A pathological complete response after neoadjuvant combination chemotherapy in breast cancer patients

Objective. To study the effect of a pathological complete response (pCR) of the tumor after neoadjuvant combination chemotherapy (NACCT) on 3-and 5-year relapse-free and overall survival rates in breast cancer (BC) patients. Subjects and methods. The authors analyzed the 2013—2020 medical records of 200 patients with Stage II—III BC (Stage IIIB was ruled out), who underwent organ-sparing surgeries and radical mastectomies at the second stage of combination treatment after NACCT at the Department of Breast and Skin Cancer and Reconstructive and Plastic Surgery, P.A. Herzen Moscow Oncology Research Institute. The distribution of BC stages was as follows: Stage I was diagnosed in 5 (2.5%) patients; Stage II in 113 (56.5%), and Stage III in 82 (41%) (Stage IIIB was ruled out). Results. A pCR was achieved in 37 (18.5%) patients; a pathological partial response was in 163 (81.5%). The pCR was most com-monly achieved in patients with invasive non-specific BC (90.5%). In the 37 patients, the pCR was achieved in patients with tri-ple-negative BC (37.5%), Her2/neu-positive BC (30%), Her2/neu-positive luminal B BC (17.5%), and Her2/neu-negative luminal B BC (15%); pCR was most frequently observed in high-grade (G3) BC (57.5%) and in moderate-grade (G2) BC (42.5%). The 5-year relapse-free and overall survival rates were 100%. One patient was noted to have progressive disease as lung metastasis at 22 months after surgical treatment. Conclusion. The investigation has established a correlation between the degree of a pathological tumor response in BC patients after NACCT and the rates of 3-and 5-year disease-free and overall survival. The predictive value of pCR is in direct proportion to the IHC-defined type of BC, which is more often detected in its aggressive morphological variants: her2/neu-positive (47.5%) and triple-negative (37.5%). © 2022, Media Sphera Publishing Group. All rights reserved.