Survival Impact of Programmed Cell Death Ligand‐1 Expression in Patients With Epithelial Ovarian Carcinoma

AIMS: To evaluate the proportion of expressed programmed cell death ligands-1 (PD-L1) in epithelial ovarian carcinoma patients, and the association with the clinicopathological, surgical outcomes, and oncologic outcomes. To compare PD-L1 protein expression with messenger ribonucleic acid (mRNA) expression. METHODS: The patients who had pathology of epithelial ovarian/tubal/peritoneal carcinoma were enrolled. The demographic data, tumor characteristics, surgical outcomes, treatment details, and treatment response were analyzed by descriptive statistics. Spearman's rank correlation coefficient test was used to determine the correlation between protein expression and mRNA expression. The survival curve was developed utilizing the Kaplan-Meier method, the log-rank test was used to compare survival distributions of patients according to the PD-L1 protein expression. RESULTS: A total of 100 patients, with high-grade serous carcinoma being the most common subtype (42%). Advanced-stage disease was present in 49% of patients, and 65% achieved optimal cytoreduction. PD-L1 protein expression was detected in 23% of tumors, while the median normalized mRNA expression was 0.015 (IQR 0.004-0.037). A moderate positive correlation was observed between PD-L1 protein and mRNA expression (Spearman's rho = 0.407, p < 0.001). The mean progression-free survival (PFS) and overall survival (OS) were 44.32 ± 4.04 months and 74.19 ± 3.33 months, respectively. CONCLUSIONS: PD-L1 protein expression was observed in a minority of patients and was not significantly associated with survival outcomes. There was a moderate correlation between PD-L1 protein and mRNA expressions.