Efficacy and safety of neoadjuvant immunotherapy combined with chemotherapy for resectable esophageal cancer: a systematic review and meta-analysis.

Background: Esophageal cancer is often overlooked in its early stages, with approximately 70% of patients being diagnosed at a locally advanced or late stage. Surgical treatment and chemotherapy are the mainstays of esophageal cancer management. However, for locally advanced esophageal cancer, both surgery alone and chemotherapy alone have high rates of recurrence and metastasis. The objective of the research was to investigate the security and therapeutic efficacy of neoadjuvant immunochemotherapy (NICT) in the treatment of resectable, locally advanced esophageal squamous cell carcinoma (ESCC). Methods: We conducted a literature search on PubMed, Embase, Cochrane, Web of Science, China National Knowledge Infrastructure (CNKI), China Science and Technology Journal Database (VIP), China Biomedical Literature Database, and Wanfang for studies published before November 2023 that investigated on the clinical effectiveness and safety of neoadjuvant immunotherapy in resectable ESCC. The Newcastle-Ottawa Quality Assessment Scale (NOS) was used for assessment, and Stata 17.0 was utilized for meta-analysis and sensitivity analysis. Results: A total of 13 retrospective cohort studies involving 1,276 patients were included in this analysis. The NICT group showed a higher pathological complete response (pCR) rate [odds ratio (OR) =5.72; 95% confidence interval (CI), 3.40-9.63]. The major pathologic response (MPR) rate, objective response rate (ORR), R0 resection rate, and 1-year overall survival (OS) in the NICT group were better than those in the neoadjuvant chemotherapy (NCT) group (OR =3.70, 95% CI: 2.32-5.91; OR =2.22, 95% CI: 1.44-3.40; OR =2.63, 95% CI: 1.58-4.38; OR =10.08, 95% CI: 4.32-23.56). However, the NICT group also showed a drawback in terms of adverse reactions and postoperative complications. The incidence of rash (OR =4.69, 95% CI: 1.42-15.49) and pleural effusion (OR =3.99, 95% CI: 1.75-9.07) was significantly higher in the NCT group compared to the NICT group. The subgroup analysis indicates that the use of camrelizumab is associated with an increased incidence of rash. Additionally, performing a left thoracic esophagectomy and esophagogastric thoracic procedure significantly improved the R0 resection rate. Conclusions: Neoadjuvant immunotherapy has shown promising efficacy in patients with locally advanced ESCC; however, it is linked to a higher occurrence of adverse events. Therefore, its use in clinical practice should be carefully considered.