Prognostic value of PD-L1 overexpression for pancreatic cancer: evidence from a meta-analysis

• Published in: OncoTargets and therapy Vol. 10; pp. 5005 - 5012
• Main Authors: Zhuan-Sun, Yongxun, Huang, Fengting, Feng, Min, Zhao, Xinbao, Chen, Wenying, Zhu, Zhe, Zhang, Shineng
• Format: Journal Article
• Language: English
• Published: New Zealand Dove Medical Press Limited 01-01-2017; Taylor & Francis Ltd; Dove Medical Press
• Subjects: Cancer therapies; Care and treatment; Development and progression; Diagnosis; Health aspects; Immune checkpoint; Immune response; Ligands; Lung cancer; Lymphocytes; Medical prognosis; Meta-analysis; Metastasis; Original Research; Pancreatic cancer; PD-L1 protein; Prognosis; Radiation therapy; Studies; Survival analysis; Tumors; China; clinicopathologic characteristics; meta-analysis; pancreatic cancer; programmed death-ligand 1; prognosis; immune checkpoint
• ISSN: 1178-6930; 1178-6930
• DOI: 10.2147/ott.s146383

Programmed death-ligand 1 (PD-L1) is an immune checkpoint that is often activated in cancer and plays a pivotal role in the initiation and progression of cancer. However, the clinicopathologic significance and prognostic value of PD-L1 in pancreatic cancer (PC) remains controversial. In this study, we conducted a meta-analysis to retrospectively evaluate the relationship between PD-L1 and PC. PubMed and other databases were searched for the clinical studies published up to March 21, 2017, to be included in the meta-analysis. Hazard ratios and their 95% CIs were calculated. Risk ratios (RRs) were extracted to assess the correlations between the clinicopathologic parameters and PD-L1 expression. Ten studies including 1,058 patients were included in the meta-analysis. The pooled results indicated that positive PD-L1 expression was correlated with a poor overall survival outcome in PC patients (hazard ratio =1.76, 95% CI: 1.43-2.17,
<0.00001). Interestingly, high PD-L1 expression was correlated with poor pathologic differentiation (RR =1.57, 95% CI: 1.25-1.98,
=0.0001) and neural invasion (RR =1.30, 95% CI: 1.03-1.64,
=0.03). However, there were no significant correlations between PD-L1 expression and other clinicopathologic characteristics. In summary, our meta-analysis implied that PD-L1 could serve as a negative predictor for the overall survival of PC patients, and high expression of PD-L1 was correlated with poor differentiation and neural invasion, indicating that anti-PD-L1 treatments should be evaluated in PC patients, especially in those who exhibit these two characteristics.