The immune microenvironment of bladder cancer

The analysis of tumor-infiltrating lymphocytes (TILs) is recognized as a prognostic factor in several cancers. The objective of our work was to study by immunohistochemical method the phenotype, density and distribution of TILs in urothelial carcinomas of the bladder and to analyze their prognostic impact. This was a retrospective descriptive study involving 35 samples of urothelial carcinomas of the bladder infiltrating at least the chorion, collected at the pathological anatomy department of the Marsa internal security forces hospital between 2010 and 2021. TILs were detected using anti-differentiation cluster antibodies CD3, CD8 and CD25, intra- and peri-tumoral. The cell count was carried out on 5 consecutive fields at high magnification. An Immunoscore as well as the CD25/CD3 ratio were calculated in each case. Densities and ratios were categorized into low and high based on the median. The correlation between: clinicopathological parameters and the density of TILs, Immunoscore, CD25/CD3 ratio was studied.