Evaluation of changes of biologic markers ER, PR, HER 2 and Ki-67 in breast cancer with administration of neoadjuvant dose-dense doxorubicin, cyclophosphamide followed by paclitaxel.

To assess the changes of biologic markers estrogen receptors (ER), progesterone receptors (PR), HER 2 and Ki-67 in locally advanced breast cancer patients after neoadjuvant chemotherapy. Data from 63 locally advanced breast cancer patients (stage II or III), whose histological diagnosis was made by core biopsies were retrospectively evaluated. The patients were given 4 cycles of 600 mg/m(2) cyclophosphamide, 60 mg/m(2) doxorubicin every 15 days, followed by 4 cycles of paclitaxel 175 mg/m(2), followed by mastectomy within 2 weeks after the last chemotherapy cycle. The changes in ER, PR, HER 2 and Ki-67 status of the operated tumor tissue were compared with the material obtained by initial core biopsies. The patient mean age was 49.2±10.7 years. Most (57.1%) were premenopausal. Clinical disease stages ranged between T2N1 and T3N2. Pathological complete response (pCR) rate was 14.9 7 percent; (n=9). Two (5.7%) patients who were ER positive prior to treatment showed ER negativity after treatment. In 7 (21.1%) patients PR became negative and in 3 (9.0%) became positive after neoadjuvant chemotherapy. Changes in ER and PR receptors were not statistically significant (p=0.500 and PR p=0.549, respectively), whereas in 2 (5.8%) patients hormonal status changed significantly when compared to initial biopsies (p=0.003). In addition, the median value of PR intensity decreased from 20 to 10% (p=0.003) and Ki-67 decreased from 10 to 1% (p<0.001) following neoadjuvant therapy. Five (14.1%) patients exhibited some changes in HER 2 expression: HER 2 expression became 2+ in 3 patients previously being HER 2 negative, and in 2 patients HER 2 became negative whilst it was 1+ and 2+ prior to neoadjuvant chemotherapy. It was observed that the biologic markers ER, PR, HER 2 and Ki-67, from the same tumor material demonstrated differences after neoadjuvant treatment in breast cancer patients. These changes may affect the treatment decision.