The aim of this study was to develop and validate a practical prognostic nomogram integrating preoperative inflammatory and nutritional indicators to assess the survival outcomes of patients with early-onset rectal cancer (EORC).

A total of 326 patients with EORC who underwent radical resection were retrospectively included and randomly divided into a training cohort and a validation cohort. Preoperative inflammatory and nutritional indicators were calculated based on routine laboratory test data, and an inflammatory-nutritional risk score (RS) was constructed. The RS was obtained through a weighted linear combination of the LASSO-sellected neutrophil/lymphocyte ratio (NLR), systemic inflammatory response index (SIRI), systemic immune-inflammatory index (SII), platelet/lymphocyte ratio (PLR), nutritional immune-inflammatory index (ALI), and prognostic nutritional index (PNI). Multivariate survival analysis was used to screen independent prognostic factors, and a nomogram for predicting overall survival (OS) was established. The performance of the model was evaluated using discrimination, calibration, and clinical decision curve analysis (DCA).

Multivariate analysis showed that age, TNM stage, serum albumin level, and the inflammatory-nutritional risk score were independent predictors of OS. The constructed nomogram demonstrated good discrimination and calibration for 1-year, 3-year, and 5-year OS in both the training cohort and validation cohort.

This study developed and validated a simple and clinically practical inflammatory-nutritional nomogram that can integrate routine preoperative indicators, providing an auxiliary decision-making basis for postoperative risk stratification and individualized follow-up management of patients with EORC.