O-152 Benign epithelial ovarian tumors following use of fertility drugs: a register-based cohort study from Denmark

Abstract Study question Is use of fertility drugs associated with an increased risk benign epithelial ovarian tumors among women infertility? Summary answer Among infertility, is not tumors. What known already Benign are the most common neoplasms in ovaries. These share some same factors, which cancer. The general understanding pathogenesis and etiology cancer sparse; therefore, knowledge on factors influencing development tumors—and hence likely cancer—is warranted. Previous studies association between treatment conflicting, whereas no previous study has examined design, size, duration Retrospective register-based cohort nearly 145,000 included Danish Infertility Cohort during 1995–2017 at age 20–45 years. Women were followed from one year after infertility diagnosis until first tumor or censoring criteria: borderline tumor, cancer, oophorectomy, emigration, death end follow-up (December 31, 2018). Participants/materials, setting, methods Using Aalen-Johansen estimator, we determined 10-year cumulative risks approximately 25,000 who used (defined within diagnosis: clomiphene citrate, gonadotropins, human chorionic gonadotropin, gonadotropin-releasing hormone [GnRH] receptor modulators, progesterone) compared diagnosed drug use. Additionally, Cox proportional hazards regression models to calculate hazard ratios (HRs) 95% confidence intervals (CIs). Main results role chance Our showed that crude 0.32% (95% CI: 0.29%–0.36%) for any 0.49% 0.40%–0.60%) (risk difference: -0.17% [95% -0.28–(-0.07)]). When adjusted age, calendar period diagnosis, educational level, parity, obesity, polycystic ovary syndrome, origin information, HR was 0.73 CI 0.55–0.96). In general, differences as well HRs each evaluated separately similar drug. Lastly, tested robustness our by various pre-defined secondary analyses, this did change results. Limitations, reasons caution We include information number cycles regimens these only partly available registers. Wider implications findings observe a lower relative treated drugs. However, finding translates into small decrease absolute risk, does appear have clinical relevance. Trial registration Not applicable