Micronutrients and ovarian cancer: a case-control study in Italy

Background: The role of selected micronutrients, vitamins and minerals in the aetiology of epithelial ovarian cancer was investigated using data from a case-control study conducted between 1992 and 1999 in five Italian areas. Patients and methods: Cases were 1031 patients with histologically confirmed incident epithelial ovarian cancer. Controls were 2411 subjects admitted for acute, non-neoplastic diseases to major hospitals in the same catchment areas. Dietary habits were elicited using a validated food frequency questionnaire including 78 food groups and recipes. Odds ratios (OR) and 95% confidence intervals (95% CI) were computed by quintiles of intake of nutrients. Results: Inverse associations emerged for vitamin E (OR = 0.6; 95% CI: 0.5-0.8), beta-carotene (OR = 0.8; 95% CI: 0.6-1.0), lutein/zeaxanthin (OR = 0.6; 95% CI: 0.5-0.8 for the highest vs. the lowest quintile of intake), and calcium intake (OR = 0.7; 95% CI: 0.6-1.0). When the combined effect of calcium and vitamin E was considered, the OR reached 0.4 (95% CI: 0.3-0.7) for subjects in the highest compared to those in the lowest intake tertile of both micronutrients. Results were consistent across strata of menopausal status, parity and family history of ovarian or breast cancer. Conclusions: The intake of selected micronutrients, which were positively correlated to a diet rich in vegetables and fruits, was inversely associated with ovarian cancer.