An Open Trial to Assess the Efficacy and Safety of Oral Thalidomide in Patients With Hormone-Refractory Prostate Cancer

* Trial objectives: The primary objective is to determine the proportion of patients who have 50% decrease in PSA maintained for at least 4 weeks, in advanced hormone-refractory prostate cancer (HRPC) patients who receive thalidomide (100 mg BID). Secondary objectives include the objective tumor response rate for measurable lesions, the median duration of tumor response, median time to disease progression and assessments of clinical benefits, quality of life, and safety profile. * Number of patient : about 70 evaluable patients .Simon's optimal two-stage design will be used to allow early termination should sufficient evidence of non-effectiveness are collected. Thalidomide is considered non-effective if the proportion of PSA response is 14% or lower, and is worthy of further study if the proportion of response is 30% or higher. Controlling the risk for accepting thalidomide when it is non-effective to be at most 5% and the risk for rejecting thalidomide when it is effective to be at most 10%, this design calls for 26 patients at the first stage. If four or less PSA response is observed, then the study will be terminated. Otherwise, additional 44 patients will be entered at the second stage. The treatment will be rejected if a total of 14 or less PSA responses are observed out of 70 patients. This design has 70% chance of termination after the first stage if the true PSA response rate is 14% or lower. With 70 patients, the study will provide 95% assurance to claim that the difference between the estimated and true proportion will be within 11%. * Medication and Dose: Thalidomide (THADO 50mg/cap.) 100mg, BID. * Duration: Continue treatment until disease progression, unacceptable toxicity or when patient meets any off-study criteria. * Efficacy assessments: % of patients with 50% decrease in PSA maintained for at least 4 weeks,Objective tumor response Median duration of tumor response Median time to disease progression, Clinical benefits pain, performance status, weight * Quality of life (evaluated by the instruments of EORTC-QLQ-C30, FACT-prostate)Safety assessments: * Toxicity -Adverse Event -Laboratory Test