Breast Cancer — TNM (Anatomic Stage)

AJCC 8th edition (2017) anatomic stage from T / N / M. Biomarkers are recorded but the prognostic stage is not computed here.

T — primary tumour

Tis — carcinoma in situ (DCIS) or Paget disease without an invasive tumour

T0 — no evidence of primary tumour

T1mi — microinvasion ≤ 1 mm

T1a — > 1 to ≤ 5 mm

T1b — > 5 to ≤ 10 mm

T1c — > 10 to ≤ 20 mm

T2 — > 20 to ≤ 50 mm

T3 — > 50 mm

T4a — extension to the chest wall (not pectoralis alone)

T4b — skin oedema (peau d'orange), ulceration, or satellite skin nodules

T4c — both T4a and T4b

T4d — inflammatory carcinoma

N — regional lymph nodes

N0 — no regional lymph node metastasis

N1mi — micrometastases (> 0.2 mm or > 200 cells, none > 2 mm)

N1 — 1–3 axillary nodes, and/or internal mammary nodes detected only by sentinel biopsy

N2 — 4–9 axillary nodes, or clinically detected internal mammary nodes without axillary involvement

N3 — ≥ 10 axillary nodes, or infraclavicular/supraclavicular nodes, or extensive internal mammary + axillary disease

M — distant metastasis

M0 — no distant metastasis

M1 — distant metastasis

Biomarkers (recorded — not used for staging)

Histological grade

Grade 1 — well differentiated

Grade 2 — moderately differentiated

Grade 3 — poorly differentiated

Oestrogen receptor (ER)

Positive

Negative

Unknown / not done

Progesterone receptor (PR)

Positive

Negative

Unknown / not done

HER2

Positive

Negative

Unknown / not done

Evidence

Original publication

Giuliano AE, Connolly JL, Edge SB, et al. Breast cancer — major changes in the AJCC eighth-edition cancer staging manual. Retained the anatomic (TNM) stage and added a prognostic stage that incorporates histological grade and ER, PR and HER2 status; biomarkers can move the prognostic stage up or down relative to the anatomic stage.

CA: A Cancer Journal for Clinicians, 2017

Open source

Guideline

Amin MB, Edge SB, Greene FL, et al., eds. AJCC Cancer Staging Manual, 8th edition. Chicago: Springer; 2017. Only the flagship prognostic-stage rules are implemented here; combinations not covered fall back to the anatomic stage. Confirm the assigned stage against the full AJCC prognostic-stage table.

Last reviewed: 2026-09

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