Neoadjuvant chemotherapy has several advantages, including reducing the number of mastectomies. Breast conserving surgeries avoid certain complications and sequelae, reduces hospital stays and improves patients’ quality of life and aesthetics. The objective was to investigate factors associated with breast conserving surgery after neoadjuvant chemotherapy for breast cancer.

A single-center, retrospective, observational cohort study was conducted. For all women diagnosed with breast cancer between 2012 and 2022 who had received neoadjuvant chemotherapy prior to surgery, sociodemographic, clinical, anatomopathological and radiological data before and after neoadjuvant chemotherapy were recorded. Patients were divided into two groups: “breast conserving” surgery and “total mastectomy” surgery. Descriptive statistics were used to summarize the data. Factors associated with breast conserving surgery were studied using univariate and multivariate (logistic regression model) analyses.

A total of 361 patients were included: 212 (58.7%) with breast conserving surgery and 149 (41.3%) with total mastectomy surgery. In multivariate analysis, unifocal disease (OR = 3.4; 95% CI [1.5; 7.6]; p = 0.004), clinical complete response (OR = 4.4; 95% CI [2.1; 9.1]; p < 0.0001) and clinical tumor less than 5 cm (stages T0, T1 or T2) (OR = 3.4; 95% CI [1.6; 6.9]; p = 0.001) were independently associated with breast conserving surgery. There was no difference in Scarff Bloom and Richardson grade, Ki67 proliferation index, molecular subtype or metastatic status.

Several factors were independently associated with breast conserving surgery, including: unifocality, clinical complete response (cCR) and clinical tumor less than 5 cm.