Clinicopathologic analysis of BRCA1- or BRCA2-associated hereditary breast carcinoma in Japanese women.

BACKGROUND

The purpose of this investigation was to elucidate the clinicopathologic characteristics of BRCA1- and BRCA2-associated hereditary breast carcinomas (HBCs) in Japanese women.

METHODS

Various clinicopathologic characteristics of HBCs arising in patients 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 younger than that of the control group (54 years) and the incidence of bilateral tumors was significantly higher in the BRCA1-associated HBCs (32%) and BRCA2-associated HBCs (29%) than in the control group (6%). BRCA1-associated HBCs showed a tendency (P = 0.06) toward an increase in solid-tubular type tumors and a significant increase in histologic grade 3 tumors (P < 0.01) and lymphatic invasion positive tumors (P < 0.05) compared with the control group. BRCA1-associated HBCs were significantly more estrogen receptor negative (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 group. However, there was no significant difference in these parameters between the BRCA2-associated HBCs and the control group.

CONCLUSIONS

BRCA1-associated HBCs in Japanese women have biologically aggressive phenotypes. However, BRCA2-associated HBCs are without distinctive clinicopathologic features compared with sporadic breast carcinomas.