Comparison of prognostic markers detected by immunohistochemistry in male and female breast carcinomas.

Male infiltrating breast carcinomas are rare and seem to have different characteristics, prognosis and sensitivity to hormonal treatment than those of female breast carcinomas. Our aim was to determine whether markers which have an established role in women are also important in men. 66 male infiltrating-ductal breast carcinomas were compared with 190 female breast carcinomas of the same type. Various markers were studied using immunohistochemistry. Tumour size at diagnosis, grade, number of axillary metastases and prognosis were comparable in male and female breast carcinomas. However, male breast carcinomas were characterised by a higher percentage of oestrogen receptor (OR) reactivity, and weekly associated with markers that, in women, are under oestrogen control. Male breast carcinomas were positive for markers under androgen control. Male breast carcinomas also differed from female carcinomas by the low percentage of p53+ and the high percentage of bcl-2+ tumours. The phenotype of male breast carcinomas has characteristics that could have repercussions on prognosis and on the choice of hormonal treatment. Only a few male breast cancers are p53+. OR, which are frequently present in male tumours, are probably not functional. In contrast, androgen receptors seem efficient, as several markers under androgen control are expressed. Therefore, the selection of hormonal therapy should not be based on OR status only.