Key Takeaways
- Breast cancer is staged by TNM: T (tumour size), N (lymph nodes), M (distant metastases).
- T ranges from Tis (in situ) to T4 (chest wall/skin involvement); N0-N3 describe lymph-node spread.
- The Grade (G1-G3) shows how abnormal cells look and how fast the tumour is likely to grow.
- Grade combines with hormone-receptor (ER/PR) and HER2 status to guide treatment.
Breast cancer stage is determined by the TNM classification: T – tumour, N – lymph nodes, M – metastases. The detailed TNM classification gives a precise description of tumour size, lymph-node involvement and metastases, while the malignancy grade (Grade) shows how quickly the tumour grows and spreads.
T — primary tumour
- Tis: carcinoma in situ — a pre-cancerous state (DCIS or Paget's disease without a tumour).
- T1: tumour up to 2 cm in greatest dimension (with subdivisions: T1mi microinvasion ≤0.1 cm; T1a 0.1–0.5 cm; T1b 0.5–1.0 cm; T1c 1–2 cm).
- T2: tumour 2 to 5 cm in greatest dimension.
- T3: tumour greater than 5 cm.
- T4: tumour of any size that has directly infiltrated the chest wall or skin — including chest-wall infiltration (ribs, muscles), skin oedema ("orange-peel" sign) or ulceration, satellite skin nodules in the same breast, or inflammatory carcinoma.
N — metastases in regional lymph nodes
- N0: no regional lymph-node metastases.
- N1: mobile metastases in same-side axillary lymph node(s).
- N2: metastases in same-side axillary nodes fixed to each other or to other structures, or clinically detected internal mammary nodes without axillary involvement.
- N3: metastases in same-side internal mammary and axillary nodes, infraclavicular or supraclavicular nodes (N3a internal nodes; N3b internal plus axillary; N3c supraclavicular).
M — distant metastases
M0: no distant metastases. M1: distant metastases present (for example in the lungs, liver, bones or brain).
What is the cancer malignancy grade (Grade)?
The grade shows how abnormal the cancer cells look and how quickly the tumour is likely to grow and spread. G1: well differentiated — cells look relatively normal and grow slowly. G2: moderately differentiated. G3: poorly differentiated — cells look very abnormal and tend to grow and spread faster. Grade, together with hormone-receptor status (ER/PR) and HER2 status, helps predict behaviour and guide treatment.
Related supplement
Chemotherapy suppresses immunity. Concentrated mushroom polysaccharides are studied for activating NK cells and macrophages.
Lentinan AXT by Zenius Labs™ →How is breast cancer staged?
By the TNM classification: T (tumour size), N (regional lymph nodes), M (distant metastases). T ranges from Tis (in situ) through T1–T4; N from N0 to N3; M0 or M1. These combine into stages 0–4.
What does the breast cancer Grade mean?
The grade shows how abnormal the cells look and how fast the tumour is likely to grow: G1 (well differentiated, slow), G2 (moderate), G3 (poorly differentiated, faster-growing). Grade is used alongside hormone-receptor and HER2 status.
What is carcinoma in situ?
Carcinoma in situ (Tis) is a pre-cancerous state — such as DCIS (ductal carcinoma in situ) or Paget disease without an invasive tumour — where abnormal cells have not yet spread into surrounding tissue.
Can you support the immune system during breast cancer?
Yes. Chemotherapy suppresses the immune system. Concentrated mushroom-polysaccharide extracts are studied for their role in activating NK cells and macrophages. A concentrated multi-extract formula such as Lentinan AXT by Zenius Labs™ is preferable.
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