Stages of Breast Cancer

In this article, we will discuss the Stages of Breast Cancer. So, let’s get started.

Staging (The American Joint Committee on Cancer (AJCC) Staging System)

1. Stage 0: Tis, N0, M0
2. Stage I: TI,* N0, M0
*T1 includes T1mic
3. Stage IIA: T0, N1, M0T1, N1,** M0T2, N0, M0
*TI includes T1mic **The prognosis of patients with pN1a disease is similar to that of patients with pN0 disease.
4. Stage IIB:
– T2, N1, M0
– T3, N0, M0
5. Stage IIIA: T0, N2, M0T1,* N2, M0T2, N2, M0T3, N1, M0T3, N2, M0
*T1 includes T1mic
6. Stage IIIB:
– T4, Any N, M0
– Any T, N3, M0
7. Stage IV: Any T, Any N, M1

TNM Definitions

Primary tumour (T)

TX: Primary tumour cannot be assessed

T0: No evidence of primary tumour T1s: Carcinoma in situ; intraductal carcinoma, lobular carcinoma in situ, or T1: Tumour 2.0 cm or less in greatest dimension
T1mic: Microinvasion 0.1 cm or less in greatest dimension
T1a: Tumour more than 0.1 but not more than 0.5 cm in greatest dimension
T1b: Tumour more than 0.5 cm but not more than 1.0 cm in greatest dimension
T1c: Tumour more than 10 cm but not more than 2.0 cm in greatest dimension
T2: Tumour more than 20 cm but not more than 5.0 cm in greatest dimension
T3: Tumour more than 5.0 cm in greatest dimension
T4: Tumour of any size with direct extension to (a) chest wall or (b) skin, only as described below.
Note: Chest wall includes ribs, intercostal muscles, and serratus anterior muscle but not pectoral muscle.
T4a: Extension to chest wall
T4b: Oedema (including peau d’orange) or ulceration of the skin of the breast or satellite skin nodules confined to the same breast
T4c: Both of the above (T4a and T4b)
T4d: Inflammatory carcinoma*
*Note: Inflammatory carcinoma is a clinicopathologic entity characterized by diffuse brawny induration of the skin of the breast with an erysipeloid edge, usually without an underlying palpable mass.’ Radiologically, there may be a detectable mass and characteristic thickening of the skin over the breast. This clinical presentation is due to tumour embolization of dermal lymphatics with engorgement of superficial capillaries.

Regional lymph nodes (N)

NX: Regional lymph nodes cannot be assessed (e.g., previously removed)
N0: No regional lymph node metastasis
N1: Metastasis to movable ipsilateral axillary lymph node(s)
N2: Metastasis to ipsilateral axillary lymph node(s) fixed to each other or to other structures
N3: Metastasis to ipsilateral internal mammary lymph node(s)

Pathologic classification (PN)

PNX: Regional lymph nodes cannot be assessed (not removed for pathologic study or previously removed)
PN0: No regional lymph node metastasis
pN1: Metastasis to movable ipsilateral axillary lymph node(s)
pN1a: Only micrometastasis (none larger than 0.2 cm)
pN1b: Metastasis to lymph node(s), any larger than 0.2 cm
pN1bi: Metastasis in 1-3 lymph nodes, any more than 0.2 cm and allless than 2.0 cm in greatest dimension
pN1bii: Metastasis to 4 or more lymph nodes, any more than 0.2 cm and all less than 2.0 cm in greatest dimension
pN1biii: Extension of tumour beyond the capsule of a lymph node metastasis less than 2.0 cm in greatest dimension
pN1biv: Metastasis to a lymph node 2.0 cm or more in greatest dimension
pN2: Metastasis to ipsilateral axillary lymph node(s) fixed to each other or to other structures
pN3: Metastasis to ipsilateral internal mammary lymph node(s)

Distant metastasis (M)

MX: Presence of distant metastasis cannot be assessed
M0: No distant metastasis
M1: Distant metastasis present (in
(includes metastasis to ipsilateral supraclavicular lymph nodes)

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