User’s Guide to Essential TNM

Essential TNM, a simplified staging system for cancer registries, is a complement to the full Tumour, Node, Metastasis (TNM) classification, to assign cancer stage at diagnosis. It is for use by cancer registrars when either the traditional (or full) TNM stage group (I, II, III, or IV) or the TNM staging components (T, N, and M) have not been explicitly recorded in the patient’s record.

This user’s guide provides general instructions for abstracting information on extent of disease using Essential TNM. Site-specific coding flow charts are provided for eight selected cancer sites: breast, cervix, colorectum, liver, lymphoma, oesophagus, ovary, and prostate. The flow charts include relevant questions and diagrams to help identify the extent of disease in the different cancer sites.

Essential TNM is a valuable tool to reduce gaps in cancer staging information. This user’s guide will facilitate the extraction of data from medical records, the coding of the T, N, and M components, and the combination of these elements into stage groups.