PD-1/PD-L1 based immunochemotherapy vs chemotherapy alone for advanced
esophageal squamous cell carcinoma: a meta-analysis focus on PD-L1
expression level
Abstract
Objective: Immunochemotherapy has become a new treatment for advanced
esophageal squamous cell carcinoma (ESCC). We aimed to study the
clinical efficacy and toxicity of immunochemotherapy based on PD-1/PD-L1
compared with chemotherapy alone in the treatment of advanced ESCC,
focusing on analyzing the influence of PD-L1 expression level. Methods:
Randomized controlled trials comparing PD-1/PD-L1 based
immunochemotherapy wirh chemotherapy alone for advanced ESCC were
included. We extracted efficacy data [objective response rate (ORR),
disease control rate (DCR), overall survival (OS) rate, progression-free
survival (PFS) rate] and safety data (treatment-related adverse
events, treatment-related mortality) and performed meta-analyses.
Results: 5 articles were included. Compared with chemotherapy alone, the
ORR and DCR of immunochemotherapy increased by 2.05 times and 1.54
times, respectively. Overall, patients receiving immunochemotherapy had
a significant long-term survival advantage [OS: hazard ratio
(HR)=0.68, 95% hazard ratio (CI) 0.61-0.75; PFS: HR=0.62, 95%CI 0.55,
0.70, respectively]. Even with PD-L1 tumor proportion score
<1%, immunochemotherapy also showed a significant survival
advantage [OS: HR=0.65, 95%CI 0.46-0.93; PFS: HR=0.56, 95%CI
0.46-0.69, respectively]. However, for PD-L1 combined positive score
(CPS)<1, the survival advantage of immunochemotherapy was not
significant [OS: HR=0.89, 95%CI 0.42-1.90; PFS: HR=0.71, 95%CI
0.47-1.08, respectively]. The toxicity of immunochemotherapy was
higher than that of chemotherapy alone, but there was no statistical
difference in treatment-related mortality (odds ratio=1.11, 95%CI
0.67-1.83). Conclusions: In this study, PD-1/PD-L1 based
immunochemotherapy significantly could improve survival outcomes in
patients with advanced ESCC. For patients with CPS<1, the
survival advantage of immunochemotherapy was not significant. The
toxicity of immunochemotherapy was acceptable.