Stages of Breast Cancer

The stage of breast cancer is determined by the cancer’s characteristics.


Stage 0

Non invasive; hasn’t spread to the surrounding tissue of the breast

Stage I (IA and IB)

    The tumor is small, invasive and
  • Has not spread to the lymph nodes(Stage IA)
  • Has spread to the lymph nodes and is 0.2mm to 2mm in size(Stage IB)

Stage II (IIA and IIB)

  • No evidence of a tumor in the breast, but the cancer has spread to 1 to 3 axillary lymph nodes
  • The tumor is 20 mm or smaller and has spread to 1 to 3 axillary lymph nodes
  • The tumor is larger than 20 mm but not larger than 50 mm and has not spread to the axillary lymph nodes
  • The tumor is larger than 20 mm but not larger than 50 mm and has spread to 1 to 3 axillary lymph nodes
  • The tumor is larger than 50 mm but has not spread to the axillary lymph nodes

Stage III (IIIA ,IIIB, and IIIC)

Stage III breast cancer has a tumor of any size and the cancer has spread to the axillary lymph nodes and some other lymoh nodes and to the chest wall, but not to other parts of the body.

The cancer of any size has spread to 4 to 9 axillary lymph nodes or to internal mammary lymph nodes.

  • The tumor has spread to the chest wall or caused swelling or ulceration of the breast
  • May or may not have spread to up to 9 axillary or internal mammary lymph nodes

Has spread to 10 or more axillary lymph nodes, the internal mammary lymph nodes, and/or the lymph nodes under the collarbone

Stage IV

The tumor can be any size and has spread to other organs, such as the bones, lungs, brain, liver, distant lymph nodes, or chest wall

The different stages can be classified in the following manner (TNM classification)10

may
Stage Primary tumour (T)* Regional lymph node status (L) Distant metastasis (M)
T- Tumour 0 Tis N0 M0
T1 Tumour ≤ 2 cm I T1 N0 M0
T2 Tumour ≥ 2 cm but ≥ 5 cm - T0 N1 M0
T3 Tumour ≥ 5 cm IIA T1 N1 M0
T4 Tumour of any size with direct extension to chest wall or skin - T2 N0 M0
N- Lymph node IIB T2 N1 M0
N0 No cancer in regional node - T3 N0 M0
N1 Regional movable metastasis III A T0 N2 M0
N2 Non-movable regional metastases - T1 N2 M0
N3 Cancer in the internal - T2 N2 M0
M- Metastasis - T3 N1/N2 M0
M0 No distant metastases III B T4 Any N M0
M0 No distant metastases III C Any T N3 M0
M1 Distant metastases IV Any T Any N M1
    References
  1. Breast Cancer Stages Available at https://www.breastcancer.org/symptoms/diagnosis/staging Accessed on 28 July 2021