Male breast carcinoma: Correlation of ER, PR, Ki-67, Her2-neu, and p53 with treatment and survival, a study of 65 cases

Male breast cancer is rare, and experience of it in any single institution is limited. Our current understanding regarding its biology, natural history, and treatment strategies has been extrapolated from its female counterpart. The aim of this study is to evaluate the expression patterns of estrogen receptor (ER), progesterone receptor (PR), MiB1 (Ki67), Her2/neu (c-erbB2), and p53 and to correlate them with the prognosis, presentation, staging, management, and survival/outcome in male breast carcinoma identified through the Veterans Administration, nationwide cancer registry. Sixty-five cases of male breast cancer were reviewed for classification. Tumor blocks were requested from each institution for immunohistochemical staining and evaluation of ER, PR, p53, Her2-neu, and MiB1. Seventeen age- and disease-matched male veteran patients with breast gynecomastia were used as controls. Traditional prognostic data were collected for comparison with female breast cancers (i.e., age, lymph node status, clinical staging, tumor size, histological grade, and disease-free and overall survival). Male breast carcinoma had worse disease-free survival than controls (P =.03). The clinical stage regardless of tumor size or lymph node metastasis was the single most significant prognostic factor (P <.0001). ER-positive patients appeared to have a better survival than did Ell-negative patients (P =.03, univariate; P not significant in multivariate) and did not benefit from treatment with tamoxifen (P = .0027, univariate; P =.42, multivariate). MiB1 and PR expressions did not correlate with treatment or survival, and p53 was associated with shorter disease free survival (P =.07, univariate; P =.047, multivariate). Stage for stage, Her2-neu was associated with shorter disease-free survival (P <.0001) and correlated with positive lymph nodes (P =.08). Surgery alone versus surgery with adjuvant treatments (chemotherapy, radiotherapy, tamoxifen, or combination) did not show any survival difference. Adjuvant therapy seemed to be associated with worse outcome. In the Veterans Administration hospital setting, the clinical stage and the expressions of p53 and Her2-neu in male breast carcinoma may be prognostically useful markers in guiding future treatment in prospective studies, whereas ER, PR, and MiB1 expressions are of limited value.