Abstract
Background: Several reports showed that high soluble programmed death-ligand 1(sPD-L1) level was a risk factor for poor prognosis in various tumors. To date, the clinicopathologic and prognostic impact of sPD-L1 level in patients with hepato-biliary-pancreatic cancer have not been determined. Methods: A total of 119 patients (66 patients with hepatocellular carcinoma, 23 patients with cholangiocarcinoma, 30 patients with pancreatic cancer) who were treated at the Toho University Omori Hospital (Tokyo, Japan) from 2008 to 2016 were retrospectively analyzed. sPD-L1 levels were measured using an enzyme-linked immunosorbent assay for PD-L1 to evaluate clinicopathologic and prognostic impact. Results: sPD-L1 levels were significantly higher in low-albumin group than normal albumin group. According to stages in hepatocellular carcinoma and cholangiocarcinoma, there were no significant differences in sPD-L1 levels, which gradually increased according to stage in pancreatic cancer. Using a cut-off value of 81.6pg/ml for sPD-L1level, the high sPD-L1 group showed significantly worse prognosis than the low sPD-L1 group in patients with pancreatic cancer. Multivariate analysis identified sPD-L1 level ≥ 81.6 mg/dl ( p = 0.047) as an independent predictor of poor overall survival in patients with pancreatic cancer.Conclusion: Using a cut-off value of 81.6pg/ml for sPD-L1level, high sPD-L1 levels were independently associated with poor prognosis in patients with pancreatic cancer. However, this association in hepatocellular carcinoma or cholangiocarcinoma was not clear.