IBCN 2019: Association of Immunohistochemical Markers Molecular Subtypes in Bladder Cancer

Aarhus, Denmark (UroToday.com) Dr. Charles Guo from the University of Texas MD Anderson Cancer Center presented data investigating immunohistochemical markers that may be associated with molecular subtypes in bladder cancer. Fresh frozen samples (n=132) and formalin-fixed paraffin-embedded (FFPE) samples (n=89) from patients with bladder cancer, with genomic mRNA expression characterized. 

Gene signatures for luminal and basal subtypes were identified, with a basal-luminal transition (BLT) score calculated for each sample based on expression levels of basal and luminal genes. A positive BLT score indicated a luminal subtype, while a negative BLT score was associated the basal subtype.

Positive BLT scoring tumors (luminal subtype) were associated with luminal IHC markers KRT 20, uroplakin II, and GATA3, while negative BLT scoring tumors (basal subtype) were associated with basal IHC markers KRT5/6, KET14, and p63. Dr. Guo noted that IHC expression of GATA3 and KRT5/6 were highly effective in identifying a tumor’s molecular respective subtype.

IBCN Charles Guo

Take home messages:

  • IHC expression of GATA3 and KRT5/6 may be effective in identifying luminal and basal molecular subtypes

Presented by: Charles C. Guo, MD, Professor, Department of Pathology, Division of Pathology/Lab Medicine, The University of Texas MD Anderson Cancer Center, Houston, TX

Written by Dr. Vikram M. Narayan (@VikramNarayan), Urologic Oncology Fellow with Ashish M. Kamat, MD (@UroDocAsh), Professor, Department of Urology, Division of Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX at the 17th meeting of the International Bladder Cancer Network, (IBCN, #IBCN2019) October 3rd – 5th, 2019 in Aarhus, Denmark.

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