Which four prognostically distinctive classes were identified in early urothelial carcinoma gene expression profiling?

• A. UroB, UroA, GU, & SCCL
• B. UroX, UroA, GU, & SCCL
• C. UroB, UroA, GUT, & SCCL
• D. UroB, UroA, GU, & SCCP

Answer: (A)

Gene expression profiling in early urothelial carcinoma identified four prognostically informative groups: two urobasal subtypes (A and B) and two other distinct types called Genomically Unstable and SCC-like. Urobasal A and Urobasal B reflect urothelial differentiation patterns, with Urobasal A generally linked to a more favorable prognosis and Urobasal B to a poorer outlook. Genomically Unstable has extensive genomic alterations and tends to behave more aggressively, while the SCC-like group shows squamous differentiation with its own distinct biology and prognosis. The option listing UroB, UroA, GU, and SCCL matches these four recognized classes, making it the best choice. The other labels do not correspond to the established classifications.