Active and passive tobacco smoking and the risk of borderline and invasive ovarian cancer (United States).

OBJECTIVE

A population-based case-control study was conducted to examine the hypothesis that active and passive tobacco smoking were associated with the risk of epithelial ovarian cancer.

METHODS

In-person interviews were obtained from 558 women with epithelial ovarian cancer (431 invasive, 127 borderline) and 607 population controls regarding active lifetime tobacco smoking, environmental tobacco smoke exposure in utero and during childhood, and other factors that may be related to the development of ovarian cancer.

RESULTS

No significant associations of ever or former tobacco smoking with the risk of invasive or borderline ovarian cancer were found, although long-term ex-smokers of 20 years or more were at significantly reduced risk of invasive cancer. Significant, positive dose-response relations of the number of cigarettes smoked per day and pack-years with the odds ratios for borderline cancer were evident. No association of active tobacco smoking with risk was found by histologic subtype of invasive ovarian cancer. Smokers were at significantly increased risk for borderline serous cystadenoma (OR: 1.91; 95% confidence intervals, CI: 1.09-3.34), but not for borderline mucinous cystadenoma. When we limited the analyses to current smokers, age-started smoking was significantly inversely related to the risk of invasive, but not borderline ovarian cancer. We found no association of gestational or childhood environmental tobacco smoke exposure with the risk of invasive or borderline ovarian cancer among never smokers.

CONCLUSIONS

These findings do not support an association of active tobacco smoking with the risk of invasive ovarian cancer. An increased risk of borderline serous cystadenoma among smokers must be viewed with caution.