Development of a simplified tumor-lymph node ratio classification system for patients with resected gastric cancer: A western study

Introduction: Gastric cancer (GC) shows high recurrence and mortality rates. The AJCC TNM staging system is the best prognostic predictor, but lymph node assessment is a major source of controversy. Recent studies have found that lymph node ratio (LNR) may overcome TNM limitations. Our aim is to develop a simplified tumor-LNR (T-LNR) classification for predicting prognosis of resected GC. Methods: Retrospective study of all GC resected in a tertiary center in Spain (N = 377). Clinicopathological features were assessed, LNR was classified into N0:0%, N1:1-25%, N2:>25%, and a T-LNR classification was developed. Statistical analyses were performed. Results: 317 patients were finally included. Most patients were male (54.6%) and mean age was 72 years. Tumors were intestinal (61%), diffuse (30.8%) or mixed (8.1%). During follow-up, 36.7% and 27.4% of patients progressed and died, respectively. T-LNR classification divided patients into five prognostic categories (S1-S5). Most cases were S1-S4 (26.2%, 19.9%, 22.6% and 23.6%, respectively). 7.6% of tumors were S5. T-LNR classification was significantly associated with tumor size, depth, macroscopical type, Lauren subtype, signet ring cells, histologic grade, lymphovascular invasion, perineural infiltration, infiltrative growth, patient progression and death. Kaplan-Meier curves for OS showed an excellent patient stratification with evenly spaced curves. As for DFS, T-LNR classification also showed good discriminatory ability with non-overlapping curves. T-LNR classification was independently related to both OS and DFS. Conclusions: T-LNR classifications can successfully predict prognosis of GC patients. Larger studies in other geographic regions should be performed to refine this classification and to validate its prognostic relevance.

Automated summary

Analyzing the tumor-LNR classification can successfully predict the prognosis of resected gastric cancer patients. The T-LNR classification is significantly associated with tumor characteristics, patient progression, and death, demonstrating good stratification and discrimination capabilities.