Folate intake may alter risk of advanced prostate cancer

[unseennude]

Folate nutrition is not associated with the incidence of prostate cancer, but does seem to influence disease severity somewhat, according to findings published in the June issue of the American Journal of Epidemiology.

"Folate has important roles in DNA synthesis, repair, and methylation, and is inversely associated with the risk of some cancers," Dr. Victoria L. Stevens and colleagues from the American Cancer Society, Atlanta, Georgia, write.

The researchers examined the association between folate and prostate cancer among 65,836 men in the Cancer Prevention Study II Nutrition Cohort. A total of 5158 subjects were diagnosed with prostate cancer during 9 years of follow-up.

The team estimated folate intakes from questionnaires administered at baseline in 1992 to 1993. Dietary folate intakes ranged from less than 204 mcg/day in the lowest quintile to more than 347 mcg/day in the highest quintile. Total folate intake ranged from less than 223 mcg/day in the lowest quintile to more than 640 mcg/day in the highest quintile.

No significant association was observed between dietary or total folate intake and overall prostate cancer risk. An association was found between higher folate levels and a nonsignificant decreased risk of advanced prostate cancer (multivariate rate ratio = 0.79 for the highest versus lowest quintile of total folate).

"The association was similar for quintiles 2-5, suggesting that only a small increase in folate intake was needed to alter the risk of advanced prostate cancer," Dr. Stevens and colleagues note. However, the statistical power of the study was limited by the small number of cases of advanced prostate cancer.