Evaluation of survival after induction immunochemotherapy followed by concurrent chemoradiotherapy in unresectable esophageal cancer: A systematic review, meta-analysis, and network meta-analysis.

Abstract

e16137 Background: Concurrent chemoradiotherapy (CCRT) remains the standard treatment for nonsurgical esophageal cancer (EC); however, the prognosis remains poor. The clinical benefits of the combination of immunotherapy with CCRT for unresectable EC remain controversial. Therefore, we performed a systematic review and meta-analysis of published studies to evaluate the potential benefits of different combined immunotherapeutic strategies based on CCRT for patients with unresectable EC. Methods: We employed single-arm, pairwise and network meta-analysis methods to analyze the overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and safety of several combined treatment strategies based on CCRT. Results: 28 single-arm trials and 34 controlled trials involving a total of 8104 participants were included. Single-arm meta-analysis have demonstrated that CCRT plus consolidation immunotherapy (CCRT-IO) has the highest 1-year OS rate of 85.7% (95%CI 73.6-97.8, I² = 86.4%) and 2-year OS rate of 67.3% (95%CI 58.8-75.9, I² = 35.2%). However, due to the limited number of available studies, pairwise and network meta-analyses could not be performed. The pairwise meta-analysis showed that, compared with CCRT alone, induction immunochemotherapy plus CCRT (ICT-CCRT) had significantly improved OS (0.49, 95%CI 0.32-0.74, I² = 0.0%) and PFS (HR 0.54, 95%CI 0.37-0.79, I² = 0.0%). The network meta-analysis showed that ICT-CCRT yielded the best OS and PFS results, with substantial benefits over CCRT alone (HR 0.73, 95% CI 0.58-0.92; HR 0.77, 95% CI 0.60-0.98). Conclusions: The study revealed that ICT-CCRT significantly improves patient survival compared to CCRT. CCRT-IO has also been associated with a survival benefit, achieving the highest 1- and 2-year OS rates in single-arm studies. Due to the limited number of available studies, a statistical comparison of survival benefits between CCRT-IO and ICT-CCRT was not feasible.