Carcinomas of the renal medulla: A comprehensive genomic profiling (CGP) study.

640Background: Collecting duct carcinoma (CDC) and renal medullary carcinoma (RMC) represent rare tumors that arise in the renal medulla are therapy resistant tumors that progress rapidly. Methods: DNA was extracted from 40 microns of FFPE specimen from refractory CDC (46 cases) and RMC (24 cases). CGPwas performed using a hybrid-capture, adaptor ligation based next generation sequencing assayto a mean coverage depth of > 800X. Tumor mutational burden (TMB) was calculated from a minimum of 1.11 Mb of sequenced DNA as previously described and reported as mutations/Mb. Microsatellite instability status (MSI) was determined on 114 loci. Results: All CDC patients were older and more frequently male (Table). Sickle cell trait was identified in both CDC and RMC, but far more frequently associated with RMC. All (100%) of CDC and RMC were clinically advanced Stage III and IV tumors with the primary tumor used for CGP in 70% of cases and a metastasis biopsy was sequenced in 30%. All (100%) CDC and RMC were interme...