Cigarette smoking, alcohol consumption, and endometrial cancer risk: a population-based study in sweden

Objective: To assess effects of cigarette smoking and alcohol consumption on the risk of endometrial cancer among postmenopausal women. Methods: We performed a nationwide population-based case-control study among postmenopausal women aged 50-74 years in Sweden, including 709 incident endometrial cancer cases and 3368 controls. Results: Compared to never smokers, recent/current smokers had a decreased risk of endometrial cancer (multivariate OR 0.61, 95% CI 0.47-0.80), but former smokers presented no substantial difference in risk (multivariate OR 0.90, 95% CI 0.72-1.14). We observed a decreased risk of endometrial cancer for postmenopausal smoking, but there was no clear impact on risk for premenopausal smoking. The inverse association of smoking with risk was not explained by differences in body mass index between smokers and nonsmokers. Alcohol consumption was not clearly associated with risk of endometrial cancer. The multivariate OR for women consuming up to 1.6 g of alcohol per day was 1.12 (95% CI 0.88-1.44), and 0.92 (95% CI 0.70-1.20) for women consuming more than 4 g per day (p for trend over categories=0.44). Conclusions: Current cigarette smoking reduces the risk of postmenopausal endometrial cancer, but the inverse association dissipates after smoking cessation. Premenopausal smoking might not affect risk of postmenopausal endometrial cancer. Alcohol consumption is not materially associated with risk.