(UroToday.com) While the preponderance of patients with bladder tumors have urothelial histology, up to 25% of tumors are of pure variant or mixed urothelial and variant histology. These variant histologies are associated with more advanced stage at presentation and worse response to systemic therapy. In a poster presentation at the 2021 ASCO GU Cancers Symposium, Dr. Andrew Lenis and colleagues presented a genomic analysis of bladder cancers with variant histology.