Impact of neoadjuvant chemotherapy in the surgical treatment of breast cancer

Introduction: Neoadjuvant chemotherapy is an increasingly frequent option in the treatment of breast cancer. One of the goals of neoadjuvant chemotherapy is to change the indication for a mastectomy to a conservative surgery, and for axillary lymphadenectomy to sentinel lymph node assessment. Methods: This was an observational, cross-sectional, retrospective study that evaluated response to neoadjuvant chemotherapy in breast cancer patients undergoing surgical treatment. Patients were divided into three groups when the surgery indication was changed after neoadjuvant chemotherapy: downgrade, unchanged, upgrade. Results: During the study period, 355 patients were included with a mean age of 55 years. Neoadjuvant chemotherapy promoted a downgrade in 38.7% of patients with indication for mastectomy and an upgrade in 36.8% of patients with indication for conservative surgery; in the total group, the maintenance of indication for surgery was 62,2%. In the axillary approach, lymphadenectomy downgrade was 6.9% and sentinel lymph node biopsy upgrade was 34% with 27% being due to positivity and 7% due to disease progression. Multivariate analysis found a significant difference between clinical staging and change in surgical indication for both breast and axilla (p<0.0001). In the multivariate analysis of pathologic complete response and change of indication for breast and axilla surgery, triple negative and HER-2-positive tumors showed a significant difference (p<0.0001). Conclusions: Neoadjuvant chemotherapy was able to perform a downgrade of breast and axilla surgery in few patients and there was no relationship between the change of indication and pathologic complete response.