Comprehensive Genomic Profiling of Renal Cell Carcinoma at Initial Diagnosis and Putative Local Recurrence

In the context of metastatic renal cell carcinoma, it would typically be assumed that the site of recurrence is derived from the original tumor. Through the use of comprehensive genomic profiling in a case of localized disease with a subsequent recurrence in the renal fossa, we determined that the latter was a wholly distinct tumor. The original tumor harbors mutations in PBRM1, while the second harbors mutations in KDM5C. These findings, if further validated, could prompt caution in interpretation of genomic tests used for risk stratification and could have implications for ongoing studies of adjuvant therapy.