TNM Classification & Clinical Staging of Breast Carcinoma from 7th Ed. of AJCC

TNM

Code

Description

T

TX

primary tumor cannot be assessed

T0

no evidence of primary tumor

Tis, Tis (DCIS), Tis (LCIS), Tis (Paget's)

carcinoma in situ, ductal (DCIS) or lobular (LCIS) or Paget's disease

T1

tumor <= 20 mm in maximum dimension

T1mi

tumor <= 1 mm in maximum dimension

T1a

tumor > 1 mm and <= 5 mm in maximum dimension

T1b

tumor > 5 mm and <= 10 mm

T1c

tumor > 10 mm and <= 20 mm

T2

tumor > 20 mm and <= 50 mm in maximum dimension

T3

tumor > 50 mm in maximum dimension

T4

tumor of any size with direct extension to chest wall or skin (ulceration, skin nodule)

T4a

extension to the chest wall (excluding only pectoralis muscle adherence or invasion)

T4b

edema (including peau d'orange) not meeting criteria for inflammatory carcinoma; ulceration of the skin; satellite skin nodules confined to same breast (ipsilateral)

T4c

both T4a and T4b findings

T4d

inflammatory carcinoma

N

NX

regional lymph nodes cannot be assessed, including previous removal

N0

no regional lymph node metastasis

N1

metastasis to ipsilateral level I and/or level II axillary lymph nodes, movable

N1mi

metastasis microscopic only

N2

metastasis to ipsilateral level I and/or II axillary lymph nodes (fixed to one another or to other structures) OR metastasis to ispilateral internal mammary lymph nodes

N2a

metastasis to ipsilateral level I and/or II axillary lymph nodes, fixed to one another (matted) or to other structures, without metastases to ipsilateral mammary lymph nodes

N2b

metastasis in clinically detected ipsilateral internal mammary nodes, without metastases to axillary lymph nodes

N3

metastasis in infraclavicular lymph nodes (Level III axillary); clinically evident metastases in internal mammary and Level I or II axillary lymph nodes; metastasis in ipsilateral supraclavicular lymph nodes

N3a

metastasis to ipsilateral infraclavicular lymph nodes (Level III axillary)

N3b

metastasis to ipsilateral internal mammary AND axillary lymph nodes

N3c

metastasis to ipsilateral supraclavicular lymph nodes

M

M0

no clinical or radiological evidence of distant metastasis

M1

distant metastasis and/or histologically proven > 0.2 mm in diameter

cMo(i+)

no clinical or radiological evidence of distant metastasis but microscopic or molecular evidence of tumor in blood, bone marrow, nonregional lymph node or other site AND <= 0.2 mm in diameter

AJCC Stage

T

N

M

0

is

0

0 or 0(i+)

IA

1mi or 1

0

0 or 0(i+)

IB

0

1mi

0 or 0(i+)

IB

1mi or 1

1mi

0 or 0(i+)

IIA

0

1

0 or 0(i+)

IIA

1mi or 1

1

0 or 0(i+)

IIA

2

0

0 or 0(i+)

IIB

2

1

0 or 0(i+)

IIB

3

0

0 or 0(i+)

IIIA

0

2

0 or 0(i+)

IIIA

1mi or 1

2

0 or 0(i+)

IIIA

2

2

0 or 0(i+)

IIIA

3

1

0 or 0(i+)

IIIA

3

2

0 or 0(i+)

IIIB

4

0

0 or 0(i+)

IIIB

4

1

0 or 0(i+)

IIIB

4

2

0 or 0(i+)

IIIC

any

3

0 or 0(i+)

IV

any

any

1