Programmed Death Ligand 1 expression in Urothelial Carcinoma.A retrospective study in Duhok City-Iraq.

Background and objective: Programmed death ligand-1 protein expression has been linked to the severity of Urothelial cancer. The objectives of this study were to evaluate the expression of programmed death-ligand 1 and determine the association with tumour grade, stage, type (Papillary and non papillary), muscle invasion, age, and gender. Methods: This retrospective study was carried out from 2015 to 2022 on fifty-eight blocks belonging to patients with urothelial carcinoma, which were obtained from Duhok central lab and private laboratory. From each block, two sections were made; one of which was stained with Hematoxylin and Eosin for histological re-assessment and the other one for immunostaining for programmed death-ligand-1, which was calculated in tumour cells and inflammatory cells regardless of staining intensity and then the combined positive score was determined and considered positive when is more than 10. Result: This study included 58 cases of Urothelial carcinoma, Females represent 8 (13.79%) cases and males 50 (86.21%) cases, with a female-to-male ratio of 1/6.25. No statistically significant association existed between the histological subtypes and gender. Combined positive score was positive in (32.76%) of cases and negative (67.24%) cases. The association was significant with the stage of the tumor (p=0.03), muscle invasion (p=0.02) and highly significant with grade (p<0.001). Conclusion: patients with urothelial carcinoma who have higher tumour grade, advanced stage and those who with muscle invasion can benefit from immune check point inhibitors.