Continuous skeletal muscle gauge enhances preoperative risk stratification in intrahepatic cholangiocarcinoma: A
Liquan Shen1, Dihang Wu1, Jianlin Lai2
1Shengli Clinical Medical College of Fujian Medical University, Fuzhou, China; Department of Hepatobiliary Pancreatic Surgery, Fuzhou University Affiliated Provincial Hospital, Fujian Provincial Hospital, Fuzhou, China.
Background:
Sarcopenia-related skeletal muscle abnormalities have been established as prognostic indicators in intrahepatic cholangiocarcinoma (ICC); however, the most appropriate CT-derived skeletal muscle parameter for its assessment remains uncertain. The skeletal muscle gauge (SMG), a composite measure combining both muscle quantity and quality (SMG = SMI × SMD), has yet to be systematically evaluated in ICC.
Methods:
In this multicenter retrospective study, 760 patients with ICC who underwent curative resection between 2015 and 2021 at seven hepatobiliary centers were analyzed. Preoperative computed tomography (CT) scans were used to quantify skeletal muscle index (SMI), skeletal muscle density (SMD), and SMG. Independent prognostic factors were determined via Cox proportional hazards regression. Five predictive models were generated and compared, after which the best-performing model was used to develop nomograms. Model performance was evaluated using time-dependent ROC curves, calibration plots, and decision curve analysis (DCA).
Results:
Continuous SMG was independently associated with both overall survival (OS) (P < 0.001) and recurrence-free survival (RFS) (P < 0.001). The continuous SMG-based model showed higher performance (OS: C-index 0.756, AUC 0.917; RFS: C-index 0.728, AUC 0.935) than cut-off-based and alternative models. The resulting nomograms displayed good calibration and discrimination and suggested potential utility as prognostic assessment tools in both the training and validation cohorts.
Conclusions:
Continuous SMG serves as an independent prognostic indicator for ICC. The SMG-based nomogram suggests potential clinical utility as an adjunct for individualized prognostic assessment and risk evaluation.