158PPlasma KIM-1 is associated with clinical outcomes after resection for localized renal cell carcinoma: A trial of the ECOG-ACRIN Research Group (E2805)

Abstract Background There is currently no circulating biomarker for renal cell carcinoma (RCC). The use of adjuvant sunitinib for RCC after nephrectomy is controversial, and a biomarker could help to select the patients at highest risk for recurrence. Kidney injury molecule-1 (KIM-1) is overexpressed in RCC and its ectodomain can be detected in circulating plasma. We therefore investigated whether KIM-1 is associated with worse outcomes in patients with localized RCC after nephrectomy. Methods In the ECOG-ACRIN 2805 (ASSURE) trial, 1943 patients with resected high-risk RCC were randomized 1:1:1 to sunitinib, sorafenib, or placebo. Post-nephrectomy baseline samples from 182 randomly selected patients (9.4% of the study population) was available for this post-hoc biomarker analysis. Samples were analyzed using a previously validated microbead-based assay. Kaplan-Meier and Cox proportional hazards models were used to test for association between circulating KIM-1 and disease free survival (DFS) as well as overall survival (OS). ROC analysis was performed to evaluate test characteristics for KIM-1 in predicting RCC recurrence within 6 months after nephrectomy. Results Higher KIM-1 levels were associated with worse DFS and OS after nephrectomy. This association remained independently significant after controlling for pathologic stage, sarcomatoid features, and Fuhrman grade (DFS: HR 1.20 per log increase in KIM-1, 95% CI 1.09-1.33, p