Predictive Value of Circulating Tumor Cells for Evaluating Short- and Long-Term Efficacy of Chemotherapy for Breast Cancer

BACKGROUND The present study investigated the role of circulating tumor cells (CTCs) counts in predicting the short- and long-term efficacy of chemotherapy for breast cancer (BC). MATERIAL AND METHODS Peripheral venous blood was extracted from 187 BC patients. CTCs were measured by flow cytometry. Spearman's correlation analysis was performed to examine the correlation between the efficacy of chemotherapy and CTC counts. A receiver operating characteristic (ROC) curve was plotted to estimate the predictive value of CTC counts. The Kaplan-Meier method was employed to calculate disease-free survival (DFS) and overall survival (OS). Cox regression analysis was used to determine risk factors for prognosis of BC. RESULTS Complete response (CR) + partial response (PR) was achieved by 65.8% of BC patients. After chemotherapy, CTC counts were decreased in both the CR + PR and SD + PD groups. Spearman's correlation analysis indicated that CTC counts before chemotherapy were positively correlated with clinical response to chemotherapy (r=0.45, P<0.05). For predicting clinical response to chemotherapy, CTC counts yielded an area under the curve (AUC) of 0.958, with sensitivity reaching 96.9% and specificity reaching 85.4%. The Kaplan-Meier method and Cox regression analysis indicated that tumor node metastasis (TNM) staging, lymph node metastasis (LNM), ki-67, endocrine therapy, and CTC counts were risk factors for prognosis of BC. CONCLUSIONS These findings indicate that BC patients with CTCs ³8 exhibited poor response to chemotherapy and poor OS. CTC counts can serve as an indicator in predicting short- and long-term efficacy of chemotherapy for BC.