Molecular Subtypes of Bladder Cancer

Area of Science:

• Oncology
• Genomics
• Molecular Biology

Background:

• Primary human bladder cancers can be classified into basal and luminal molecular subtypes based on whole genome characterization.
• These subtypes exhibit distinct biological and clinical properties, influencing disease progression and treatment response.

Purpose of the Study:

• To provide an overview of the basal and luminal molecular subtypes of human bladder cancer.
• To discuss the biological and clinical characteristics of these subtypes.
• To explore their differential responses to various therapeutic interventions.

Main Methods:

• Genomic characterization of primary human bladder cancers.
• Analysis of histopathological features, genetic mutations (TP53, RB1, FGFR3), and gene expression signatures.
• Review of clinical data regarding stage, metastasis, prognosis, and treatment response.

Main Results:

• Basal cancers present at advanced stages, show squamous/neuroendocrine features, and harbor TP53/RB1 mutations; they include epithelial, mesenchymal, and neuroendocrine subsets.
• Luminal cancers often display papillary features, FGFR3 mutations, and variable stromal infiltration and genomic instability.
• Molecular subtypes demonstrate differential sensitivity to neoadjuvant chemotherapy, immune checkpoint blockade, and potentially radiation therapy.

Conclusions:

• Bladder cancer molecular subtypes are associated with different prognoses and responses to therapies.
• Further validation in prospective studies may lead to the integration of molecular subtyping into clinical management.
• Ongoing research aims to correlate subtypes with histopathological variants and upper tract urothelial cancer.