[Therapeutic options in advanced cancer of the prostate]

Drug therapy modalities in locally advanced and metastatic carcinoma of the prostate are primarily palliative. Therefore, the goal of systemic therapy is prevention or palliation of complications, such as pain, obstructive symptoms and bleeding. Thus far, there seems to be no survival benefit from hormonal treatment. The first step is always withdrawal of male sex hormones by means of orchiectomy or administration of LH-RH analogues, 70 to 80% of the patients respond favorably. Orchiectomy and LH-RH analogues are considered equal with regard to effectiveness and side effects, however, in the latter case an antiandrogen must be administered during the two weeks prior to start of treatment to prevent the flare-up phenomenon. Estrogens are rarely used anymore, because they can cause cardiovascular complications. In asymptomatic patients, the question remains to be answered if androgen withdrawal should be performed immediately at the time of diagnosis or delayed in case of possible symptoms. Antiandrogen agents block directly the androgen receptors in the prostatic cell. However, monotherapy with antiandrogens is not yet an established procedure. Instead, since 5% of circulating androgens are of adrenal origin, antiandrogens are combined with either orchiectomy or LH-RH analogues for total androgen suppression. The benefit of such a combined androgen suppression could not be proven conclusively and might be minimal at best. Novel modalities of hormonal therapy like intermittent androgen suppression are currently being investigated. In most cases, tumor progression after hormonal therapy is due to hormone-refractory cell lines. Cytotoxic chemotherapy is largely ineffective in treating prostatic cancer. Commonly used chemotherapeutic substances lead to temporary remission in 10 to 20% of the patients at most. External beam irradiation or Strontium-89 therapy are useful in palliation of painful bone metastases.