Prognostic impact of myopenia and establishment of a nomogram for predicting survival following radical gastrectomy in patients with gastric cancer: A multicenter study.

INTRODUCTION

The prognostic value of myopenia following radical gastrectomy (RG) remains controversial.

MATERIALS AND

METHODS

Patients who underwent RG between January 2015 and December 2018 at two East Asian centers were retrospectively included. Myopenia was defined using sex-specific computed tomography-derived L3 skeletal muscle index, with cut-off values determined by X-tile software based on overall survival (OS). Cox regression models identified independent prognostic factors for OS and disease-free survival (DFS), whereas logistic regression identified risk factors for textbook outcomes (TO). A LASSO-based prognostic nomogram was developed, and its performance was evaluated using calibration curves, concordance index, time-dependent receiver operating characteristic, and decision curve analysis.

RESULTS

Overall, 943 patients were included (211 and 732 with and without myopenia, respectively). The myopenia group had a significantly lower TO rate (P = 0.003), and myopenia was confirmed as an independent risk factor for TO failure (P < 0.05). Moreover, the myopenia group had significantly lower 5-year OS (45.5 % vs. 69.3 %, P < 0.001) and DFS (45.0 % vs. 66.8 %, P < 0.001), with myopenia independently associated with poor prognosis. The nomogram developed in this study outperformed the tumor-node-metastasis staging system in predicting 3- and 5-year OS (both P < 0.05), demonstrating superior net clinical benefits across a threshold range of 10 %-80 %. Risk stratification effectively discriminated 5-year OS (94.3 % vs. 61.2 % vs. 24.2 %, P < 0.001). These results were reproduced in the validation cohort.

CONCLUSIONS

Myopenia independently predicts both short-term outcomes and long-term prognosis after RG. The myopenia-integrated nomogram showed strong predictive accuracy and clinical utility for individualized prognostic assessment of patients with gastric cancer.