Dietary and other methyl-group availability factors and pancreatic cancer risk in a cohort of male smokers

The authors examined prospectively whether dietary folate and other factors known to influence methyl-group availability were associated with the development of exocrine pancreatic cancer within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort. Of the 27,101 healthy male smokers aged 50-69 years who completed a self-administered dietary questionnaire at baseline, 157 developed pancreatic cancer during up to 13 years of follow-up from 1985 to 1997. Cox proportional hazards models were used to estimate the hazards ratios and 95% confidence intervals. The adjusted hazards ratio comparing the highest with the lowest quintile of dietary folate intake was 0.52 (95% confidence interval: 0,31, 0.871 p-trend = 0.05). Dietary methionine, alcohol intake, and smoking history did not modify this relation. No significant associations were observed between dietary methionine, vitamins B-6 and B-12, or alcohol intake and pancreatic cancer risk. Consistent with prior studies, this study shows that cigarette smoking was associated with an increased risk (highest compared with lowest quintile, cigarettes per day: hazards ratio = 1.82; 95% confidence interval: 1.10, 3.03; p-trend = 0.05). These results support the hypothesis that dietary folate intake is inversely associated with the risk of pancreatic cancer and confirm the risk associated with greater cigarette smoking.