Part of Cancer staging guidance sheets
Breast tumours (ICD10 C50)
Introduction
This is the data sheet for TNM 8th edition staging of breast tumours (ICD10 C50)
For more detailed information regarding TNM staging, please see pages 151-158 of the UICC TNM 8 book or visit the Wiley and UICC website.
Stage groupings
|
Stage Group |
T stage |
N stage |
M stage |
|---|---|---|---|
|
Stage 0 |
Tis |
N0 |
M0 |
|
Stage IA |
T1* |
N0 |
M0 |
|
Stage IB |
T0, T1 |
N1mi |
M0 |
|
Stage IIA |
T0, T1 |
N1 |
M0 |
|
|
T2 |
N0 |
M0 |
|
Stage IIB |
T2 |
N1 |
M0 |
|
|
T3 |
N0 |
M0 |
|
Stage IIIA |
T0, T1, T2 |
N2 |
M0 |
|
|
T3 |
N1, N2 |
M0 |
|
Stage IIIB |
T4 |
N0, N1, N2 |
M0 |
|
Stage IIIC |
Any T |
N3 |
M0 |
|
Stage IV |
Any T |
Any N |
M1 |
Note:
* T1 includes T1mi
TNM clinical classification
T - primary tumour
| T value | Description |
|---|---|
|
TX |
Primary tumour cannot be assessed |
|
T0 |
No evidence of primary tumour |
|
Tis |
Carcinoma in situ |
|
Tis (DCIS) |
Ductal carcinoma in situ |
|
Tis (LCIS) |
Lobular carcinoma in situ a |
|
Tis (Paget) |
Paget disease of the nipple not associated with invasive carcinoma and/or carcinoma in situ (DCIS and/or LCIS) in the underlying breast parenchyma. Carcinomas in the breast parenchyma associated with Paget disease are categorized based on the size and characteristics of the parenchymal disease, although the presence of Paget disease should still be noted. |
|
T1 |
Tumour 2 cm or less in greatest dimension T1mi - Microinvasion 0.1 cm or less in greatest dimension b T1a - More than 0.1 cm but not more than 0.5 cm in greatest dimension T1b - More than 0.5 cm but not more than 1 cm in greatest dimension T1c - More than 1 cm but not more than 2 cm in greatest dimension |
|
T2 |
Tumour more than 2 cm but not more than 5 cm in greatest dimension |
|
T3 |
Tumour more than 5 cm in greatest dimension |
|
T4 |
Tumour of any size with direct extension to chest wall and/or to skin (ulceration or skin nodules) c T4a - Extension to chest wall (does not include pectoralis muscle invasion only) T4b - Ulceration, ipsilateral satellite skin nodules, or skin oedema (including peau d'orange) T4c - Both 4a and 4b |
|
T4d |
Inflammatory carcinoma d |
Note:
a - The AJCC exclude Tis (LCIS).
b - Microinvasion is the extension of cancer cells beyond the basement membrane into the adjacent tissues with no focus more than 0.1 cm in greatest dimension. When there are multiple foci of microinvasion, the size of only the largest focus is used to classify the microinvasion. (Do not use the sum of all individual foci.) The presence of multiple foci of microinvasion should be noted, as it is with multiple larger invasive carcinomas.
c - Invasion of the dermis alone does not qualify as T4. Chest wall includes ribs, intercostal muscles, and serratus anterior muscle but not pectoral muscle.
d - Inflammatory carcinoma of the breast is characterized by diffuse, brawny induration of the skin with an erysipeloid edge, usually with no underlying mass. If the skin biopsy is negative and there is no localized measurable primary cancer, the T category is pTX when pathologically staging a clinical inflammatory carcinoma (T4d). Dimpling of the skin, nipple retraction, or other skin changes, except those in T4b and T4d, may occur in T1, T2, or T3 without affecting the classification.
N - regional lymph nodes
| N value | Description |
|---|---|
|
NX |
Regional lymph nodes cannot be assessed (e.g., previously removed) |
|
N0 |
No regional lymph node metastasis |
|
N1 |
Metastasis in movable ipsilateral level I, II axillary lymph node(s) |
|
N2 |
Metastasis in ipsilateral level I, II axillary lymph node(s) that are clinically fixed or matted; or in clinically detected* ipsilateral internal mammary lymph node(s) in the absence of clinically evident axillary lymph node metastasis N2a - Metastasis in axillary lymph node(s) fixed to one another (matted) or to other structures N2b - Metastasis only in clinically detected* internal mammary lymph node(s) and in the absence of clinically detected axillary lymph node metastasis |
|
N3 |
Metastasis in ipsilateral infraclavicular (level III axillary) lymph node(s) with or without level I, II axillary lymph node involvement; or in clinically detected* ipsilateral internal mammary lymph node(s) with clinically evident level I, II axillary lymph node metastasis; or metastasis in ipsilateral supraclavicular lymph node(s) with or without axillary or internal mammary lymph node involvement N3a - Metastasis in infraclavicular lymph node(s) N3b - Metastasis in internal mammary and axillary lymph nodes N3c - Metastasis in supraclavicular lymph node(s) |
Notes:
* Clinically detected is defined as detected by clinical examination or by imaging studies (excluding lymphoscintigraphy) and having characteristics highly suspicious for malignancy or a presumed pathological macrometastasis based on fine needle aspiration biopsy with cytological examination.
Confirmation of clinically detected metastatic disease by fine needle aspiration without excision biopsy is designated with a (f) suffix, e.g. cN3a(f).
Excisional biopsy of a lymph node or biopsy of a sentinel node, in the absence of assignment of a pT, is classified as a clinical N, e.g., cN1. Pathological classification (pN) is used for excision or sentinel lymph node biopsy only in conjunction with a pathological T assignment.
M - distant metastasis
| M value | Description |
|---|---|
|
M0 |
No distant metastasis |
|
M1 |
Distant Metastasis |
TNM pathological classification
pT - primary tumour
The pT categories correspond to the T category.
When classifying pT the tumour size is a measurement of the invasive component. If there is a large in situ component (e.g., 4 cm) and a small invasive component (e.g., 0.5 cm), the tumour is coded pT1a.
pN - regional lymph nodes
The pathological classification requires the resection and examination of at least the low axillary lymph nodes (level I). Such a resection will ordinarily include 6 or more lymph nodes. If the lymph nodes are negative, but the number ordinarily examined is not met, classify as pN0.
| pN value | Description |
|---|---|
|
pNX |
Regional lymph nodes cannot be assessed (e.g., previously removed, or not removed for pathological study) |
|
pN0 |
No regional lymph node metastasis* |
|
pN1 |
Micrometastases; or metastases in 1 to 3 axillary ipsilateral lymph nodes; and/or in internal mammary nodes with metastases detected by sentinel lymph node biopsy but not clinically detected* pN1mi - Micrometastases (larger than 0.2 mm and/or more than 200 cells, but none larger than 2.0 mm) pN1a - Metastasis in 1–3 axillary lymph node(s), including at least one larger than 2 mm in greatest dimension pN1b - Internal mammary lymph nodes pN1c - Metastasis in 1–3 axillary lymph nodes and internal mammary lymph nodes. |
|
pN2 |
Metastasis in 4–9 ipsilateral axillary lymph nodes, or in clinically detected* ipsilateral internal mammary lymph node(s) in the absence of axillary lymph node metastasis pN2a - Metastasis in 4–9 axillary lymph nodes, including at least one that is larger than 2 mm pN2b - Metastasis in clinically detected internal mammary lymph node(s), in the absence of axillary lymph node metastasis |
|
pN3 |
pN3a - Metastasis in 10 or more ipsilateral axillary lymph nodes (at least one larger than 2 mm) or metastasis in infraclavicular lymph nodes pN3b - Metastasis in clinically detected** internal ipsilateral mammary lymph node(s) in the presence of positive axillary lymph node(s); or metastasis in more than 3 axillary lymph nodes and in internal mammary lymph nodes with microscopic or macroscopic metastasis detected by sentinel lymph node biopsy but not clinically detected pN3c - Metastasis in ipsilateral supraclavicular lymph node(s) |
Post‐treatment ypN:
• Post‐treatment yp ‘N’ should be evaluated as for clinical (pretreatment) ‘N’ methods (see Section N – Regional Lymph Nodes). The modifier ‘sn’ is used only if a sentinel node evaluation was performed after treatment. If no subscript is attached, it is assumed the axillary nodal evaluation was by axillary node dissection.
• The X classification will be used (ypNX) if no yp post‐treatment SN or axillary dissection was performed
• N categories are the same as those used for pN.
Note:
* Isolated tumour cell clusters (ITC) are single tumour cells or small clusters of cells not more than 0.2 mm in greatest extent that can be detected by routine H and E stains or immunohistochemistry. An additional criterion has been proposed to include a cluster of fewer than 200 cells in a single histological cross section. Nodes containing only ITCs are excluded from the total positive node count for purposes of N classification and should be included in the total number of nodes evaluated.
** Clinically detected is defined as detected by imaging studies (excluding lymphoscintigraphy) or by clinical examination and having characteristics highly suspicious for malignancy or a presumed pathological macrometastasis based on fine needle aspiration biopsy with cytological examination.
Not clinically detected is defined as not detected by imaging studies (excluding lymphoscintigraphy) or not detected by clinical examination.
Last edited: 21 December 2022 5:12 pm
