The importance of the stable category for chemotherapy treated patients with advanced and relapsing prostate cancer.

Categories of objective response to chemotherapy for 460 advanced relapsing prostate cancer patients evaluated in the initial first four randomized clinical trials of the National Prostatic Cancer Project were compared by survival and other patient and disease characteristics. The response criteria for stable were shown to delineate patients with markedly improved survival and other disease conditions relative to those designated as progression. Survival was similar for stable and partial regression patients despite more frequent reduction of primary tumor and subjective improvement in performance status, pain, and body weight in the partial regression patients. Consequently, we feel that in these studies the stable category is valid and useful for determining efficacy of treatment in patients with advancing prostate cancer.