Prognostic factors for survival after neoadjuvant chemotherapy in operable breast cancer. the role of clinical response.

The aim of this retrospective study was to assess predictive factors for clinical response to preoperative chemotherapy and prognostic factors for survival. From 1981 to 1992, 936 patients with T2-T3, N0-N1 breast cancer who received 2-6 months (median 4) of preoperative chemotherapy were selected from the Institute Curie database. Preoperative treatment was followed by surgery and/or radiotherapy. Median follow-up was 8.5 years (range 7-211 months). The objective response rate before surgery and/or radiotherapy was 58.3%. In stepwise multivariate analysis (Cox model), favourable prognostic factors for survival were the absence of pathological axillary lymph node involvement (Relative Risk (RR) 1.54; P=0.0004), low histological tumour grade (RR=1.54; P=0.0017), clinical response to preoperative chemotherapy (RR=1.45, P=0.0013), positive progesterone receptor (PR) status (RR=1.56; P=0.0001), smaller tumour size (RR=1.37; P=0.005) and lack of clinical lymph node involvement (RR=1.42; P=0.007). The association of clinical tumour response with survival is independent of the baseline characteristics of the tumour. Clinical response could be used as a surrogate marker for evaluation of the efficacy of neoadjuvant chemotherapy before assessment of the pathological response.