Endometriosis and risk of ovarian and endometrial cancers in a large prospective cohort of U.S. nurses
- 774 Downloads
Endometriosis is associated with ovarian cancer, but the relation with endometrial cancer is unclear. Prior studies generally were retrospective and had potential limitations, including use of self-reported endometriosis, failure to account for delays between symptom onset and endometriosis diagnosis, and changes in risk factors post-endometriosis diagnosis. We evaluated whether these limitations obscured a weak association with endometrial cancer and the extent to which these limitations impacted associations with ovarian cancer.
Cox proportional hazards regression models were used to assess associations between endometriosis and cancer risk, evaluating the impacts of self-reported vs. laparoscopically confirmed endometriosis, delayed diagnosis, and post-endometriosis diagnosis changes in risk factor exposures on relative risk estimates.
Over 18 years of follow-up, we identified 228 ovarian and 166 endometrial cancers among 102,025 and 97,109 eligible women, respectively. Self-reported endometriosis was associated with ovarian cancer [relative risk (RR): 1.81; 95% confidence interval (CI): 1.26–2.58]; this association was stronger for laparoscopically confirmed endometriosis (HR: 2.14; 95% CI 1.45–3.15). No association was observed with endometrial cancer (self-report RR: 0.78; 95% CI 0.42–1.44; laparoscopic-confirmation RR: 0.76; 95% CI 0.35–1.64). Accounting for diagnosis delays or post-endometriosis diagnosis changes in risk factors had a little impact.
This study adds to the evidence that endometriosis is not strongly linked to endometrial cancer risk and that the association with ovarian cancer is robust to misclassification, diagnostic delay, and changes in exposures post-endometriosis diagnosis. Our analysis suggests that confounding and misclassification do not obscure a weak association for endometrial cancer risk, although our results should be replicated.
KeywordsEndometriosis Ovarian cancer Endometrial cancer
The authors wish to thank the participants and staff of the Nurses’ Health Study II for their valuable contributions as well as the following state cancer registries for their help: AL, AZ, AR, CA, CO, CT, DE, FL, GA, ID, IL, IN, IA, KY, LA, ME, MD, MA, MI, NE, NH, NJ, NY, NC, ND, OH, OK, OR, PA, RI, SC, TN, TX, VA, WA, and WY. This work was supported by the National Institutes of Health (R01 HD57210, UM1 CA176726) and Dana Farber Cancer Institute Mazzone Award.
This work was supported by the National Institutes of Health (R01 HD57210, UM1 CA176726) and Dana Farber Cancer Institute Mazzone Award.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no financial or personal relationships that might influence this work.
- 5.Brinton LA, Sakoda LC, Sherman ME et al (2005) Relationship of benign gynecologic diseases to subsequent risk of ovarian and uterine tumors. Cancer epidemiology, biomarkers and prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive. Int Soc Cell 14:2929–2935Google Scholar
- 13.Nnoaham KE, Hummelshoj L, Webster P et al (2011) Impact of endometriosis on quality of life and work productivity: a multicenter study across ten countries. Fertil Steril 96(366–73):e8Google Scholar
- 24.Hosmer DW, Lemeshow S (1999) Applied survival analysis: regression modeling of time to event data. Wiley, New YorkGoogle Scholar
- 34.Sato N, Tsunoda H, Nishida M et al (2000) Loss of heterozygosity on 10q23.3 and mutation of the tumor suppressor gene PTEN in benign endometrial cyst of the ovary: possible sequence progression from benign endometrial cyst to endometrioid carcinoma and clear cell carcinoma of the ovary. Cancer Res 60:7052–7056PubMedGoogle Scholar
- 39.Brasky TM, Felix AS, Cohn DE et al (2017) Nonsteroidal anti-inflammatory drugs and endometrial carcinoma mortality and recurrence. J Natl Cancer Inst 109(3):djw251. doi: 10.1093/jnci/djw251
- 41.Brinton LA, Trabert B, Anderson GL et al (2016) Serum estrogens and estrogen metabolites and endometrial cancer risk among postmenopausal women. Cancer epidemiology, biomarkers and prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive. Int Soc Cell 25:1081–1089Google Scholar