Immunohistochemical Evaluation of Basal and Luminal Markers in Bladder Cancer: A Study from a Single Institution

Abstract

Background: Bladder cancer (BC) presents significant molecular diversity, which affects both prognosis and treatment results. Immunohistochemistry (IHC) facilitates the identification of molecular subtypes and their relationships with clinicopathological features. Methods: We performed an IHC analysis on tissue samples from 107 BC patients, evaluating the expression of markers GATA3, CD44, CK5/6, and CK20. We applied two methods to classify the tumor samples into basal and luminal subtypes. The relationships between these marker expressions, molecular subtypes, clinicopathological characteristics, and TILs were explored. Results: Most samples showed the expression of GATA3 and CD44, with notable correlations found between CD44 and CK5/6 as well as GATA3 and CK20. CD44 and CD20 expression were linked to a poorer prognosis. Additionally, the luminal and basal subtypes had distinct TIL patterns, which influenced overall survival. A poor prognosis was associated with the basal subtype with low TIL infiltration and the luminal subtype with high TIL infiltration. Conclusions: Our study clarifies the molecular characteristics of BC, underlining the prognostic importance of CD44 expression and the role of TILs in influencing subtype-specific outcomes. IHC proves valuable in subtype identification and supports personalized treatment strategies.

Keywords

• bladder cancer
• immunohistochemistry
• molecular subtypes
• tumor-infiltrating lymphocytes