Abstract 69P
Background
Biliary tract cancer (BTC) is associated with poor prognosis because of its aggressive and heterogeneous nature. Programmed death ligand 1 (PD-L1) has been considered as a novel biomarker for prognosis and response of immune checkpoint inhibitors (CPIs) in various tumors. However, there are limited data reporting on the role of PD-L1 in advanced BTC patients.
Methods
We analyzed 186 patients with advanced BTC who received palliative gemcitabine and platinum between May 2010 and December 2019. All patients were evaluated for PD-L1 expression by combined positive score (CPS) positivity.
Results
In all 186 patients, the median age was 62 years (range 38-82), and the primary tumor location was intrahepatic cholangiocarcinoma (IH-CCC) in 72 patients (38.7%), extrahepatic (EH)-CCC in 90 (48.4%), and gallbladder (GB) cancer in 24 (12.9%). There were 158 (84.9%) patients with recurrent disease and 28 (15.1%) with metastatic disease. Among the 186 patients, 53 (28.5%) had PD-L1 CPS positivity, and 133 were CPS negative. The median overall survival (OS) of patients with PD-L1 CPS positivity or negativity was 12.1 and 15.4 months, respectively. The median progression-free survival (PFS) in patients with PD-L1 positivity or negativity was 5.7 and 7.1 months, respectively. The OS and PFS were not statistically different between groups. In sub-group analysis, EH-CCC patients with PD-L1 negativity had more favorable OS (17.2 vs. 11.6 months, p=0.002) and PFS (7.8 vs. 5.4 months, p=0.005) than those that were PD-L1 negative. However, this finding was not reproduced in patients with IH-CCC or GB cancer.
Conclusions
This study demonstrated that PD-L1 expression might be a novel prognostic biomarker in patients with EH-CCC but not for patients with IH-CCC or GB cancer.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.