Array CGH analysisin neoadjuvant chemotherapy for breast cancer.

786 Background: To assess a potential and common pattern of genetic alterations in Korean women's breast cancer correlated with clinicopathologic parameters and to assess the potential genes which may be helpful to predict the response of neoadjuvant chemotherapy, we analyzed 13 tumors from breast cancer patients by microarray-based CGH.,Array CGH(including 350 cancer-related genes and 1,090 STS) was performed with fresh frozen tumor tissue from the breast cancer patients. Ten cases of them received neoadjuvant chemotherapy(cyclophosphamide 600 mg/m, adriamycin 50 mg/m(CA); cyclophosphamide 600 mg/m, adriamycin 50 mg/m, 5-FU 500 mg/m(CAF); cyclophosphamide 600 mg/m, methotrexate 40 mg/m, 5-FU 500 mg/m(CMF); CA and Taxol; Nabelvine), 2 cases adjuvant chemotherapy and 1 case had no history of chemotherapy. Immunohistochemical study for ER, PR, p53, and Her-2 were also done.,In array CGH analysis, the patients showed typical imbalances for breast cancer; gain of 8q(84.6%), 11q13(69.2%), 16p(84.6%), 22q(69.2%), 3p(61.5%) and losses of 1p(61.5%), 18q(38.5%) and 2q(38.5%). Other recurrent imbalance of newly recognized pattern for breast cancer was gain of 1p(92.3%). One patient, died within 5 months with pulmonary metastasis after diagnosis, displayed gains of 20q13, 8q and losses of 13q21, 18p and 18q which were known as chromosomal changes related with adverse prognosis in previous reports. Genetic alterations in the "progress" group after neoadjuvant chemotherapy showed gain of MAFG(v-maf musculoaponeurotic fibrosarcoma oncogene homolog G; 17q25) which was related to cellular stress response and loss of DCC(18q21.3) whose function was induction of apoptosis. Genetic alterations in the "stable" and "partial remission" group were gain of p73(1p36), which was p53-related protein, and activated by chemotherapy and thereafter contributed to the reduction of the tumor size.,These data suggest that gains of 1p might be a newly identified CGH finings which characterize the Korean women breast cancer. These findings suggest that loss of DCC and gain of MAFG and p73 might be a possible predictor for the response of neoadjuvant chemotherapy. No significant financial relationships to disclose.