Factors Affecting Pathological Complete Response in Patients with Breast Cancer Treated with Neoadjuvant Chemotherapy

Background & Objective: Neoadjuvant chemotherapy (NACT) is used to treat advanced or irreversible breast cancer tumors and increases the possibility of Breast-conserving surgery. There is evidence that pathological complete response (pCR) after NACT reduces the risk of recurrence and increases survival. This study aimed to investigate the factors affecting the pathological complete response in breast cancer patients treated with NACT. Materials & Methods: We identified non-metastatic breast cancer patients receiving NACT during 2010–2020. Patients’ and disease characteristics, rates of pCR based on these characteristics were recorded in different subgroups. Analyzes were performed by descriptive and analytical statistics using SPSS.ver26 (IBM, USA). Results: 204 patients had mean age of 45.3 years, 32.4% had grade 3, and 89.7% had ductal histology. Overall pCR rate was 33.3% and differed according to disease subtype (P<0.001), receptor status (P<0.001), grade (P=0.015), ki-67 (P=0.004), but not according to age, BMI, menopausal status, tumor size, surgery type after NACT. Conclusion: In our study, pCR rates are conformed with other studies. Many patients have residual disease following NACT that suggests lower survival or higher risk of recurrence, therefore determining the factors affecting the pathological complete response can help physicians in treatment decisions.