A modified nutritional inflammation score to predict prognosis in patients with unresectable esophageal squamous cell carcinoma receiving first-line immunotherapy

Abstract Objectives While biomarkers related to nutrition and inflammation have been widely recognized as reliable prognostic indicators for esophageal squamous cell carcinoma (ESCC), their combined predictive efficacy in unresectable ESCC patients undergoing first-line immunotherapy has not been fully verified. Moreover, there is still a shortage of simple and specialized combined prognostic scoring tools for these patients. This study aims to construct a novel modified nutrition-inflammation index to predict the clinical prognosis of patients with unresectable ESCC treated with first-line immunotherapy. Methods A total of 330 individuals were included in this retrospective analysis. The random forest algorithm was applied to assess the prognostic significance of baseline nutritional and inflammatory markers, facilitating the development of a comprehensive nutritional-inflammation score (NIS). Differences in overall survival (OS) across risk groups were evaluated using Kaplan-Meier survival analysis with log-rank tests. Subsequently, the prognostic performance of the NIS across various clinical subgroups was further examined. Cox hazard model was utilized to verify the predictive impact of the NIS on OS, followed by the construction of a nomogram based on significant independent predictors to systematically evaluate its predictive ability. Results Patients with a high NIS demonstrated significantly prolonged OS in both the overall cohort and all predefined subgroups. Multivariate analysis identified Eastern Cooperative Oncology Group Performance Status (ECOG PS) score, distant organ metastasis, immunotherapy modality, and NIS as independent prognostic factors (all p<0.001). The nomogram exhibited robust predictive performance, yielding a C-index of 0.734 (95 % CI: 0.688–0.780). Conclusions The novel NIS serves as an effective prognostic indicator for patients with unresectable ESCC undergoing first-line immunotherapy.