Prognostic value and clinicopathological characteristics of PD-L1 overexpression in non-Hodgkin lymphoma: a meta-analysis
Abstract Abstract Background: Programmed cell death ligand 1 (PD-L1) has already been detected in various carcinomas. In non-Hodgkin lymphoma (NHL), however, the prognostic value of PD-L1 overexpression remains unclear. Methods: A meta-analysis of 2,321 NHL patients from 12 studies was performed. HRs with 95% CIs were used to evaluate the correlation between PD-L1 overexpression and prognosis of NHL, and odds ratios (ORs) with 95% CIs were used to assess the association of PD-L1 overexpression with clinicopathological factors. Results: The result showed that no significant difference between PD-L1 positive and negative groups was detected in NHL (hazard ratio [HR]: 1.40, 95% confidence interval [CI]: 0.90-2.19; P =0.137). Nevertheless, the result indicated that PD-L1 overexpression was associated with poor prognosis in the subtype of diffuse large B cell lymphoma (DLBCL) (HR: 1.70, 95%CI: 1.05-2.74; P =0.031). We also performed subgroup analyses and meta-regression. The pooled odds ratios(ORs) showed that PD-L1 overexpression was associated with B symptoms, higher international prognostic index (IPI) score (3, 4 and 5 points) and Ann Arbor Stage III and IV. Conclusions: T he meta-analysis demonstrated that PD-L1 expression was not associated with prognosis of NHL but associated with prognosis of DLBCL. Key words: PD-L1, non-Hodgkin lymphoma, prognosis, meta-analysis