Breast cancer grade

Breast cancers are given a grade according to:

• How different the cancer cells are to normal breast cells 
• How quickly they are growing

The grade of cancer is different from the cancer stage. 

A doctor called a pathologist will look at the cancer cells under a microscope to determine the grade. They’ll do this using tissue from a biopsy or after breast cancer surgery.

There are 3 grades of invasive breast cancer:

1. Grade 1 – the cells look the most like normal breast cells and are slower growing
2. Grade 2 – the cells look less like normal breast cells and are growing faster than grade 1
3. Grade 3 – the cells look the least like normal breast cells and are growing quicker

Sometimes the grade given to a cancer after a biopsy can change after surgery. This is because there’s more tissue for the pathologist to look at after surgery, which can give them more detailed information about the cancer.

Your treatment team will consider the grade of your cancer when deciding which treatment to offer you. 

If you have grade 3 breast cancer, you’re more likely to be offered chemotherapy. This is to help destroy any cancer cells that may have spread as a result of the cancer growing more quickly.  

You’re less likely to be offered chemotherapy for grade 1 and grade 2 cancers. 

Your treatment team will consider the grade alongside all other information about your cancer when deciding on the best treatment options for you.

DCIS is an early form of breast cancer.

There are 3 grades of DCIS. DCIS is graded as:

1. Low grade – the cancer cells look most like normal breast cells and are usually slow-growing
2. Intermediate grade – the cancer cells look less like normal breast cells and are growing faster than low grade
3. High grade – the cancer cells look different to normal breast cells and may be fast-growing