Background: Perineal talc use and douching could affect the risk of uterine cancer through several possible pathways, including inflammation response, microbiota changes, or endocrine disruption. Two previous cohort studies of the association between talc use and uterine cancer have reported weak positive associations, but we know of no previous evaluations of the relationship between douching and uterine cancer.
Methods: Using a large prospective cohort, we examined the relationship between incident uterine cancer and self-reported use of talc or douche using Cox proportional hazards models.
Results: After excluding those with prior hysterectomy, 271 of 33,609 women reported incident uterine cancer (mean follow-up = 8.3 years in noncases; maximum 12.6 years). Overall, 26% of women reported ever using talc and 15% reported ever having douched. Ever talc use was associated with an increase in risk of uterine cancer (adjusted hazard ratio [HR] = 1.2; 95% confidence interval [CI] = 0.94, 1.6), with some evidence of a dose-response for frequency of talc use (P-for-trend = 0.07). Ever douching was not associated with uterine cancer risk (HR = 1.0; 95% CI = 0.72, 1.5), with no evidence of a frequency dose-response (P = 0.96). The estimates were similar when we restricted to invasive endometrial cancers, but not when we further restricted to endometroid adenocarcinomas.
Conclusion: The positive association we observed between talc use and uterine cancer risk is consistent with findings from previous prospective cohort studies of endometrial cancer. The relationships between uterine cancer and both douching and talc use merit further consideration, particularly as both exposures are preventable.