A critical analysis of response criteria in patients with prostatic cancer treated with cis-diamminedichloride platinum II.

Cis-diamminedichloride platinum II (DDP), 50--70 mg/m2 iv, q 3w was administered to 25 patients with Stage D adenocarcinoma of the prostate. Since the assessment of tumor regression in a disease-oriented phase II study demands a clear end-point of response, case selection was restricted to patients who had objectively measurable lesions, i.e., nodes, skin, lung, and liver metastasis. Partial remission occurred in 3 (12%) and stabilization of disease in 1 patient. Responders lived 53 weeks vs. 20 weeks for non-responders. In the dosage and schedule used in this protocol, DDP was not an active agent in the treatment of prostatic cancer. Various patient characteristics are examined and correlations made between remission rates and survival in this study vs. 4 other response schemata. A critical analysis of patient selection, "lead time" -- diagnosis to chemotherapy, and the definitions of the terms "measurable" lesions, "evaluable" parameters, "objective response", stabilization of disease and response criteria employed in the 4 schemata are also discussed.