ATR and BRCA2 Simultaneous Mutation in a ccRCC With Sarcomatoid Differentiation and Extensive Metastases: A Case Report

The genomic landscape and driver-gene mutations differ significantly among diverse histological subtypes of clear cell renal cell carcinoma (ccRCC) due to the intratumoral heterogeneity. Frequent mutations in canonical DNA damage response genes, such as BRCA1/2 or ATR serine/threonine kinase (ATR) haven't been reported even in large-scale genomic profiling of ccRCC researches. Herein, we reported a rare ccRCC harboring ATR and BRCA2 simultaneous mutation with complicated morphologies and extensive metastases. Our case indicates that the deleterious alteration of DNA damage response genes, increasing CD8+ TILs, high PD1/PD-L1 expression and high TMB might contribute to this patient's tumor metastasis and aggressive biological behavior.