Comparison of Lymphatic System Staging Classifications in Patients with Gastric Cancer.

ABSTRACT

UNLABELLED Despite an observed decrease in the incidence of gastric cancer, it still remains an important clinical problem. It is the fourth most common cancer in the world and the second cause of death in cancer patients. The quality of lymphadenectomy procedure and the number of analysed lymph nodes are both important factors influencing the treatment of the patient. The aim of the study was to compare the lymph node ratio staging system with the 6th and 7th edition of the TNM classification. MATERIAL AND METHODS: A group consisting of 493 patients who underwent surgery in 1998-2010 due to gastric cancer was used to compare the staging systems. Following statistical analysis, the following cut-off points were adopted for the lymph node ratio for the purpose of comparison 0, from 0.05 to 0.3, from 0.3 to 0.5 and over 0.5. Subsequently the homogeneity (using chi-square test for linear trend) and the predictive value of the different classifications (using Akaike information criterion) were assessed in order to compare the lymph node ratio staging system with the 6th and 7th edition of the TNM classification. RESULTS: The lymph node ratio classification has a higher discriminatory value than the TNM classifications (higher linear trend result). What is more, the lymph node ratio classification (LNR) had a lower Akaike information criterion value, which means that it has a higher prognostic value than the other classifications. ROC curves and the area under the curve (AUC) were utilised for the analysis of predictive value of the different classifications in patients with gastric cancer. CONCLUSION: One may conclude, therefore, that the lymph node ratio staging system is the best classification of the lymphatic system in the presented group of patients.