Diet and the risk of vulvar cancer.

In this case-control study, 201 case patients with vulvar cancer and 342 community control subjects responded to a 61-item food frequency questionnaire. Risk was unrelated to intake of dark green vegetables, citrus fruits, legumes, and vitamins A and C and folate. Risk increased modestly with decreased intake of dark yellow-orange vegetables; the relative risk for the lowest versus the highest quartile was 1.6. Analyses using preliminary determinations of the major carotenoids in common fruits and vegetables suggested that alpha carotene might be the protective constituent in dark yellow-orange vegetables. Intake of beta carotene and provitamin A carotenoids was unrelated to risk. Multivitamin users were at lower risk, compared to nonusers, but no trend was observed with increasing years of use, suggesting that this association was due to unmeasured differences in life-style factors. Risk increased irregularly with the number of cups of coffee consumed per week whereas consumption of alcohol was unrelated to risk.