Heterogeneity of Patients With Intermediate-Prognosis Metastatic Renal Cell Carcinoma Treated With Sunitinib.

BACKGROUND: The Memorial Sloan Kettering Cancer Center (MSKCC) and International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) models categorize patients with 1 or 2 risk factors as intermediate prognosis (INTMP). This category encompasses 15 and 19 permutations of the MSKCC and IMDC risk factors, respectively. The purpose of the present retrospective analysis of data from INTMP patients in 6 clinical trials was to determine whether this heterogeneity influences the response to sunitinib. PATIENTS AND METHODS: Patients with INTMP metastatic renal cell carcinoma (mRCC) were identified using the MSKCC and IMDC classifications. The statistical data were analyzed using Cox regression analysis, Kaplan-Meier methods, and Pearson χ2 tests. RESULTS: The patient characteristics and risk factors were similar in the MSKCC (n = 548) and IMDC (n = 517) groups. Overall, 59% had 1 risk factor and 41% had 2 risk factors. The most common was low hemoglobin alone or with an interval of < 1 year since diagnosis. In both groups, patients with 1 risk factor had longer overall survival (OS) and progression-free survival (PFS) than did those with 2 risk factors (P < .001 for both outcomes). Patients in the IMDC group with 1 risk factor had a greater objective response rate (ORR; P = .023). In both groups, OS was longer for patients with Eastern Cooperative Oncology Group performance status (ECOG PS) 0 than for those with ECOG PS 1 or 2 (P < .001). An ECOG PS of 0 was also associated with superior PFS and ORR in the MSKCC group (P < .05). CONCLUSION: INTMP comprises a heterogeneous group of mRCC patients in whom the number of risk factors and ECOG PS might predict the outcome with sunitinib.