Prognostic impact of regional lymph node excision in T3-4N+M0 gastric cancer: a retrospective cohort study on
Chenrui Tian1,2, Aiping Sun3, Haodi Yu1
1Department of Oncology, Henan Provincial International Coalition Laboratory of Oncology Precision Treatment, Henan Provincial People's Hospital, Henan, China.
Background:
Locally advanced gastric cancer, especially T3-4N + M0 cancer, has been recognized as a significant clinical challenge among all kinds of gastric cancer. Although the surgery played a crucial role in the management of T3-4N + M0 gastric cancer, the number of regional nodes excision (RNE) exerted discernible impacts on the prognosis of this type of patients. This study aims to assess the potential survival benefit associated with excision of at least 18 lymph nodes and to develop a nomogram for predicting the 5-year survival rate in T3-4N + M0 gastric cancer patients.
Patients And Methods:
This retrospective cohort study analyzed data from patients diagnosed with T3-4N + M0 gastric cancer between 2000 and 2019 from the Surveillance, Epidemiology, and End Results (SEER) database and our cohort (1 January 2015 to 2019). Participants were divided into train and test cohorts. The intervention included RNE, with exposure groups defined by lymph node count (≥18 vs <18) and postoperative radiotherapy. Primary outcome was overall survival (OS). Statistical analyses involved LASSO regression for variable selection, Cox proportional hazards models for identifying prognostic factors, restricted cubic spline (RCS) for modeling nonlinear relationships, and evaluation of the predictive nomogram using receiver operating characteristic (ROC) curves, calibration plots, and decision curve analysis (DCA).
Results:
Multivariable analysis identified ≥18 RNE and postoperative radiotherapy as independent favorable prognostic factors for OS (RNE≥18: HR = 0.47, P < 0.001; SRT: HR = 0.65, P = 0.03), while advanced nodal disease (N2/N3) and extended gastrectomy were associated with poorer outcomes. The nonlinear association between RNE and survival was statistically significant (P = 0.009) and predominantly nonlinear within the observed range. The developed nomogram demonstrated consistent discriminative ability, with AUCs of 0.722-0.765 in the train set and 0.713-0.801 in the external test set across 1, 3, and 5 years.
Conclusions:
This study establishes that resection of ≥18 lymph nodes and postoperative radiotherapy on those who underwent ≥18 lymph nodes significantly improves survival in T3-4N + M0 gastric cancer. We developed and validated a prognostic nomogram to guide individualized therapy. These findings advocate for standardized lymph node dissection in multimodal management, while prospective trials remain necessary to validate broader applicability. Besides, an online calculator is provided at https://yhd2314.shinyapps.io/huahuadan9_15/ to facilitate individual risk prediction.
