[Hormonal chemotherapy for hormone-refractory prostate cancer]

To our knowledge, no standard chemotherapy for patients with hormone-refractory prostate cancer (HRPC) has been established. Since most patients with HRPC are elderly and have bone metastasis, cytotoxic chemotherapy causes them to be at high risk for myelosuppression. Therefore, chemotherapeutic agents with low toxicity and good compliance should be elected. We conducted three regimens for HRPC on an outpatient basis. Eligibility criteria were defined as serial rising PSA values on 3 or more occasions at least 2 weeks apart or radiological new or extensive lesions under hormonal therapy. The first regimen is comprised of cyclophosphamide (CPM), 100 mg/day, UFT, 400 mg/day, and estramustine phosphate (EMP), 560 mg/day in two daily fractions. The second regimen is comprised of an oral administration of dexamethasone (DEX) (0.5-2 mg/day). The third regimen is comprised of DEX, 1 mg/day, cyclophosphamide, 100 mg/day and UFT, 400 mg/day in two daily fractions. Post-therapy prostate-specific antigen (PSA) level in serum, objective response on bone scan or measurable disease, and symptomatic response on bone pain were assessed. All regimens showed clinical efficacy with mild toxicity. Indications and limitations of these regimens are discussed. Further, the combination trials of taxane and EMP in patients with HRPC are reviewed.