Stages of breast cancer

The stage of breast cancer is a way of describing how big the breast cancer is and which parts of the body are affected.

The stage is used to decide what treatment options are recommended.

Stages of breast cancer are numbered from 0 to IV:

  • Stage 0 refers to ‘pre-invasive’ breast cancer such as ductal carcinoma in situ (DCIS) or lobular carcinoma in situ (LCIS)
  • Stage I, Stage IIA and Stage IIB (early) refer to early breast cancer
  • Stage IIB (advanced), Stage IIIA, Stage IIIB, Stage IIIC and Stage IV refer to advanced breast cancer (locally advanced breast cancer or secondary breast cancer).

 

Breast cancer stage Size of cancer Have cancer cells been found in...
...lymph nodes? ...other parts of the body?
0 Size not used for stage 0 No No
I <2 cm No No
IIA <2 cm Yes
(Category 1)
No
2–5 cm No No
No cancer found in breast Yes
(Category 1)
No
IIB 2–5 cm Yes
(Category 1)
No
>5 cm No No
IIIA <2 cm Yes
(Category 2)
No
2–5 cm Yes
(Category 2)
No
>5 cm Yes
(Category 1)
No
>5 cm Yes
(Category 2)
No
No cancer found in breast Yes
(Category 2)
No
IIIB Any size but the cancer hasspread to nearby muscles and skin Any
(Can be yes or no)
No
IIIC Any size Yes
(Category 3)
No
IV Any size Any
(Can be yes or no)
Yes

Categories

  • Category 1 means breast cancer cells have been found in one to three lymph nodes in the armpit.
  • Category 2 means breast cancer cells have been found in:
    • 4–9 lymph nodes in the armpit, and the lymph nodes are also enlarged, and/or attached to each other or to nearby tissue; or
    • 1 or more lymph nodes under the breastbone, but not in any lymph nodes in the armpit.
  • Category 3 means breast cancer cells have been found in:
    • 10 or more lymph nodes in the armpit; or
    • 1 or more lymph nodes above or below the collarbone; or
    • 1 or more lymph nodes under the breastbone and 1 or more lymph nodes in the armpit.