[Secondary hormonal ablation in hormone-independent prostate cancer]

After an average of 18-24 months under androgen suppression therapy, almost all patients with prostate cancer show a PSA progress. At this hormone-independent stage, a PSA regress can be achieved by secondary hormonal manipulation in approximately 50% of patients for 6-12 months before they become hormone-refractory. After progress under complete androgen ablation, in 40% of cases a temporary regress can be achieved by discontinuing of the anti-androgen. The administration of an alternative anti-androgen results in a PSA decrease in 80% of the patients responding to anti-androgen deprivation. Inhibition of the adrenal testosterone synthesis by oral administration of ketoconazol can further delay disease progression. Transdermal application of estrogens also allows temporary control of tumor activity by modulating the LHRH and testosterone release as well as directly effecting tumor cell apoptosis. Recent therapeutic modalities as for example somatostatin analogues influence the microenvironment of tumor cells and thereby intensify the effect of anti-tumor therapy.