TNM staging system for renal-cell carcinoma: current status and future perspectives

The Tumour, Nodes, and Metastasis (TNM) staging system is a method of stratifying patients with cancer and is based on data obtained from large multicentre studies that involved large numbers of patients, and have a good level of evidence. However, despite continual revisions to the methodology to incorporate evidence from new clinical studies, the optimum stratification of patients with renal-cell carcinoma (RCC) using the TNM staging system remains controversial and further revisions, in our opinion, are needed. Revision of the TNM staging system for renal-cell cancer could also result in the simultaneous update of the integrated prognostic systems that are currently used along side this traditional method of staging. These integrated systems could become key instruments for guiding patient counselling, for appropriate follow up strategies, for patient selection for clinical trials, and for appropriate assessment of results if the perception that they are complex is overcome. This perception is driven by the presence of more than one system, the heterogeneity of clinical and pathological variables included in the methodology, and the need for robust comparative studies between the various systems. Therefore, in everyday clinical practice, the TNM system is regarded as a more reliable method of staging. In this Essay, we aim to highlight the problems associated with the current version of the TNM staging system and highlight areas in which this grading instrument can be improved in future to become a more refined and standardised method of communication between all clinicians involved in clinical management of RCC.