Clinical and pathological factors predictive of response to neoadjuvant chemotherapy in breast cancer: A single center experience.

Neoadjuvant chemotherapy (NAC) of breast cancer (BC) improves outcomes, especially in patients with locally advanced and inflammatory cancer. Further insight into clinic-pathological factors influencing outcomes is essential to define the optimal therapeutic strategy for each category of patients and to predict the response to the treatment. In total, 117 patients with BC were treated with NAC with or without trastuzumab between 2010 and 2015. The histologic response to NAC was defined as a pathological complete response (pCR) when there was no evidence of residual invasive tumor in the breast or axillary lymph nodes. Relapse-free survival (RFS) was estimated using the Kaplan-Meier method and compared using log rank analysis. P-value <0.05 was considered statistically significant. The median age of the 117 patients enrolled in the present study was 52 years (age range, 35-85 years). The overall response rate (complete and partial responses) assessed by radiological and pathological evaluation were 76 and 72%, respectively. pCR was achieved in 35 out of 117 patients (~30%). In total, 6 patients (5%) developed progressive disease during chemotherapy. The RFS was 85 months (SE=3; 95% CI 79-91). The median was not reached and the mean follow-up time was 55 months (median 52 months; range 11-100 months). In this time, 20 patients (17%) experienced tumor recurrence. From the univariate analysis, the pathological response was significantly associated with receptor-based subtype, menopausal status and T-stage. From the multivariate analysis by using linear multiple regression and including receptor- menopausal status and T-stage, the model was not significant (P=0.062). However, by using the multiple logistic regression, and including age, pCR was significantly associated with ER+ HER2neg (P=0.006), T2 (P=0.043) and T3 (P=0.018). T-stage, menopausal status and receptor status are significantly associated with the pathological response in patients with inoperable BC treated with NAC.