Predictive value of microtubule-associated protein Tau in patients with recurrent and metastatic breast cancer treated with taxane-containing palliative chemotherapy.

Tau is a member of microtubule-associated proteins (MAPs) and expressed in normal breast epithelium and breast cancer cells. Tau expression levels in early breast cancer were correlated with the responsiveness of taxane-containing chemotherapy. However, it is unknown whether Tau contributes to breast cancer progression. Herein, Tau expression in recurrent and metastatic breast cancer (RMBC) and its predictive significance in taxane-containing palliative chemotherapy were investigated. Immunohistochemical (IHC) staining was conducted to detect Tau protein expression levels in biopsies from 285 patients with RMBC, and the correlation between Tau expression and sensitivity to taxane was evaluated. One hundred twenty-one (42.46 %, 121/285) patients were Tau positive in their tumor. One hundred ninety-four (68.07 %, 194/285) patients were effective clinical remission, which evaluated with response evaluation criteria in solid tumors (RECIST) criteria. In this group, 141 (85.98 %, 141/194) patients were Tau negative. We further analyzed the correlation between Tau expression and clinicopathological characteristics. Tau expression was positively correlated to estrogen receptor (ER) status. Multivariate logistic regression analysis showed that Tau expression significantly differentiated patients with effective response to treatment (95 % confidence interval (CI): 4.230-13.88, P < 0.01). Tau expression was identified as an independent factor to predict the sensitivity of tumors to taxane-containing palliative chemotherapy in RMBC, suggesting that Tau expression in RMBC may serve as a clinical predictor for taxane-containing palliative chemotherapy.