Survival Outcomes of Breast-Conserving Surgery Versus Mastectomy in Locally Advanced Breast Cancer Following Neoadjuvant Chemotherapy: A Meta-Analysis

BACKGROUND: Mastectomy (MT) and breast conservation surgery (BCS) are two common surgical options for the treatment of locally advanced breast cancer (LABC). Neoadjuvant chemotherapy (NACT) is frequently administered before surgery to shrink tumors and improve surgical outcomes. However, there is a lack of consensus on the optimal surgical approach after NACT and its impact on survival outcomes. OBJECTIVE: This meta-analysis aims to compare the survival outcomes between MT and BCS in patients treated with NACT. METHOD: A PRISMA selection was used to identify studies across electronic database such as PubMed, and Cochrane Library from inception until 11th July, 2023. A total of 10 comparative studies involving a total of 5018 patients were included. Among them, 2898 patients underwent MT while 2120 underwent BCS after receiving NACT. The outcomes assessed were the 5-year overall survival (OS) and 5-year disease-free survival (DFS). The data from the included studies were pooled, and odds ratios (OR) with 95% confidence intervals (CI) were calculated to evaluate the differences between MT and BCS in terms of survival outcomes. Prospero: CRD42024496831. RESULT: The meta-analysis revealed that patients who underwent MT after NACT had a higher 5-year OS compared to those who underwent BCS (OR 2.68, 95% CI [2.19-3.28; p < 0.00001]). Additionally, the 5-year DFS was significantly better for patients who underwent MT (OR 3.11, 95% CI [1.80-5.38; p < 0.0001]). CONCLUSION: MT after NACT may be associated with better 5-year OS and DFS compared to BCS.