Prognostic role of PD-L1 expression in patients with salivary gland carcinoma: A systematic review and meta-analysis

Abstract

Background Although programmed cell death-ligand 1 (PD-L1) has been recognized as a potential marker in several cancers, the relationship between PD-L1 expression and survival in patients with salivary gland carcinoma (SGC) has remained unclear. We aimed to evaluate the association of PD-L1 expression with clinicopathological features and prognosis in SGC patients. Methods The databases Ovid Medline, PubMed, Scopus, and EMBASE were searched for relevant studies that detected PD-L1 expression in SGC. The meta-analysis was performed according to the preferred reporting items for systematic reviews and meta-analyses (PRISMA), and the reporting recommendations for tumor marker prognostic studies (REMARK) was used to assess the quality of research eligible for this meta-analysis. Included studies were assessed using the Quality in Prognosis Studies (QUIPS) tool. Odds ratios (ORs) with 95% confidence interval (CI) were calculated to estimate the correlation between PD-L1 expression and clinicopathological features. Hazard ratios (HRs) with 95% CI were applied to assess the association between PD-L1 expression and survival outcomes of patients. Results A total of ten studies (including 952 patients with SGC) were evaluated. The meta-analysis showed that positive PD-L1 expression in SGC was significantly associated with male patients, older age, Tumor stage, lymph node metastasis, high pathological grade, and non-adenoid cystic carcinoma subtype. The pooled data demonstrated that high PD-L1 expression was associated with poor overall survival and disease-free survival. There was no significant correlation between PD-L1 expression and progression-free survival or disease-specific survival of SGC patients. Conclusion According to the meta-analysis, positive PD-L1 expression may play an important role as an effective marker of poor prognosis in patients with SGC. However, large-scale, prospective investigations are still needed to confirm the findings. The assessment of PD-L1 expression may aid in the personalized management of SGC.

Revisiting the Role of PD-L1 Overexpression in Prognosis and Clinicopathological Features in Patients with Oral Squamous Cell Carcinoma

“…In OSCC, Levounel et al [27] found that overexpression of PD-L1 had a worse survival measured as DSS and DFS. The other meta-analysis, done by Wu L et al [32], suggest that PD-L1 may play an important role as an effective marker of poor prognosis in salivary gland carcinomas. On the contrary, X.…”

Exploring Immunological Effects and Novel Immune Adjuvants in Immunotherapy for Salivary Gland Cancers

“…Further studies are required to standardize the method to detect PD-L1 expression and to apply PD-L1 as an accurate prognostic marker in SGCs. Wu et al conducted a meta-analysis regarding the association between PD-L1 positivity and prognosis in SGCs [ 74 ]. This study revealed that high PD-L1 expression is associated with poor OS and DFS, indicating the importance of PD-L1 in SGC progression.…”

Molecular Factors in Carcinoma Ex Pleomorphic Adenoma: Systematic Review and Meta‐Analysis

“…1,10,11,[20][21][22] Although multiple reviews have been published on salivary gland tumours, 7,10,13,18,23 including CXPA, 10,13,23,24 it has been a decade since the last dedicated systematic review pertaining to molecular genetics in CXPA was published. 1 Existing reviews on important biomarkers, such as PD-L1, 25 PLAG1, 12 and other targeted therapies, 18,19 do not address CXPA as a distinct entity. Aside from HER2, 22 the exact role of molecular markers in the diagnosis and treatment of CXPA is yet to be precisely defined.…”