TNM staging system

The TNM Classification of Malignant Tumours (TNM) is a cancer staging notation system that gives codes to describe the stage of a person's cancer, when this originates with a solid tumor.

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.[1] It has gained a wide degree of 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.[2]

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.

General outline

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.

Mandatory parameters

Diagram showing the T stages of bladder cancer

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

Other parameters

Prefix modifiers

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

Examples

Uses and aims

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.

Versions

It is crucial to be aware that the criteria used in the TNM system have varied over time, sometimes fairly substantially, according to the different editions that AJCC and UICC have released. The dates of publication and adoption for use of AJCC editions is summarized here; past editions are available from AJCC for web download.[4]

As a result, a given stage may have quite a different prognosis depending on which staging edition is used, independent of any changes in diagnostic methods or treatments, an effect that has been termed "stage migration." The technologies used to assign patients to particular categories have changed also, and by intuitive consideration it can be seen that increasingly sensitive methods tend to cause individual cancers to be reassigned to higher stages, making it improper to compare that cancer's prognosis to the historical expectations for that stage. Finally, of course, a further important consideration is the effect of improving treatments over time as well.

Cancer types

See also

References

  1. Denoix PF. Enquete permanent dans les centres anticancereaux. Bull Inst Nat Hyg 1946;1:70–5.
  2. Tobias Jeffrey S., Hochhauser, Daniel, Cancer and its Management, p. 43, 2013 (6th edn), ISBN 1118713257, 9781118713259
  3. "Cancer staging". National Cancer Institute. Retrieved 4 January 2013.
  4. American Joint Committee on Cancer. Past Editions of the AJCC Cancer Staging Manual available at

External links

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