Abstract
Ovarian cancer causes significant morbidity and is associated with the highest mortality among gynecologic cancers. Etiologic theories of ovarian cancer indicate that oxidative stress may have a role its development. It has been suggested that limiting oxidative stress to the ovarian epithelium could be considered a first-line defense against ovarian cancer. Although evidence for an association between individual dietary antioxidant intake and ovarian cancer risk is conflicting, the combined evidence suggests a modest inverse association with intake.
We evaluated the role of total dietary antioxidant capacity and intake of individual antioxidants (vitamin C, vitamin E, beta-carotene, selenium, lutein, and lycopene) on ovarian cancer risk in a population-based case-control study in New Jersey. Cases included women ages 21 years and older with newly diagnosed epithelial ovarian cancer who resided in six counties of New Jersey. Controls were women in the same age range who resided in the same geographic area. Women with a hysterectomy or bilateral oophorectomy were excluded. Dietary intake was assessed using the Block food frequency questionnaire (FFQ), and total antioxidant indices were constructed by linking FFQ-derived estimates to two standardized antioxidant capacity databases, the USDA Oxygen Radical Absorbance Capacity (ORAC) Database, and the University of Olso's Antioxidant Food Database. Multivariate logistic regression models were used to calculate odds ratios and 95% confidence intervals while controlling for major ovarian cancer risk factors.
Total antioxidant intake was not found to be associated with ovarian cancer risk. However, a strong protective effect was observed for the highest tertile of dietary selenium intake compared to the lowest (OR: 0.41; 95%CI: 0.20–0.85). In contrast, supplement use was associated with significant increased risks for all micronutrients. Vitamin C supplement use was associated with an increased risk of 1.63 (95%CI: 1.01–2.62), with similar results for vitamin E supplement use (OR: 1.63; 95%CI: 1.02–2.63), beta-carotene supplement use (OR: 1.69; 95%CI: 1.08–2.66) and selenium supplement use (OR: 1.64; 95%CI: 1.05–2.56).
In conclusion, we observed a strong decreased risk for ovarian cancer with dietary selenium intake. No associations were observed with total antioxidant intake or any other antioxidant micronutrients, while increased risks were observed with antioxidant supplement intake. Additional research is needed to confirm these findings.
Citation Information: Cancer Prev Res 2011;4(10 Suppl):PR-02.
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