PD-L1 expression in Advanced Urothelial Carcinomas in two reference institutions in Colombia.

Abstract

Abstract OBJECTIVE: To determine and characterize the expression level of PD-L1 in a group of local patients analyzed by: age, gender, functional status, and other potential prognostic factors. METHODS: Descriptive, retrospective, observational cohort study. PD-L1 expression levels were measured by a validated immunohistochemistry method using 22C3 antibody, with the Combined Positive Score methodology. Demographics and other variables were collected from medical records. RESULTS: 59 tissue samples were collected for biomarker testing. 22.0% (n=13) of the Urothelial cancer samples had a PD-L1 CPS score ≥10 and 54.2% (n=32) had a PD-L1 ≥1; for the score of ≥5 28.8% of samples fell in that category. Most cases were bladder cancers, in histopathological diagnosis most of cases were either High grade Urothelial Carcinoma or High grade Papillary Urothelial Carcinoma (64%). CONCLUSION: The PD-L1 expression prevalence in a cohort of urothelial Colombian population has been studied. PD-L1 CPS score ≥10 prevalence was less for UC when compared with previous reports for these tumors in clinical trials. Further studies focused on evaluating PD-L1 expression in Colombian patient influenced by own environment and genetics are needed to define characteristics that could support decision-making for tumor treatment.