Clinicopathologic analysis of BRCA1- or BRCA2-associated hereditary breastcarcinoma in Japanese women

BACKGROUND. The purpose of this investigation was to elucidate the clinicop athologic characteristics of BRCA1- and BRCA2-associated hereditary breast carcinomas (HBCs) in Japanese women. METHODS. Various clinicopathologic characteristics of HBCs arising in patie nts with BRCA1 or BRCA2 germline mutations were compared with those of the control group (sporadic breast carcinomas). RESULTS. The mean age at the time of diagnosis of BRCA1-associated HBCs and that of BRCA2-associated HBCs (44 years for both) were significantly young er than that of the control group (54 years) and the incidence of bilateral tumors was significantly higher in the BRCA1-associated HBCs (32%) and BRC A2-associated HBCs (29%) than in the control group (6%). BRCA1-associated H BCs showed a tendency (P = 0.06) toward an increase in solid-tubular type t umors and a significant increase in histologic grade 3 tumors (P < 0.01) an d lymphatic invasion positive tumors (P < 0.05) compared with the control g roup. BRCA1-associated HBCs were significantly more estrogen receptor negat ive (P < 0.01), c-erb B-2 negative (P < 0.05), and p53 positive (P < 0.01), and they also showed a significant increase in MIB-1 staining grades (P < 0.01) as well as microvessel counts (P < 0.05) compared with the control gr oup. However, there was no significant difference in these parameters betwe en the BRCA2-associated HBCs and the control group. CONCLUSIONS. BRCA1-associated HBCs in Japanese women have biologically aggr essive phenotypes. However, BRCA2-associatcd HBCs are without distinctive c linicopathologic features compared with sporadic breast carcinomas. Cancer 1999;85:2200-5. (C) 1999 American Cancer Society.