PAM50 for prediction of response to neoadjuvant chemotherapy for ER-positive breast cancer.

Purpose: There is an urgent need for the development of a predictor of response to chemotherapy for ER-positive breast cancer which is less chemosensitive than for ER-negative breast cancer in order to avoid unnecessary chemotherapy. In the present study, intrinsic subtyping by PAM50 was evaluated for its ability to predict a response to chemotherapy.

Patients And Methods: For this study, 124 patients with ER-positive breast cancer treated with neoadjuvant sequential paclitaxel and FEC (NAC) were evaluated.