Cigarette smoking and epithelial ovarian cancer by histologic type

Objective: To examine cigarette smoking as a risk factor for different type s of epithelial ovarian cancer. Methods: We used data from the Cancer and Steroid Hormone Study, a multicen ter, population-based, case control investigation. Cases were 447 women age d 20-54 years with diagnoses of epithelial ovarian cancer. Controls were 38 68 women selected by random-digit dialing. Conditional logistic regression was used to obtain odds ratios (ORs) and 95% confidence intervals (CIs) as estimators of the relative risk of ovarian cancer. With age and study site as conditioning variables, OR point estimates were additionally adjusted fo r parity and use of oral contraceptives. Results: The OR of mucinous epithelial ovarian cancer for women who had eve r smoked was 2.3 (95% CI 1.4, 3.9) and for current smokers was 2.9 (95% CI 1.7, 4.9). The OR of mucinous tumors for current smokers was significantly elevated regardless of years since first cigarette or age at which women fi rst smoked. The OR of mucinous tumors for current smokers increased slightl y as cumulative pack-years of smoking increased, although the trend was not significant. Similar patterns of elevated risk were not observed among ser ous, endometrioid, or other histologic types. Odds ratio point estimates fo r former smokers were not significantly elevated for any]histologic type. Conclusion: Current cigarette smoking was a risk factor for mucinous epithe lial ovarian cancer, but not other histologic types. (Obstet Gynecol 2000;9 5:255-60. (C) 2000 by The American College of Obstetricians and Gynecologis ts.).