CT-based Fat Distribution-Informed Reinterpretation of BMI for Disease-Weighted Nutritional Risk Classification in...

Nutritional and metabolic status may influence prognosis in locally advanced gastric cancer (LAGC), yet current AJCC staging systems mainly reflect tumor burden and do not account for treatment-related nutritional changes during neoadjuvant chemotherapy (NACT).

A total of 643 consecutive patients with LAGC undergoing NACT followed by curative gastrectomy across five centers were retrospectively analyzed. Changes in the visceral-to-subcutaneous adipose ratio (ΔVSR) combined with baseline body mass index were used to establish a sex-specific Nutritional Risk Score Scale (NRSS). A disease-weighted classification integrating NRSS and ypN stage (NRSS-ypN, Grades I-IV) was further developed. Prognostic performance was compared with AJCC 8th ypTNM staging.

Increasing NRSS stage was associated with significantly worse overall survival (OS) and disease-free survival (DFS) (both log-rank P < 0.05). Multivariable analyses identified both NRSS and ypN stage as independent prognostic factors for OS and DFS. The integrated NRSS-ypN classification demonstrated clear prognostic stratification, with 3-year OS rates of 87.9%, 77.9%, 58.9%, and 29.5% across Grades I-IV (log-rank P < 0.0001). Grade IV patients showed particularly poor outcomes, with median OS and DFS of 16 months. Compared with AJCC 8th ypTNM staging, the NRSS-ypN classification showed improved prognostic discrimination for OS (C-index: 0.715 vs. 0.693, P < 0.05), with similar findings for DFS.

The NRSS-ypN classification integrates nutritional-metabolic status with tumor burden and may improve postoperative risk stratification in patients with locally advanced gastric cancer undergoing neoadjuvant therapy followed by curative (R0) resection.