2022-RA-1504-ESGO Tamoxifen-megestrol acetate combination hormonal therapy is an effective fertility-sparing treatment in early-stage endometrial cancer patients who have failed progestin only hormonal therapy. (20th October 2022) - Lim, Hyunji
Abstract : Introduction/Background: Tamoxifen is a selective estrogen receptor modulator, which inhibits the binding of estradiol to estrogen receptors in endometrial cancer. It can also increase progesterone receptors, making tumors more responsive to progestin therapy. Hence, we investigated the effectiveness of tamoxifen-progestin combination (T-P) therapy as a fertility-sparing treatment option in early-stage endometrial cancer patients who have previously failed progestin only (P-only) therapy. Methodology: We identified 129 patients with 2008 International Federation of Gynecology and Obstetrics stage IA-IB endometrioid endometrial cancer who received one or more hormonal treatment (HT) for preserving fertility between 2003 and 2021. P-only therapy included megestrol acetate (80–400 mg/day), medroxyprogesterone acetate (500 mg/day), and/or levonorgestrel-releasing intrauterine device. T-P therapy consisted of tamoxifen 20 mg/day for 3 weeks followed by megestrol acetate 160–400 mg/day for 3 weeks. We collected patients' baseline characteristics, HT regimens, cycles, doses, response to HT, and referral for hysterectomy. Patients who failed to follow-up at least 6 months before completion of HT and patients with grade 3 disease were excluded. Results: In total, 83 patients were included in this analysis. Two patients who received T-P as primary HT reached complete response (CR). Among patient who received P-only therapy (n=81), 35 (43.2%) achieved CR, while 46 (56.8%) did not. Of those with persistent disease, 31 (67.4%) underwent hysterectomy and others (n=15) were recommended T-P therapy. Except for five patients who did not complete medication, 10 patients completed T-P therapy at least 6 cycles with median observation period of 41.4 months. Among them, seven (70%) showed CR, and only three (30%) underwent hysterectomy for persistent disease. Conclusion: T-P therapy should be considered as one of the treatment options for early-stage endometrial cancer patients who have previously failed P-only therapy. More studies are needed to predict the response to HT by investigating the molecular classification of endometrial cancer.