Menopausal hormone therapy after ovarian cancer: A 10‐year survival analysis in premenopausal women

Abstract Introduction Premenopausal women treated with bilateral salpingo‐oophorectomy (BSO) for ovarian cancer (OC) enter surgical menopause. Our objective was to evaluate whether postoperative systemic menopausal hormone therapy (MHT) after BSO due to treatment for epithelial ovarian cancer (EOC), non‐epithelial ovarian cancer (NEOC), or borderline ovarian tumor (BOT) has an impact on long‐term overall survival (OS). Material and Methods A nationwide Swedish population‐based cohort study of women aged 18–50 diagnosed with OC (FIGO stage I–IV) and treated with BSO between 2008 and 2015, identified from The Swedish Quality Register for Gynecological Cancer. Exposure to postoperative MHT from 1 month before to 5 years after surgery was assessed by linking the cohort to the National Prescribed Drug Register to capture drug dispensing data. Standardized OS was estimated for MHT users and non‐users, adjusted for covariates included in multivariable models. EOC, NEOC, and BOT were analyzed separately. Results A cohort of 779 premenopausal women with a median age of 45 years at BSO, of whom 472 had an EOC, 68 a NEOC and 239 a BOT, was identified. Median follow‐up in the total cohort was 11.7 (9.6–13.6) years. Among women with EOC, 33% were postoperative MHT users. For the EOCs, the 10‐year OS for postoperative MHT users versus non‐users was 52.4% (95% CI 46.7–58.8) and 51.7% (95% CI 47.4–56.4), respectively. No significant difference in 10‐year OS was found between postoperative MHT users and non‐users (HR 0.97; 95% CI 0.73–1.30; p = 0.84). Among 367 women with EOC and no residual disease at surgery, there was no difference in 10‐year OS between postoperative MHT users and non‐users (HR 1.00; 95% CI 0.70–1.43; p = 0.98). For women with a BOT, the 10‐year OS was 96.2% (95% CI 91.6–98.2) for postoperative MHT users versus 95.3% (95% CI 87.8–98.2) for non‐users. Among women with a NEOC, OS was not analyzed due to the few events. Conclusions In this nationwide cohort, postoperative MHT use after surgically treated OC was not associated with impaired 10‐year survival. These findings offer reassurance about the safety of MHT in young ovarian cancer survivors.