RESUMO
BACKGROUND: Despite the announcement of the 8th edition of TNM classification, the 7th edition (2010) is still being used for prognostic assessment in gastric cancer patients. A proposed new staging system (termed as the Kiel proposal) claims to offer a better prognostic stratification. Our objective was to retrospectively evaluate the Kiel proposal and compare it with the 6th and 7th TNM editions on a collected database. METHODS: We retrospectively analyzed gastric cancer patients who had undergone surgical resection without any previous treatment from selected randomized trials and from a cohort of patients operated at the University Hospital of Mainz, Germany. All patients were restaged using the 3 staging systems and overall survival was estimated and compared. RESULTS: A study population of 491 patients was identified. Relevant changes in stage distribution between the 6th and 7th TNM and the Kiel staging systems were observed. The 6th classification appears to display the best discriminatory measures. The Kiel staging system is slightly less prognostic than the TNM editions, but provides clearly separated strata as with the 6th edition. CONCLUSIONS: The Kiel staging system for gastric cancer appears promising in terms of simplicity, predictability and applicability and should be taken into consideration in future TNM revisions.