Validation of the 2009 TNM Version in a Large Multi-Institutional Cohort of Patients Treated for Renal Cell Carcinoma: Are Further Improvements Needed?

Background: A new edition of the TNM was recently released that includes modifications for the staging system of kidney cancers. Specifically, T2 cancers were subclassified into T2a and T2b ( 10 cm), tumors with renal vein involvement or perinephric fat involvement were classified as T3a cancers, and those with adrenal involvement were classified as T4 cancers. Objective: Our aim was to validate the recently released edition of the TNM staging system for primary tumor classification in kidney cancer. Design, setting, and participants: Our multicenter retrospective study consisted of 5339 patients treated in 16 academic Italian centers. Intervention: Patients underwent either radical or part…