Broadening horizons in medical management of prostate cancer.

UNLABELLED

HORMONAL THERAPY: Testosterone suppression achieved either medically or surgically is the standard initial treatment for men with advanced prostate cancer. Most men respond but the disease progresses after a median of 1-2 years. Clinical trials suggest that intermittent androgen deprivation therapy (ADT) provides equal or longer time to castration-independence than continuous ADT, and is preferred, especially since there are subtle long-term toxicities associated with ADT. Further hormonal manipulations (including addition and withdrawal of peripheral antiandrogens, steroid synthesis inhibitors such as ketoconazole, and estrogens) can be transiently effective in selected patients with castration-resistant prostate cancer (CRPC). Androgen-dependent signalling pathways remain active in most men with CRPC and are associated with mutation, changes in expression or modulation of the androgen receptor (AR); abiraterone acetate and MDV3100 are promising drugs being evaluated in clinical trials that may lead to further hormonal response.

CHEMOTHERAPY

Eventually men who progress rapidly, are symptomatic, and/or develop metastasis to visceral organs require chemotherapy. Three-weekly docetaxel with prednisone has been shown to improve survival and relieve symptoms but eventually men develop progressive disease or become intolerant to docetaxel. Multiple trials are evaluating new drugs (mainly molecular targeted agents) either given first line with docetaxel chemotherapy, or to men who have progressive disease after receiving docetaxel. Cabazitaxel was shown recently to improve survival as compared to mitoxantrone when used second line and has been approved by the United States Food and Drug Administration (FDA).

CONCLUSION

Despite major advances, treatment of men with advanced CRPC remains a challenge both for the seeker and giver of care.