Introduction

Cancers of the kidney, renal pelvis, ureter, bladder and urethra account for 143,190 new cases and 31,540 deaths in 2016. Accurate cancer staging is critical for predicting prognosis and defining optimal treatments. Cancer stages are defined by the American Joint Committee on Cancer (AJCC) which produces and updates the evidence-based Cancer Staging Manual (CSM). In October, 2016 the AJCC released the CSM 8th edition, which is effective for all cancer cases diagnosed on or after January 1, 2017. The aim of this project is to provide a summary of the changes to the classification of these cancers of the urinary tract. _x000D_ _x000D_

Methods

To update the CSM 8th Edition, the AJCC convened an international multispecialty expert panel of leading cancer physicians, population scientists, cancer registrars and statisticians. TNM cancer classification is based primarily on anatomic information regarding extent of the primary tumor (T), regional lymph node status (N), and presence of distant metastases (M). Changes in TNM classification were made by the panel after evidence review and expert consensus. The AJCC Evidence-Based Medicine and Statistics Core determined levels of evidence (1 to 4) for each change through analysis of the number and quality of studies used in decision-making.

Results

CSM 8th Edition changes in urinary tract cancers are detailed in table 1. In summary, the T3a definition for kidney cancer was modified to include tumors invading the pelvicalyceal system. For cancer of the renal pelvis and ureter, prior categorization of N3 metastasis was collapsed into the N2 category. Changes in bladder cancer staging included reclassification of perivesical lymph node involvement, sub-classification of distant metastases and addition of prognostic subgroups for stages 3 and 4. For urethral cancer, urothelial carcinoma in situ of the prostate was collapsed into single stage (Tis), clarification was made for T1 and T4 disease, and distinction was made between N1 and N2 disease. _x000D_ _x000D_

Conclusions

The AJCC CSM reflects the latest evidence and expert consensus for cancer staging. The 8th Edition refines the TNM classifications of urinary tract cancers and represents a further step toward a personalized approach to cancer staging.

Funding

none