New Response Evaluation Criteria in Solid Tumors (RECIST) Guidelines for Advanced Non-Small Cell Lung Cancer: Comparison With Original RECIST and Impact on Assessment of Tumor Response to Targeted Therapy

OBJECTIVE. The purpose of this article is to compare the recently published revised Response Evaluation Criteria in Solid Tumors (RECIST) guidelines (version 1.1) to the original guidelines (RECIST 1.0) for advanced non–small cell lung cancer (NSCLC) after erlotinib therapy and to evaluate the impact of the new CT tumor measurement guideline on response assessment.MATERIALS AND METHODS. Forty-three chemotherapy-naive patients with advanced NSCLC treated with erlotinib in a single-arm phase 2 multicenter open-label clinical trial were retrospectively studied. CT tumor measurement records using RECIST 1.0 that were generated as part of the prospective clinical trial were reviewed. A second set of CT tumor measurements was generated from the records to meet RECIST 1.1 guidelines. The number of target lesions, best response, and time to progression were compared between RECIST 1.1 and RECIST 1.0.RESULTS. The number of target lesions according to RECIST 1.1 decreased in 22 patients (51%) and did not change in ...