Prediction of acute postoperative protein depletion risk in colon cancer using an in-context learning foundation model: a retrospective cohort study

Abstract

Background Acute postoperative protein depletion, including hypoalbuminaemia and hypoproteinaemia, frequently complicates colon cancer surgery and exacerbates adverse outcomes, yet early risk stratification remains challenging. Aims To develop a predictive model utilising a tabular foundation model for acute postoperative protein depletion in colon cancer patients, alongside an interpretable clinical web tool. Methods We retrospectively evaluated perioperative data from 812 colon cancer patients treated between 2020 and 2025. Following recursive feature elimination, eight traditional machine learning algorithms and the TabICLv2 tabular foundation model were trained. Discrimination, calibration, incremental risk stratification, and clinical utility were assessed using the area under the receiver operating characteristic curve (AUC), paired DeLong tests, calibration curves, Brier score, net reclassification improvement (NRI), integrated discrimination improvement (IDI), and decision curve analysis. SHapley Additive exPlanations (SHAP) were used to visualise feature contributions. Results TabICLv2 achieved the numerically highest validation AUC among the evaluated algorithms using nine selected predictors, with an AUC of 0.766 (95% CI: 0.699–0.832) and a Brier score of 0.158. DeLong tests showed no statistically significant AUC differences between TabICLv2 and XGBoost or Random Forest. NRI/IDI analyses indicated improved event reclassification across comparator models, with significant total NRI and IDI improvement over Random Forest, whereas incremental improvement over Logistic Regression and XGBoost was limited. Sensitivity analyses using albumin-only and total-protein-only endpoints showed broadly consistent discrimination. SHAP analysis revealed age, prealbumin (PA), and globulin (GLO) as the leading contributors to model predictions. A web-based calculator was subsequently deployed to facilitate clinical translation. Conclusion: TabICLv2 integrates demographic, nutritional, and immunological profiles to predict acute postoperative protein depletion with moderate discrimination. The accompanying application may provide adjunctive individualised risk assessment, but prospective multicentre validation is required before routine clinical implementation.