Impact of negative lymph node removal on survival in esophageal cancer: a systematic review and meta-analysis

Recent studies have reported that a high number of negative lymph nodes (NLNs) removed can be associated with improved survival in esophageal cancer( EC) after surgery; however, the effect size of a high number of removed NLNs on survival rates has been reported to vary, which may be due to the small sample size of early studies. This meta-analysis aimed to evaluate the effect of the high number of NLNs removed on the survival rate of patients with EC after surgery.

We searched PubMed, Embase, Scopus, Web of Science, and Google Scholar databases with relevant Mesh terms to find studies that investigated the effect of the number of NLNs resected on the survival of EC patients after surgery until February 17, 2025. This systematic review was conducted based on the PRISMA 2020 checklist. Cochran's I² was used to evaluate heterogeneity between studies. Publication bias was evaluated using the Egger test. Heterogeneity between studies was controlled by meta-regression. Finally, eight studies involving 5,521 EC patients were included.

The survival rate in patients whose number of removed NLNs ≥ 19 was significantly better than those with removed NLNs < 19 (HR: 0.88, 95% CI: 0.81, 0.95, I² = 84.4). Subgroup analysis of 8 studies showed that the protective effect of the high number of removed NLNs) ≥ 19 (was greater in adenocarcinoma patients than in SCC (Pooled HR: 0.63 vs. 0.88).

The high number of NLNs removed (≥ 19) during surgery was associated with improved survival after surgery, especially in patients with adenocarcinoma. Removing ≥ 19 NLNs significantly improves survival in EC patients, particularly those with adenocarcinoma. This threshold should be incorporated into surgical guidelines.