Gastric cancer, Progression-free survival, Nomogram, Risk stratification, Vascular invasion and neural invasion, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

Abstract Objective To identify high-risk gastric carcinoma patients with concurrent vascular and neural invasion (“double invasion”) who are at heightened risk of progression-free survival (PFS) decline, enabling personalized clinical management. Methods In this multi-center retrospective study, 559 patients with double invasion who underwent curative gastrectomy between May 2002 and December 2020 were analyzed. Prognostic factors for PFS were identified using Lasso-Cox regression. Model validation included internal bootstrapping, calibration plots, and comparison against the American Joint Committee on Cancer(AJCC) 8th edition TNM staging system via Harrell’s C-index, decision curve analysis (DCA), and time-dependent receiver operating characteristic (ROC) curves. Results The nomogram integrated gender, positive lymph node count, surgical gastrectomy method, PTEN/FHIT expression levels, and maximum tumor diameter. It demonstrated superior predictive accuracy to AJCC staging, with a C-index of 0.651 (95% CI: 0.612–0.691) versus 0.543 (95% CI: 0.517–0.569). Calibration plots showed strong agreement between predicted and observed outcomes. The area under the curve(AUC) for 3- and 5-year PFS predictions were 0.719 (95% CI: 0.655–0.771) and 0.767 (95% CI: 0.670–0.841), respectively. DCA confirmed clinical utility across decision thresholds, and risk stratification effectively differentiated low- and high-risk groups. In the training cohort, the model significantly outperformed AJCC staging (NRI: 0.218, p