Proliferative activity and steroid hormone receptor status in male breast carcinoma

Hormonal factors have been implicated in the development of both female and male breast cancers (MBC). However, MBCs are rare and seem to have differe nt biological behavior than those of females. The aim of this study was to evaluate proliferative activity and to establish an association with steroi d hormone receptor concentration and clinicopathological parameters in MBC. Proliferative activity was assessed in 18 MBC by mitotic figure counts and immunohistochemical evaluation of MIB-1 and proliferating cell nuclear ant igen (PCNA). Estrogen (ER), progesterone (PR) and androgen (AR) receptors w ere evaluated in serial section from the same tumor by immunohistochemistry . PCNA (range 17-73%; mean, 51.6%) and MIB-1 (range 18.5-58%; mean 38.4%) w ere positive correlated with the mitotic rate. High proliferative activity assessed either by mitotic index or MIB-1 expression was associated with mo re poorly differentiated tumors. Sixty one percent (11/18) of the tumors we re ER+, 72% (13/18) PR+ and 38.5% (5/13) AR+. Proliferative activity in tum ors displaying ER+ /PR+ phenotype showed a tendency to be higher than in ER -/PR- tumors. This difference was statistically significant when MIB-1 expr ession was used as proliferation marker. An association between AR concentr ation and age at diagnosis was found; in the AR negative group (8/13) mean age at diagnosis was 54.4 +/- 7.3 which was significantly lower than the ag e of patients with AR+ tumors, 63.2 +/- 11.1 (5/13). Results presented here show that decreased androgen action (AR-) within the breast might contribu te to an earlier development of MBC. Besides that, the presence of ER and P R in carcinoma cells is considered to provide a growth advantage as shown b y the positive association between the phenotype (ER+/PR+) and high prolife rative activity. These results add information for a better understanding o f hormonal control of MBC growth and development. (C) 1998 Elsevier Science Ltd. All rights reserved.