Low-stage carcinoma of the male breast - A histologic, immunohistochemical, and flow cytometric comparison with localized female breast carcinoma

Male breast carcinoma (MBC) accounts for only 1% of total mammary carcinoma s. Controversy exists about whether MBC differs clinically and pathological ly from female breast carcinoma (FBC). We compared 10 archival cases with 7 5 stage-matched FBCs. Clinical data, histologic details, immunostains for m ammary lineage markers, and results of several putative "prognostic" analys es were addressed including DNA ploidy and expression of c-erbB-2 (neu) onc oprotein and p53 protein. Cumulative literature data on 2,530 MBCs were con trasted with information from 135 institutional cases of FBC. A statistical ly significant difference in grade 3 lesions at low stage persisted when MB Cs of all stages were compared with similar FBCs. For stages I and IIA, 5-y ear survival was 60% and 86% for MBCs and FBCs, respectively (also statisti cally significant). This difference disappeared when all stages were compar ed. A similar number of MBCs and FBCs, regardless of stage, demonstrated DN A aneuploidy with or without synthesis of S-100 protein, gross cystic disea se fluid protein-15, c-erbB-2 protein, and p53 protein. Hormone receptor po sitivity was more common in MBC than in FBC at high tumor stages. Law-stage MBC and FBC differ biologically; MBCs fend to manifest at a higher grade w ith lessened 5-year survival. However; aside from distinctions in hormone r eceptor proteins, broader comparison of MBC and FBC at stages IIB and highe r shows no significant differences in 5-year survival or expression of brea st cancer-associated gene products.