 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. 