Triple-negative breast cancer exhibits a favorable response to neoadjuvant chemotherapy independent of the expression of topoisomerase IIα.

The present study retrospectively analyzed the utility of topoisomerase IIα expression as a prognostic marker to predict the neoadjuvant chemotherapeutic response and survival among different breast cancer subtypes. The patients were subtyped and the expression of topoisomerase IIα was determined using immunohistochemistry. All patients (n=147) received an anthracycline-containing regimen preoperatively, and 139 (95%) patients also received docetaxel. Of the 147 patients, 25 (17%) were triple-negative and 20 (17%) were human epidermal growth factor receptor 2 (HER2)-positive. Among these subtypes, a significantly higher a rate (P<0.0001) and higher incidence of topoisomerase IIα expression (P=0.036) were observed compared with that in the hormone receptor-positive and HER2-negative breast cancer types. However, the expression of topoisomerase IIα revealed no correlation with the treatment response or survival in any of the subtypes. Therefore, these results indicated that the favorable response to anthracycline-containing chemotherapy among triple-negative and HER2-positive breast cancer was independent of the expression of topoisomerase IIα.