Predictive factors of pathologic complete response and clinical tumor progression after preoperative chemotherapy in patients with stage II and III breast cancer

Background This study aimed to define predictive factors of pathologic complete response (pCR) and disease progression in stage II and III breast cancer patients. Patients and Methods Three hundred thirty-eight patients were included in the study. Patients had received preoperative chemotherapy as follows: 101 had doxorubicin plus cyclophosphamide (AC); 91 had doxorubicin plus docetaxel; 103 had docetaxel plus capecitabine; and 43 had paclitaxel plus gemcitabine. A pCR was defined as the absence of residual invasive carcinoma in the breast. Results The majority of patients (73%) were premenopausal with a median age of 44 (range, 21-76) years. Fifty-four patients (16%) achieved pCR and were distributed among the 4 breast cancer subtypes as follows: 10% of patients with -ER or PR+/HER2-, 13% with ER or PR+/HER2+, 33% with ER-/PR-/HER2+, and 19% with ER-/PR-/HER2-(p = 0.001). Taxane-containing regimen (p = 0.042) and Breast cancer subtype (p = 0.005) were significant predictive variables for pCR. On the other hand, significantly more patients who received non-taxane-containing regimen (AC) experienced no response (p = 0.001) or progression (p = 0.006). Conclusions Patients with ER-/PR-/HER2+ tumors and those who received taxane-containing regimen achieved a higher pCR rate, while significantly more patients developed tumor progression by preoperative non-taxane-containing regimen (AC) compared to those who received taxane-containing chemotherapy.