Ratio of metastatic lymph nodes: Impact on staging and survival of gastric cancer

Abstract Aims No consensus exists on the level and number of lymph nodes to be dissected and examined for accurate staging of patients with resectable gastric cancer. The aim of this study was to examine the prognostic value and staging accuracy of the metastatic lymph nodes ratio (NR). Methods The postoperative survival of 247 patients with gastric cancer who underwent gastrectomy was analyzed. Lymph nodes status was assigned according to three different classifications: 6th UICC/AJCC TNM; JGCA; NR (NR0: 0%; NR1: ≤20%; NR2: >20%). Staging accuracy of the three classifications was compared according to patients survival. Results A significant difference in survival was observed in patients with NR1 versus NR2. At multivariate analysis only NR along with pT and grading were found to be independent prognostic factors. Stage migration was present in 84 cases (51%) with JGCA classification, in 30 (19%) with 6th UICC/AJCC TNM classification and in only 18 cases (11%) when NR was applied. Conclusions Our data showed that NR is a simply reproducible and highly reliable staging system with a strong ability to predict patients' outcome. Compared to other nodal staging classifications, NR is less influenced from the number of the lymph nodes dissected and examined, reducing the stage migration phenomenon.