[Systemic therapy of male breast cancer]

Due to its low incidence there is only few information on optimal systemic therapy of male breast cancer. There are no prospective randomized trials, neither for early breast cancer nor for advanced stages. Retrospective analyses mostly comprise long-term-data from a small number of patients. In terms of epidemiology, cellular receptors or genetics there exist some significant differences between male and female breast cancer. Therefore, the possibility to extrapolate treatment recommendation for male patients from female breast cancer-trials is limited. Despite a high rate of receptor positivity, hormonal therapy seems to be less efficient in men, possibly due to different biological factors. The current standard in endocrine therapy is tamoxifen. It is not known whether tamoxifen therapy is as effective as orchiectomy, but tamoxifen is favoured because of its low side effects. The use of aromatase inhibitors needs to be considered carefully, since aromatization is blocked, but 5-alpha-reductase increases estrogen-like androstanediole. There might be a benefit from additional therapy with GnRH-analoga respectively 5-alpha-reductase inhibitors, but data is not available yet. Combination of GnRH-analoga and antiandrogens does induce tumor remission, but comparison to other endocrine therapies is still lacking. Currently, the efficiency of fulvestrant, an estrogen receptor destructor, is being examined. Cytostatic therapy seems to be as effective as in female breast cancer patients. Nevertheless, convincing prospective trials for the management of early and advanced male breast cancer need to be performed.