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.