Induction chemotherapy for breast carcinoma: predictive markers and relation with outcome

Induction chemotherapy provides an excellent model for evaluation of potential predictive factors. We studied expression of SBR grade, estrogen (ER) and progesterone (PR) receptors, HER2, Ki67 and P53 on core biopsies before and after chemotherapy in a series of 115 patients, who received anthracycline-based induction chemotherapy for primary breast cancer. HER2 overexpression independently predicted response to neoadjuvant anthracycline-based chemotherapy. Patients with HER2-positive status are 4.54 times more likely to have a pathological complete response than those with negative status (p<0.005). HER2, ER and PR status were stable during treatment. P53 and Ki67 significantly increased after treatment (p<0.005 and p<0.0005). SBR grade, proliferation markers, ER evaluated before and after treatment predicted disease-free survival (DFS) in univariate analysis.