Radiation-induced Ovarian Ablation and Survival in Breast Cancer: A Single-Institutional Evaluation

Abstract

Background: Radiation-induced ovarian ablation (ROA) was one of the main modalities in the early years in inducing suppression of hormone levels of estradiol (E2) and follicle-stimulating hormones (FSHs) in estrogen receptor/progesterone receptor-positive breast cancer patients. However, as newer techniques such as medical ovarian suppression (MOS) and laparoscopic oophorectomies (LOs) emerged, ROA began to take a back seat. Nonetheless, ROA remains a valuable option for certain patients with specific indications. It is worth noting that ROA is still as effective as MOS and LO in achieving desired hormonal suppression levels. Materials and Methods: After receiving approval from the institutional ethics committee, we enrolled 41 female breast cancer patients who were scheduled for ROA at our institute between 2016 and 2018. Two patients declined to participate and were, therefore, excluded from the final analysis. Patients were evaluated for pre- and postradiation hormone levels, specifically E2 and FSH, cessation of menstrual periods, radiation-induced toxicity, disease-free survival (DFS), overall survival (OS), and the clinical profile as well. Results: Among 39 patients, 89.74% (n = 35) achieved postmenopausal hormone levels after ROA. Only 17.94% (n = 7) patients were menstruating before radiation exposure to the pelvis (postchemotherapy) and among these, 3 patients (42.85%) attained amenorrhea after ROA. The mean age of patients was 42 years, and the most common stage at presentation was Stage III (n = 15) 38.5%. Her2 positivity was seen in (n = 11) 28.2%. Breast conservation surgery was done in 64.1% (n = 25) and mastectomy was done in 23.1% (n = 9). About 71.7% (n = 28) have received tamoxifen, 43.5% (n = 17) were on letrozole, and 17.9% (n = 7) have received trastuzumab. None had shown any Grade 3 or 4 acute skin toxicity during treatment and late radiation-induced complications during their follow-up. The mean 5-year DFS was 62.2% and the mean 5-year OS was 59%. Conclusion: ROA is not widely used anymore due to its irreversible nature, and there are now reversible and noninvasive methods for ovarian suppression. Observing the effectiveness of ROA, it may still be an option for a selective group of breast cancer patients especially those who have contraindications for MOS or are willing for a short course of treatment.