Systematic review and meta-analysis of the results of breast-conserving surgery after neoadjuvant chemotherapy in breast cancer patients

Background. Neoadjuvant chemotherapy (NACT) is a standard of care for locally advanced breast cancer patients. One of the main advantages of NACT is the reduction of the tumor size and regression of lymph node metastasis. The aim of the study was to analyze the outcomes of breast-conserving surgery after NACT compared to adjuvant chemotherapy, including the examination of the width of resection margins and the frequency of re-operations, the volume of tissue removed and cosmetic outcomes. Material and Methods. We analyzed 1219 publications available from PubMed, Medline, Cochrane Library, 1057 of them did not meet the inclusion criteria, 162 publications were selected to cover all the following inclusion criteria: surgical margin status, frequency of re-operations, volume of tissue removed and cosmetic outcomes. Finally, 22 studies met fully specified criteria. Results. Studies included in this review demonstrated a different frequency of positive resection margins (2-39.8 %), reoperations (0-45.4 %), the volume of tissue removed (43.2-268 cm3), and the weight of the resected breast tissue (26.4-233 grams) after NACT. Conclusion. The data obtained showed a decrease in the frequency of positive resection margins and re-operations in patients who received NACT compared to patients who did not receive NACT (5-39.8 % versus 13.1-46 % and 0-45.4 % versus 0-76.5 %, respectively), as well as a decrease in the amount of the removed breast tissue without the negative effect on the frequency of resection margins, thus allowing minimization of the extent of surgery and improvement of cosmetic outcomes.