Comparison of different lymph node staging systems in prognosis of gastric cancer: a bi-institutional study from Hungary

OBJECTIVE The Union for International Cancer Control (UICC) Node (N) classification is the most common used staging method for the prognosis of gastric cancer. It demands adequate, at least 16 lymph nodes (LNs) to be dissected; therefore different staging systems were invented. METHODS Between March 2005 and March 2010, 164 patients were evaluated at the Department of General Surgery in the Kenézy Gyula Hospital and at the Department of General, Thoracic and Vascular Surgery in the Kaposi Mór Hospital. The 6th, 7th and 8th UICC N-staging systems, the number of examined LNs, the number of harvested negative LNs, the metastatic lymph node ratio (MLR) and the log odds of positive LNs (LODDS) were determined to measure their 5-year survival rates and to compare them to each other. RESULTS The overall 5-year survival rate for all patients was 55.5% with a median overall survival time of 102 months. The tumor stage, gender, UICC N-stages, MLR and the LODDS were significant prognostic factors for the 5-year survival with univariate analysis. The 6th UICC N-stage did not follow the adequate risk in comparing N2 vs. N0 and N3 vs. N0 with multivariate investigation. Comparison of performances of the residual N classifications proved that the LODDS system was first in the prediction of prognosis during the evaluation of all patients and in cases with less than 16 harvested LNs. The MLR gave the best prognostic prediction when adequate (more than or equal to 16) lymphadenectomy was performed. CONCLUSIONS We suggest the application of LODDS system routinely in western patients and the usage of MLR classification in cases with extended lymphadenectomy.