Abstract
Response criteria for phase II and phase III trials of prostate carcinoma patients of the EORTC Genito Urinary‐Group are described. These criteria, initially closely related to National Prostatic Cancer Project criteria, have gone through a development into the direction of more stringency. Admission of patients to phase II trials is now restricted to those showing objectively measurable lesions, excluding bone metastases. World Health Organization criteria are applied to these patients. For phase III trials, progression to Metastatic TNM system status, time to progression, and duration of survival are recommended as end points. Measurable marker lesions, as for phase II trials and subjective and nonspecific response criteria, are accepted as parameters for progression. Response usually is not evaluated in these studies. Based on recent literature and personal experiences, the author suggests that serum acid phosphatase (SPAP) and volume changes of the primary tumor can be used as indicators for response under certain conditions. There is obviously a great need for further development of objective response criteria for prostatic cancer patients.