Prognostic criteria are routinely used in selecting patients for systemic therapy and entry into clinical trials, but there is limited evidence for their use in the selection of patients for CN. Patients are often selected for CN based on volume of disease in the primary vs. in the metastases; if the bulk of disease is in the primary, then CN is often recommended.
However, the authors of this study assessed the utility of the International mRCC Database Consortium prognostic model (IMDC-M), which has been shown to be prognostic in patients presenting with mRCC at diagnosis, for selecting patients for CN.
They utilized data from 250 patients presenting with mRCC without prior CN between 2001 and 2017 to 2 Scottish Institutions – this was a retrospective analysis. IMDC-M stratification was calculated for each patient when sufficient data was available. Complete data was available for 215 patients [85 (40%) intermediate prognosis and 129 (60%) poor prognosis].
First, they validated the utility as a prognostic indicator in patients presenting with metastatic disease. Overall survival (OS) was significantly better in intermediate compared to poor prognosis patients (mean OS 22 months and 6 months respectively, p<0.001). However, only low hemoglobin (HR 1.6, p=0.022), high neutrophil count (HR 2.2, p<0.001) and KPS <= 80% (HR 3.00, p<0.001), but not elevated platelet count and elevated calcium were independently predictive of death on cox multivariate regression analysis.
Next, they assessed its ability to predict utility of CN. 108 (53.5%) patients had a CN. CN was more common in intermediate (65%) compared to poor prognosis (42%) patients (p<0.001). There was significantly improved OS in patients who underwent nephrectomy across both prognostic categories. The survival advantage was greater in the intermediate prognosis group compared to poor prognosis group undergoing CN. Importantly, the mean age and KPS >80 were significantly different between groups.
However, as you can imagine, with a retrospective analysis, there is significant selection bias. Patients were somehow assessed by the clinician to have likely benefit with CN, so these patients are bound to have better outcomes, regardless of their IMDC-M stratification.
The authors acknowledge this, to some degree, when they conclude: “However, this prognostic tool should not be used alone for predicting outcome after CN as CN may have a OS benefit in all risk groups.” The reason they had benefit in all groups is that these were the patients selected by the clinician to have benefit.
Presented by: J. Hendry, Queen Elizabeth University Hospital, Dept. of Urology, Glasgow, United Kingdom
Co-Authors: Beh I.2 , Clement K.1 , O’Connor K.2 , Riddick A. 2 , Stewart G.2 , Aboumarzouk O.1 , McNeill A.2 , Leung S.2 , Oades G.1 , Laird A.2
Author Information: 1Queen Elizabeth University Hospital, Dept. of Urology, Glasgow, United Kingdom, 2NHS Lothian, Dept. of Urology, Edinburgh, United Kingdom
Written by: Thenappan Chandrasekar, MD Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 2018 European Association of Urology Meeting EAU18, 16-20 March, 2018 Copenhagen, Denmark