Prognostic implications of PD-L1 expression in patients with angiosarcoma

Aim: There are limited data on the feasibility of programmed death ligand-1 (PD-L1) expression as a prognostic biomarker in metastatic angiosarcoma. Patients & methods: We retrospectively collected and analyzed the data on PD-L1 expression in 70 angiosarcoma patients who were diagnosed at our center between 2005 and 2019. Results: Thirteen (19%) patients had PD-L1 expression. Metastatic angiosarcoma patients who were PD-L1-negative (n = 24) showed longer median progression-free survival (4.9 vs 1.6 months; p = 0.04) and median overall survival (OS; 10.9 vs 5.4 months; p = 0.01) than those who were PD-L1-positive (n = 4). PD-L1 status proved to be a significant factor for OS. Conclusion: Metastatic angiosarcoma patients with PD-L1 expression showed shorter survival. PD-L1 status is an independent prognostic factor for OS in metastatic angiosarcoma patients. Lay abstract Angiosarcoma, a rare subtype of sarcoma, is highly aggressive and has poor prognosis. The majority of patients are diagnosed at advanced and metastatic stages, and treatment options for these subsets of patients are limited to cytotoxic chemotherapy. Validation of prognostic markers including PD-L1 expression remain to be fully carried out in metastatic angiosarcoma. In our study, we assessed the PD-L1 expression in metastatic angiosarcoma and its role as a prognostic biomarker.