The sex hormone profile of male patients with breast cancer.

The mean total serum oestradiol level was found to be significantly increased in 8 patients with carcinoma of the breast when compared with 8 healthy reference subjects matched for race, sex and age. The calculated mean free oestradiol index was also higher in these patients. There were no significant differences, however, between the levels of LH, FSH, prolactin. DHEA-S, testosterone and SHGB in the 2 groups. The patients showed a significantly increased LH response to GnRH while there was no difference in the FSH response. Only 1/7 patients had a tumour devoid of steroid hormone receptors. It may be that an increased level of circulating oestradiol-17 beta is an important factor in the aetiology of hormone-dependent male breast cancer.