Ketoconazole therapy for advanced prostatic cancer: feasibility and treatment results

To investigate the feasibility and antitumoral effect of ketoconazole in the treatment of disseminated prostatic cancer, 22 patients with stage D2 disease were treated with 400 mg. ketoconazole orally every 8 hours. Of the 17 patients evaluable for antitumoral effect an initial tumor response of 88 per cent was observed (1 complete and 8 partial responses, and 6 with stable disease) with a mean duration of 15.8 months (range 5 to more than 30 months). Treatment-related side effects were encountered in 21 patients and consisted of asthenia, gastrointestinal complaints, skin reactions and cardiovascular complications. They were judged to be mild in 8 patients, moderate in 5 and severe in 8. Treatment had to be discontinued because of side effects in 7 patients (32 per cent). During treatment with ketoconazole serum testosterone levels decreased rapidly and attained nearly castrate levels at the end of week 3. However, after 1 month a steady increase was noted and the testosterone levels reached low normal ranges after 5 months. No hormonal or biochemical indications of adrenocortical insufficiency were noted. High dose ketoconazole is effective in the treatment of disseminated prostatic cancer. Its use is limited by the side effects and the inability to maintain castrate levels of testosterone.