Epithelial ovarian cancer

Several studies of dietary and serum antioxidant micronutrients (vitamins A, C, and E, and beta-carotene) suggest that higher levels may be protective for ovarian cancer. None of these has examined supplements. The present study used a food frequency questionnaire and additional questions on supplements to study 168 histologically confirmed epithelial ovarian cancer cases, 159 community controls, and 92 hospital-based controls. This case-control study was conducted in New York, NY, from 1994 to 1998. Women at least 18 years of age, who were diagnosed with histopathologically confirmed, invasive epithelial ovarian cancer within the past year, were recruited from Memorial Sloan-Kettering Cancer Center and New York Hospital. Controls were matched by socioeconomic characteristics.

The researchers interviewed women about the known and putative risk factors for epithelial ovarian cancer. Usual intake of antioxidants from diet and supplements was measured using a self-administered food frequency questionnaire. The daily intake of antioxidants from individual supplements and multivitamins was calculated.

Controls were younger than cases. Mean body mass index and total daily caloric intake were similar for cases and controls. The proportion that used multivitamins and each vitamin and mineral supplement was similar among cases and controls. In the total control population, 60 percent reported use of any multivitamin and/or individual vitamin and mineral supplements compared with 55 percent of the cases. The most commonly used individual supplements were vitamins C and E: Each was used by approximately one-third of cases and controls. Women whose food contained more antioxidants tended to use more supplements, although the association was not especially strong. The mean intake of antioxidants from foods was similar among supplement users and nonusers: 175.6 and 167.4 mg/day, respectively. High consumption of vitamins C and E was associated with a reduced risk. in comparison of cases with community controls, there was a 60 percent reduced risk of ovarian cancer among women who used vitamin C lesser than 90 mg/day from supplements compared with nonusers. For vitamin E, there was a 67 percent reduced risk of ovarian cancer for those who used lesser than 30 mg/day. The intake of vitamin A, beta-carotene, and selenium from supplements was not related to risk.

Smoking did not significantly modify the effects of the antioxidants. However, the protective effect of vitamin C differed between smokers and non-smokers to some extent. Women who never smoked received slightly more benefit from high intake of vitamin C from supplements than those who smoke currently or smoked in the past. In conclusion, vitamin C and E supplements, from multi-vitamins and from individual vitamin C and E tablets, are associated with a reduced risk of ovarian cancer. In this study, supplemental vitamin C lesser than 90 mg/day and vitamin E lesser than 30 mg/day are associated with a reduced risk of epithelial ovarian cancer.

AT Fleischauer, SH Olson, L Mignone, N Simonsen, TA Caputo, S Harlap. "Dietary Antioxidants, Supplements, and Risk of Epithelial Ovarian Cancer. "Nutr Cancer 40(2):92-98 (2002) Correspondence: A.T. Fleischauer, Dept. of Epidemiology, CB 7435, School of Public Health, University of North Carolina, Chapel Hill, NC 27599