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.
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.
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.
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.
From the aEpidemiology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC
bBiostatistics and Computational Biology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, NC
cSocial and Scientific Systems, Inc., Durham, NC
dEpidemiology Department, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC.
Submitted November 16, 2018; accepted July 25, 2019.
This work was supported by the Intramural Research Program of the National Institutes of Health, National Institute of Environmental Health Sciences (Z01-ES044005 to D.P.S. and Z01-ES102245 to C.R.W.).
Disclosure: The authors report no conflicts of interest.
Requests for de-identified Sister Study data, including the data used in this manuscript, can be requested through the study website (https://sisterstudy.niehs.nih.gov/English/data-requests.htm). The Sister Study is an ongoing prospective study, and the data sharing policy was developed to protect the privacy of study participants. It is consistent with study informed consent documents as approved by the NIEHS Institutional Review Board.
Correspondence: Katie O’Brien, 111 TW Alexander Dr., Research Triangle Park, NC 27709. E-mail: email@example.com.