Folate intake and pancreatic cancer risk: an overall and dose-response meta-analysis.

ABSTRACT

OBJECTIVE: Inconsistent findings of association between supplemental folate consumption and pancreatic cancer risk have been observed in the literature. This study aims to summarize the relationship between folate intake and risk of pancreatic cancer. STUDY DESIGN: Pertinent studies published before November 2011 were identified by searching PubMed and Embase and by reviewing the reference lists of retrieved articles. The summary relative risks were estimated by the random effects model. A linear regression analysis of the natural logarithm of the relative risk (RR) was carried out to assess a possible dose-response relationship between folate intake and pancreatic cancer risk. RESULTS: Ten studies on dietary and supplemental folate intake and pancreatic cancer (4 case-control and 6 cohort studies) were included in the meta-analysis. The pooled RRs of pancreatic cancer for the highest vs lowest categories of dietary folate intake and supplemental folate intake were 0.66 (95% CI 0.49-0.88) and 1.08 (95% CI, 0.82-1.41), respectively. The dose-response meta-analysis indicated that a 100 µg/day increment in dietary folate intake conferred a RR of 0.93 (95% CI 0.90-0.97). These findings support the hypothesis that dietary folate may play a protective role in carcinogenesis of pancreatic cancer.