Efficacy of Lymph Node Location-Number Hybrid Staging System on the Prognosis of Gastric Cancer Patients

SIMPLE SUMMARY: Lymph node staging is very important for the prognosis of patients with gastric cancer. Currently, the internationally accepted lymph node staging method is the 8th AJCC staging, which divides lymph nodes into different stages according to the number of positive lymph nodes. This staging method is simple and convenient, but ignores the laterality of lymph nodes. In this paper, we for the first time combined the location and number information of positive lymph nodes to create a novel lymph node staging system for gastric cancer. After training cohort and validation cohort tests, this staging is more accurate in predicting the prognosis of patients than the 8th AJCC staging. ABSTRACT: Background: Lymph node metastasis location and number significantly affects the prognosis of patients with gastric cancer (GC). This study was designed to examine a new lymph node hybrid staging (hN) system to increase the predictive ability for patients with GC. Methods: This study analyzed the gastrointestinal treatment of GC at the Harbin Medical University Cancer Hospital from January 2011 to December 2016, and selected 2598 patients from 2011 to 2015 as the training cohort (hN) and 756 patients from 2016 as the validation cohort (2016-hN). The study utilized the receiver operating characteristic curve (ROC), c-index, and decision curve analysis (DCA) to compare the prognostic performance of the hN with the 8th edition of AJCC pathological lymph node (pN) staging for GC patients. Results: The ROC verification of the training cohort and validation cohort based on each hN staging and pN staging showed that for each N staging, the hN staging had a training cohort with an AUC of 0.752 (0.733, 0.772) and a validation cohort with an AUC of 0.812 (0.780, 0.845). In the pN staging, the training cohort had an AUC of 0.728 (0.708, 0.749), and the validation cohort had an AUC of 0.784 (0.754, 0.824). c-Index and DCA also showed that hN staging had a higher prognostic ability than pN staging, which was confirmed in the training cohort and the verification cohort, respectively. Conclusion: Lymph node location-number hybrid staging can significantly improve the prognosis of patients with GC.