TNM staging system

The TNM Classification of Malignant Tumours (TNM) is a cancer staging notation system that describes the stage of a cancer which originates from a solid tumor with alphanumeric codes.

The TNM staging system for all solid tumors was devised by Pierre Denoix between 1943 and 1952, using the size and extension of the primary tumor, its lymphatic involvement, and the presence of metastases to classify the progression of cancer. It has gained wide international acceptance for many solid tumor cancers, but is not applicable to diffused cancers such as leukaemia and is of limited use for other cancers such as diffuse lymphoma and ovarian cancer.

TNM is developed and maintained by the Union for International Cancer Control (UICC) to achieve consensus on one globally recognised standard for classifying the extent of spread of cancer. The TNM classification is also used by the American Joint Committee on Cancer (AJCC) and the International Federation of Gynecology and Obstetrics (FIGO). In 1987, the UICC and AJCC staging systems were unified into a single staging system.

Most of the common tumors have their own TNM classification. Not all tumors have TNM classifications, e.g., there is no TNM classification for brain tumors.

The general outline for the TNM classification is below. The values in parentheses give a range of what can be used for all cancer types, but not all cancers use this full range.

The Mx designation was removed from the 7th edition of the AJCC/UICC system, but referred to cancers that could not be evaluated.

For the T, N and M parameters exist subclassifications for some cancer-types (e.g. T1a, Tis, N1i)

Some of the aims for adopting a global standard are to:

Since the number of combinations of categories is high, combinations are grouped to stages for better analysis.

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