TNM Classification and Clinical Staging of Breast Carcinoma

Description

Staging of breast carcinoma is useful to determine a patient's prognosis and to assist in planning therapeutic intervention.

Staging elements:

(1) primary tumor

(2) lymph node involvement

(3) distant metastases

Anatomic subsites of the female breast:

(1) nipple

(2) central subareolar region

(3) lower inner quadrant

(4) lower outer quadrant

(5) upper inner quadrant

(6) upper outer quadrant

(7) axillary tail

Regional lymph nodes to the breast:

(1) axillary

(1a) Level I (low axilla): lymph nodes lateral to the lateral border of the pectoralis minor muscle; includes also intra-mammary lymph nodes

(1b) Level II (mid-axilla): lymph nodes between the medial and lateral borders of the pectoralis minor muscle and the interpectoral lymph nodes

(1c) Level III (apical axilla): lymph nodes medial to the medial margin of the pectoralis minor muscle, including those designated subclavicular, infraclavicular or apical

(2) internal mammary, ipsilateral

Lymph nodes coded as distant metastasis:

(1) ipsilateral supraclavicular

(2) ipsilateral cervical

(3) contralateral internal mammary

(4) other lymph node involvement

TNM Clinical Classification

TNM	Code	Description
T	TX	primary tumor cannot be assessed
	T0	no evidence of primary tumor
	Tis	carcinoma in situ
	T1	tumor <= 2 cm in maximum dimension
	T1a	tumor <= 0.5 cm in maximum dimension
	T1b	tumor > 0.5 and <= 1 cm
	T1c	tumor > 1 cm and <= 2 cm
	T2	tumor > 2 cm and <= 5 cm in maximum dimension
	T3	tumor > 5 cm in maximum dimension
	T4	tumor of any size with direct extension to chest wall or skin
	T4a	extension to the chest wall
	T4b	edema (including peau d'orange) ulceration of the skin satellite skin nodules confined to same breast
	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 lymph nodes, movable
	N2	metastasis to ipsilateral lymph nodes, fixed to one another or to other structures
	N3	metastasis to ipsilateral internal mammary lymph nodes
M	MX	presence of distant metastasis cannot be assessed
	M0	no distant metastasis
	M1	distant metastasis

where:

• multiple simultaneous ipsilateral tumors are assigned the T designation for the largest focus, but annotated as "multiple simultaneous ipsilateral carcinomas"

• inflammatory carcinoma is a condition due to dermal lymphatic invasion, resulting in a diffuse, brawny induration of the skin with an erysipeloid edge.

• simple skin dimpling or nipple retraction does not change the classification

AJCC Stage	T	N	M	approximate 5 year survival
0	is	0	0	100%
I	1	0	0	95%
IIA	0 1 2	1 1 0	0 0 0	85%
IIB	2 3	1 0	0 0	70%
IIIA	0 1 2 3	2 2 2 1-2	0 0 0 0	50%
IIIB	4	1-3	0	48%
IV	1-4	1-3	1	18%

5 year survival estimated from Figure 25-1, page 165, AJCC (1993).

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Description

Specialty

ICD-10