RESPONSE RATE ACCURACY IN ONCOLOGY TRIALS - REASONS FOR INTEROBSERVERVARIABILITY

Purpose: We evaluated the impact of an evaluation committee (EC) on pa tients' overall response states in a large multicenter trial in oncolo gy. We identified reasons for disagreements between investigators and the EC. Materials and Methods: The Cancer Renal Cytokine (CRECY) study was a French multicenter trial that rested cytokine therapy in 489 pa tients with metastatic renal cell carcinoma. Objective response (OR) e valuation included medical imaging and was studied according to intern ational guidelines. A blinded peer review of all responders and litigi ous cases was performed by an EC. Results: Major disagreements occurre d in 40% and minor disagreements in 10.5% of the reviewed files. The n umber of significant tumor responses was reduced by 23.2% after review by the EC. Reasons for disagreements included errors in tumor measure ments, errors in selection of measurable targets, intercurrent disease s, and radiologic technical problems. These reasons for disagreements are analyzed and discussed. Conclusion: We conclude that all therapeut ic trial results should be reviewed by peer analysis of all presumed r esponders by an EC. international guidelines for response evaluation s hould be updated by including more reliable methods of measurements an d definition of minimal imaging procedures. (C) 1997 by American Socie ty of Clinical Oncology.