Staging and grading of breast cancer in women
The stage of a cancer describes its size and if it has spread from where it started. This information affects the decisions you and your doctor make about yourtreatment . They won’t know the exact stage of the cancer until after your operation
The TNM staging system gives the complete stage of the cancer:
T describes the size of the tumour.
N describes whether the cancer has spread to the lymph nodes and which nodes are involved. For example, N0 is no lymph nodes affected while N1 means there are cancer cells in 1–3 of the lymph nodes.
M describes if the cancer has spread to another part of the body. For example, M0 means the cancer has not spread (metastasised) to other parts of the body.
Breast cancer can also be divided into four number stages:
The cancer (lump) is 2cm or smaller and has not spread to the lymph nodes in the armpit.
Stage 2 is divided into two stages:
Stage 2A – the cancer is smaller than 2cm and has spread to the lymph nodes in the armpit OR is bigger than 2cm and has not spread to the lymph nodes OR it can’t be found in the breast but is in the lymph nodes.
Stage 2B – the cancer is smaller than 5cm and has spread to the lymph nodes in the armpit OR is bigger than 5cm but has not spread to the lymph nodes.
Stage 1 or 2 breast cancer is often called early breast cancer.
Stage 3 is divided into three stages:
Stage 3A – the cancer can’t be found in the breast OR it is under 5cm and has spread to the lymph nodes in the armpit (which are clumped together) OR it is bigger than 5cm and has spread to the lymph nodes.
Stage 3B – the cancer has spread to tissue near the breast and may be attached to skin or muscle. There are usually cancer cells in the lymph nodes in the armpit.
Stage 3C – the cancer has spread to 10 or more lymph nodes in the armpit, or to lymph nodes below the breastbone, near the neck or under the collarbone.
Sometimes stage 3 breast cancer is called locally advanced breast cancer.
The cancer has spread to other parts of the body such as the bones, liver or lungs. This is called secondary or metastatic breast cancer.
The grade of a cancer gives an idea of how quickly it might grow. The grade is decided based on what the cancer cells look like under a microscope compared with normal cells. Knowing the grade helps your doctor decide which other treatments you need after surgery.
Grade 1 or low-grade
The cancer cells look similar to normal cells (are well differentiated) and usually grow slowly. The cancer cells are less likely to spread.
Grade 2 or moderate- or intermediate-grade
The cancer cells look more abnormal and grow slightly faster than grade 1 cells.
Grade 3 or high-grade
The cancer cells look very different from normal cells (are poorly differentiated) and may grow quicker than grade 1 or 2 cells.