Programmed death ligand-1 expression levels, clinicopathologic features, and survival in surgically resected sarcomatoid lung carcinoma

Aim To determine the programmed death ligand-1 (PD-L1) expression rates in sarcomatoid lung carcinomas and to compare clinicopathologic features and survival rates of PD-L1-positive and negative patients. Methods PD-L1 expression was evaluated in 65 surgically resected sarcomatoid carcinomas. The clinicopathologic features of cases with PD-L1-positive and negative tumors were compared. Kaplan-Meier survival analysis was performed. Multiple Cox proportional hazard regression analysis was performed to determine independent predictors of overall survival. Results PD-L1 antibody positivity was found in 72.3% of surgically resected sarcomatoid lung carcinomas. Regarding histopathologic subtypes, PD-L1 expression was positive in 80.4% of pleomorphic carcinomas, 62.5% of spindle- and/or giant-cell carcinomas, and 16.7% of carcinosarcomas. Pleural invasion was observed in 68.1% of PD-L1-positive cases and 27.8% of PD-L1-negative cases (P = 0.008). No difference in survival was found between PD-L1-positive and -negative tumors. The only factor significantly associated with poor survival was the pathological stage of the tumor. Conclusions This study reveals a high rate of PD-L1 positivity in a large number of sarcomatoid lung carcinoma cases with pleomorphic carcinoma, spindle- and/or giant-cell carcinoma, and carcinosarcoma subtypes. The only significantly different clinicopathologic feature in PD-L1-positive cases is pleural invasion. PD-L1 positivity is not a significant predictor of survival in sarcomatoid lung carcinomas.