Comparison of clinical outcomes of conservative treatment and surgery for esophageal cancer patients who achieve a clinical complete response following neoadjuvant chemoradiotherapy: a systematic review and meta-analysis

BACKGROUND: Although the clinical complete response (cCR) for esophageal cancer patients after neoadjuvant chemoradiotherapy (nCRT) may be related to the good survival prognosis, the choice of conservative and surgical treatments is still controversial. This study sought to compare the clinical outcomes of these two treatments. METHODS: A systematic search was conducted according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of the PubMed, Embase, and Cochrane Library databases to retrieve articles published between January 1, 2010 and March 31, 2022 on the efficacy of conservative treatment or surgery in esophageal cancer patients who had achieved a cCR after nCRT The predominant endpoints were overall survival (OS), disease-free-survival (DFS), local recurrence, and distant metastasis. Odds ratios (ORs) were generated for the dichotomous variants by meta-analysis. The software implemented was Stata 16.0 MP. This research was prospectively registered under PROSPERO (registration number: CRD42022332143). RESULTS: Ultimately, eight retrospective cohort studies and one randomized controlled trial, comprising 749 patients (nCRT group: 333 and nCRT + surgery group: 416), were included in the meta-analysis after two researchers independently assessed the risk of bias for all included studies. The 2-year OS [OR =1.239, 95% confidence interval (CI): 0.891 to 1.723] and 5-year OS (OR =1.369, 95% CI: 0.963 to 1.947) were comparable between the nCRT group and nCRT plus surgery (nCRT + S) group. Patients in the nCRT + S group had significantly longer DFS (2 and 5 years, OR ranging from 0.303 to 0.357) and lower local recurrence rate (OR =0.179, 95% CI: 0.104 to 0.291) than those in the nCRT group. However, the distant metastasis rate was similar between the nCRT group and the nCRT + S group. CONCLUSIONS: Esophageal cancer patients who achieved a cCR after nCRT and received an esophagectomy had better DFS and lower local recurrence than those who received conservative treatment; however, this DFS advantage did not lead to a significant difference in OS. Salvage surgery may be a feasible option for resectable patients who have local recurrence after achieving cCR.