Folate intake and squamous-cell carcinoma of the oesophagus in Italian and Swiss men.

BACKGROUND Dietary folate has been inversely related to the risk of several cancers. However, studies on the role of dietary folate in oesophageal cancer are scanty. PATIENTS AND METHODS Using data from a multicentric case-control study conducted in Italy and Switzerland between 1992 and 1999, we investigated the association between dietary folate intake and oesophageal squamous-cell carcinoma (OSCC) among 351 men with incident, histologically confirmed OSCC and 875 hospital controls admitted for acute, non-neoplastic conditions, unrelated to alcohol and smoking consumption. Intake of folate and other nutrients was computed from a validated food frequency questionnaire. RESULTS The multivariate odds ratios (ORs) of OSCC were 0.68 (95% confidence intervals, CI: 0.46-1.00) for the highest versus the lowest tertile of folate intake, and 0.84 (95% CI: 0.72-0.99) for an increment of folate intake equal to a standard deviation (98 microg/day). The inverse relation was somewhat stronger in strata of high methionine, vitamin B6 and alcohol intake, and did not vary substantially according to age and smoking habits. CONCLUSION Dietary folate was inversely related to OSCC risk in this population with high alcohol consumption and infrequent use of supplements and multivitamins.