RT Journal Article SR Electronic T1 The prognostic value of programmed cell death ligand 1 expression in non-Hodgkin lymphoma: a meta-analysis JF Cancer Biology and Medicine JO Cancer Biol Med FD China Anti-Cancer Association SP 290 OP 298 DO 10.20892/j.issn.2095-3941.2018.0047 VO 15 IS 3 A1 Zhao, Shu A1 Zhang, Minghui A1 Zhang, Yu A1 Meng, Hongxue A1 Wang, Yan A1 Liu, Yupeng A1 Jing, Jing A1 Huang, Lan A1 Sun, Mengqi A1 Zhang, Yue A1 Zhang, Qingyuan YR 2018 UL http://www.cancerbiomed.org/content/15/3/290.abstract AB Objective: Although the prognostic value of programmed cell death-ligand 1 (PD-L1) expression in non-Hodgkin lymphoma (NHL) has been evaluated in many studies, the results remain controversial. To investigate the prognostic role of PD-L1 expression and the association between PD-L1 expression and clinicopathological features of NHL, we performed a meta-analysis.Methods: The PubMed, EMBASE, and Cochrane Library databases were searched up to November 30, 2017. The hazard ratio (HR), 95% confidence interval (CI), and odds ratios (OR) with 95% CIs were combined to evaluate the association of PD-L1 expression with overall survival (OS) and clinicopathological features. Review manager 5.3 and STATA 12.0 were used in this meta-analysis.Results: A total of 2,005 patients across nine studies were enrolled in our meta-analysis, and the pooled results showed that high PD-L1 expression was associated with a poor prognosis (HR=2.04, 95% CI: 1.18–3.54, P=0.01). In the subgroup analysis according to histology types, pooled results demonstrated that an increased PD-L1 expression was an unfavorable prognostic factor for diffuse large B-cell lymphoma (HR=1.92, 95% CI: 1.06–3.48, P=0.03) but not for natural killer/T-cell lymphoma (HR=2.41, 95% CI: 0.47–12.22, P=0.29). Pooled ORs indicated that PD-L1 expression was higher in NHL with international prognostic indices of ≥3. However, PD-L1 expression had no correlation with gender, age, disease stage, lactate dehydrogenase level, B symptoms, and germinal center B-cell-like lymphoma.Conclusions: High PD-L1 expression was a poor prognostic biomarker in patients with NHL. Because of our limited sample size, high-quality studies with larger sample sizes are needed to validate our results.