Influence of luminal and basal subtype in prognosis of high-grade non muscle invasive urothelial carcinoma.

BACKGROUND

Recent studies have shown that the classification of high-grade urothelial carcinoma non-muscle invasive (HGBCNMI) based on molecular subtypes might be a valuable strategy to identify patients with a worse clinical prognosis.

OBJECTIVE

Determine the effect of the luminal and basal molecular subtype determined by immunistochemical on prognosis in patients with HGBC in Mexican population.

METHODS

Phenotypes were evaluated by immunohistochemical staining of luminal (GATA3, FOXA1) and basal (CK5/6, CK14) markers in paraffin-embedded tissue samples from 45 patients with a diagnosis of HGBCNMI treated at Instituto Nacional de Cancerología-México (INCan) between 2009 and 2019. The association with prognosis was evaluated using Kaplan-Meier curves and multivariable-adjusted Cox models.

RESULTS

HGBCNMI patients showed mean age of 58.77 years (SD: ±12.08 years). We identified expression of the luminal molecular subtype in 35 cases (77.78 %), and 10 cases (22.22 %) with "combined" expression of the molecular subtype (basal and luminal expression). The combined phenotype was statistically more frequent in metastatic cases (p-value = 0.028). In Kaplan-Meier curves, combined expression of luminal and basal molecular markers was associated with disease progression (p-value = 0.002, log-rank test). Cox regression models confirmed this association, which was not influenced by age (p-value = 0.007) or gender (p-value = 0.007). No association of phenotypes with overall survival (p-value = 0.860) or relapse (p-value = 0.5) was observed.

CONCLUSION

The combined expression of immunohistochemical markers of the luminal and basal subtype might be considered as predictor for disease progression in patients with HGBCNMI in Mexican population.