Stage

T

N

M

Description

0

Tis

N0

M0

Tumor that has not grown beyond its site of origin and invaded the neighboring tissue. It includes the DCIS and LCIS.

IA

T1 (tumor ≤ 20 mm)

N0

M0

Tumor which is not “in situ” but it is ≤20 mm in greater dimension.

IB

T0 or T1

N1mi (micro metastases)

M0

Tumor ≤ 20 mm in greater dimension with nodal micrometastasis (greater than 0.2 mm and/or more than 200 cells, but none greater than 2 mm).

IIA

T0 or T1

T2 (20 mm < tumor ≤ 50 mm)

N1 (metastases in 1 - 3 ipsilateral ALN(s)

N0

M0

M0

Tumor ≤ 20 mm in greater dimension with involvement of axillary lymph nodes or tumour from 20 to 50mm without involvement of any ALNs.

IIB

T2

T3 (tumor > 50 mm

N1

N0

M0

M0

Tumor from 20 to 50 mm with involvement of ALNs or tumor > 50 mm without involvement of any ALNs.

IIIA

T0, T1 or T2

T3

N2 (metastases in 4 - 9 ipsilateral

ALNs)

N1 or N2

M0

M0

Tumor > 50 mm with spread to ALNs, or tumor of any size with metastases in ALNs which are knitted to each other or with the surrounding tissue.

IIIB

T4 (tumor of any size with direct extension to the chest wall and/or to the skin

N0, N1, N2

M0

Tumor of any size with metastases into the skin,

chest wall or internal LNs of the mammary gland.

IIIC

Any T

N3 (metastases in ≥10 ALNs, or in infra-clavicular LNs or ipsilateral internal mammary LNs)

M0

Tumor of any size with a more widespread metastases and involvement of more LNs.

IV

Any T

Any N

M1 (distant organs’

metastases)

Any tumor spreads to parts of the body that relocated far removed from the chest (bones, lungs, liver or distant LNs).