Effects of ovarian ablation or suppression in premenopausal breast cancer: A meta-analysis of randomized controlled trials

Background: The effect of ovarian ablation or suppression (OAS) in premenopausal women with breast cancer is controversial. The overall survival (OS), disease-free survival (DFS) and adverse event of OAS versus no OAS were. compared. Methods: A literature review of EMBASE, Web of Science, PUBMED, and Cochrane Library was conducted. The hazard ratio (HR) and 95% confidence interval (CI) for OS and DFS, as well as risk ratio (RR) and 95% CI for adverse events were evaluated. I-squared statistic (I-2) represents heterogeneity. Results: Twenty-nine studies with a total of 21,249 women were included. In premenopausal women aged 40 years or younger, there were significant differences in OS (HR 0.78, 95% CI: 0.66-0.94, P = 0.008, I-2 = 0%) and DFS (HR 0.84, 95% CI: 0.73-0.97, P = 0.02, I-2 = 0%) between OAS and no OAS. In advanced stage breast cancer, a significant differelice was found in OS (HR 0.76, 95% CI: 0.60-0.96, P = 0.02, I-2 = 0%). Patients treated with OAS had more chances to have hot flushes (RR 1.91, 95% CI: 1.62-2.26, P < 0.01, I-2 = 0%) and vaginal dryness (RR 1.19, 95% CI: 1.08-1.31, P = 0.0003, I-2 = 0%). No significant difference in depression (RR 1.28, 95% CI: 0.94-1.74, P = 0.12, I-2 = 0%). Conclusions: The study shows that OAS plays a beneficial role in premenopausal women aged 40 years or younger and advanced stage breast cancer. However, OAS is associated with increase in hot flushes and vaginal dryness. (C) 2016 Elsevier Ltd, BASO similar to The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.