Urothelial Cancers with Small Cell Variant Histology Have Confirmed High Tumor Mutational Burden, Frequent TP53 and RB Mutations, and a Unique Gene Expression Profile (European Urology Oncology)

Small cell bladder cancer (SCBC) is aggressive, excluded from bladder cancer trials; thus, response to checkpoint inhibition is unknown. We confirm that SCBC has a similar mutation profile to small cell lung cancer and may similarly benefit from immunotherapy. Distinct RNA expression profiles between the more common urothelial bladder and small cell bladder cancer may help explain its aggressive behavior.