Douching, Talc Use, and Risk for Ovarian Cancer and Conditions Related to Genital Tract Inflammation.

BACKGROUND: Douching is associated with disorders involving genital tract inflammation and genital talc use with epithelial ovarian cancer (EOC), but their joint effects are infrequently considered.
METHODS: From 2,040 cases of EOC and 2,100 controls enrolled in eastern Massachusetts and New Hampshire, we used unconditional logistic regression to estimate risk for EOC associated with douching and/or talc use. In subsets of cases and controls, we also collected information about pelvic inflammatory disease (PID), ectopic pregnancy, and cervical neoplasia to estimate risk for these events from douching and/or talc use.
RESULTS: The adjusted OR and 95% confidence interval (CI) for all EOC was 0.94 (0.76-1.16) in women who douched but never used talc and 1.28 (1.09-1.51) in women who used talc but never douched. Compared with women who never regularly douched or used talc, ORs (95% CIs) were 0.83 (0.52-1.33) for women who both used talc and homemade douches and 1.53 (1.11-2.10) for women who both used talc and store-bought douches. Cases who both douched and used talc were more likely to have had PID compared with cases who had used neither [OR = 5.03 (95% CI, 1.61-15.7)].
CONCLUSIONS: Douching is not an independent risk factor for ovarian cancer, but the combination of talc use and store-bought douches may modestly increase the risk for EOC beyond that for talc use alone. IMPACT: The joint effect of talc use and douching, especially with commercial products, should be considered in evaluating risks associated with disorders involving genital tract inflammation or EOC. ©2019 American Association for Cancer Research.