Metastatic renal cell carcinoma (mRCC) in young patients: A comprehensive genomic profiling (CGP) study.

Abstract

727 Background: We studied the genomic alterations (GA) in patients with mRCC under 40 years of age (<40) and patients 40 years of age or older (>40). Methods: 2,128 mRCC underwent hybrid-capture based CGP. Clear cell (ccRCC), papillary (pRCC), sarcomatoid (sRCC), NOS (nosRCC), chromophobe (chrRCC), medullary (medRCC) and collecting duct (cdRCC) were separately evaluated. Tumor mutational burden (TMB) was determined on up to 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. PD-L1 expression was determined by IHC (Dako 22C3). Results: Male preponderance in all subsets increased in the >40 patients. The GA/tumor increased significantly in the >40 cohorts except for in medRCC. The relatively low TMB was higher in all >40 and MSI high status was infrequent in all groups. PD-L1 expression was generally low, the 44% high positive PD-L1 in sRCC was noteworthy. Significant differences in GA in <40 vs >40 RCC included increased PBRM1 and SETD2 GA in >40 vs <40 ccRCC; increased C DKN2A/B and TERT and decreased FH GA in >40 vs <40 pRCC; increased TP53, PTEN and TERT GA with decreased NF2 GA in >40 vs <40 sRCC; increased TP53, VHL and TERT in >40 vs <40 nosRCC. Changes in GA in <40 vs >40 chrRCC, medRCC and cdRCC were noted but insufficient cases prevented statistical evaluation. Conclusions: When evaluated by age, CGP of mRCC demonstrates significant differences in the genomic landscapes with >40 cases featuring increasing male preponderance and higher GA/tumor, TMB and increases in TP53, CDKN2A/B and TERT GA. These findings may play important roles in the planning of future clinical trials designed to personalize the treatment of mRCC.[Table: see text]