Value of Ki-67 expression in triple-negative breast cancer before and after neoadjuvant chemotherapy with weekly paclitaxel plus carboplatin

Neoadjuvant chemotherapy (NCT) is one of the main treatment strategies for patients with locally advanced breast cancer. In this study, we focused on the predictive and prognostic value of Ki-67 in triple-negative breast cancer (TNBC) patients who received NCT. Data from 280 patients with stage II-III TNBC were collected. All patients were treated according to the same protocol with weekly paclitaxel and carboplatin. The overall pCR rate was 33.9%. Both the categorical and linear Ki-67 were independently correlated with pCR (P < 0.001). There were also statistically significant differences among Ki-67 categories with respect to clinical response (P < 0.001), Miller-Payne (MP) grades (P < 0.001), and node status (P < 0.001). A significant reduction of Ki-67 after NCT was most likely observed in patients with a relatively better response. In the multivariate model for non-pCR patients, Ki-67 reduction presented an independent prognostic value for relapse of disease (HR = 0.986, 95%CI: 0.978-0.994; P = 0.001). This study had indicated that the primary Ki-67 might help in further classifying TNBCs into subtypes with different responses to chemotherapy and a significant reduction of Ki-67 after treatment could indicate a favorable prognosis in non-pCR patients.