TNM staging of renal cell carcinoma

Abstract

TNM classification, including the classification of renal cell carcinoma, has been revised for the 1997 fifth editions of both the UICC1 and AJCC2 publications (Table 1). T1-T2. The breakpoint between T1 and T2 was felt by some participants to be too high in terms of prognostic value3,4 and for treatment planning (for example, in the selection of patients for partial nephrectomy). An optional division of T1 was proposed for the present: T1a: Tumor 4 cm or smaller, limited to the kidney; T1b: Tumor larger than 4-7 cm, limited to the kidney. T3a. It was emphasized that invasion of the adrenal gland means direct invasion and not metastasis from the kidney. T3a. Invasion of "perinephric tissues" should denote perirenal fat and/or renal sinus fat. T3b. More specificity was thought to be needed in defining involvement of the renal vein. The following definition was recommended: T3b: Tumor grossly extends into the renal vein or its segmental (muscle-containing) branches, or vena cava below the diaphragm. T3c. Macroscopic invasion of the wall of the vena cava is worth noting, more so than the level of extension of tumor within the vena cava. Recent data suggest that involvement of the supradiaphragmatic vena cava, in the absence of direct caval wall invasion, is not associated with impaired survival.5 N. In the 1997 revision, the N categories have changed from the N1, 2, 3, of 1987 to the following: N1: Metastasis in a single regional lymph node; N2: Metastasis in more than one regional lymph node. An adequate number of negative regional lymph nodes (4-8) was considered important for establishment of pNO status. Stage grouping. The stage grouping of the 1997 classification has changed because of the changes in contents of the T and N categories. These points of clarification and suggestions for optional division of existing categories should be considered for inclusion in the next edition of the TNM Supplement. Avoid stripping the capsule before dissecting the tumor. The specimen should be sectioned with the perinephric tissues attached so that small foci of capsular penetration can be found. For detection of multiple tumors, thin slices (5-10 mm) of the kidney are needed. Such thin slicing is best carried out after overnight fixation of the bisected kidney. For partial nephrectomy specimens, accurate assessment needs examination of at least two sections from each parenchymal margin and, for central tumors, one section from the adjacent renal sinus.