Predictive factors of achievement pathological complete response at neoadjuvant chemotherapy of primary operable breast cancer

Objective. To study the predictive factors of achievement pathological complete response (pCR) at neoadjuvant chemotherapy primary operable breast cancer. Materials and methods. Analyze of the rate of pCR after neoadjuvant systemic therapy in different clinical factors and biological characteristics was made for 164 patients (24-76 years; median - 47 years) treated in RCRC from 2004 to 2016. Results. Predictive factors for high rate of pCR after neoadjuvant systemic therapy in primary operable breast cancer were hormone negative status, HER2-overexpression, Ki-67≥20% and Grade 3 of tumors, p<0.05. Extremely low frequency of pCR was observed for HER2- negative luminal cancer (0% - for luminal A and 10.7% - for luminal B subtype); the highest rate of pCR was seen in HER2+ breast carcinomas (50% - non luminal; 38.1% - luminal) and in patients with triple-negative cancers (34.5%), p=0.003. The rate of pCR depends from type of neoadjuvant chemotherapy: the highest rate pCR (71.4%) was seen in serial combination anthracycline → taxanes and platinum regimes; 58.3% - in taxanes and platinum combination; 51.7% - in anthracycline and taxanes combination, p=0.001. Neoadjuvant chemotherapy with trastuzumab in HER2 + breast cancer reached the highest pCR (71.4%), p=0.001. Conclusions. The optimal assignments of neoadjuvant chemotherapy in primary operable breast cancer are the patients with HER2+ carcinomas (at adding trastuzumab) and triple negative breast cancer. Neoadjuvant chemotherapy in luminal HER2-negative breast cancer is associated with very low rate of pCR, which makes it inappropriate in this cohort of patients.

preoperative/neoadjuvant systemic therapy, primary operable breast cancer, pathological complete response (pCR), predictive factors of achievement pathological complete response, biological subtype breast cancer