independent variables; this study addressed the following research questions (RQs) and hypotheses:
RQ1: Is cigarette smoking associated with the etiopathogenesis of pancreatic cancer and cancer types with shared gene association (CTSG-A)?
H01: Smoking level has no correlation with prevalence of PC and CTSG-A.
H1: Smoking can increase the risk of PC and CTSG-A.
RQ2: Is there a relationship between the combined role of age and gender in the etiopathogenesis of PC and CTSG-A?
H02: Age and gender have no correlation with prevalence of PC and CTSG-A.
H2: Age and gender are correlated with the prevalence of PC and CTSG-A.
The unique contribution of this dissertation to the current body of knowledge involved examining the links between tobacco use, gender, age, PC, and shared genes. This dissertation could promote population health, and lessons learned could reshape the current understanding of cancer epidemiology by providing the scientific justification for the implementation of screening, surveillance, and education programs. The outcome of this dissertation would fit into the practical intervention approach of adopting a healthy lifestyle such as smoking cessation as part of positive, meaningful social change to improve prognosis and quality of life during PC progression.
Pandol et al. (2012) noted the economic burden of PC with an expected yearly cost of $4.9 billion and underscored the significance of determining the mechanisms underlying the effect of smoking compounds that may provide additional insights into the pathogenesis of the disease. The investigation gave valuable insights into the etiopathogenesis of pancreatic growth from its induction and promotion. Moreover, findings of Hart, Kennedy, and Harvey (2008); and Schenk et al. (2001) support the unique probable contribution of this dissertation to the existing body of knowledge, generating a snapshot of a possible correlation of smoking, gender, and age to the development of PC and CTSG-A, enhancing the knowledge on the pathopoiesis mechanism of these predictors in disease induction and promotion. The plethora of findings of the past and present studies highlighted the causal significance of modifiable risk factors and genetics in the pathosis of PC. The goal of these studies falls largely within the confines of understanding the insights of genetic alterations and specific modifiable risk factors. Much of the recent research concentrates in this line of inquiry; therefore, recognizing the modifying effect of smoking to individuals with family aggregation justifies the merit of this dissertation and future endeavors.
Blackford et al. (2009) noted that previous researchers overlooked the distinction between the passenger and driver mutations that explains the often unconvincing associations between smoking and driver mutations. Recognizing this gap, and while there are continued studies on different aspects of the PC genomic landscape, this dissertation intends to provide a descriptive analysis of the prevalence pattern of PC and CTSG-A known to have increased risk of extrapancreatic malignancies versus nonsmokers. The mechanisms through which smoking, gender, age, and CPG affect PC remain unknown, making it critical to explore the role of these three predictors in the disease clustering to develop a more efficient management and clinical approach. With an exhaustive understanding of the patterns of somatic alteration in pancreatic carcinogenesis comes the opportunity to understand the influence of these factors on metastatic progression (Yachida & Iacobuzio-Donahue, 2013). The burden of chronic diseases such as PC is often neglected on the public agendas. The increasing annual economic burden of PC is beyond genetics and social inequalities, making it necessary to embrace the shift in the level of analysis from traditional to modern epidemiologic and New Public Health approach. The significance of the successful delivery of the New Public Health both at the level of society and individual behavior (Halpin et al., 2010) justifies the intent of this dissertation on the need for further exploration of the pathopoiesis mechanism of tobacco use and FCH, the etiopathogenic role of gender and age. The unveiling of the “Precision Medicine Initiative” during the State of the Union Address of President Barack Obama on January 20, 2015, springboard the new effort of revolutionizing a new model of patient-powered research that could accelerate biomedical discoveries and provide clinicians with new tools, knowledge, and therapies. New research directions are warranted to reverse the lethal outcome of this disease.
Study Design and Approach
The causality of tobacco-related mutagenic risk factors and the correlation between gender and age and CPG will not only raise awareness of the significance of cancer risk screening and counseling but will also increase the understanding of environmental, genetic, and biodemographic interaction (EGBI) contributing to the development and progression of PC. The results of this study may be used to promote lifestyle change in reducing cancer risk. Improving the perceived corollary of individuals with inherited genes and quality of life during the expression or final stage of the disease is dependent on the favorable adjustment of behavioral risk factors. This study intended to explore the association between smoking, gender, and age in individuals with CPG. I used a cross-sectional design to determine the prevalence of pancreatic cancer and CTSG-A among smokers and non-smokers. The potential association of smoking, gender, and age as predictors of the outcome variable (PC/CTSG-A) were explored using a cross-sectional design. Secondary data were recoded and randomized using IBM Statistical Package for the Social Sciences (SPSS, Version 23, 64-bit edition). Although logistic regression makes no assumptions about the distributions of the predictor variables (smoking, gender, age), ordinal modeling was the fundamental property of the design of this study to test whether smoking level and age are effect modifiers to inherited genes or combined causative predictors in the induction and promotion of PC and CTSG-A.
The population for the study was defined as participants of the Behavioral Risk Factor Surveillance System (BRFSS) survey. Subject selection criteria were set narrowly, by selecting specifically those who smoke and do not smoke with PC/CTSG-A (survivorship module), versus non-smokers with PC/CTSG-A. Association between smoking, age, gender, PC, and PC/CTSG-A are explored using hypothetical conceptual cohort. A hypothetical conceptual cohort is defined as participants from the 2014 BRFSS survey who qualified as high-risk based on the level of smoking. The dependent variable under Level 1 or Category 1 in this dissertation comprised cancer types with P16(CDKN2A) and PRSS1 mutations. The cancer types that were included as part of this category were pancreatic, melanoma, esophageal, leukemia, lung, bladder, renal, brain, osteosarcoma (bone), and cancer of the head and neck. Level two or category two includes cancer types with BRCA1, STK11, and LKB1 mutations. While p16 is related to breast cancer, BRCA1 is two times to have a relative risk of PC, with higher risk by age 70. The cancer types that are considered to be part of this category are breast, ovarian, and prostate cancer. Level three or category three are composed of cancer types with bMLH1, and bMSH2 mutations. The cancer types in this category are endometrial, colorectal, and stomach cancer. Regression methods were used to assess and adjust for confounding, and determine whether there is effect modification, as well as simultaneously evaluate the relationships of risk factors (smoking, age, gender). Given that this study involves PC/CTSG-A, and more than one independent variables, ordinal logistic regression analysis was performed to assess confounding and effect modification. The impact of multiple risk factors (smoking, gender, age) is examined as opposed to focusing on a single risk factor. Two separate logistic regression analyses were conducted to assess differences in induction and promotion of pancreatic cancer/CTSG-A by gender and three age groups (<51, 52-69, 70>).
The effect of tobacco use, age, and sex in the etiopathogenesis of PC and CTSG-A was assessed using cumulative odds ordinal logistic regression with proportional odds. While the results of this study supported the null hypotheses that smoking does not correlate with the prevalence of PC and CTSG-A as confirmed by the GENLIN parameter estimates, both gender and age are statistically significant predictors with <.05 p-values. The odds of male respondents developing PC and CTSG-A versus the female respondents is .418 (95% Cl, .344 to .509) with a statistically significant effect, X2 (1) = 75.507. The odds ratio of 1.374 (95% CI, 1.184 to 1.595), Wald χ2(1) = 17.538 is suggestive to the increased probability of developing the disease as the persons reach the age between 62 and 69 years of age. Separate binomial logistic regression analysis shows age was associated with an increased likelihood of developing the disease. Analogous to the results of the ordinal logistic regression analysis, the odds of the male participants of the 2014 BRFSS survey is 2.472 times greater to develop the disease as opposed to female respondents. The findings of this study could support the importance of behavioral risk factor and their roles in reducing the prevalence of PC and CTSG-A, enhancing the late-stage quality of life.
Ab-initio studies have established that family history of PC can manifest due to genetic factors and shared environmental factors. The scientific perspective of this dissertation, current, and past studies are parallel to Albert Einstein’s concept of “natura naturans”—everything is connected. In this dissertation, the assumption that P16(CDKN2A), PRSS1, BRCA1, STK11, LKB1, bMLH1, and bMSH2 are correlated with the development of the disease is mathematically or statistically correct and deserves further investigation.
Presenting a New Metatheory
The Unified Paradigm of Cancer Causation (UPCC), a metatheory introduced in this dissertation could provide arguments on the positive association (synergism) between tobacco use and FCH, giving more clarity to Rothman’s notion of epidemiologic interaction or the paradigm of sufficient cause. UPCC is a composite construct of the germ theory and the somatic mutation theory of carcinogenesis (SMT) in combination with the traditional or Darwinian evolutionary system (Greaves & Maley, 2012), Knudson’s two-hit theory (Hermanowicz, 2015), genome theory, Darwinian theory of social change (Richerson & Boyd, 2000), and the multi-level biologic, social integrative construct (MBASIC). The theoretical cocktail of UPCC could interlock new insights on tumor initiation, metastases diagnostic, and treatment strategies. The dynamic interplay of gene-culture transmission recognized in UPCC could initiate the evolution of culture that embraces the value of evidence-based screening, surveillance, management, and personal genomics. Central to human adaptations is the use of socially learned information (Richerson, Boyd & Henrich, 2010), from literacy program of a health system, emphasizing the significance of 21st-century approach. The combined causal association of a variety of levels as recognized by Lynch and Rebbeck (2013) that are linked to cancer incidence and mortality justify the supposition of UPCC. It is critical to underscore the magnitude of intercalating the mandatory early screening, and management of the health system. The complex, integrative approach of UPCC supports the views of Loomis, and Wing (1990), Pearce (1996), and McEwen and Getz (2013) in embracing the new epidemiologic paradigm congruent to the advances in cancer genome sequencing. Theorizing the pathopoiesis mechanism of smoking, inherited genes, and association of gender and age in the etiopathogenesis of PC/CTSG-A warrants exploration of its causal footprints, conjoining both biomedical and lifestyle (Krieger, 2011).
New Public Health at the Level of Society and Individual Behavior
Darwinism is a collection of concepts, empirical methods and mathematical tools designed to understand the dynamics of genetics and cultural evolution (Richerson & Boyd, 2000). Therefore, this dissertation supports the rationale of cultural value transmission of smoking cessation that could lower the risk to individuals with CPG. Smoking cessation as a cultural item is a clear implication for positive social change. While smoking cessation is the probable social implication of this dissertation, it is important to stress the epidemiologic value of a study on the apparent correlation between gender and age, modification effect of tobacco use among individuals with PC and CTSG-A. The outcome of a risk factor epidemiologic study in individual terms could uplift precision medicine to meet the challenges in tailoring medical interventions based on patient’s biological profile, genetic and epigenetic traits, giving a better understanding of EGBIs. The results of this dissertation have several implications for social change, such as recognizing cultural values in developing effective communication structured from the statistically significant etiopathogenic role of gender and age in the development of PC and CTSG-A. This will give a clear understanding of what to ask, and what actions to take, allowing the family to openly explore treatment alternatives during the terminal phase of the illness (Ballard-Reisch & Letner, 2003). Primary prevention must be prioritized as an integral part of global cancer control. No regulatory standards nor advanced innovations could change the hearts and minds of the general population unless evidence-based studies support it. Social change will be dependent upon the continued dissemination of current cancer research built on integrative social molecular pathological epidemiology (MPE). Pearce (1996) argue that epidemiology must reintegrate itself into public health and must rediscover the population perspective. However, while the new paradigm of downstream (individual) approach could produce a lifestyle approach to social policy, the cumulative outcome of research in cancer epidemiology could equate positive implications to population health.
Improving the future of individuals diagnosed with PC through the concerted efforts of policymakers, public health professionals, clinicians and scientists, the Recalcitrant Cancer Research Act of 2012 lays the foundation for a heightened focused on further development and use of prevention, screening and therapeutic strategy (Rahib et al., 2014). The genuine progress against PC as recalcitrant cancer warrants strategic direction and guidance on the continued understanding, development of efficient early detection strategy and identifying therapeutic targets that could stem the tide of its growing economic burden.
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Cancer is a growing global problem and is increasing in the proportion of the burden among low income and middle-income countries. While the pattern can be blamed on demographic change and to transition in risk factors, it can be prevented by present knowledge of modifiable risk factors and continued research on cancer genetic landscape. Pancreatic cancer (PC) has the lowest 5-year relative survival rate, and treatment for metastatic pancreatic cancer are minimally effective. In early 2000, incidence rates of PC have been approximately stable in many European countries. Ma, Siegel, & Jemal (2013) noted that the complex patterns of PC death rate trends remain unexplained by known risk factors. Given that there are only 20% of patients diagnosed with the disease are eligible for surgical resection (Spanknebel & Conlon, 2000); it is paramount to rationalize the importance of the development of public health policies designed in lowering the economic burden of the disease. Money saved from reducing the overall economic burden of the disease could open up resources and funding allocation to pursue other public health projects for the better good of the many. A synergy begets by outcomes research and epidemiology can provide unique and compelling insights on the significance of interventions designed to improve the quality and effectiveness of care in populations. Recent developments in non-communicable diseases (NCDs) epidemiology highlight the increasing worldwide burden of NCDs as the result of complicated interactions between several demographic, economic and social structural changes (Suhrcke et al., 2006), considered to be strongly associated with the globalization of unhealthy lifestyles (Ferretti, 2015). Between 1997 and 2002, unhealthy behavior index (UBI) tends to increase along with the level of human development. In the USA and Japan, mortality has been declining since the previous decades, including Argentina, Colombia, Puerto Rico and Hong Kong, with a reversal of trends over the most recent years (Bosetti et al., 2012). Trends were also declining in countries of central/eastern Europe with highest rates, such as the Czech Republic, Croatia, and Hungary, but mortality rates reached 8.5/100,000 men in 2006 in Russia. Ferretti (2015) found that Belarus and Russian Federation are the two countries with the unhealthiest NCD-related lifestyle. Tobacco use, and in particular cigarette smoking, is the single largest preventable cause of cancer in the European Union (EU), including second-hand smoke (SHS), that is still common in indoor, indoor public places, and more so in the homes of smokers (Leon et al., 2015). Secondhand smoke, referred to as ETS, contains many of the same carcinogenic compounds as the mainstream smoke inhaled by active smokers (World Health Organization, International Agency for Research on Cancer, 2004; Bao et al., 2009).
In early 2000, incidence rates of PC have been approximately stable in many European countries, Japan, Australia and the US. Overall trends are likely to improve in the next future with more favorable recent trends in young adults from 30 to 49 years old (Bosetti et al., 2012). PC has the global ranking of 13 as the most common cause of cancer and represents the 7th most frequent cause of cancer death, and accounts for about 3% of all cancers in the US with cancer mortality of 7% (American Cancer Society, Inc., 2016). PC ranked fourth among all cancers in the U.S. (Jamal et al., 2003), the mortality rate of the disease in China ranks sixth (Ding et al., 2015). There are more than 278,000 new diagnoses of pancreatic ductal adenocarcinoma (PDAC) annually worldwide, accounting for 10% of all digestive system cancers (Ferlay, et al., 2010). The 5-year survival rate makes the prognosis of this disease dismal and the twelfth most common cancer in the world with 338,000 new cases diagnosed in 2012. Czech Republic had the highest rate of pancreatic cancer with a 9.7 age-standardized rate per 100,000 (World), followed by Slovakia and Armenia. (World Cancer Research Fund International, 2015). The highest incidence of PC is found in the Czech Republic, ranking second in men (11.9 per 100,000) and first in women (7.9 per 100,000). The key PC statistics according to the American Cancer Society are lifetime risk of 1.5% (1 in 65) for both men and women; 27,670 men and 25,400 women will be diagnosed; 21,450 men and 20,330 women will die of the disease. Using data from nine registries of the Surveillance, Epidemiology and End Results (SEER) program, Shaib, Davila and El‐Serag (2006) examined temporal changes in the incidence and survival of patients with pancreatic adenocarcinoma. The study identified 58,655 cases of pancreatic cancer. Age-adjusted and age-specific was calculated grouped in 5 yearly intervals: 1977–1981, 1982–1986, 1987–1991, 1992–1996 and 1997–2001. The average age-adjusted yearly incidence of PC was 11.3 per 100 000 in 1977–1981 and 10.9 per 100 000 in 1997–2001. Overall incidence rates were also calculated for different subgroups based on gender (men, women) and race (White, Black, others) and geographic location as defined by SEER registries. Men had approximately 30% higher incidence rates than women with an overall average age-adjusted yearly incidence rate of 13.0 per 100 000 (95% CI: 12.9–13.2) among men and 9.8 per 100 000 (95% CI: 9.7–9.9) among women. Among different racial groups, Blacks were approximately 50% more affected when compared with Whites and people of other races. The overall average age-adjusted yearly incidence rates were 16.4 per 100 000 (95% CI: 16.0–16.9) for Blacks, 10.8 per 100 000 (95% CI: 10.7–10.9) for Whites and 9.8 per 100 000 (95% CI: 9.4–10.1) for people of other races. The overall average age-adjusted yearly incidence rates were 16.4 per 100 000 (95% CI: 16.0–16.9) for Blacks, 10.8 per 100 000 (95% CI: 10.7–10.9) for Whites and 9.8 per 100 000 (95% CI: 9.4–10.1) for people of other races.
Primary prevention must be prioritized as an integral part of global cancer control. According to Vineis et al., (2014), primary prevention has several advantages: the effectiveness could have benefits for people other than those directly targeted, avoidance of exposure to carcinogenic agents is likely to prevent other non-communicable diseases, and the cause could be removed or reduced in the long term through regulatory measures against occupational or environmental exposures such as environmental tobacco smoke (ETS). Improving the future of individuals diagnosed with PC through the concerted efforts of policymakers, public health professionals, clinicians and scientists, the Recalcitrant Cancer Research Act of 2012 lays the foundation for a heightened focused on further development and use of prevention, screening and therapeutic strategy (Rahib et al., 2014). Introduced initially as the Pancreatic Cancer Research and Education Act, the Recalcitrant Cancer Research Act was signed into law as part of the National Defense Authorization Act on January 2, 2013, through broad bi-partisan and bi-cameral support (The Pancreatic Cancer Action Network, 2013). The genuine progress against PC as a recalcitrant cancer warrants strategic direction and guidance on the continued understanding, development of efficient early detection strategy and identifying therapeutic targets that could stem the tide of its growing economic burden.
PubMed, Google Scholar, and JSTOR were searched from 1990 to present. Scholarly materials considered in this systematic literature review are epidemiologic research of environmental tobacco smoke (ETS) and assess its relationship to pancreatic cancer, as well as other demographics related to the disease. Peer-reviewed literature is identified using Thoreau Multi-Database. I identified a total of 25 studies, 15 articles met the final inclusion criteria.
After the completion of the Human Genome Project (HGP) in 2003, the theory used in the studies in this systematic scholarly literature review is the Genome Theory of Cancer Evolution. Moreover, building on the premise of one of the variants of sociopolitical epidemiologic theory, the fundamental cause approach in the 2014 study of Rubin et al. stated that while the variant’s hypothesis predicts the increased prevention of lung cancer with the development and dissemination of knowledge of the causal link of tobacco use to the disease. There has been no change in the mortality of pancreatic cancer because of lack of major prevention or treatment innovations. The data analyzed in this study supported the fundamental cause hypothesis and asserted the impact of access to resources amplified by the availability of preventive knowledge. The study highlighted the role of public health interventions and policies in facilitating more equitable distribution of new health-enhancing knowledge and the faster uptake and utilization among lower socioeconomic status (SES) group. On the contrary, the argument of integrating the individual-biologic and population levels of analysis that embody the premise of ecosocial framework put public health in the conundrum of the proximal-distal divide. The interlinking of the traditional epidemiologic level of intervention (upstream or distal) and the modern epidemiologic level of intervention (downstream or proximal) embraced by both biomedical and social determinist frameworks are proposed to be replaced with explicit language about levels, pathways, and power (Krieger, 2008). Parallel to the argument of integrating the individual-biologic and population levels of analysis (Chen et al., 2015), utilizing a 2 × 2 factorial design, patients were randomized to either observation, 5-FU based chemotherapy, 5-FU based chemoradiation, or both after undergoing curative resection, Neoptolemos et al. (2004) investigated the efficacy of both chemotherapy and chemoradiation in patients undergoing surgical resection (p. 15565). In this 2004 study of Neoptolemos et al., a significant survival benefit was found in patients who received systemic 5-FU based chemotherapy, leading to a European standard of care that does not include radiation therapy in the multimodal treatment of the disease. On the other hand, because of the randomization scheme, the relatively low-dose of radiation administered and the lack of quality control of the radiotherapy administered, the negative prognostic effect of chemoradiotherapy was not accepted within the United States. Overall, after a review of clinically relevant biomarkers in PC, while the neoadjuvant approach is presently the best available strategy, both epigenetic profiling and the identification of various oncologic microRNA molecules, contributes to the field of PC treatment (Neoptolemos et al., 2004). While the predictive and prognostic abilities, of molecular biomarkers, have gained popularity, surgical resection in combination with chemotherapy and/or chemoradiation have the best opportunity for long-term survival.
In the discussions on the impact of environmental exposures on human health, Peters, Hoek and Katsouyanni (2012) emphasized on the significance of environmental epidemiology in providing robust evidence to assist timely and sufficient protection of vulnerable subgroups of populations from environmental hazards. While the researchers discussed some limitations of the exposome in biological samples, the study noted individual’s exposure that begins before birth and over his or her lifetime. The notion of considering the vulnerable periods and assessment of environmental exposures in a life-course fashion is a precious concept embedded in the exposome paradigm argued in this study as a missing feature in environmental epidemiology. Another missing feature is the combined analyses of studies from different life phases that need conceptual and statistical methodological developments along with integrative exposures assessment combined with traditional and novel approaches. Peters et al. acknowledged the significance of emerging wealth of methods and data, as well as asserted the necessity to integrate environmental questions into research on disease mechanisms that is overturning paradigms based on technical innovations (p. 104). ETS is an example of environmental exposure that has been associated with an array of adverse effects on health. Secondhand smoke, referred to as ETS, contains many of the same carcinogenic compounds as the mainstream smoke inhaled by active smokers (World Health Organization, International Agency for Research on Cancer, 2004; Bao et al., 2009). Given that the role of passive smoking in pancreatic carcinogenesis remains unclear, Bao et al. (2009) examined the association of ETS with PC risk. In this prospective study, 86,673 women in the Nurses’ Health Study was considered, and ETS exposure was assessed through questionnaires. Using Cox proportional hazards models, relative risks (RR) and 95% confidence intervals (CI) were estimated. Bao et al. (2009) found that maternal smoking significantly increased the risk of PC (RR, 1.42; 95% CI, 1.07–1.89). Conceding the fact that the risk associated with maternal smoking remained elevated, no association was found for adult passive exposure at work or home. Paternal smoking was not related to the risk (RR, 0.97; 95% CI, 0.77–1.21). In addition to self-reported indicators of exposure through questionnaires or interviews that was used by the Bao et al. in their 2009 study, there are other ways to measure ETS: measuring tobacco smoke components in the air to which subjects are exposed (environmental measurements), and the use of biomarkers to measure concentrations of components of smoke in the body of exposed individuals. While environmental measures are considered suboptimal and may not reflect the dose of ETS that reaches the body; self-reports and biomarkers have been more commonly used in epidemiologic studies. Questionnaires are not only inexpensive to administer to large numbers of subjects; this measurement tool has been successfully used in many smoking cessation studies (Fergusson et al., 1998; World Health Organization, 2001; Brooks et al., 2004). A meta-analysis of studies that validated self-reported smoking behavior with biochemical measurements, Patrick et al. (1994) concluded that self-reports of smoking status are accurate in most studies. However, using questionnaire data alone makes analysis and quantification of ETS exposure challenging and need more objective and reliable methods. Hatsukami et al. (2003) proposed several potential biomarkers that measure ETS exposure and include carboxyhemoglobin, thiocyanate, carbon monoxide (CO), DNA adducts, protein adducts, nicotine, and cotinine (p. 11). Both self-reports and biomarkers help in producing evidence-based studies needed in the development of smoke-free air policies. Without reliable ETS exposure measurements, there will be no scientific evidence that will support the significance of smoke-free policy adoption. On the other hand, environment measurements could play a major role in evaluating policies that have been implemented. In the Netherlands Cohort Study, Heinen et al. (2010) examined the role of active cigarette smoking, smoking cessation, and passive smoking as determinants consisted of 120,852 men and women who completed a baseline in a 1986 questionnaire. Using a case-cohort approach, person-years of follow-up of a random subcohort (n = 5,000) was chosen. Multivariable-adjusted hazard rate ratio (HR) of 1.34; 95% confidence interval (CI), 1.02-1.75 and HR, 1.82; 95% CI, 1.40-2.38 after comparison with never cigarette smokers. While there are no association was observed between passive smoking exposure and PC risk in women; Heinen et al. observed an increased risk per increment of 10 years of smoking (HR, 1.15; 95% CI, 1.08-1.22) and an HR of 1.08 per increment of 10 cigarettes/d (95% CI, 0.98-1.19). There are 520 PC incident cases was observed after 16.3 years of follow-up. The study confirmed that cigarette smoking is an important risk factor for the disease, and quitting smoking benefits the burden on incidence level.
While smoking has been established as a PC risk factor, passive smoking remains to confirm as an environmental factor. According to Simard, Rosner and Michels (2008), recent studies argue that passive smoking put fetuses to have a higher risk of illnesses later in life. Ding et al. (2015) explored the relationship between PC and passive smoking. In this study, a Hospital-based case-control study on PC was conducted from the inpatient of five hospitals from Oct. 1991 to Sep. 2014. History of exposure to ETS was quantified using Cox proportional hazards models to estimate relative risks (RR) and 95% confidence intervals (CI). From 1991 to 2014, 686 men and 390 women were diagnosed with PC, and compared to paternal smoking (RR, 0.97; 95% CI, 0.77-1.21; P = 0.084), maternal smoking significantly increased the risk of pancreatic cancer (R, 1.56; 95% CI, 1.13-1.98; P = 0.018). In this study, the risk associated with maternal smoking remained elevated compared to the never smokers (RR, 1.49; 95% CI, 1.072.27). The results of this study are suggestive of the positive association between maternal smoking and the potential role of early exposure to environmental tobacco smoke in pancreatic carcinogenesis. Ding et al. confirmed the significant overall risk of PC maternal smokers, but not among paternal smokers. The researchers suggested that the only way to reduce the burden of the disease is maternal smoking inhibition. Canada like the U.S., PC is the fourth leading cause of cancer mortality. While obesity and diet have been identified as modifiable risk factors associated with the etiology of this disease (Hanley, Johnson, Villeneuve & Mao, 2001; Michaud et al., 2001), it has been estimated that both active and passive smoking is 27-33% attributable to all PC cases (Silverman et al., 1994; Siemiatycki, Krewski, Franco & Kaiserman, 1995), containing numerous carcinogenic constituents. ETS contains 43 known carcinogens with smaller particle sizes (vapor phase constituents rather than particulate phase) making it unclear which cancer sites may be affected by ETS exposure. In 2004 of Villeneuve, Johnson, Mao, and Hanley, the relationship between PC incidence and ETS was explored using data collected from a Canadian population-based case-control study that was conducted in 8 provinces between 1994 and 1997. The researchers examined the same subjects of their 2000 study who formed the basis of risk assessment to evaluate the associations between PC, coffee consumption, alcohol, and measures of tobacco use among smokers, and using methods developed previously to assess the relationship between ETS and other type of cancers within is a large-scale Canadian research initiative called as the National Enhanced Cancer Surveillance System (NECSS). Mailed questionnaires, with telephone follow-up if necessary to clarify the lifetime history of potential exposure at home and work to passive smoking. Multivariate models were adjusted for the effects of other known or suspected risk factors of PC, and risk assessment was performed for males, females and both. An odds ratio of 1.21 (95% CI=0.60-2.44) among never smokers, those who were exposed to ETS both as a child and as an adult relative to those with no exposure. Villeneuve et al. (2004) found that risk increases were more pronounced among active smoker with an increased number of years of smoking, cigarette pack-years, years since quit smoking, and an average number of cigarettes smoked daily, compared to those who are never smokers and had not been regularly exposed to ETS (p. 34). While the results of this study are suggestive of a weak association between PC and ETS, the results show the probable confounding role of ETS smoking in the association of active smoking with PC.
In the study on pathological changes in the pancreas of smokers, Tomioka et al. (1990) examined histopathologically 73 pancreases obtained by autopsy from 42 heavy cigarette smokers and 31 non-smoker patients. One invasive adenocarcinoma measuring 2 cm in diameter and three small carcinomas (2-5 mm in diameter) were found in smokers and one small carcinoma in a non-smoker patient. The pathological difference between smokers and non-smokers in this study was statistically not significant, albeit the incidence of PC in smokers was higher than in non-smokers. The type and the incidence of ductal alterations, two had lung cancer, one skin cancer, one colon cancer and one was free of any malignancies. Ductal changes, including mucinous or squamous cell metaplasia and papillary hyperplasia) were found with equal frequencies in both smokers and non-smokers. Exclusion of other relevant variables (diet, diabetes, alcohol) weakens the strength of this study. Considering that the results of this study are subjective to age-related incidence rather than smoking history, the researchers should have included risk factors such as family history of PC, high-risk inherited syndromes such as among Ashkenazi Jews, and other environmental tobacco exposures such as cigar, and pipe smoking. Using these approach, the researchers could have the chance to compare tumor size differences between smokers and non-smokers that could be associated with these demographics including race, and high fat/high cholesterol diet., obesity, chronic pancreatitis, and diabetes mellitus. Results of such research design could have a more meaningful outcome and amplify the significance of the result especially in correlating the study shared exposure of subjects to ETS. It is important to acknowledge the need for continued research to establish a meaningful risk prediction models that could be practically applied in clinical settings to raise the accuracy of predicting the potential for PC. Given that surgical resection procedure is the only treatment approach that could improve survival rate, establishing a high-risk prediction model using novel early identification protocol of pre-malignant lesions and molecular profiling is paramount, as part of a personalized therapeutic approach and standardized methods of early detection, and prevention.
PC involves both genetic and environmental factors, and like any other human diseases, PC is complex and multifactorial that has the greatest burden on society. According to Bookman et al. (2011), the development of high-density genotyping platforms has allowed investigators to screen hundreds of thousands of genetic variants to test for associations with disease (p.2). Hindorff et al. (2011) asserted that to date, Genome Wide Association Studies (GWAS) have identified over 900 statistically significant findings in various diseases and conditions. Parallel to this argument, Yeo et al. (2009) characterized one of the largest national registries of familial PC and sporadic PC, focusing on demographics, survival status, clinical factors, self-reported environmental and occupational lifetime exposures. In this retrospective cross-sectional study, the data was aggregated from the Johns Hopkins National Familial Pancreas Tumor Registry (NFPTR) enrolled between 1994 and 2005. While the study did not perform a comparative histopathological assessment, Yeo et al. conducted a case-only analysis that includes cases of 569 FPC (n=569) and 689 SPC. In addition to the reported risk factors such high-risk inherited syndromes, family history of PC, exposure to occupational and environmental carcinogens, cigarette, pipe smoking, and cigar, other demographics included in this study are age, race, chronic pancreatitis, diabetes mellitus, high fat/high cholesterol diet and obesity. The results show that exposure to tobacco carcinogens and environmental tobacco smoke (ETS) could lead to the earlier occurrence of PC. Yeo et al. (2009) concluded that the findings provided a risk prediction model that support the benefit of early identification of pre-malignant lesions and molecular profiling, as methods of early detection, prevention, and personalized therapy for high-risk individuals. While Yeo et al. was the first to generate the findings that occupational and environmental exposures may act synergistically with inherited or acquired genetic polymorphisms; Gallicchio et al. (2006) examined the association of household passive smoke exposure and active cigarette smoking in the development of PC using a prospective cohort design from the Washington County Cancer Registry. Current active smokers were found to have a two-fold increased risk of PC using Poisson regression analysis in both cohorts, the 1963 cohort to 1978 (n = 45,749) and 1975 cohort from 1975–1994 (n = 48,172). While household passive smoke exposure was not associated with an increased risk of PC among never-smokers in each cohort that could be explained by wide confidence limits due to a small number of cases, Gallicchio et al. further documents the approximate doubling of PC risk in current active smokers. Vrieling et al. (2010) examined the association between ETS exposure and tobacco use with PC risk within the European Prospective Investigation into Cancer and Nutrition (EPIC). Data analysis was based on 465,910 participants, including 524 first incident PC cases diagnosed after a median follow-up of 8.9 years. In this study, using Cox proportional hazard models, an increased risk of PC was found among current cigarette smokers with greater intensity and pack-years compared with never smokers (HR = 1.71, 95% CI = 1.36–2.15). Among never smokers with daily ETS exposure during childhood, increased PC risk was found with HR = 2.61, 95% CI = 0.96–7.10 and HR = 1.54, 95% CI = 1.00–2.39 among those who are exposed to ETS at home and/or work. The results of this study show that while PC risk is reduced to levels of never smokers within five years of quitting, increased risk of the disease is associated with both active cigarette smoking and ETS exposure. Studies of passive smoking or the use of noncigarette tobacco products often are limited by the small number of exposed individuals among never smokers, albeit the high prevalence of cigarette smoking among PC patients. Hassan et al. (2007) assessed the associations between the risk of pancreatic cancer and passive smoking and the use of other tobacco products using a large-scale case-control study from 2000 to 2006. In this hospital-based study of 808 patients with pancreatic adenocarcinoma with a control group of 808 healthy individuals, analysis of data includes the relation between PC and smoking cigarettes, cigars, and pipes; the use of smokeless tobacco products; and passive smoking after controlling for the effects of other confounders and major risk factors for this disease (p. 2). All participants were enrolled prospectively at The University of Texas M. D. Anderson Cancer Center and controls were selected from M. D. Anderson healthy visitors who accompanied cancer patients. All controls have no cancer history and are not genetically related family members (spouses) of patients with cancers. The patients and controls were frequency-matched by age (±5 years), race/ethnicity, and sex (Hassan et al., 2007). Stata software (Stata Corporation, College Station, TX) was used for data management and statistical analysis. Univariate and multivariate analyses, unconditional logistic regression was performed to compare the demographic characteristics and proportions of potential risk factors among patients and controls. Previously reported association between active smoking and increased risk for PC was confirmed in this study with adjusted odds ratio (AOR) of 1.7 (95% CI, 1.4-2.2) for regular smokers, 1.8 (95% CI, 1.4-2.4) for long-term smokers, and 3.1 (95% CI, 2.2-4.3) for former smokers. While passive smoking has an AOR of 1.3; 95% CI, 0.9-1.7 and never smokers (AOR, 1.1; 95% CI, 0.8-1.6), suggesting to nonsignificantly elevated risk for PC in the entire study population (AOR, 1.3; 95% CI, 0.9-1.7), Hassan et al. found the association of ever smokers with the disease (AOR, 1.7; 95% CI, 1.03-2.6) but was absent among never smokers (AOR, 1.1; 95% CI, 0.8-1.6). Chewing tobacco, snuff, and pipes also showed a non-significant risk elevation for PC after controlling for the confounding effects of demographics and other known risk factors. Hassan et al. noted that neither intensity nor duration of passive smoking modified the risk of PC among never smokers, but the use of cigars in never smokers showed a borderline significant increase in risk for the disease with an AOR, 2.2; 95% CI, 1.0-4.7; P =.05. It was concluded in this study that results are not enough to support the role of passive smoking or the use of noncigarette tobacco products in the PC etiology. Hassan et al. asserted the need to confirm the association between cigar use and the disease in other study populations.
Going back to the concept of gene-environment (G x E) interaction by Fisher (1958) and Hogben (1968) emphasized the need to consider the fundamental, philosophical differences between a variation partitioning approach and a mechanism-elucidation approach that provides the initial understanding of some aspects of genetics in association to smoking in cancer causation. The reason why the results of risk factor research for PC appears to be generic could be explained by the failure of the researchers to focus on a multi-level approach, failing to connect the gap between individual, macroenvironmental and biologic level. While the failure to appreciate the importance of the biological pathways is a more serious problem, Rutter (2015) noted that failure to pay proper attention to the methodological checks needed to highlight G X E in cancer causation results in some poor research that lead to disputable outcomes.
Bao et al. (2009) and Heinen et al. (2010) shared the same argument of the positive association between maternal smoking and the development of PC. In this study, it was found that early exposure to ETS and maternal smoking could lead the potential in utero to a lifetime risk of this lethal disease. An earlier study of Villeneuve et al. (2004) also recognized the role of ETS as a risk factor for PC and noted the probable confounding role of active cigarette smoke. Gallicchio et al. (2006) confirmed the approximate doubling of pancreatic cancer risk in current active smokers. While Hassan et al. (2007) observed significant associations between passive smoking, the use of noncigarette tobacco products and risk of pancreatic cancer, Hassan et al. highlighted the need for future assessment of the role of passive tobacco use in population-based studies. The synergistic interaction of occupational and environmental exposures and its role in the early occurrence of PC was explored in the 2009 study by Yeo, Hruban, Brody, Brune, Fitzgerald, and Yeo, C. J., aligning to the intent of the 2010 study of Vrieling et al. to examine the association between cigarette smoking and exposure to ETS with PC risk in the European Prospective Investigation into Cancer and Nutrition (EPIC). The overall findings of these studies support the obligation of environmental epidemiology and the importance of inter-disciplinary collaboration to provide robust evidence on the positive role of active and passive smoking, ETS-related carcinogens to protect vulnerable population subgroups. Identification of pre-malignant lesions and molecular profiling is paramount, as methods of early detection, prevention, and personalized therapy for high-risk individuals. While the study of Yeo et al. considered the causality of predictors at an individual and biologic level; including etiologic agents at macroenvironment-level could have given a more citable outcome. Given that the study has access to one of the largest national registries of familial PC, the researchers did not utilize the extensive data available and assessed the data within hierarchical levels. Integrating individual and biologic level to macroenvironment-level into a multilevel framework will allow the interdisciplinary exchange of knowledge, optimizing the value of multilevel studies for both clinical and public health activities. Lynch et al. (2013) proposed a multilevel approach to bridge the gap between individual, macroenvironmental and biologic level called “Multi-level Biological And Social Integrative Construct” (MBASIC). The primary goal of the MBASIC is to guide researchers to consistently, and systematically incorporate biological mechanisms generate significant statistical or epidemiological model better to understand the complex nature a lethal disease like PC. Lynch et al. highlighted the significance of MBASIC in expanding the utility of the multilevel approach by including levels of etiology and carcinogenesis with levels of intervention and implementation/evaluation. The interaction of these levels could provide a resource-efficient approach to early PC screening and detection.
The exposure to rare chemicals may pose a large individual risk if a child is exposed, justifying the need to consider the impact of maternal smoking during pregnancy and postnatal environmental tobacco smoke (ETS) exposure. ETS exposure and other exposures to common substances in the perspective of public health equates a relative risk that could have a progressive/cumulative effect to the public. Röösli (2011) argued that children differ from adults in many aspects which are relevant when assessing health risks from chemicals; therefore future research warrants a working framework that addresses the potential for non-cancer effects resulting from continuous short-duration and intermittent exposures to chemicals. A good example is the framework of Haber et al. (2016) presents an integrated, tiered approach that could be adopted in assessing the acceptability of toxicity reference values (TRVs) in relation to short-duration or intermittent exposure scenarios. Environmental tobacco smoke (ETS) is an example of environmental exposure that has been associated with an array of adverse effects on health. Secondhand smoke, referred to as ETS, contains many of the same carcinogenic compounds as the mainstream smoke inhaled by active smokers (World Health Organization, International Agency for Research on Cancer, 2004; Bao et al., 2009). Under the lens of public health, quitting smoking could decrease the incidence of PC, by protecting vulnerable members of the population. The rapid uptake and use of new health information among groups with lower SES and access to health-enhancing treatment and technologies will be dependent upon the development and implementation of public health policies that include equal allocation of resources to every enclave of the community. While the past and current research could help continue the improvement of the accuracy of passive smoking measurement, it is critical for the continuance of applying the exposome concept to environmental health problems. Research outcomes that help the drafting of amendments to policies and approaches, built on existing policies such as cigarette labeling acts, smoking bans, and distribution of cessation tools will not only improve mortality level of the disease, but population health as a whole. Overall, the results of articles reviewed between 1990 to present suggest the potential role of early exposure to environmental tobacco smoke in pancreatic carcinogenesis. While maternal smoking cessation is the only way to reduce the burden of PC to both the baby, the mother and others who shared the exposure, future research needs to confirm the positive association of PC with maternal smoking and ETS. Continued research on the association between passive smoking exposure and the disease, as well as early shared exposure of these predictors, are critical to better understand its association to lifetime risk. The focus on obtaining a larger number of endpoints, it is paramount for future research to combine more cohorts to have a stronger and standardized sampling that yields a statistically significant assessment of predictors associated with pancreatic cancer.
The argument on the gene-environment interaction paradigm to genome-wide studies in relation to the development of a public issue was discussed in the 2014 study of Boardman et al., highlighting the importance of integrating social and genetic perspectives in enhancing findings for both biologically and socially focused research such as the causality of active and passive smoke exposure to lifetime risk of a fetus to develop a lethal disease like PC. For decades, behavior geneticists have been working to disentangle the genomic component of family risk from the social and behavioral component. According to Boardman et al. (2104), understanding the genomic component in combination with specific environmental contexts could provide the pertinent information about an individual’s likelihood of exhibiting a particular behavior at a given time, critical not only to social and genetic epidemiologists, but to the understanding of the association of modifiable behavioral risk and adjustable predictors in the development of the disease. New evidence for genetic influences on most health behaviors, new statistical methods, and new genetic data sources could help confirm the impact of environmental influences on individual’s genetic composition that could be contingent on the social environment in which one resides, works, and plays. The findings of the literature reviewed in this paper will not only add to the wealth of information needed in the development of a standard PC risk model but also highlight the significance of the early screening and molecular profiling, as a prudent approach to the prevention of PC. Parallel to the intent of my dissertation on “Pathopoiesis Mechanism of Smoking and Family Cancer History in Pancreatic Cancer,” findings discussed in this paper emphasize the need for novel therapeutic strategies that will improve survival level and quality of life for late-stage PC patients.
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The protozoan parasite Trypanosoma cruzi was first described by Carlos Chagas after isolation of the organism from the blood of a Brazilian patient in 1909 (Garcia et al., 2015). An estimated 7.5 to 10 million persons are infected with Chagas disease worldwide (Hotez et al., 2008; Hotez et al., 2014). In the United States, the disease is anecdotally referred to as a “silent killer” with a 30% chance of those infected to develop a potentially fatal cardiac disease. According to Cantey et al. (2012), Chagas disease is emerging as a significant public health concern in the United States. Given the proximity of Texas to Latin America, cases imported from highly endemic areas in Latin America would likely occur in Texas. Recent communication from the Centers for Disease Control and Prevention that the bite of blood-sucking triatomine bugs in the subfamily Triatominae also termed “kissing bugs” that transfers the parasites to humans have now been found in 28 states, including California and Pennsylvania. Garcia et al. (2015) argued that despite the numerous publications related to Chagas disease in the southern US and northern regions of Mexico, very little is known about the disease burden from imported and locally acquired T. cruzi infection.There is concern that Chagas disease might be undiagnosed in the US as a result of documented low physician awareness (Stimpert & Montgomery, 2010). While the zoonotic nature of Chagas’ life cycle implies unfeasible eradication; entomological surveillance is and will remain crucial to containing Chagas disease transmission (Tarleton et al., 2007).
While it is considered safe to breastfeed even if the mother has Chagas disease (Centers for disease control and prevention, 2013); people can also become infected through blood transfusion, congenital transmission (from a pregnant woman to her baby), organ transplantation, accidental laboratory exposure and consumption of uncooked food contaminated with feces from infected bugs. If the mother has cracked nipples or blood in the breast milk, it is warranted to pump and discard the milk until the bleeding resolves and the nipples heal (Centers for disease control and prevention, 2013). The enduring challenge of household reinfestation by locally native vectors as stated by Abad-Franch et al. (2011), horizontal strategies works better when the community takes on a protagonist role. Encouraging vector notification by residents and other simple forms of participation can substantially enhance the effectiveness of surveillance (Abad-Franch et al., 2011). Therefore, control programs in concert with community-based approaches as a strategic asset from inception that requires a timely, professional response to every notification, benefiting from a strengthened focus on community empowerment. According to Schofield (1978), when bug population density is low, vector detection failures are unavoidable. Decision-making will be dependent upon the accurate estimation of infestation rates (World Health Organization, 2002), and imperfect detection can seriously misguide Chagas disease control management program. Continued attentiveness from governmental and health organizations are warranted, as this disease continue to be a globalized public health issue. Improved diagnostic tools, expanded surveillance and increased research funding will be required in maintaining existing effective public health strategies and in preventing the spread of the disease to new areas and populations (Bonney, 2014). To improve outbreak control, and improve Chagas disease response, it is essential to discuss the gaps in the scientific knowledge of the disease. Moreover, crucial in improving the morbidity in the state of Texas and neighboring states is the recommendation of the needed steps to enhance the understanding of T. cruzi.
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In most countries, public health approaches to address violent radicalization are already applied in street violence and bioterrorism; but leaders and stakeholders need to embrace the significance of public health interventions and research on violent radicalization (Bhui et al., 2012). While past studies (Bakker, 2006; Loza, 2007) found that overwhelming majority of people who become radicalized to violence in the West are young and male, generally aged between mid-teens and mid-20s; scarcity of research findings on the extent and nature of women’s roles in group and community radicalization (Carter, 2013). The recent acts of terrorism around the world, especially the event in San Bernardino California, it is important to note the urgent need to look at the significance of a public health approach to understanding violent radicalization. Recognizing this sense of urgency introduce the possible role of collective responsibility of leaders in epidemiology, sociology, psychology and other behavioral sciences in developing novel epidemiologic measures towards prevention strategies (Bhui, Hicks, Lashley, & Jones, 2012). While most nation’s counterterrorism approaches are grounded in inter-governmental intelligence data exchange and criminal justice systems, embracing the perceived belief that existing legal system can deal with violent radicalization effectively; it is paramount to argue that new players be included in the collection of relevant data needed in the development of public health approach to address violence such as the World Health Organization’s Violence Prevention Alliance, and the Centers for Disease Control and Prevention (CDC). The goal of CDC’s “Public Health Approach to Violence Prevention” is to decrease risk factors and increase protective factors. The logical argument for this proposed study is the need for public health research, and establish a new approach to guard against violent radicalization.
Given the current integrated surveillance system that monitors death and injuries as a direct effect of terrorism events, it is critical to recognize the risk and protective factors for violent radicalization. Bhui et al. (2102) noted “the perceived discrimination in the population as a whole or amongst distinct segments of the population; trust in authorities and their counterterrorism approaches; perceived or real economic inequalities patterned by ethnicity or religious groups; and international conflict in which the authorities appear to be biased or unfair towards a specific migrant, religious or ethnic group.” For future research, it is paramount to identify the possible independent variables that are associated with the increased probability of radicalization in certain communities such as marginalized communities, diaspora communities, and ideology. The perceived feeling of inclusion or integration in a larger, popular community was theorized to amplify the extent of susceptibility to radicalization. Baumeister and Leary (1995) asserted on the importance of adapting psychological theories on stable interpersonal relationships. It is critical to examine the perceived instability in diaspora communities that could increase the risk of marginalization. Indicators related specifically to diaspora communities are language, the size of the community, the arrival age of immigrant(s) to the community, the age structure of the population, and the spatial concentration of the community. Marret et al. (2013) asserted the importance of understanding the core of radicalization process that demands the necessity to question and debate the concept of violent radicalization at the theoretical level and the empirical level. The motivation for an individual or group to commit extremist violence or terrorism is not grounded in a single ideology, but selectively demonstrate their commitment from different clusters of belief systems. Behavioral indicators as stated by Fishman (2010) could be generated from social media, chat rooms, and involvement in public ideologically motivated legal activities might provide insights into community-based ideological sentiments.
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When I was inducted into the Honor Society in winter 2013, I thought that being on top of my batch will be enough to get me through my journey as a Public Health Ph.D. candidate. Recruiting a dissertation chair is the most challenging so far, especially getting a response from them. What if I do not get a dissertation chair who will be a good match with my dissertation topic? Can I submit my premise and finish my dissertation to another university? A night before my youngest brother passed away; I was on the phone with him. He told me that he is too tired, and I responded that it is okay to let go. He asked me to promise him to go back to school and take on a graduate degree to make a difference. “Promise me that at some point to be involved in a research project that could make a difference to individuals diagnosed with pancreatic cancer.” He passed away in 2007, a few weeks before his 40th birthday, and three months before his only daughter’s first birthday.
Focusing on the impact of cigarette smoking as a factor that promotes pancreatic cancer rather than initiates it will amplify the importance of behavioral change, and enhance the quality of life. The outcome of pancreatic cancer remains dismal, even with treatment combinations of surgery, radiotherapy and chemotherapy with an estimated annual economic burden of $4.9 billion annually (Pandol, Apte, Wilson, Gukovskaya, and Edderkaoui, 2012). Advances in patient management and understanding the biology of pancreatic cancer has taken substantial progress over the years. Herman, Schulick, Hruban and Goggins (2011) found that screening first-degree relatives of individuals with family members affected by pancreatic cancer can identify non-invasive precursors of the disease. In this 2011 study shows the gradual rise in the incidence and number of deaths caused by pancreatic tumors, even with the decline in incidence and mortality of other common cancers. Furthermore, Vincent et al. found that despite developments in detection and management of pancreatic cancer, only about 4% of patients will live five years after diagnosis. Moreover, Vincent et al. (2011) found that present surgical resectioning offers the only chance of cure and improve the survival rate for those with malignant disease localized to the pancreas. Statistical analysis in 2012 study shows 80–85% of patients with advanced unresectable disease responds poorly to most chemotherapeutic agents. Therefore, it is warranted to have continued understanding of the biological mechanisms contributory to the development and progression of pancreatic tumors. On the other hand, Klein et al. (2004) emphasized the significance of quantification of the risk of individuals with a family history of pancreatic cancer as a rational basis for cancer risk screening and counseling. In a prospective registry-based approach of this 2004 study, the risk of these individuals showed an increased risk of developing the disease. Klein et al. (2004) performed standardized incidence ratios and compared the number of incident pancreatic cancers observed with those expected using Surveillance, Epidemiology and End Results (SEER) rates. It was quantified in this registry-based study the pancreatic cancer risk in kindreds with a family member who was diagnosed with the disease, supporting the hypothesis of increased risk in association with family history. While Blackford et al. (2009) failed to identify the signature tobacco-related mutation in cigarette smokers that could have strong implication to the development of pancreatic cancer; this 2009 study found the nonspecific DNA damage caused by tobacco carcinogens. Furthermore, the combined causality of non-tobacco-related mutagenic risk factors such as inherited predisposition to cancer may share mutagenic properties with the tobacco mutagens active in pancreatic tissues (Ding et al., 2008; Prokopczyk et al., 2002). The types and patterns of these mutations provide insight into the mechanisms by which cigarette smoking causes pancreatic cancer (Blackford et al., 2009). Porta et al. (2009) and Blackford et al. (2009) suggested that smoking enhances the risk for pancreatic cancer through mechanisms other than genetic mutation. The development of pancreatic cancer may have a non-significant association to pipe smoking and smokeless tobacco use, but in a large collaborative pooled analysis of non-cigarette tobacco use in 11 studies within the International Pancreatic Cancer Case-Control Consortium (PanC4) found that cigar smoking is associated with an excess risk of the disease (Bertuccio et al., 2011). Cigarette smoking was found to be an established risk factors— both exposure to environmental tobacco smoke (ETS), and active cigarette smoking (Vrieling et al., 2010). Over 40,000 individuals are diagnosed with pancreatic cancer, and less than 5% of patients diagnosed has a survival rate of five years. The component of the smoke of cigarettes that produced in the body as a metabolite of nicotine and the most abundant carcinogens in tobacco smoke is 4-(methyl nitrosamine)-1-(3-pyridyl)-1-butanone (NNK). Vary widely in nicotine content and carcinogenic nicotine metabolites, cigarettes, cigars, and other tobacco products—nicotine reaches the lungs and is quickly absorbed into the bloodstream during smoking. A cigar containing as many as 20 grams of tobacco can have nicotine between 5.9 and 335.2 mg per gram of tobacco (Henningfield, Fant, Radzius, & Frost, 1999). Prokopczyk et al. (2002) noted that the nicotine levels in pancreatic juice in smokers is seven times higher than non-smokers. Blackford et al. (2009) concluded that smokers diagnosed with pancreatic carcinomas harbors more mutations than the non-smoker, therefore, doubles the risk, accounting for 20 to 25% of pancreatic cancers.
Pandol et al. (2012) stated that the pro-carcinogenic effects of smoking on the pancreas are inadequately studied, confirming that tobacco smoking is the strongest avoidable risk and the major environmental factor for pancreatic cancer. Pandol et al. provided valuable insights into the pathogenesis of pancreatic cancer, particularly in the initiation and progression of the disease. Determining the mechanisms underlying the effect of smoking compounds on fibrosis and inflammation will improve our limited knowledge of pancreatic biology. Pancreatic cancer can be classified as genetic, environmental, or both; as well as a disease caused by inherited DNA mutation or mutation by chance. While advances in Genomics gives the promise to early pancreatic cancer detection through better understanding of pancreatic biology, it is paramount to embrace the significance of lifestyle habits that can be modified to evidence-based healthier concepts that translates to reduced cancer risk. Applying lessons learned from the outcome of my proposed study, and existing body of knowledge will prevent the emergence of pancreatic cancer, reduce cancer risk and advance population health. Early behavioral change and interventions will improve the survival rate and quality of life during the time course of pancreatic cancer progression.
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The traditional researcher concept that big data equates statistical significance could always eclipse the importance of understanding the interrelationship between the effect size, power, and sample size that could translate to both practical and statistical significance. In Texas, everything is bigger, everything a Texan do is bigger, but in the context of data collection—is bigger better? Current big data opportunities facing science, technology communities, and the health community is facing a tsunami of health- and healthcare-related content generated from numerous patient care points of contact, sophisticated medical instruments, and web-based health communities (Chen, Chiang & Storey, 2012). Two primary sources of health big data are payer–provider big data (electronic health records, insurance records, pharmacy prescription, patient feedback and responses), and data from my favorite field-genomics. I cannot help to imagine how many interesting research studies I could do with genomics-driven big data (genotyping, gene expression, sequencing data). Extracting knowledge from health big data poses significant research and practical challenges, especially considering the HIPAA (Health Insurance Portability and Accountability Act) and IRB (Institutional Review Board) requirements for building a privacy-preserving and trust-worthy health infrastructure and conducting ethical health-related research (Gelfand, 2011). Setting aside these challenges, can big data provide both practical and statistical significance? Just think about terabytes of expected raw sequencing data that associate variants that affect variation in two common highly heritable measures of obesity, weight and body mass index (BMI). For this discussion, let me broach the 2012 study of Hutchinson and Wilson in improving nutrition and physical activity in the workplace. The cumulative knowledge found in the meta-analysis of Hutchinson & Wilson (2012) found the extant results of 29 intervention studies examining physical activity or nutrition interventions in the workplace, published between 1999 and March 2009. The results from these 29 intervention studies were synthesized using meta-analyses in terms of the effectiveness of workplace health promotion programs to resolve inconsistent findings. The challenge of extant results that are sometimes discordant, Hutchinson & Wilson (2012) took into consideration the limitations in the methodology of some of the studies reviewed that demonstrated modest success in achieving long-term change. The importance of interventions’ association with successful outcomes that includes behavior maintenance and generalization was also considered in this study. Weighted Cohen’s d effect sizes, percentage overlap statistics, confidence intervals and failsafe Ns were calculated. The increased prevalence of obesity and its association with increased risk for chronic diseases including cancer, diabetes, cancer and cardiovascular disease warrants the needs for innovative and efficient interventions. Green (1988), stated that the workplace is a valuable intervention site for a number of reasons including the amount of time people spend at work, access to populations that may be difficult to engage in different settings and the opportunity to utilize peer networks and employer incentives. These reasons justify the practical significance of the study. Moreover, the statistical significance was established by the methodology of Hutchinson & Wilson (2012) developing inclusion criteria of the 29 identified studies. The inclusion criteria are published studies on workplace intervention; a control group, not receiving the intervention, health, and in particular diet, nutrition or physical activity as outcome measures; and statistical information for the calculation of effect sizes, (e.g. means and standard deviations, the results of t-tests or one-way F tests).Change over time (mean and standard deviation) data were requisite to calculate effect sizes for interventions. Studies that did not provide this data, the means and standard deviations at the end of the intervention of controls and interventions groups were compared. Statistical analyses was performed such as Cohen’s d to calculate effect sizes for the difference between the intervention and control groups on each outcome measure (diet measures: fruit, vegetables, fat; physical activity measures: activity, fitness; health measures: weight, cholesterol, blood pressure, heart rate or glucose). Based on outcome measures and the form of intervention, effect sizes were aggregated. Mean effect size, standard deviation and 95% confidence interval were calculated for each grouping (Zakzanis, 2001). Fail safe Ns (Nfs) were calculated to address the potential for studies with statistically significant results. The conclusion of this 2012 meta-analysis in terms of study design—randomized controlled trials were associated with larger effects; therefore, long-term maintenance of changes should be evaluated in order to determine the extent to which workplace interventions can make sustainable changes to individuals’ health.
Chen, H., Chiang, R. H., & Storey, V. C. (2012). Business Intelligence and Analytics: From Big Data to Big Impact. MIS quarterly, 36(4), 1165-1188. Cohen, J. (2013). Statistical power analysis for the behavioral sciences. Academic press. Ellis, P. D. (2010). The essential guide to effect sizes: Statistical power, meta-analysis, and the interpretation of research results. Cambridge University Press. Forthofer, R.N., Lee, E.S. & Hernandez, M. (2006). Biostatistics: A Guide to Design, Analysis and Discovery. 2nd Edition [Vital Source Bookshelf version]. Retrieved from http://online.vitalsource.com/books/9780123694928 Gelfand, A. (2011). Privacy and biomedical research: building a trust infrastructure: an exploration of data-driven and process-driven approaches to data privacy. Biomed Comput Rev, 2012, 23-28. Green, K. L. (1988). Issues of control and responsibility in workers’ health. Health Education & Behavior, 15(4), 473-486. Hutchinson, A. D., & Wilson, C. (2012). Improving nutrition and physical activity in the workplace: a meta-analysis of intervention studies. Health promotion international, 27(2), 238-249. Labilles, U. (2015). Big Data: Does it matter? Can it give a practical significance? Is bigger better? (Unpublished, Advanced Biostatistics (PUBH – 8500 – 1), 2015 Spring Qtr. Wk2DiscLabillesU) Walden University, Minneapolis. Thorleifsson, G., Walters, G. B., Gudbjartsson, D. F., Steinthorsdottir, V., Sulem, P., Helgadottir, A., … & Stefansson, K. (2009). Genome-wide association yields new sequence variants at seven loci that associate with measures of obesity. Nature genetics, 41(1), 18-24. Zakzanis, K. K. (2001). Statistics to tell the truth, the whole truth, and nothing but the truth: formulae, illustrative numerical examples, and heuristic interpretation of effect size analyses for neuropsychological researchers. Archives of clinical neuropsychology, 16(7), 653-667.
Last Christmas Eve, I received a wonderful and encouraging letter from the President. My daughter Abby opened it with excitement, and after reading his letter, she asked if she could keep it. We may all have something to say regarding what are happening around us, and we may all have our default someone to blame, but in the eyes of a growing citizen of this great country of ours, what is paramount is learning respect and love for our country. In the eyes of a child, a leader is someone who will make her/his place in this world a better place to live. They do not know about political parties, politicians at each other’s throat, but just a very simple concept “Peace.” After watching the movie “Unbroken” last night, she told me that she need to write the President a thank you letter. I told her that I already did via e-mail. Then she said, I need to thank him too since like Louis in the movie, he does not give up to something what is right. Enjoy what is left with the Holiday Season everyone.