Predictive value of PD-L1 expression in response to immune checkpoint inhibitors for gastric cancer treatment: a systematic review and meta-analysis

ABSTRACT

Background

Which patients may benefit more from immune checkpoint inhibitors (ICIs) is still an important question. The present study aimed to investigate the role of the PD-L1 molecule in predicting the effectiveness of PD-1/PD-L1 inhibitors in gastric cancer patients.

Method

We searched PubMed, Scopus, Web of Science, and EMBASE databases as of 25 March 202225 March 2022.

Results

Ten articles were included. When we used the TPS method for PD-L1 expression, none of the patients in tumor proportion score (TPS)≥1% and TPS < 1% groups took advantage of ICI therapy in terms of OS and PFS. However, gastric cancer patients with combined-positive score (CPS)≥1, CPS ≥ 5, and CPS ≥ 10 tumors represented superior OS for ICIs over the control agents, while their counterparts (i.e. patients with CPS < 1, CPS < 5, and CPS < 10 tumors) did not. In the subgroup analysis when patients with CPS ≥ 1 were selected, Nivolumab improved the OS and PFS remarkably by 26% and 25% when compared with control agents, respectively. However, Pembrolizumab significantly increased the rate of disease progression by 47% relative to the control medications.

Conclusion

Among patients suffering from gastric cancer, considering PD-L1 CPS thresholds seems to be a more reliable predictive factor than TPS threshold for lower rate of mortality when PD-1/PD-L1 inhibitors are administered.

KEYWORDS:

• Gastric cancer
• immune checkpoint inhibitors
• PD-1
• PD-L1
• nivolumab
• pembrolizumab

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Author contribution statement

MN and DB designed the study. MN and FF performed the study selection and data extraction. MN conducted the analysis. MN and FF wrote the first draft of the manuscript. MN, FF, MRZ, and DB critically revised the manuscript. All authors reviewed the drafted manuscript for critical content. All authors approved the final version of the manuscript.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/14737140.2023.2238896.

Additional information

Funding

This paper received no funding.