Title : Refined ypTNM staging for gastric cancer after neoadjuvant therapy based on optimal lymph node staging
Abstract:
Background: The 8th edition of the AJCC staging system for gastric cancer introduced the ypTNM staging. However, in clinical practice, we have observed that the accuracy of its prognostic assessment remains controversial. This study aims to develop a more precise and refined ypTNM staging system to better delineate the prognosis of patients.
Methods: We retrospectively analyzed the clinicopathological data of 1,078 patients with advanced gastric cancer from an international multicenter cohort who underwent gastrectomy with curative intent after neoadjuvant therapy. Based on the patients' overall survival (OS), we constructed a refined ypTNM staging system. To further validate the effectiveness of this system, we selected 1,637 patients from SEER database as a validation cohort. Subsequently, we compared the performance of the AJCC 8th edition ypTNM staging with our refined staging in assessing the prognosis of patients after neoadjuvant therapy.
Results: Statistical analysis showed that the refined staging significantly outperformed the AJCC 8th edition staging in terms of discriminatory ability (c-index), predictive homogeneity (likelihood ratio chi-square), predictive accuracy (mean difference in Bayesian Information Criterion, Net Reclassification Improvement, Integrated Discrimination Improvement), and model stability. In the external validation cohort, the refined ypTNM staging also demonstrated better prognostic predictive ability (all p < 0.05).
Conclusion: This study successfully developed and validated a refined ypTNM staging system using multicenter data. This system significantly outperforms the AJCC 8th edition ypTNM staging in assessing the prognosis of gastric cancer patients after neoadjuvant therapy and provides a more precise tool for clinical decision-making.
Keywords: Gastric Cancer ; Neoadjuvant Therapy ; Staging system ; Survival.
