Dai C, et al. – This meta–analysis aimed at determining the prognostic impact of PD–L1 expression in digestive system cancers. An association between the expression of PD–L1 and worse overall survival (OS) in digestive system cancers was highlighted. This link was more significant in gastric cancer and pancreatic cancer. This study emphasised PD–L1 as a new parameter for predicting poor prognosis and a promising target for anticancer therapy in digestive system cancers.

Methods

• The PubMed, Embase, and the Chinese National Knowledge Infrastructure were searched for publications concerning PD-L1 expression in digestive system cancers.
• Experts tested correlations of PD-L1 expression level with overall survival (OS), disease-free survival (DFS), and recurrence-free survival (RFS).

Results

• This work incorporated 32 studies with 7,308 patients.
• An association of results PD-L1 expression with poorer OS (hazard ratio [HR] =1.44, 95% confidence interval [CI] =1.18–1.76, P<0.001), was noted.
• However, it was not seen for DFS (HR =0.91, 95% CI =0.61–1.37, P=0.657) or RFS (HR =1.27, 95% CI =0.75–2.14, P=0.368).
• Significant associations between PD-L1 expression and OS were found in Asians (HR =1.50, 95% CI =1.19–1.89, P=0.001), gastric cancer (HR =1.43, 95% CI =1.05–1.94, P=0.021), and pancreatic carcinoma (HR =2.64, 95% CI =1.78–3.93, P<0.001), in the subgroup analysis.