(ChemotherapyAdvisor) – RECIST (Response Evaluation Criteria In Solid Tumors) criteria, Choi and modified Choi (mChoi) criteria fail to predict progression-free survival (PFS) among patients with metastatic renal cell carcinoma (mRCC) treated with the mTOR inhibitor everolimus, according to a retrospective analysis of data from the randomized, double-blind, placebo-controlled phase 3 RECORD-1 clinical trial. The new analysis was presented at the Radiological Society of North America (RSNA)’s 2012 Scientific Assembly and Annual Meeting in Chicago, IL.
“Neither RECIST, CHOI nor mCHOI criteria could discriminate responders from non-responder patients in the group treated with everolimus,” reported a team of French coauthors led by Samar A. Raslan, MD.
The authors reviewed computed tomography (CT) images from 105 patients with mRCC who participated in the RECORD-1 trial. During RECORD-1, RECIST criteria were assessed using CT images taken at baseline and every 2 months to assess progression-free survival (PFS). The authors of the new analysis used computer software to reassess partial response (PR) from RECORD-1’s CT images using Choi criteria (which defines PR as a ≥10% decrease in tumor size or ≥15% decrease in CT attenuation) and mChoi criteria, which defines PR as a ≥10% decrease in tumor size and ≥15% decrease in attenuation. They then compared Choi and mChoi criteria results with patients’ PFS times.
When both placebo- and everolimus-arm patients were included in the analysis, “2D CHOI criteria identified 25% of PR without differences for median PFS compared to non-responders (2.3 vs 1.8 months, respectively), while mCHOI criteria found 0% of PR,” Dr. Raslan and coauthors reported.
Among patients in the everolimus treatment arm, “2% and 98% of patients were considered PR and SD (stable disease), respectively with RECIST criteria (median PFS – 5.5 months for both),” the coauthors reported. “48% of patients were considered PR with 2D CHOI criteria without differences for median PFS compared to non-responders (5.4 and 5.8 months) while mCHOI found 8% PR without significant differences for PFS (5.4 and 4.6 months).”
Similar results were obtained using 3D assessments of the attenuation Choi criterion, Dr. Raslan noted.