Comparison of pre-treatment MSKCC and IMDC prognostic risk models in patients with synchronous metastatic renal cell carcinoma treated in the era of targeted therapy.

Retrospective analysis of pre-therapeutic MSKCC and IMDC prognostic factors and outcomes in patients with synchronous mRCC treated at a single institute in the targeted therapy era was performed. Cytoreductive nephrectomy (CN) was performed in patients with WHO performance 0-1 and limited metastasis.

Patients with synchronous mRCC and poor risk by MSKCC or ≥4 IMDC factors have a short survival expectancy, and CN may not be the primary objective in this population. Conversely, with either MSKCC or IMDC intermediate risk the probability to survive 2 years is 38.6-45.7 %, which suggests that a subgroup of patients live long enough to derive a potential benefit of CN.

Of 190 patients, only 2 had favourable risk. Overall, 141 patients received targeted therapy and 97 underwent CN. By MSKCC score, 143 (76.1 %) patients were intermediate risk (median OS 16 months) but only 97 (51.9 %) by IMDC (median OS 23 months). Conversely, 46 of the MSKCC intermediate-risk patients (31.2 %) were IMDC poor risk. Only poor risk by MSKCC and ≥4 IMDC factors had similar poor outcome (median OS 5 months and OS 2 years of 4.1 % and 10.4 %, respectively). Following CN, baseline elevated platelets and neutrophils decreased to normal in 61.5 and 75 %, respectively. This suggests that the primary tumour may influence baseline counts resulting in more IMDC poor risk. In both models, CN status was associated with better OS.

To compare prognostic performance of MSKCC and IMDC risk models in patients with synchronous mRCC.