Prognostic value of nutritional risk index in esophageal cancer: A protocol for systematic review and meta-analysis

Background: The nutritional risk index (NRI) and its modified version, the geriatric nutritional risk index (GNRI), are simple formula-based tools reflecting nutritional and inflammatory status. While several studies have investigated their prognostic value in esophageal cancer (EC), results remain inconsistent, and no prior meta-analysis has directly compared NRI and GNRI in this context. Therefore, this meta-analysis was conducted to thoroughly assess the prognostic significance of NRI/GNRI in EC. Methods: Possible studies were obtained from Embase, Web of Science, PubMed, and Cochrane Library from their inception to November 2024. A relative ratio (RR) and a hazard ratio (HR) were extracted and pooled to analyze the correlation between the prognosis of EC and NRI/GNRI. Results: The final meta-analysis included 10 studies, with 2600 patients. As displayed in the pooled results, high NRI/GNRI predicted superior overall survival (HR = 1.78, 95% confidence interval [CI]: 1.53–2.07, P < .01) and distant metastasis-free survival/progression-free survival/recurrence-free survival (HR = 1.95, 95% CI: 1.52–2.51, P < .01). The association was presented between low NRI/GNRI and more lymph node metastasis (RR = 1.18, 95% CI: 1.01–1.38, P = .040), deeper tumor invasion (RR = 1.18, 95% CI: 1.01–1.38, P = .040), as well as advanced tumor stage (RR = 1.32, 95% CI: 1.10–1.58, P = .003). Conclusion: Both NRI and GNRI are independent prognostic factors in EC. Incorporating nutritional risk screening into routine clinical practice may support early intervention and improve treatment outcomes, particularly in surgical patients.