Clinicopathological study and molecular subtyping of muscle-invasive bladder cancer (MIBC) using dual immunohistochemical (IHC) markers.

Background: Muscle-invasive bladder carcinomas (MIBCs) exhibit significant heterogeneity, with diverse histopathological features associated with varied prognosis and therapeutic response. Although genomic profiling studies have identified several molecular subtypes of MIBC, two basic molecular subtypes are identified - luminal and basal, differing in biological behaviour and response to treatment. As molecular subtyping is complex, surrogate immunohistochemical (IHC) markers have been used to determine the molecular subtypes with good correlation to genomic profiling.