614P - The role of PD-L1 expression in prognosis of osteosarcoma patients: A systematic review and meta-analysis

Background

Programmed Death Ligand-1 (PD-L1) is expressed in most type of cancer cells, including osteosarcoma. However, the role of PD-L1 expression in prognosis of osteosarcoma patients remains unclear. Thus, this study aims to investigate the association between PD-L1 expression and prognosis of Osteosarcoma patients.

Methods

Data was gathered from PubMed, PMC, and ScienceDirect databases on September 08, 2022, using keywords associated with PD-L1, Osteosarcoma in relation to the prognosis, which is measured by overall survival (OS), progression free survival (PFS), and event free survival (EFS). Publications included are associated with Osteosarcoma patients that are limited to English manuscripts within the last 10 years. Review articles, publications without full paper, and case report studies are excluded. The quality of each included study was assessed using the Newcastle Ottawa Scale (NOS), JBI Critical Appraisal for Quasi Experimental Studies, and Grading of recommendations, assessment, development, and evaluations (GRADE).

Results

A total of 7 studies consisting of 289 Osteosarcoma patients were included. All 6 studies have good quality based on NOS and one study categorized as include based on JBI. All 7 studies showed that high expression of PD-L1 correlates with poor prognosis of Osteosarcoma patients. Pooled analysis showed that high PD-L1 expression correlates with inferior OS (HR=2.03; 95%CI, 1.12-3.69; p=0.02) and PFS (HR= 1.18; 95%CI, 1.06-1.31; p=0.003). However, no significant association between PD-L1 expression and EFS (HR=1.05; 95%CI, 0.40-2.75; p=0.92). Based on GRADE, the result of this study is moderate in quality, as there is no inconsistency in results and publication biases are minimal.

Conclusions

Current studies demonstrated that high PD-L1 expression is associated with inferior OS and PFS, but not EFS in osteosarcoma patients, which warrants further prospective studies.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.