Breast tumours (ICD10 C50)

This is the data sheet for TNM 9th edition staging of breast tumours (ICD10 C50)

For more detailed information regarding TNM staging, please see pages 151-157 of the UICC TNM 9 book. 

Note:

* T1 includes T1mi

T - primary tumour

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

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

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 six or more lymph nodes. If the lymph nodes are negative, but the number ordinarily examined is not met, classify as pN0.

Post‐treatment yp Classification:

• Post‐treatment y-pathological (yp) classification should be based on the y-clinical stage information supplemented and/or modified by operative findings and pathological evaluation of the resection specimen
• ypT and ypN categories correspond to the pT and pN categories respectively. The ypT category must be based on the largest continuous focus of residual invasive cancer (if present and not including treatment-related fibrosis). Multiple foci of residual cancer should be classified accordingly with the ‘m’ suffix. The inclusion of additional information in the pathology report to estimate the extent of residual disease by the ‘residual cancer burden method’ is recommended
• The modifier ‘sn’ is used only if a sentinel node evaluation was performed after treatment. If no subscript is attached, it is assumed that the axillary node evaluation was by axillary node dissection
• The X classification should be used (ypNX) if no yp post-treatment SN or axillary dissection was performed

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.