Breast Cancer Stages

Breast cancer stages are based on a number of things, such as the size of the tumour, whether the lymph nodes are affected, whether or not it is invasive and whether or not the cancer has spread into surrounding tissues and organs.

By determining the stage of your breast cancer you and your carers will be able to understand and determine your prognosis, decide alongside other tests which treatments are most suitable for you, and provide a common description of breast cancer for those working in the field allowing them the opportunity to compare and understand the results of different cancer treatments.

Breast cancer stages are split into the following groupings:

Stage 0

Stage 0 breast cancers are non-invasive and show no sign of the cancer cells or non-cancerous abnormal cells spreading into the surrounding normal tissue.

Stage 1

Stage 1 breast cancers describe invasive breast cancer (ie the cancer cells are spreading into surrounding normal tissue) and the the tumour measures up to 2 centimeters. However, no lymph node are yet affected.

Stage 2

Stage 2 breast cancer is split into 2 groupings, 2A and 2B.

Stage 2A is an invasive breast cancer. It can take several forms:

there is no tumour within the breast. Instead cancer cells are found in the the lymph nodes in the armpit; Or

the tumour is 2 centimeters or less and has spread to the lymph nodes in the armpit; Or

the tumour measures larger than 2 centimeters but smaller than 5 centimeters and has not spread to the lymph nodes in the armpit.

Stage 2B describes invasive breast cancer in which:

the tumour is bigger than 2 centimeters but smaller than 5 centimeters and has spread to the lymph nodes in the armpit, Or

the tumour is bigger than 5 centimeters but has not spread to the lymph nodes in the armpit.

Stage 3

Stage 3 breast cancer is split into 3 groupings, 3A, 3B, and 3C.

Stage 3A is an invasive breast cancer in which either:

no tumour is found in the breast. Cancer is found in axillary lymph nodes that are clumped together or sticking to other structures, or cancer may have spread to lymph nodes near the breastbone, OR
the tumour is 5 centimeters or smaller and has spread to axillary lymph nodes that are clumped together or sticking to other structures, OR
the tumour is larger than 5 centimeters and has spread to axillary lymph nodes that are clumped together or sticking to other structures

Stage 3B describes invasive breast cancer in which:

the tumour may be any size and has spread to the chest wall and/or skin of the breast AND
may have spread to axillary lymph nodes that are clumped together or sticking to other structures, or cancer may have spread to lymph nodes near the breastbone
Inflammatory breast cancer is considered at least stage 3B.

Stage 3C describes invasive breast cancer in which:

there may be no sign of cancer in the breast or, if there is a tumour, it may be any size and may have spread to the chest wall and/or the skin of the breast, AND
the cancer has spread to lymph nodes above or below the collarbone, AND
the cancer may have spread to axillary lymph nodes or to lymph nodes near the breastbone

Stage 4

Stage 4 describes invasive breast cancer in which:

the cancer has spread to other organs of the body. The organs affected are most often the lungs, liver, bone, or brain

"Metastatic at presentation" is a medical term which will be used when breast cancer has spread beyond the breast and nearby lymph nodes. this may be the case even if it is your first diagnosis of breast cancer. What it means is that the primary or initial breast cancer was not discovered whilst it was confined inside the breast. Unfortunately metastatic cancer is considered stage 4.