The efficacy of immune checkpoint inhibitors on low PD-L1 cervical cancer: A meta-analysis

Background and Aims: The effectiveness of immune checkpoint inhibitors (ICIs) in low programmed death ligand 1 (PD-L1) expression in cervical cancer (CC) patients remains unknown. We aimed to evaluate the efficacy of ICIs in low PD-L1 expression CC patients. Methods: The study is an individual patient data (IPD)-based meta-analysis. IPD were compiled through KMSubtraction and IPDfromKM methodologies from high-quality randomized clinical trials and single-arm studies which reported overall survival (OS) or progression-free survival (PFS) stratified by PD-L1 expression. Kaplan-Meier curves and Cox regression analysis were employed to evaluate the survival benefits of ICIs. Results: A total of eight studies and 1110 cases were included in the analysis. Within the low PD-L1 expression subgroup, ICI combination therapy, but not ICI monotherapy, demonstrated significant OS benefits over non-ICI treatment (hazard ratio [HR] = 0.61, 95% confidence interval [CI]: 0.36-1.04, p = 0.06). Concerning PFS, ICI monotherapy was associated with a negative effect compared to non-ICI treatment (HR = 4.59, 95% CI: 2.32-9.07, p < 0.001). Notably, both OS and PFS outcomes were unfavorable for ICI monotherapy compared to both non-ICI and ICI combination therapy in the combined positive score <1 subgroup (OS: HR = 2.60, 95% CI: 1.31-5.16, p = 0.008; PFS: HR = 7.59, 95% CI: 3.53-16.31, p < 0.001). Conclusion: In patients with CC and low PD-L1 expression, ICI monotherapy may not be considered as the optimal treatment strategy when compared to non-ICI treatment or ICI combination therapy.