4. Patients must have evidence of progressive disease (e.g. progressive bone pain from bone metastases, increasing bidimensional disease on clinical examination or X-rays or appearance of new lesions on bone radiographs). Alternatively, for patients without such evidence of progression, PSA-progression is defined by 2 consecutive rises in prostate-specific antigen (PSA), each an absolute change of at least 1ng/ml, measured at least 2 weeks apart.