High serum PD-L1 level is a poor prognostic biomarker in surgically treated esophageal cancer.

BACKGROUND: Programmed death ligand 1 (PD-L1) inhibitor has been approved as one of the standard therapies for various cancers. Some reports have shown that serum PD-L1 level is associated with advanced tumor stages and poor prognosis; however, corresponding pathological information in esophageal cancer patients is lacking. Therefore, we evaluated the clinicopathological and prognostic impact of serum PD-L1 levels in surgically treated esophageal cancer. METHODS: A total of 150 patients who underwent radical resection for esophageal cancer were included in the study. Preoperative serum PD-L1 levels were analyzed using the enzyme-linked immunosorbent assay kit. A cutoff level of 65.6 pg/mL was used to divide the patients into two groups, and univariate and multivariate analyses were conducted to compare the clinicopathological characteristics and prognoses between these two groups. RESULTS: Although significant associations between serum PD-L1 levels and clinicopathological variables were observed, serum PD-L1 level was significantly associated with high neutrophil counts, high CRP levels, low albumin levels, and high squamous cell carcinoma antigen levels. Furthermore, serum PD-L1 level was associated with poor overall survival independent to TNM factors. CONCLUSIONS: High preoperative level of serum PD-L1 is a prognostic factor for poor overall survival in patients with surgically treated esophageal cancer.