The role of biological markers as predictors of response to preoperative chemotherapy in large primary breast cancer.

The aim of this prospective study was to evaluate biological markers, their correlation with response and outcome, and the change in these markers under the influence of preoperative chemotherapy (PCT) in patients with a large primary breast cancer. One hundred and thirty-five women were treated with PCT, followed by locoregional therapy and adjuvant treatment. Estrogen receptor (ER), progesterone receptor (PgR), HER-2, p53, and cathepsin D were determined by immunohistochemistry (IHC) before and after PCT. The overall response (OR) was 70% and the pathologic complete response (pCR) was 13%. Forty-four percent of the patients could be offered breast-conserving surgery (BCS). At a median follow-up of 50 mo the overall survival is 82% and the disease-free survival is 70%. No local recurrence (LR) has developed following BCS. Invasive ductal carcinoma (IDC) was more frequently ER-negative and HER-2-positive than invasive lobular carcinoma (ILC). P53-negative and ER-negative patients seemed to be more chemosensitive compared to p53-positive patients (74% vs 53%) and ER-positive patients (75% vs 65%), but this difference did not reach statistical significance. A trend toward higher complete pathologic remission rate was seen for ER-negative patients (p = 0.0609). PgR, HER-2, and cathepsin D were not related to response. The pattern of biological markers did not change with PCT, making repeated determination useless.