Bcl-2 expression in male breast carcinoma

Abstract

We have analysed the expression of bcl-2 protein retrospectively in 34 primary male breast carcinomas (MBC), using the monoclonal antibody bcl-2 in formalin-fixed, paraffin-embedded tissues. Bcl-2 expression was compared with tumour clinicopathological features, sex steroid hormone receptors, DNA content, p53 immunoreactivity and cell proliferative activity assessed by counts of the argyrophilic nucleolar organizer regions (AgNORs), the monoclonal antibody PC10 against proliferating cell nuclear antigen and the monoclonal antibody MIB-1. Most (28, or 82.3%) of the 34 cases of MBC were bcl-2 positive. No association was found with clinicopathological features of the tumours, although bcl-2 tended to be more frequently expressed in small tumours (P=0.09) and in cases without necrotic areas (P=0.1). Nor was any association found with hormone receptor status, p53 immunoreactivity, DNA content, cell proliferative activity or patient survival. In multivariate analysis, only proliferative activity (expressed by AgNOR counts) and p53 immunoreactivity had independent prognostic significance. Our results indicate that MBC differs from FBC in that in MBC bcl-2 protein is not related to an oestrogen-dependent transcription pathway and bcl-2 alone is not sufficient to induce increased proliferation. These characteristics, together with the high prognostic value of cell proliferation and the lack of prognostic significance for hormone receptor status, support the hypothesis that MBC is biologically different from FBC.

Prognostic Value of Mitotic Index and Bcl2 Expression in Male Breast Cancer

“…The Bcl2/mitotic index combination as previously described in FBC as a useful prognosticator, did not predict survival of MBC either. The widespread Bcl2 expression as demonstrated in the present study is largely in accordance with the few previous studies on Bcl2 in MBC [2], [13], [14], [15], although the percentages of positive cases vary somewhat in these studies due to variations in methodology and thresholds (Table 4). …”

“…Bcl2 is an anti-apoptotic protein which is significantly more often expressed in male breast cancer compared to FBC [13], [14], [15]. Although there are some data published regarding Bcl2 expression and its prognostic value in MBC, the prognostic value of Bcl2 combined with mitotic index has not been studied in MBC.…”

Oncogenes in Male Breast Cancer

“…This supports the hypothesis that MBC may be under different growth control mechanisms than FBC. 5 The low number of male patients with breast cancer prevents conclusions about the prognostic value of oncogenes in MBC. A large number of MBC patients is necessary to achieve reliable results.…”

“…4,6 Tumors with bcl-2 overexpression have low proliferative potential and prolonged cell survival. 5 bcl-2 overexpression has been detected in 67% to 94% of MBC 1,2 and as biomarker had no prognostic value in a number of reports. 2,4,6 In the present study, a series of 30 MBCs were immunostained and retrospectively analyzed.…”

“…1,2 Data regarding oncogene alterations and their prognostic significance in MBC are limited. [1][2][3][4][5][6][7] The human epidermal growth factor receptor-2 protooncogene has been localized to chromosome 17q and encodes 185-kD glycoprotein, called the c-erbB-2 receptor. Overexpression of c-erbB-2 protein has been detected in 0% to 94% of MBC.…”