Folate intake post‐folic acid grain fortification and pancreatic cancer risk in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial

Abstract

Folate plays a critical role in DNA methylation, synthesis, and repair. Several epidemiologic studies suggest that higher folate intake is associated with reduced pancreatic cancer risk. We investigated the association between dietary folate intake and pancreatic cancer in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial (PLCO) cohort. Dietary data were collected using a food frequency questionnaire (1998–2005). Among the 51,988 male and 57,187 female participants, aged 55–74 years at enrollment, 162 men and 104 women developed pancreatic cancer during follow‐up (median 6.5 years). We used Cox proportional hazard regression to calculate hazard ratios (HR) and 95% confidence intervals (CI). The highest compared to the lowest quartile of food folate was associated with a significantly reduced pancreatic cancer risk among women, (≥ 253.3 vs. ≤ 179.1 μg/day, HR = 0.47, 95% CI 0.23, 0.94, ptrend = 0.09) but not among men (≥ 229.6 μg/day vs. ≤ 158.0 μg/day, HR = 1.20, 95% CI, 0.70, 2.04, ptrend = 0.67, p‐interaction by sex = 0.03). There was also a significant inverse trend in risk of pancreatic cancer across increasing quartiles of total folate in women (ptrend = 0.04) but not men (ptrend = 0.65). Folic acid supplements were not associated with pancreatic cancer. These findings support an association between higher food and total folate intakes and reduced risk of pancreatic cancer in women but not men.Grant Funding Source: NIH Cancer Research Training Award