Vitamin D intake and gastric cancer in Viet Nam: a case-control study.

BACKGROUND: Most recent laboratory studies have suggested a promising role of vitamin D and its analogs as novel chemotherapeutic agents for cancer treatment. However, epidemiological evidence, especially regarding the effects of vitamin D on gastric cancer is still inconsistent. OBJECTIVES: Our research aimed to evaluate the associations between vitamin D intake and the risk of developing gastric cancer through a case-control study in North Vietnam. METHODS: We accessed databases of the previous completed case-control studies to derive 1182 incident gastric cancer cases and 2995 hospital controls selected from hospitals in Hanoi from 2003 to 2019. Vitamin D intake was computed by multiplying the food frequency intake with nutrient content based on the Viet Nam Food Composition Tables. Data were collected through face-to-face interviews by trained interviewers using the validated semi-quantitative food frequency and demographic lifestyle questionnaires. The odds ratio and 95% confidence interval (OR and 95%CI) were estimated using unconditional logistic regression analysis. RESULTS: We observed a continual decline in gastric cancer risk according to the level-up of vitamin D intake in both genders, men, and women [Fifth vs. bottom quintile, OR, 95%CI: 0.68 (0.53, 0.86), OR, 95%CI: 0.72 (0.53, 0.97), OR, 95%CI: 0.58 (0.38, 0.89), respectively. Per increment quintile, the statistically significant decreased risk was seen by 7% in men and 13% in women. The significant inverse association between vitamin D intake remained in the subgroups of ever and never tobacco smoking; negative and positive H. pylori infection. CONCLUSION: The findings suggested that sufficient vitamin D intake was associated with a lower risk of Gastric Cancer in the Vietnamese population.

A prospective cohort study on the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam.

Tobacco consumption, as a worldwide problem, is a risk factor for several types of cancer. In Vietnam, tobacco consumption in the form of waterpipe tobacco smoking is common. This prospective cohort study aimed to study the association between waterpipe tobacco smoking and gastric cancer mortality in Northern Vietnam. A total of 25,619 eligible participants were followed up between 2008 and 2019. Waterpipe tobacco and cigarette smoking data were collected; semi-quantitative food frequency and lifestyle questionnaires were also utilized. Gastric cancer mortality was determined via medical records available at the state health facilities. A Cox proportional hazards model was used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI). During 314,992.8 person-years of follow-up, 55 men and 25 women deaths due to gastric cancer were identified. With never-smokers as the reference, the risk of gastric cancer mortality was significantly increased in participants who were ever-smoking (HR = 2.43, 95% CI = 1.35-4.36). The positive risk was also observed in men but was not significantly increased in women. By types of tobacco use, exclusive waterpipe smokers showed a significantly increased risk of gastric cancer mortality (HR = 3.22, 95% CI = 1.67-6.21) but that was not significantly increased in exclusive cigarette smokers (HR = 1.90, 95% CI = 0.88-4.07). There was a significant positive association between tobacco smoking and gastric cancer death for indicators of longer smoking duration, higher frequency per day, and cumulative frequency of both waterpipe and cigarette smoking. Waterpipe tobacco smoking would significantly increase the risk of gastric cancer mortality in the Vietnamese population. Further studies are required to understand the waterpipe tobacco smoking-driven gastric cancer burden and promote necessary interventions.

Mortality due to HIV/AIDS in Viet Nam: time trend and related socio-economic status in some populations and periods from 2005 to 2014.

The study examined mortality due to HIV/AIDS and its time trend and ecological variables of socio-economic status during 2005-2014. Mortality data were obtained from the database of population-based mortality registration. Five variables including name, age, sex, date of death, and cause of death were collected from 10,184 of 10,769 local state health centers. Mortality rates ratio and 95% confidence interval (MRR, 95%CI) were calculated to observe the risk of death from HIV/AIDS-related to socio-economic status and time trends. The age-adjusted HIV/AIDS mortality rate increased from 5.49 per 100,000 during 2005 to 6.03 during 2006 and 6.20 during 2007. An elevated risk of death was seen in high mountain districts in Nghe An province, adjusted MRR = 5.38, 95%, CI: 4.76-6.08 relative to the urban areas of Vinh and Cua Lo cities. The highest age-adjusted mortality rate (147.1 per 100,000) was observed in a commune located in Thai Nguyen province. There was a statically significant decrease in HIV/AIDS mortality in Nghe An province from 2005-2006 to 2013-2014 (p < 0.05). The findings suggest that people living with HIV/AIDS in disadvantaged regions have a higher risk of death but there was a significant decrease in HIV/AIDS mortality in Nghe An province by 2013-2014.

Waterpipe tobacco smoking and risk of all-cause mortality: a prospective cohort study.

BACKGROUND: Despite an increasing proportion of smokers who use non-cigarette products, the harmfulness of these is inconsistent. This study aimed to evaluate the impact of waterpipe tobacco (WTP) smoking on all-cause mortality. METHODS: A prospective cohort study followed up on 35 646 participants from 2007 to 2019 in Northern Viet Nam. Data for each type of cigarette and WTP smoking were collected based on demographic lifestyle and semi-quantitative food frequency questionnaires. Smokers were categorized as current smokers and former smokers who were lifetime ever smokers but stopped smoking >6 months before the interview. Data on all-cause mortality (2449 deaths) were obtained from medical records at the state health facilities. The hazard ratios (HRs) and 95% CIs for mortality were estimated using a Cox proportional-hazards model. RESULTS: Compared with non-smokers, ever smokers had a higher all-cause mortality risk (HR = 1.29, 95% CI = 1.16-1.43). Current WTP (HR = 1.37, 95% CI = 1.19-1.57), current cigarette (HR = 1.40, 95% CI = 1.22-1.60) and former WTP smokers (HR = 1.39, 95% CI = 1.10-1.76) showed an elevated risk of dying. The mortality risk was significantly elevated in dual smokers using WTP and cigarettes (HR = 1.55, 95% CI = 1.35-1.79) and exclusive WTP smokers (HR = 1.38, 95% CI = 1.21-1.57). Elevated risk was observed for the main targeted attractions of cancer, diabetes and heart diseases. Smoking cessation of >10 years decreased the risk of all-cause mortality (HR = 0.61, 95% CI = 0.44-0.85) and cancer (HR = 0.24, 95% CI = 0.11-0.52). CONCLUSIONS: WTP smoking increases the risk of all-cause mortality. A unique programme to control exposure to WTP should be a high priority in Viet Nam and other countries.

Tryptophan intake and pancreatic cancer: findings from a case-control study.

BACKGROUND: Pancreatic cancer is a leading cause of cancer-related death worldwide. Tryptophan plays a vital role in cell growth and maintenance as a building block of protein and coordination of organismal responses to environmental and dietary cues. Animal model study showed that dietary tryptophan improved treatment response in those who received chemotherapy or immune checkpoint inhibitors. Limited data are available assessing the association between tryptophan intake and risk of pancreatic cancer. We aimed to evaluate this association in a case-control study in Vietnam. METHODS: We analyzed data from a case-control study, including 3759 cancer cases and 2995 control subjects of whom 37 with pancreatic cancer cases. Tryptophan intake was derived from food frequency questionnaire. Unconditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for different levels of tryptophan intake with pancreatic cancer risk. RESULTS: Overall, tryptophan intake was inversely associated with pancreatic cancer risk in a dose-dependent manner. The ORs and 95% CIs of pancreatic cancer were 0.51 (0.29-0.92) for continuous scale, 0.27 (0.10-0.73) for tertile 2 and 0.34 (0.11-1.06) for tertile 3, compared with tertile 1 (the lowest intake) ( Ptrend = 0.02). In stratified analysis, this inverse association pattern was present among those with BMI < 23 kg/m 2 and ever drinkers. CONCLUSION: A diet with a higher intake of tryptophan was significantly associated with a lower incidence of pancreatic cancer among Vietnamese population. These suggest that dietary modification may be an effective strategy for primary prevention of pancreatic cancer development.

Novel hazards of waterpipe tobacco and the benefits of stop smoking in men, a prospective cohort study.

Waterpipe smoking is an emerging epidemic and a severe public health problem worldwide. Observational studies on the hazards of a specific new waterpipe tobacco product are timely needed. The objectives were to analyze how dangerous waterpipe tobacco smoking is on the causes of all mortality, including cancer, and how effective smoking cessation is for improving health. We analyzed the hazards of exclusive waterpipe smoking through a prospective cohort study in Northern Vietnam. We obtained exposure data on the smoking status of specific cigarette and waterpipe and smoking cessation histories from each study participant. The outcome includes deaths due to all causes. The cause of death for each case is determined based on medical records. HR (95%CI) was estimated using a Cox proportional-hazards-regression analysis for overall mortality and all cancers. The ever-cigarette smoking group as the reference group, the exclusive waterpipe smoking group had a statistical increase in the risk for overall mortality HR (95% CI): 1.63 (1.32, 2.00), and all cancers HR (95%CI): 1.67 (1.18, 2.38). The risk of death increased statistically in the group of waterpipe smoking over 20 years for overall mortality HR (95%CI): 1.82 (1.45, 2.29), and all cancers HR (95%CI): 1.91 (1.27, 2.88). After stopping smoking, the risk of death decreased steadily. The risk of death was reduced by 41% for overall mortality HR (95%CI): 0.59 (0.39, 0.89), and 74% for death from cancers HR (95%CI): 0.26 (0.08, 0.83) after ten years or longer of cessation. Life expectancy was shortened by more than six years for the group of exclusive waterpipe smokers compared to non-smokers. This study found new novel hazards of exclusive waterpipe tobacco smoking. The findings are scientific evidence for developing strategies, policies, and budget allocations to control this novel tobacco product and promote cessation to improve life expectancy.

Exclusive waterpipe smoking and the risk of nasopharynx cancer in Vietnamese men, a prospective cohort study.

Tobacco smoking is carcinogenic to humans. Besides cigarettes, the most common form of tobacco smoking, there was sparse evidence of waterpipe's carcinogenicity-induced nasopharyngeal cancer (NPC). This study investigated the association between waterpipe smoking and NPC mortality. Our study followed up with 20,144 eligible man participants from nine northern Vietnam communes between 2007 and 2019. Face-to-face interviews were conducted to gather data on exclusive waterpipe and cigarette smoking and dietary intake using structured semi-quantitative food frequency and lifestyle questionnaires. Nasopharyngeal cancer was determined by accessing the medical records at the state health facilities. We estimated the Cox proportional hazard ratio and 95% confidence intervals, HR (95% CI). The proportion of never smokers, exclusive waterpipe, exclusive cigarette, and dual waterpipe and cigarette smokers was 55.8%, 14.5%, 16.6%, and 13.1%, respectively. Exclusively waterpipe smokers increased the risk of NPC death compared to exclusively cigarette smokers, HR (95% CI): 4.51 (1.25, 16.31), p = 0.022. A dose-dependent positive relationship between NPC and exclusive waterpipe smoking was significantly seen for higher intensity HR (95% CI): 1.35 (1.07, 1.71), earlier age of smoking initiation HR (95% CI): 1.26 (1.06, 1.50), longer duration HR (95% CI): 1.31 (1.04, 1.66), and the cumulative number of a smoke lifetime HR (95% CI): 1.37 (1.08, 1.74). We observed a significant positive association between exclusive waterpipe smoking and NPC in men. The findings suggested that waterpipe smoking is likely more harmful than cigarettes in developing this cancer. A firm tobacco control against waterpipe smoking is highly recommended.

A Prospective Pooled Analysis of Meat Mutagens and Colorectal Adenoma and Cancer in the US and EPIC Studies: Findings with an Emphasis on Improving Exposure Measurements.

BACKGROUND: In animal studies, heterocyclic amines (HCAs) are recognized as having strong carcinogenicity, therefore we have hypothesized that HCAs might be associated with the risk of colorectal adenoma (CRA) and cancer (CRC). METHODS: We used the Keywords of "Heterocyclic amines and colorectal cancer" to search, there were showing published articles (n=200). After reviews of titles, abstracts, and full articles, seven prospective cohort studies were included in the pooled analysis. Exposures to HCAs 2-amino-3,8-dimethylimidazo(4,5-j)quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo(4,5-f)quinoxaline (DiMeIQx), meat-derived mutagenicity (MDM), and the risk of CRA and CRC were examined. The estimated HCA intake as ng/day and ng/1,000 kcal/day by participants and by studies were examined. The ln(HR) and se(ln(HR)) were estimated from the multivariable-adjusted HR, 95%CI derived from seven published prospective studies in the US and EPIC. The random pooled multivariable-adjusted HR, 95%CI was analyzed using ln(HR) and se(ln(HR)) by STATA-10. RESULTS: For CRC and HCA intake, the null association was observed for MDM, the random pooled multivariable-adjusted HR, (95%CI): 1.11, (1.00, 1.23); for PhIP: 1.00, (0.91, 1.09); and for DiMeIQx: 1.03, (0.87, 1.22). A significant positive association was seen for MeIQx, the random pooled multivariable-adjusted HR, (95%CI):1.12, (1.03, 1.22). For CRA and HCA intake, the null association was observed for MDM, randomly pooled multivariable-adjusted HR, (95%CI): 1.15, (0.99, 1.34), and for DiMeIQx: 1.09, (0.97, 1.23). A significant positive association was seen for PhIP, the random pooled multivariable-adjusted HR, (95%CI): 1.19, (1.02, 1.39), and for MeIQx: 1.17, (1.01, 1.35). The major instances of HCAs were contributed by chicken (54%-74%) for PhIP and by red meat (83%-92%) for MeIQx. However, the estimated PhIP intake (ng/1,000 kcal/day) was remarkably different between studies. CONCLUSIONS: We observed a positive association between exposures to MeIQx and the risk of both CRC and CRA which supports the hypothesis of the role of HCAs in developing CRA and CRC. Improving the quality of the estimated HCA intake would be highly concerned for further investigation.

Changes in the Proportion of Gastrointestinal Emergency Endoscopy and Peptic Ulcer Disease During the COVID-19 Pandemic: A Local Retrospective Observational Study From Vietnam.

OBJECTIVES: The coronavirus disease 2019 (COVID-19) pandemic has disrupted the practice of gastrointestinal (GI) endoscopy units and may increase the risk of digestive disorders. We described the situational changes in GI endoscopy and peptic ulcer disease (PUD) proportion during COVID-19 in Vietnam and examined the associated factors. METHODS: A retrospective ecological study was conducted on data of Hanoi Medical University Hospital, Vietnam. The number of upper GI endoscopy and the proportion of GI emergency endoscopy and PUD were compared between 2019 and 2020 by month (January to June). Log-binomial regression was used to explore associated factors of GI emergency endoscopy and PUD. RESULTS: The number of endoscopies decreased remarkably during the nationwide social distancing in April 2020. Compared to April 2019, the proportion in April 2020 of both GI emergency endoscopy [4.1 vs. 9.8%, proportion ratio (PR) 2.39, 95% CI 2, 2.87], and PUD [13.9 vs. 15.8%; PR, 1.14; 95% CI, 1.01, 1.29] was significantly higher. In log-binomial models, the proportion of GI emergency endoscopy was higher in April 2020 compared to April 2019 (adjusted PR, 2.41; 95% CI, 2.01, 2.88). Male sex and age of ≥50 years were associated with an increased PUD and GI emergency conditions. CONCLUSION: The proportion of both GI emergency endoscopy and PUD was significantly higher during the time of the state of emergency due to the ongoing COVID-19 pandemic in 2020 when compared to 2019 at the same health facility in Vietnam. The findings suggest that healthcare delivery reforms during the era of an emerging pandemic are required to reduce digestive disorders, in particular, and chronic diseases in general.

Clinical, Laboratory and Bacterial Profile of Spontaneous Bacterial Peritonitis in Vietnamese Patients with Liver Cirrhosis.

Aim: To determine several clinical and laboratory features as well as the bacterial profile of spontaneous bacterial peritonitis (SBP) in 58 Vietnamese patients admitted to a single center due to liver cirrhosis. Methods: We retrospectively analyzed bacteriological, clinical and laboratory characteristics of patients with SBP admitted to the Gastroenterology and Hepatology Center from July 2019 to July 2020. Results: Out of a total 58 SBP patients, 41 (70.9%) had culture-negative neutrocytic ascites. The majority of patients experienced abdominal pain (93,1%) and large ascites (65,5%). Gram-negative bacteria formed the main pathogens (14/17). Escherichia coli (9/17) was the predominant cause followed by Burkholderia cepacia (2/17). Antibiotic sensitivity rate of E. coli for third generation cephalosporin was low but high for aminoglycoside and carbapenem antibiotics. The resistance of E. coli was significant against fluoroquinolones (100%). All 3 cases of gram-positive bacteria were sensitive to vancomycin. Conclusion: Our study reported the bacteriological and clinical characteristics of patients with SBP and compared these findings between two groups: positive ascitic fluid culture and negative fluid culture. Ascitic fluid culture can guide for the right antibiotic choice since resistance to commonly prescribed antibiotics is common in SBP patients.

Heterocyclic amines detected in cooked meats and fishes from street markets and restaurants in the city of Hanoi, Vietnam: A Pilot local field investigation findings in 2020.

Background: Street food has been a typical culinary feature of many countries. These foods, mainly, meats and fish, were often fried, and grilled with varied marinade and preparation. However, foods that contain a lot of protein after processing at high temperatures always have many risks, including cancer risks of which heterocyclic aromatic amines (HAAs) have been one of the typical compounds. However, there is a lack of data on HAAs in low- and medium-income countries to date. Objective: The aim was to examine the concentration of HAAs including 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP); 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx); and 2-Amino-9H-pyrido[2,3-b]indole (AαC) in cooked meat and fish samples. Methods: Three standards including PhIP, MeIQx, AαC, and three isotopically labeled internal standards PhIP-d3, MeIQx-d3, and AαC-15N3 were purchased from Toronto Research Chemicals, Inc. (Toronto, Canada). Formic acid, HPLC-grade methanol, acetonitrile, water, sodium chloride, and magnesium sulfate were supplied by Sigma-Aldrich (St. Louis, MO, USA). We collected cooked meat and fish samples from street markets and restaurants in the area of Cau Giay district, Hanoi, Vietnam in 2020. The collected samples were prepared for LC-MS/MS analysis. Results: Among 23 selected samples of cooked beef, fish, chicken, and pork, we have detected PhIP(ng/g) in 9 samples (the mean 2.68, standard deviation 2.41, median 2.40, minimum 0.33, and maximum 7.19); and AαC(ng/g) in 6 samples (the mean 0.74, standard deviation 0.75, median 0.45, minimum 0.12, and maximum 1.90); and MeIQx(ng/g) was not detected in all samples. Three grilled pork samples were positive with AαC at a concentration of 0.75-1.95 ng/g. Five fish samples have been detected to contain PhIP at the concentration of mean of 3.17; the standard deviation of 1.47, and the median of 3.90 ng/g. Two fried chickens have been detected to contain PhIP at the concentration of 0.41 and 7.19 ng/g. Conclusions: We detected a considerable amount of PhIP concentration in the collected fried fish and other fried meat samples and AαC in grilled and fried pork, beef, and chicken samples. The findings warrant further measuring more compounds of the HAA group and extending the number of real samples, as well as types of samples for example cooked meats, fish, fried eggs, tofu, and other cooked food receipts by regions in Vietnam.

Case-Control Study of Alcohol Usage and Fruit Intake and Stomach Cancer in the North Viet Nam.

BACKGROUND: The aim was to examine the association between alcohol usage, fruit intake and stomach cancer treated in hospitals in the Hanoi city during 2018-2019. METHODS: A case-control study was performed for 379 newly incidence cases of stomach cancer and matched 1096 hospital controls for sex and age (+/-5). We used the validated semi-quantitative food frequency questionnaire to collect data on the intake of alcohol and fruits and other food groups. The average amount of total fruits intake (grams per week) was estimated. The adjusted Odds ratio and 95% confidence interval (OR (95%CI) were estimated. RESULTS: Intake of alcohol significantly increased the risk of stomach cancer, the mean frequency of intake per year of 345.1 times vs. non-drinkers, OR (95%CI): 1.51 (1.05, 2.17), p_trend=0.026. In contrast, a higher total of fruits intake was associated with a significantly decreased risk of stomach cancer in both sexes, men, and women, (Q5 vs Q1), OR (95%CI): 0.47 (0.30, 0.72), p_trend=0.000, OR (95%CI): 0.45 (0.26, 0.77), p_trend =0.003, OR (95%CI): 0.52 (0.24, 1.12), p_trend=0.026, respectively. CONCLUSIONS: We observed alcohol usage increased the risk of stomach cancers. In contrast, a total of fruits intake was associated with a decreased risk of stomach cancer. 
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A Case-Control Study of Meat Mutagens and Colorectal Cancers in Viet Nam.

OBJECTIVE: The aim was to examine the association between heterocyclic amines 2-amino-1-methyl-6-phenylimidazo pyridine (PhIP) and the risk of colorectal cancer (CRC) in Viet Nam. METHODS: We performed a case-control study for 512 colorectal cancer patients with the histopathological confirmation and 1,096 hospital controls. We collected information on lifestyle, diet, and cooking methods from participants by trained interviewers using the validated questionnaires. We used data of PhIP concentration in cooked beef analyzed by the LC/MS/MS and cooking questionnaire to estimate the daily intake of PhIP. We divided the estimated amount of PhIP (ng/person/day) into three levels of non-intake (the reference), medium, and high to estimate the Odds ratio and 95% confidence interval (OR, 95%CI). RESULTS: The median intake of PhIP (ng/person/day) was 18ng and 102.8ng for medium and high PhIP intake, respectively. There was a significant association between PhIP intake and the risk of colorectal cancer. The adjusted OR (95%C), high intake vs. non-intake, were 4.89 (3.03, 7.89), p_trend.

H. pylori Infection and Colorectal Cancers by Anatomical Locations.

BACKGROUND: H. pylori infection may play a role in the development of colorectal cancers (CRC). We aimed to examine the association between H. pylori infection and the risk of CRC by anatomical locations. METHODS: We conducted a case-control study on 91 incidence cases of CRC and 224 hospital controls. CRC was determined by histopathological examinations. H. pylori IgG antibody in serum was tested. We collected data on the diet, nutrition, and lifestyle by the validated semi-quantitative food frequency and demographic lifestyle questionnaire. The odds ratio and 95% confidence interval (OR (95%CI) were estimated for CRC and its subgroups. RESULTS: Overall 54.95% of CRC cases and 42.41% of the controls were H. pylori-seropositive, OR (95%CI): 1.56 (0.88, 2.74), p for trend=0.115. Positive dose-response association in quartiles, highest vs lowest, was observed for total CRC, OR (95%CI): 2.14 (1.00, 4.58), p for trend=0.049, for proximal colon, OR (95%CI): 1.52 (0.37, 6.25), p for trend=0.571), and for distal colon and rectum cancers combined, OR (95%CI): 2.38 (1.03, 5.50), p for trend=0.039. CONCLUSIONS: There is a positive association between H. pylori and colorectal cancers, especially distal colon and rectum cancers combined, but additional research is needed to determine the underlying mechanism of chronic H. pylori infection-induced CRC in humans.

Meat Mutagens and Colorectal Adenoma and Cancer: A Problem with a Recently Published Systematic Review and Meta-Analysis.

Dear Editors and Authors, I had the pleasure to read the published article entitled [1] "Dietary Intake of Meat Cooking-Related Mutagens (HCAs) and Risk of Colorectal Adenoma and Cancer: A Systematic Review and Meta-Analysis" [...].

Waterpipe Tobacco Smoking and Gastric Cancer Risk among Vietnamese Men.

BACKGROUND: The association of waterpipe tobacco (WPT) smoking with gastric cancer (GC) risk was suggested. METHODS: A hospital-based case-control study was conducted to examine the association of WPT with GC risk among Vietnamese men, in Hanoi city, during the period of 2003-2011. Newly-diagnosed GC cases (n = 454) and control patients (n = 628) were matched by age (+/- 5 years) and the year of hospitalization. Information on smoking and alcohol drinking habits and diet including salty food intake and fruits/vegetables consumption were obtained by the interview. Maximum likelihood estimates of odds ratios (ORs) and corresponding 95% confidence intervals (Cis) were obtained using conditional logistic regression models. RESULTS: The group with the highest consumption of citrus fruits showed a significantly low GC risk (OR = 0.6, 95%CI = 0.4-0.8, P for trend = 0.002). However, there was no association of raw vegetable consumption with GC risk. Referring to never smokers, GC risk was significantly higher in current WPT smokers (OR = 1.8, 95%CI = 1.3-2.4), and it was more evident in exclusively WPT smokers (OR = 2.7, 95%CI = 1.2-6.5). GC risk tended to be higher with daily frequency and longer duration of WPT smoking but these trends were not statistically significant (P for trend: 0.144 and 0.154, respectively). GC risk of those who started smoking WPT before the age of 25 was also significantly high (OR = 3.7, 95%CI = 1.2-11.3). Neither cigarette smoking nor alcohol drinking was related to GC risk. CONCLUSION: The present findings revealed that WPT smoking was positively associated with GC risk in Vietnamese men.

A Prospective Analysis of Meat Mutagens and Colorectal Cancer in the Nurses' Health Study and Health Professionals Follow-up Study.

BACKGROUND: Heterocyclic amines (HCAs) in cooked meats may play a role in colorectal cancer (CRC) development. OBJECTIVES: We aimed to prospectively examine the association between estimated intakes of HCAs and meat-derived mutagenicity (MDM) in two cohorts of health professionals, the Health Professionals Follow-up Study (HPFS) and the Nurses' Health Study (NHS). METHODS: In 29,615 men and 65,875 women, intake of the HCAs 2-amino-3,8-dimethylimidazo(4,5-j)quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine (PhIP), 2-amino-3,4,8-trimethylimidazo(4,5-f)quinoxaline (DiMeIQx), and MDM was estimated using a 1996 cooking questionnaire, the 1994 food frequency questionnaire, and an online database. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) and to adjust for potential confounders. Estimates for both cohorts were pooled using random-effects meta-analysis. RESULTS: Between 1996 and 2010, 418 male and 790 female CRC cases were identified. Meat mutagen intake was not statistically significantly associated with risk of CRC [highest vs. lowest quintile, pooled HR (95% CI) for MeIQx: 1.12 (0.93, 1.34), p for trend 0.23; PhIP: 1.10 (0.90, 1.33), p for trend 0.35; MDM: 1.03 (0.86, 1.24), p for trend 0.75] or subtypes of CRC defined by tumor location (proximal or distal colon, or rectum). When analyzed by source of meat, PhIP from red but not from white meat was nonsignificantly positively associated with CRC and significantly positively associated with proximal cancers [HR (95% CI) per standard deviation increase of log-transformed intake: PhIP red meat: CRC: 1.06 (0.99, 1.12), proximal: 1.11 (1.02, 1.21); PhIP white meat: CRC: 0.99 (0.94, 1.04), proximal: 1.00 (0.93, 1.09)]. CONCLUSIONS: Estimated intakes of meat mutagens were not significantly associated with CRC risk over 14 years of follow-up in the NHS and HPFS cohorts. Results for PhIP from red but not from white meat warrant further investigation. CITATION: Le NT, Michels FA, Song M, Zhang X, Bernstein AM, Giovannucci EL, Fuchs CS, Ogino S, Chan AT, Sinha R, Willett WC, Wu K. 2016. A prospective analysis of meat mutagens and colorectal cancer in the Nurses' Health Study and Health Professionals Follow-up Study. Environ Health Perspect 124:1529-1536; http://dx.doi.org/10.1289/EHP238.