TNM

For other uses, see TNM (disambiguation)}}}.

TNM Classification of Malignant Tumours (TNM) is the cancer staging system developed and maintained by the International Union Against Cancer (UICC) to maintain consensus on one globally recognised standard for categorising 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.

Contents

1 Broad outline

1.1 Mandatory parameters ('T', 'N', and 'M')
1.2 Other parameters
1.3 Prefix modifiers

2 Examples
3 Uses and aims
4 See also
5 Reference
6 External links

Broad outline

Each tumor has its own TNM classification. Not all tumors have TNM classifications, but most do. For instance, there is no TNM classification for brain tumors.

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

Mandatory parameters ('T', 'N', and 'M')

T (a,is,(0),1-4): size of the tumour Relates to Tumour size and local spread.
N (0-3): spreading into lymphatic nodes
M (0/1): spreading into other organs (metastasis)

Other parameters

G (1-4): the grade of the cancer cells (i.e. they are "low grade" if they appear similar to normal cells, and "high grade" if they appear poorly differentiated)
R (0/1/2): the completeness of the operation (resection-boundaries free of cancer cells or not)
L (0/1): invasion into lymphatic vessels
V (0/1): invasion into veins
C (1-4): a modifier of the certainty (quality) of the last mentioned parameter

Prefix modifiers

c: stage given by clinical examination of a patient. The c-prefix is implicit in absence of the p-prefix
p: stage given by pathologic examination of a surgical specimen
y: stage assessed after neoadjuvant therapy

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

Examples

Small, low grade cancer, no metastasis, no spreading to lymph nodes, cancer completely removed, resection material seen by pathologist - pT1 pN0 M0 R0 G1
Big, high grade cancer, with spread to lymph nodes and other organs, not completely removed, seen by pathologist - pT4 pN2 M1 R1 G3

Uses and aims

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

Aid medical staff in staging the tumour helping to plan the treatment.
Give an indication of prognosis.
Assist in the evaluation of the results of treatment.
Enable facilities around the world to collate information more productively.

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

Reference

Sobin LH, Wittekind Ch (eds). TNM Classification of Malignant Tumours, 6th Edition. Wiley, 2002. ISBN 0471222887.

External links

[UICC site]
[TNM Cancer Staging System Database] (information mostly outdated, from the 1997 edition of TNM)
[TNM - Explanatory Notes]
[TNM Classification Help]

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TNM