Predictive factors determining neoadjuvant chemotherapy outcomes in breast cancer - a single center experience

From January 1, 2008 to March 31, 2010, 101 patients with stage II-III breast cancer were enrolled in this study and subjected to an anthracycline-based neoadjuvant chemotherapy regimen with or without docetaxel. Surgery was performed after 2-6 cycles of chemotherapy, and the clinical response was determined by pathological and histochemical assessments. The clinical response rate, as indicated by complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD), were 6.9, 52.5, 36.6, and 4.0%, respectively. A multivariable correlation analysis indicated that the overall clinical response rate correlated with the number of metastatic lymph nodes, number of chemotherapy cycles, and vessel invasion status. Importantly, the CR rate was only associated with the number of chemotherapy cycles. Nonparametric tests failed to detect a correlation between HER2 or Topo IIα status and clinical response to neoadjuvant chemotherapy in these patients. When they were stratified by HER2 or HR status, for HER2-positive patients the CR rate was associated with vessel invasion and Topo IIα status. Based on our findings, we propose that HR, HER-2 and Topo IIα are not putative predictive biomarkers of chemotherapy outcome for breast cancer patients. Topo IIα expression level was only inversely correlated with CR rate among HR-positive patients. Importantly, the achievement of CR was largely related to the number of chemotherapy cycles.