Evaluation of the EMT Markers SNAIL-SLUG and TWIST in Urothelial Carcinoma of the Bladder: A Retrospective Study.

Background: Bladder cancer, primarily urothelial carcinoma, is an important global health issue given its high recurrence and poor prognosis. Tumour invasion into the muscularis propria is a crucial prognostic indicator, distinguishing muscle-invasive bladder carcinoma (MIBC) from non-muscle-invasive carcinoma. Epithelial-mesenchymal transition (EMT) promotes tumour aggressiveness and metastasis and is marked by key transcription factors, such as SNAIL, SLUG and TWIST. This study investigates the association between the expression of EMT markers and histopathological features of bladder carcinoma.

Methods: This retrospective study included 36 newly diagnosed cases of urothelial carcinoma at a tertiary care centre. Immunohistochemistry was conducted to assess SNAIL-SLUG and TWIST expression. Scoring was performed on the basis of staining intensity and extent. Statistical analysis was conducted to evaluate the associations amongst EMT markers, tumour grade, muscle invasion and clinical stage.

Results: MIBC was present in 58.3% of cases, with 80.6% of cases having high-grade tumours. TWIST expression was significantly higher in MIBC (p = 0.0001) and high-grade tumours (p = 0.03), particularly in advanced T-stages, than in other tumours. SNAIL-SLUG expression was significantly associated with muscle invasion (p = 0.005) but not with tumour grade. EMT markers were not correlated with lymphovascular invasion.

Conclusions: Elevated TWIST expression is correlated with high-grade and muscle-invasive urothelial carcinoma, suggesting its prognostic importance.