The TNM classification comprises staging algorithms for almost all cancers, with the primary exception of pediatric cancers. 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 •
T: size or direct extent of the primary tumor • Tx: tumor cannot be assessed • Tis:
carcinoma in situ • T0: no evidence of tumor • T1, T2, T3, T4: size and/or extension of the primary tumor •
N: degree of spread to regional
lymph nodes • Nx: lymph nodes cannot be assessed • N0: no regional
lymph nodes metastasis • N1: regional lymph node metastasis present; at some sites, tumor spread to closest or small number of regional lymph nodes • N2: tumor spread to an extent between N1 and N3 (N2 is not used at all sites) • N3: tumor spread to more distant or numerous regional lymph nodes (N3 is not used at all sites) •
M: presence of distant
metastasis • M0: no distant metastasis • M1: metastasis to distant organs (beyond regional lymph nodes) The Mx designation was removed from the 7th edition of the AJCC/UICC system, but referred to cancers that could not be evaluated for distant 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) •
S (0–3): elevation of serum
tumor markers •
R (0–2): the completeness of the operation (
resection-boundaries free of cancer cells or not) •
Pn (0–1): invasion into
adjunct nerves •
L (0–1): invasion into
lymphatic vessels •
V (0–2): invasion into
vein (no, microscopic, macroscopic) •
C (1–5): a modifier of the
certainty (quality) of the last mentioned parameter (has been removed in the TNM 8th edition)
Prefix modifiers •
c: stage is determined from evidence acquired before treatment (including clinical examination, imaging, endoscopy, biopsy, surgical exploration). The c-prefix is implicit in absence of the p-prefix. •
p: stage given by
histopathologic examination of a surgical specimen •
y: stage assessed after
chemotherapy and/or radiation therapy; in other words, the individual had
neoadjuvant therapy. •
r: stage for a recurrent tumor in an individual that had some period of time free from the disease. •
a: stage determined at
autopsy. •
u: stage determined by
ultrasonography or
endosonography. Clinicians often use this modifier although it is not an officially defined one •
m: tumor is multifocal (more than 1 tumors). The opposite,
s, can be used when there is particular reason to emphasize that the tumor is solitary/single. For the T, N and M parameters exist subclassifications for some cancer-types (e.g. T1a, Tis, N1i)
UICC Stage and AJCC Prognostic Stage Groups The TNM system is used to record the anatomical extent of disease. It is useful to condense these categories into groups.
Carcinoma in situ is categorized stage 0; often tumors localized to the organ of origin are staged as I or II depending on the extent, locally extensive spread, to regional
nodes are staged as III, and those with distant
metastasis staged as stage IV. However, in some tumor types stage groups do not conform to this simplified schema. The stage group is adopted with the intention that categories within each group are more or less homogeneous in respect of survival, and that the
survival rates are distinctive between groups. The
Union for International Cancer Control (UICC) uses the term
Stage to define the anatomical extent of disease. The
American Joint Committee on Cancer (AJCC) uses the term
Prognostic Stage Group which may also include additional prognostic factors in addition to anatomical extent of disease. ==Examples==