Intake of selected micronutrients and the risk of endometrial carcinoma

BACKGROUND. There is some evidence that dietary habits independent of body mass may influence endometrial carcinoma risk, but the specific aspects of this hypothesis are not yet clear. METHODS. A case-control study was conducted between 1988 and 1994 in the Swiss Canton of Vaud and Northern Italy including 368 patients with histologically confirmed endometrial carcinoma and 713 controls in hospital for acute, nonneoplastic conditions, unrelated to known or potential risk factors for endometrial carcinoma. Multiple logistic regression was used to estimate the odds ratios of carcinoma of the corpus uteri according to quintile of intake of the micronutrients considered, and adjusted for potential confounding factors. RESULTS. Total energy intake was directly related to endometrial carcinoma risk Adjustment for energy substantially modified the estimated odds ratios. After allowance for calories, the relative risk of endometrial carcinoma in the highest quintile of intake, compared with the lowest quintile of intake, was 1.2 for retinol, 0.5 for beta-carotene, 0.6 for ascorbic acid, 1.8 for vitamin D, 0.9 for vitamin E, 2.9 for methionine, 0.7 for folate, and 1.5 for calcium. Allowance for other micronutrients significantly associated with endometrial carcinoma did not substantially modify the risks estimated for beta-carotene, while associations with ascorbic acid were weaker and nonsignificant. CONCLUSIONS. This study suggests that some micronutrients, including beta-carotene, may have a protective effect against endometrial carcinoma.