Clinical and pathological features of breast cancer associated with the pathological complete response to anthracycline-based neoadjuvant chemotherapy

Objective: Patients with breast cancer with a pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) have a better prognosis than patients with residual disease. The aim of the current study was to identify predictors of pCR. Methods: This retrospective study included 388 patients treated with anthracycline-based NAC. Clinicopathological parameters were compared between the patients with and without pCR in breast and axilla. Results: Treatment consisted of FAC/FEC in 230 patients (59%), TAC in 39 (10%) patients and AC followed by docetaxel in 119 (31%). In all, 36 (9.3%) patients had pCR. In univariate analysis, age, tumor size, lymph node involvement, tumor grade (p = 0.077, n = 265), ER and HER-2 status (n = 213), lymphovascular invasion (LVI), type of chemotherapy and taxane-containing chemotherapy were associated with pCR. In multivariate analysis, ER negativity (p = 0.003), the absence of LVI (p = 0.009) and taxane-containing NAC (p = 0.026) were found to be significant indicators of pCR. Median follow-up time was 69 months. Progression-free survival was significantly improved in patients achieving pCR (p = 0.001). Conclusions: pCR is associated with a better outcome regardless of clinical and pathological parameters in breast cancer patients who receive NAC. The probability of pCR was higher in ER-negative, LVI-negative tumors and in patients treated with sequential taxane-containing chemotherapy.