Individual and Combined Effects of Environmental Risk Factors for Esophageal Cancer Based on Results From the Golestan Cohort Study

BACKGROUND & AIMS

Northeast Iran has one of the highest reported rates of esophageal squamous cell carcinoma (ESCC) worldwide. Decades of investigations in this region have identified some local habits and environmental exposures that increase risk. We analyzed data from the Golestan Cohort Study to determine the individual and combined effects of the major environmental risk factors of ESCC.

METHODS

We performed a population-based cohort of 50,045 individuals, 40 to 75 years old, from urban and rural areas across Northeast Iran. Detailed data on demographics, diet, lifestyle, socioeconomic status, temperature of drinking beverages, and different exposures were collected using validated methods, questionnaires, and physical examinations, from 2004 through 2008. Participants were followed from the date of enrollment to the date of first diagnosis of esophageal cancer, date of death from other causes, or date of last follow-up, through December 31, 2017. Proportional hazards regression models were used to estimate hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) for the association between different exposures and ESCC.

RESULTS

During an average 10 years of follow-up, 317 participants developed ESCC. Opium smoking (HR 1.85; 95% CI 1.18-2.90), drinking hot tea (≥60°C) (HR 1.60; 95% CI 1.15-2.22), low intake of fruits (HR 1.48; 95% CI 1.07-2.05) and vegetables (HR 1.62; 95% CI 1.03-2.56), excessive tooth loss (HR 1.66; 95% CI 1.04-2.64), drinking unpiped water (HR 2.04; 95% CI 1.09-3.81), and exposure to indoor air pollution (HR 1.57; 95% CI 1.08-2.29) were significantly associated with increased risk of ESCC, in a dose-dependent manner. Combined exposure to these risk factors was associated with a stepwise increase in the risk of developing ESCC, reaching a more than 7-fold increase in risk in the highest category. Approximately 75% of the ESCC cases in this region can be attributed to a combination of the identified exposures.

CONCLUSIONS

Analysis of data from the Golestan Cohort Study in Iran identified multiple risk factors for ESCC in this population. Our findings support the hypothesis that the high rates of ESCC are due to a combination of factors, including thermal injury (from hot tea), exposure to polycyclic aromatic hydrocarbons (from opium and indoor air pollution), and nutrient-deficient diets. We also associated ESCC risk with exposure to unpiped water and tooth loss.

The application of six dietary scores to a Middle Eastern population: a comparative analysis of mortality in a prospective study

Background The associations between dietary indices and mortality have not been evaluated in populations from the Middle East, which have different dietary patterns compared to the US and Europe. In this study, we evaluated the association between six dietary indices and mortality in the Golestan Cohort Study (GCS) in Iran, which is the largest prospective study in the Middle East with 50,045 participants. Methods The six dietary indices, namely the Healthy Eating Index (HEI-2015), Alternative Healthy Eating Index (AHEI-2010), Alternative Mediterranean Diet (AMED), Dietary Approach to Stop Hypertension created by Fung (DASH-Fung) and Mellen (DASH-Mellen), and the World Cancer Research Fund (WCRF/AICR) index, were applied to data from a food frequency questionnaire, computed and divided into quintiles. Adjusted Cox models were used to estimate hazards ratio (HR) and 95% confidence intervals (CI) for overall and cause-specific mortality, using the lowest quintile as a reference group. Results Among 42,373 participants included in the current analyses, 4424 subjects died during 10.6 years of follow-up. Participants with the highest quintile dietary scores, compared with the lowest quintile dietary scores, had significantly decreased overall mortality in the AHEI-2010, AMED, DASH-Fung, and WCRF/AICR indices (HR 0.88, 95% CI = 0.80-0.97; 0.80, 0.70-0.91; 0.77, 0.70-0.86; and 0.79, 0.70-0.90, respectively). A reduced cardiovascular mortality was found for high AHEI-2010 and DASH-Fung scores (17% and 23%, respectively), and a reduced cancer mortality for high HEI-2015, AMED, and DASH-Fung scores (21, 37 and 25%, respectively). Conclusion Various indices of dietary quality are inversely associated with overall mortality, and selectively with cancer and cardiovascular mortality in the GCS, which contribute to the generalizability and validity of dietary guidelines.

Trends in hepatitis C treatment initiation among HIV/hepatitis C virus-coinfected men engaged in primary care in a multisite community health centre in Maryland: a retrospective cohort study

OBJECTIVES

Little is known about the cascade of hepatitis C care among HIV/hepatitis C virus (HCV)-coinfected patients in community-based clinics. Thus, we analysed our data from the interferon era to understand the barriers to HCV treatment, which may help improve getting patients into treatment in the direct-acting antivirals era.

DESIGN

Retrospective cohort study.

SETTING

Four HIV clinics of a multisite community health centre in the USA.

PARTICIPANTS

1935 HIV-infected men with >1 medical visit to the clinic between 2011 and 2013. Of them, 371 had chronic HCV and were included in the analysis for HCV care continuum during 2003-2014.

OUTCOME MEASURES

HCV treatment initiation was designated as the primary outcome for analysis. Multivariate logistic regression was performed to identify factors associated with HCV treatment initiation.

RESULTS

Among the 371 coinfected men, 57 (15%) initiated HCV treatment. Entering care before 2008 (adjusted OR [aOR, 3.89; 95% CI, 1.95 to 7.78), higher educational attainment (aOR, 3.20; 95% CI, 1.59 to 6.44), HCV genotype 1 versus non-1 (aOR, 0.21; 95% CI, 0.07 to 0.65) and HIV suppression (aOR, 2.13; 95% CI, 1.12 to 4.06) independently predicted treatment initiation. Stratification by entering care before or after 2008 demonstrated that higher educational attainment was the only factor independently associated with treatment uptake in both periods (aOR, 2.79; 95% CI, 1.13 to 6.88 and aOR, 4.10; 95% CI, 1.34 to 12.50, pre- and post-2008, respectively). Additional associated factors in those entering before 2008 included HCV genotype 1 versus non-1 (aOR, 0.09; 95% CI, 0.01 to 0.54) and HIV suppression (aOR, 2.35; 95% CI, 1.04 to 5.33).

CONCLUSIONS

Some traditional barriers predicted HCV treatment initiation in those in care before 2008; however, the patients' level of educational attainment remained an important factor even towards the end of the interferon era. Further studies will need to determine whether educational attainment persists as an important determinant for initiating direct-acting antiviral therapies.

Urinary Biomarkers of Carcinogenic Exposure among Cigarette, Waterpipe, and Smokeless Tobacco Users and Never Users of Tobacco in the Golestan Cohort Study

BACKGROUND

How carcinogen exposure varies across users of different, particularly noncigarette, tobacco products remains poorly understood.

METHODS

We randomly selected 165 participants of the Golestan Cohort Study from northeastern Iran: 60 never users of any tobacco, 35 exclusive cigarette, 40 exclusive (78% daily) waterpipe, and 30 exclusive smokeless tobacco (nass) users. We measured concentrations of 39 biomarkers of exposure in 4 chemical classes in baseline urine samples: tobacco alkaloids, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC). We also quantified the same biomarkers in a second urine sample, obtained 5 years later, among continuing cigarette smokers and never tobacco users.

RESULTS

Nass users had the highest concentrations of tobacco alkaloids. All tobacco users had elevated TSNA concentrations, which correlated with nicotine dose. In both cigarette and waterpipe smokers, PAH and VOC biomarkers were higher than never tobacco users and nass users, and highly correlated with nicotine dose. PAH biomarkers of phenanthrene and pyrene and two VOC metabolites (phenylmercapturic acid and phenylglyoxylic acid) were higher in waterpipe smokers than in all other groups. PAH biomarkers among Golestan never tobacco users were comparable to those in U.S. cigarette smokers. All biomarkers had moderate to good correlations over 5 years, particularly in continuing cigarette smokers.

CONCLUSIONS

We observed two patterns of exposure biomarkers that differentiated the use of the combustible products (cigarettes and waterpipe) from the smokeless product. Environmental exposure from nontobacco sources appeared to contribute to the presence of high levels of PAH metabolites in the Golestan Cohort.

IMPACT

Most of these biomarkers would be useful for exposure assessment in a longitudinal study.

Polycyclic aromatic hydrocarbons as a potential source of carcinogenicity of mate

Drinking mate, an infusion of the herb ilex paraguariensis, is very common in several South American countries, and has been associated with an increased risk of esophageal cancer. This increased risk may be attributed to drinking mate very hot, or to mate's potentially carcinogenic contaminants, such as polycyclic aromatic hydrocarbons (PAHs). Mate leaves are often dried via smoking, and therefore commercial samples may have high amounts of PAHs. We found 10 original articles that had measured PAHs in commercial dry samples, and nearly all found very high mass fractions. Most studies found benzo[a]pyrene mass fractions to be over 25 ng/g, and some found levels up to 600 ng/g. However, carcinogenic PAHs are often hydrophobic, and may not readily transfer into infusions. Seven articles studied transfer rates, and these rates varied from 1 to 50%, depending on the methods employed. Further careful studies of transfer rates in situations that mimic real life drinking of mate are recommended. Also, further studies of biological indicators of PAH exposure, particularly in randomized experiments, and analyzing DNA from tumor samples of mate drinkers are recommended.

Student Affect During an HBCU Summer Research Program

The popularity and effectiveness of intensive summer research programs to increase student self-efficacy is known. The Summer Research Institute (SRI) training experience, as part of undergraduate student training in Morgan State University's NIH BUILD program, uses an entrepreneurial approach to prepare students for careers in health-related research. Bandura's self-efficacy theory's (1977) four antecedents are represented in the SRI curriculum, which provides multiple opportunities for mastery experiences and for moments of roused feelings. These occurrences are accompanied by extensive multilayered mentoring, where the mentors provide verbal encouragement, and facilitate various modes of academic, psychosocial and institutional support. To our knowledge, student affect over time has not been tested to assess impact or program effectiveness in a summer research training program. This study is based on the qualitative assessment of bi-weekly journals of 28 students in the SRI. The practice of students consistently writing journals is aligned with the scaffolded knowledge integration framework proposed by Linn (1995). The journals were reviewed for their cumulative affective content and change over time. The students responded as expected with positive and negative affect throughout the program and ended with overwhelmingly positive affect with their concluding presentations. Using Linguistic Inquiry Word Count (LIWC), a text analysis program, we matched the fluctuations in affect to activities during the program and interpreted the changes for program assessment. This type of analysis opens a window into student affective responses to training components that, to our knowledge, have not been widely used for research training programs of this kind.

National Study of Opium and Cancer in Iran (IROPICAN): Study Protocol and Results of the Pilot Phase

Background: Several epidemiologic studies have reported that opium consumption is associated with higher risk of cancer and may indeed cause cancer. However, most of these studies were not primarily designed to study the effect of opium on cancer. Therefore, control selection and data collections methods were not optimized for this purpose. Aim: We designed a large multicenter case-control study to specifically investigate the association between opium use and risk of 4 cancer types (i.e., lung, bladder, head and neck and colorectal cancers). We will recruit 800 cases and 800 controls for each cancer in this project. Methods: So far we have collected 70% of the cases and controls. We report here the study protocol and results of the pilot phase. Results: During the pilot phase, we determined that hospital visitors are the most appropriate type of controls; 185 cases and 176 controls were enrolled. Controls are matched to cases for sex, age and place of residence. Collection of data using a comprehensive questionnaire, focused on measuring use of opium and its derivatives, was feasible. Underreporting of opium was estimated to be 30% among controls. Collection of other data, including data tobacco and alcohol use, and nutritional data using a food frequency questionnaire, was feasible. Biologic samples including blood and saliva sample were collected from cancer cases and controls. Results of the pilot phase and validation study were used to optimize the full study protocol and questionnaires. Conclusion: The pilot phase of the study showed that the study is feasible, the best method of control selection is from hospital visitors, and both questionnaire and biologic samples can be collected. In addition of the results from pilot phase, preliminary results from the main phase of this study will be presented.

Serum ghrelin is associated with risk of colorectal adenocarcinomas in the ATBC study

BACKGROUND

Colorectal cancers are the third most common cancers in women and men in the USA. While dietary and lifestyle factors such as Western diet, physical inactivity and obesity have been linked to an increased risk of this malignancy, the mechanisms for these associations are unclear. GI hormones, including ghrelin, are involved in energy balance by mediating appetite and metabolism; however, the association between ghrelin and colorectal cancer has not been studied.

METHODS

We conducted a case-control study nested within the all-male Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish smokers (aged 50-69 years) to examine serum ghrelin concentration and colorectal cancer risk. Data from 284 colon and 239 rectal cancers and 523 controls (matched on age, date of blood draw and serum availability) were analysed. ORs and 95% CIs were calculated using multivariable (conditional) logistic regression.

RESULTS

Overall, low-serum ghrelin was significantly associated with increased risk of colorectal cancer (Q1 vs Q4: OR:1.57, 95% CI 1.05 to 2.34). For individuals developing tumours within 10 years of blood draw, those in the lowest quartile of serum ghrelin concentrations were statistically significantly more likely to develop colorectal cancers than those with higher serum ghrelin concentrations (OR: 10.86, 95% CI 5.01 to 23.55). However, for individuals with tumours developing more than 20 years after blood draw, low-serum ghrelin concentrations were associated with a decreased risk of colorectal cancer relative to those with the highest serum ghrelin concentrations (OR: 0.26, 95% CI 0.11 to 0.64).

CONCLUSION

Low-serum ghrelin was associated with an increased colorectal cancer risk within 10 years of blood draw with a decreased risk for developing colorectal cancer more than 20 years after blood draw. These results suggest that ghrelin concentrations may vary across the carcinogenic process.

Causes of premature death and their associated risk factors in the Golestan Cohort Study, Iran

OBJECTIVES

To examine the causes of premature mortality (<70 years) and associated risk factors in the Golestan Cohort Study.

DESIGN

Prospective.

SETTING

The Golestan Cohort Study in northeastern Iran.

PARTICIPANTS

50 045 people aged 40 or more participated in this population-based study from baseline (2004-2008) to August 2017, with over 99% success follow-up rate.

MAIN OUTCOME MEASURES

The top causes of premature death, HR and their 95% CI and population attributable fraction (PAF) for risk factors.

RESULTS

After 444 168 person-years of follow-up (median of 10 years), 6347 deaths were reported, of which 4018 (63.3%) occurred prematurely. Ischaemic heart disease (IHD) accounted for 33.9% of premature death, followed by stroke (14.0%), road injuries (4.7%), stomach cancer (4.6%) and oesophageal cancer (4.6%). Significant risk/protective factors were: wealth score (HR for highest vs lowest quintile: 0.57, PAF for lowest four quintiles vs top quintile: 28%), physical activity (highest vs lowest tertile: 0.67, lowest two tertiles vs top tertile: 22%), hypertension (1.50, 19%), opium use (1.69, 14%), education (middle school or higher vs illiterate: 0.84, illiterate or primary vs middle school or higher: 13%), tobacco use (1.38, 11%), diabetes (2.39, 8%) and vegetable/fruit consumption (highest vs lowest tertile: 0.87, lowest two tertiles vs top tertile: 8%). Collectively, these factors accounted for 76% of PAF in men and 69% in women.

CONCLUSION

IHD and stroke are the leading causes of premature mortality in the Golestan Cohort Study. Enhancing socioeconomic status and physical activity, reducing opium and tobacco use, increasing vegetable/fruit consumption and controlling hypertension and diabetes are recommended to reduce premature deaths.

Nut consumption and the risk of oesophageal squamous cell carcinoma in the Golestan Cohort Study

BACKGROUND

Nut consumption has been inversely associated with gastric cancer incidence in US-based studies, but not with oesophageal cancer. However, there is aetiologic heterogeneity, among oesophageal squamous cell carcinoma (ESCC) cases in low-risk vs. high-risk populations. The objective of this study was to evaluate the association between nut consumption and risk of ESCC in a high-risk population.

METHODS

The Golestan Cohort Study enroled 50,045 participants in Northeastern Iran, between 2004 and 2008. Intake of peanuts, walnuts and mixed nuts (including seeds) were assessed using a validated food frequency questionnaire at baseline. Cox proportional hazard models were used to estimate hazard ratios (HR) and 95% confidence intervals for subsequent ESCC adjusted for potential confounders. Non-consumers of nuts were used as the reference category and the consumers were categorised into tertiles.

RESULTS

We accrued 280 incident ESCC cases during 337,983 person-years of follow up. Individuals in the highest tertiles of total nut consumption, and mixed nut consumption were significantly associated with lower risk of developing ESCC compared to non-consumers (HR = 0.60, 95% CI = 0.39-0.93, p-trend = 0.02, and HR = 0.52, 95% CI = 0.32-0.84, p trend = 0.002, respectively).

CONCLUSIONS

We found a statistically significant inverse association between total nut consumption and the risk of ESCC in this high-risk population.

Nut consumption and total and cause-specific mortality: results from the Golestan Cohort Study

Background

A number of prospective studies have observed inverse associations between nut consumption and chronic diseases. However, these studies have predominantly been conducted in Western countries, where nut consumption tends to be more common among individuals with healthier lifestyles. It is important to examine the association in other parts of the world, and particularly among populations with different patterns of disease, socioeconomic status, lifestyles and disease risk factors. Our objective was to examine the association between nut consumption and mortality in a population whose nut consumption does not track with a healthy lifestyle.

Methods

We examined the association between nut consumption and all-cause and cause-specific mortality in the 50 045 participants of the Golestan Cohort Study. Participants were aged 40 and older at baseline in 2004, and have been actively followed since that time. Dietary data were collected using a validated semi-quantitative food frequency questionnaire that was administered at baseline.

Results

During 349 677 person-years of follow-up, 3981 cohort participants died, including 1732 women and 2249 men. Nut consumption was associated inversely with all-cause mortality. The pooled multivariate adjusted hazard ratios for death among participants who ate nuts, as compared with those who did not, were 0.89 [95% confidence interval (CI), 0.82-0.95] for the consumption of less than one serving of nuts per week, 0.75 (95% CI, 0.67-0.85) for one to less than three servings per week and 0.71 (95% CI, 0.58-0.86) for three or more servings per week ( P < 0.001 for trend). Among specific causes, significant inverse associations were observed between nut consumption and deaths due to cardiovascular disease, all cancers and gastrointestinal cancers.

Conclusions

This study provides evidence for an inverse association between nut consumption and mortality in a developing country, where nut consumption does not track with a healthy lifestyle. Further work is needed to establish the underlying mechanisms responsible for this association.

Prospective Epidemiological Research Studies in Iran (the PERSIAN Cohort Study): Rationale, Objectives, and Design

Noncommunicable diseases (NCDs) account for 76% of deaths in Iran, and this number is on the rise, in parallel with global rates. Many risk factors associated with NCDs are preventable; however, it is first necessary to conduct observational studies to identify relevant risk factors and the most appropriate approach to controlling them. Iran is a multiethnic country; therefore, in 2014 the Ministry of Health and Medical Education launched a nationwide cohort study-Prospective Epidemiological Research Studies in Iran (PERSIAN)-in order to identify the most prevalent NCDs among Iran's ethnic groups and to investigate effective methods of prevention. The PERSIAN study consists of 4 population-based cohorts; the adult component (the PERSIAN Cohort Study), described in this article, is a prospective cohort study including 180,000 persons aged 35-70 years from 18 distinct areas of Iran. Upon joining the cohort, participants respond to interviewer-administered questionnaires. Blood, urine, hair, and nail samples are collected and stored. To ensure consistency, centrally purchased equipment is sent to all sites, and the same team trains all personnel. Routine visits and quality assurance/control measures are taken to ensure protocol adherence. Participants are followed for 15 years postenrollment. The PERSIAN study is currently in the enrollment phase; cohort profiles will soon emerge.

Opium Use and Risk of Pancreatic Cancer: A Prospective Cohort Study

Background: We examined the association between opium consumption and pancreatic cancer incidence in a large-scale prospective cohort of the general population in northeastern Iran.Methods: A total of 50,045 adults were systematically followed up (median of 7.4 years), and incident cases of pancreatic cancer were identified. Self-reported data on opium consumption was collected at baseline. Cumulative use (-year) was defined as number of nokhods (a local unit, approximately 0.2 g) of opium consumed per day multiplied by number of years consuming. Adjusted HRs and 95% confidence intervals (CIs) for the association between opium consumption and pancreatic cancer were calculated using Cox proportional hazards regression models.Results: Overall, 54 confirmed cases of pancreatic cancer were identified. Opium use of more than 81 nokhod-years (high cumulative use), compared with never use, was strongly associated with pancreatic cancer even after adjustments for multiple potential confounding factors [HR = 3.01; 95% CI, 1.25-7.26]. High cumulative consumption of opium was significantly associated with risk of pancreatic cancer after adjusting for cumulative dose of cigarette smoking [HR = 3.56; 95% CI, 1.49-8.50]. In a sensitivity analysis, we excluded participants (including 2 pancreatic cancer cases) who were recruited within the first 5 years of starting opium consumption; high cumulative use of opium was still associated with pancreatic cancer risk [HR = 2.75; 95% CI, 1.14-6.64].Conclusions: Our results showed a positive association between opium consumption and pancreatic cancer.Impact: This is the first prospective large-scale study to show the association of opium consumption with pancreatic cancer as a risk factor. Cancer Epidemiol Biomarkers Prev; 27(3); 268-73. ©2017 AACR.

Drug Use for Secondary Prevention of Cardiovascular Diseases in Golestan, Iran: Results From the Golestan Cohort Study

BACKGROUND

Little is known about secondary prevention of cardiovascular diseases, using cardio-protective drugs, in the community-level, especially in low- and middle-income countries. We aimed to assess main drug use and its predictors in Northeast of Iran.

METHODS

This is a cross-sectional analysis on the Golestan Cohort Study data (2004-2008) with 50 045 participants. We assessed drug use in those with a history of ischemic heart disease (IHD) or stroke, recorded by face-to-face interviews. We explored drug use predictors (i.e., age, gender, wealth, education, residency, smoking, body mass index, physical activity, hypertension, and diabetes) through multivariable logistic regression.

RESULTS

A total of 3371 (6.7%) participants (56.7 ± 9.0 years, 58.1% female) reported a history of IHD, stroke or both. Median duration since diagnosis was 3.14 years (IQR: 1.25-6.30). Rates of using anti-platelets, statins, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, and beta-blockers were 28.8% (95% CI: 27.3-30.3), 5.4 (4.7-6.2), 15.7 (14.5-17.0), and 40.6 (38.9-42.3), respectively. About 43% (41 - 45) of patients did not use any protective drugs. Use of ≥ three drugs was only 7.3% (6.6-8.2). Indicators of ≥1 drug use were: older age (OR for ≥60 vs. <50: 1.37), high wealth score (fifth vs first quintile: 1.60), literacy (1.56), city dwelling (1.32), body mass index (<18.5 and ≥30 vs. 25-29: 0.55 and 1.25, respectively), physical activity (third vs. first tertile: 0.64), hypertension (3.47), and diabetes (1.29); (all P < 0.05).

CONCLUSION

Drug use after IHD or stroke is low in Northeast of Iran. Comprehensive efforts to promote secondary prevention are urgently needed.

Improving Participants' Retention in a Smoking Cessation Intervention Using a Community-based Participatory Research Approach

Background

This study compares participant' sretention in three phases of smoking cessation interventions, one provided in a health clinic and the subsequent two in community-based settings.

Methods

Smoking cessation interventions were conducted in three phases from 2008 to 2015 in two underserved urban communities with low socioeconomic profiles and high rates of smoking (n = 951). Phase I was conducted in a clinic; Phases II and III were conducted in community venues. In Phases II and III, incremental changes were made based on lessons learned from the previous phases. Retention (attending six or more sessions) was the primary predictor of cessation and was analyzed while controlling for associated factors including age, gender, race, employment, education, and nicotine dependence.

Results

Retention increased substantially over the three phases, with rates for attending six or more sessions of 13.8%, 51.9%, and 67.9% in Phases I, II, and III, respectively. Retention was significantly higher in community settings than in the clinic setting (adjusted odds ratio [OR] = 6.7; 95% confidence intervals [CI] = 4.6, 9.8). In addition to the intervention in community venues, predictors of retention included age and unemployment. Higher retention was significantly associated with higher quit rates (adjusted OR = 2.4; 95% CI = 1.5, 3.8).

Conclusions

Conducting the intervention in community settings using trained peer motivators rather than health-care providers resulted in significantly higher retention and smoking cessation rates. This was due in part to the ability to tailor cessation classes in the community for specific populations and improving the quality of the intervention based on feedback from participants and community partners.

An entrepreneurial training model to enhance undergraduate training in biomedical research

Background

Undergraduate students who are interested in biomedical research typically work on a faculty member’s research project, conduct one distinct task (e.g., running gels), and, step by step, enhance their skills. This “apprenticeship” model has been helpful in training many distinguished scientists over the years, but it has several potential drawbacks. For example, the students have limited autonomy, and may not understand the big picture, which may result in students giving up on their goals for a research career. Also, the model is costly and may greatly depend on a single mentor.

Key highlights

The NIH Building Infrastructure Leading to Diversity (BUILD) Initiative has been established to fund innovative undergraduate research training programs and support institutional and faculty development of the recipient university. The training model at Morgan State University (MSU), namely “A Student-Centered Entrepreneurship Development training model” (ASCEND), is one of the 10 NIH BUILD-funded programs, and offers a novel, experimental “entrepreneurial” training approach. In the ASCEND training model, the students take the lead. They own the research, understand the big picture, and experience the entire scope of the research process, which we hypothesize will lead to a greater sense of self-efficacy and research competency, as well as an enhanced sense of science identity. They are also immersed in environments with substantial peer support, where they can exchange research ideas and share experiences. This is important for underrepresented minority students who might have fewer role models and less peer support in conducting research.

Implications

In this article, we describe the MSU ASCEND entrepreneurial training model’s components, rationale, and history, and how it may enhance undergraduate training in biomedical research that may be of benefit to other institutions. We also discuss evaluation methods, possible sustainability solutions, and programmatic challenges that can affect all types of science training interventions.

Oral health and mortality in the Golestan Cohort Study

Background

Previous studies have found associations between oral health and mortality, but the majority of previous studies have been conducted in high-income countries.

Methods

We used data from the Golestan Cohort Study, a study of 50 045 people aged 40 to 75 years in north eastern Iran, recruited from January 2004 to June 2008. Tooth loss and decayed, missing and filled teeth (DMFT) were assessed by trained physicians. Frequency of tooth brushing and use of dentures were self-reported. Cause-specific mortality was ascertained through March 2014. We calculated hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the associations between the oral health variables, overall mortality and cause-specific mortality.

Results

Participants with the greatest tooth loss had increased overall mortality (HR 1.43; 95% CI: 1.28, 1.61) compared with those with the least tooth loss; similar estimates were observed for DMFT score. For cause-specific mortality, an increased risk of death was found for tooth loss and mortality from cardiovascular disease (HR 1.33; 95% CI: 1.13, 1.56), cancer (HR 1.30; 95% CI: 1.03, 1.65) and injuries (HR 1.99; 95% CI: 1.28, 3.09). The associations between oral health and injury mortality were strongly attenuated after exclusion of participants with comorbid conditions at baseline. No statistical interaction was found between denture use and tooth loss or DMFT on mortality.

Conclusions

Poor oral health appears to predict overall and cause-specific mortality in populations in economic transition. Investigation of the underlying mechanisms might provide an important contribution to reducing mortality.

Toenail mineral concentration and risk of esophageal squamous cell carcinoma, results from the Golestan Cohort Study

Studies conducted in China linked selenium deficiency to higher risk of esophageal squamous cell carcinoma (ESCC), but this has not been widely tested outside that selenium-deficient region. The aim of this study was to investigate the association between selenium and other mineral concentrations in toenails and risk of ESCC in a region with high incidence rates. In this nested case-control study, we identified 222 cases of ESCC from the Golestan Cohort Study, Iran, which has followed up 50,045 participants since enrollment (2004-2008). We randomly selected one control for each case matched by age and sex, using incidence density sampling. We used toenail samples collected at baseline to measure the concentration of selenium, zinc, chromium, mercury, and scandium using instrumental neutron activation analysis. Multivariate adjusted logistic regression models were used to estimate odds ratios (OR) and 95% confidence intervals. Median nail selenium, zinc, chromium, and mercury levels were 1.01, 74.59, 0.77, and 0.018 μg/g in cases and 1.02, 75.71, 0.71, and 0.023 μg/g in controls, respectively. The adjusted odds ratios comparing each fourth quartile of mineral status versus the first quartile were as follows: selenium = 0.78 (95% CI, 0.41-1.49); zinc=0.80 (95% CI, 0.42-1.53); chromium = 0.91 (95% CI, 0.46-1.80); and mercury=0.61 (95% CI, 0.27-1.38), and all trend tests were non-significant. The nail selenium concentration in our controls reflects relatively high selenium status. No evidence of association between selenium or chromium concentrations in toenails and the risk of ESCC was detected in this population.

Hazards of cigarettes, smokeless tobacco and waterpipe in a Middle Eastern Population: a Cohort Study of 50 000 individuals from Iran

BACKGROUND

There is limited information about the hazards of cigarettes, smokeless tobacco and waterpipe in the Middle East. The aim of this study was to determine the association between different types of tobacco use and earlier death in the Golestan Cohort Study.

METHODS

The Study includes 50 045 adults (aged 40-75 years) from north eastern Iran. The baseline questionnaire (2004-2008) assessed information about use of cigarettes, chewing tobacco (nass) and waterpipe. To assess the use of each type of tobacco compared with never tobacco users, we used Cox regression models adjusted for age, socioeconomic status, area of residence, education and other tobacco used, and stratified by sex, ethnicity and opium use.

RESULTS

17% of participants reported a history of cigarette smoking, 7.5% chewing tobacco (nass) and 1.1% smoking waterpipe, and these figures declined in the later birth cohorts. During a median follow-up of 8 years, 4524 deaths occurred (mean age 64.8+9.9 years). Current (HR=1.44; 95% CI 1.28 to 1.61) and former (HR=1.35; 95% CI 1.16 to 1.56) cigarette smokers had higher overall mortality relative to never tobacco users. The highest cigarette-associated risk was for cancer death among current heavy smokers (HR=2.32; 95% CI 1.66 to 3.24). Current nass chewing was associated with overall mortality (HR=1.16; 95% CI 1.01 to 1.34), and there was a 61% higher risk of cancer death in people chewing nass more than five times a day. We observed an association between the cumulative lifetime waterpipe use (waterpipe-years≥28) and both overall (HR=1.66; 95% CI 1.11 to 2.47), and cancer mortality (HR=2.82; 95% CI 1.30 to 6.11).

CONCLUSIONS

Regular use of cigarettes, smokeless tobacco and waterpipe were associated with the risk of earlier death (particularly from cancer) in our cohort.

Mortality from respiratory diseases associated with opium use: a population-based cohort study

BACKGROUND

Recent studies have suggested that opium use may increase mortality from cancer and cardiovascular diseases. However, no comprehensive study of opium use and mortality from respiratory diseases has been published. We aimed to study the association between opium use and mortality from respiratory disease using prospectively collected data.

METHODS

We used data from the Golestan Cohort Study, a prospective cohort study in northeastern Iran, with detailed, validated data on opium use and several other exposures. A total of 50 045 adults were enrolled from 2004 to 2008, and followed annually until June 2015, with a follow-up success rate of 99%. We used Cox proportional hazard regression models to evaluate the association between opium use and outcomes of interest.

RESULTS

During the follow-up period, 331 deaths from respiratory disease were reported (85 due to respiratory malignancies and 246 due to non-malignant aetiologies). Opium use was associated with an increased risk of death from any respiratory disease (adjusted HR 95% CI 3.13 (2.42 to 4.04)). The association was dose-dependent with a HR of 3.84 (2.61 to 5.67) for the highest quintile of cumulative opium use versus never use (Ptrend<0.001). The HRs (95% CI) for the associations between opium use and malignant and non-malignant causes of respiratory mortality were 1.96 (1.18 to 3.25) and 3.71 (2.76 to 4.96), respectively.

CONCLUSIONS

Long-term opium use is associated with increased mortality from both malignant and non-malignant respiratory diseases.

International cancer seminars: a focus on esophageal squamous cell carcinoma

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.