First-line treatment of metastatic prostate cancer. Androgen suppression for symptomatic disease

Abstract

Prostate cancer sometimes metastasizes, especially to bone, which may cause pain, fractures and spinal cord compression. What are the best first-line treatment options for patients with metastatic prostate cancer? To answer this question, we conducted a review of the literature, using the standard Prescrire methodology. Suppressing androgen secretion by surgically removing the testicles (orchiectomy) or by administering a gonadorelin agonist relieves the pain associated with bone metastases in about 80% of patients. This treatment has a clear impact on symptoms, despite the lack of clinical trials versus placebo or no treatment. Its impact on overall survival is uncertain. In terms of survival, goserelin therapy appears to have similar efficacy to orchiectomy. The efficacy of other gonadorelin agonists is less well documented. Degarelix, a gonadorelin antagonist, does not appear to provide a therapeutic advantage over gonadorelin agonist. In 2012, oestrogen should not be used in the treatment of metastatic prostate cancer, because of its cardiovascular adverse effects. Antiandrogen monotherapy, preferably with flutamide, appears to be less beneficial than orchiectomy in terms of survival. Overall, adverse effects are more frequent with nonsteroidal antiandrogens than with gonadorelin agonists, but sexual dysfunction is less frequent. Cyproterone, a steroidal antiandrogen, seems to have fewer adverse effects leading to treatment discontinuation than nonsteroidal antiandrogens. There is no firm evidence that starting hormonal therapy before metastases become symptomatic is beneficial. When symptoms have disappeared and the PSA level is low, one option is to temporarily interrupt gonadorelin agonist therapy if it is poorly tolerated, even though this may shorten survival by a few months. The addition of a nonsteroidal antiandrogen to androgen suppression therapy slightly improves 5-year survival, preventing about 3 deaths per 100 patients, but at a cost of additional adverse effects. First-line hormonal treatments are initially very effective in relieving symptoms of metastatic prostate cancer. Our analysis of the available data suggests that the best treatment option is androgen suppression with goserelin. Flutamide monotherapy is an alternative for some patients.