The treatment of breast cancer depends on many factors, including:

• the stage and grade of the cancer
• your age
• whether or not you have had the menopause
• the size of the tumour
• whether the cancer cells have receptors for certain hormones (such as oestrogen) or particular proteins (such as HER2).

Most breast cancers will be treated with surgery to remove the tumour. All, or part, of the breast tissue may be removed. If the whole breast is removed, breast reconstruction may be carried out, either at the same time as the initial surgery or later. Sometimes chemotherapy or hormonal therapy may be given to shrink a cancer before surgery. This is known as neoadjuvant therapy.

After surgery, radiotherapy may be given to the breast tissue, to make sure any cancer cells that may be left in the area are destroyed. After surgery, the doctors can tell the stage and the grade of the cancer, and they can look at several other factors to predict how likely the cancer is to come back or spread.

Factors which affect the chance of the cancer coming back include:

• the size of the tumour
• whether the lymph nodes in the armpit were affected
• the grade of the tumour
• whether the cancer cells have spread into lymph or blood vessels close to the tumour (the pathologist checks for this)
• whether the cells have receptors for oestrogen or particular proteins (such as HER2) on their surface.

If the chance of the cancer spreading or coming back is very low, further treatment is not necessary. However, most women will be advised to have treatment with chemotherapy or hormonal therapy to reduce the chance of the cancer coming back. This is known as adjuvant therapy. Some women may have both treatments, but not at the same time. Some women have a large number of HER2 protein receptors on the surface of their cancer cells. This is known as being HER2 positive. In this situation, treatment with Herceptin® (trastuzumab) may be helpful. Your cancer specialist can discuss this with you.

Doctors can use various methods of calculating the chance of the cancer having spread or coming back. These are only a rough guide and cannot predict what will happen to an individual woman with breast cancer. However, they can give some idea of how effective treatment is likely to be. These methods use the following information:

• stage of the cancer
• grade of the cancer
• and whether the cells have oestrogen or HER2 receptors.

One of the most commonly used methods in the UK is the Nottingham Prognostic Index. Another method is Adjuvant-on-line.

This uses the factors above, and results from clinical trials in breast cancer, to predict a woman’s chance of being alive at 5 and 10 years after diagnosis if they have particular treatments after surgery and radiotherapy. It can help to show which of these treatments are likely to reduce the chance of the cancer coming back or spreading, and by how much.

This section discusses the treatments for stage 1-3 breast cancer. Our section on secondary breast cancer, discusses the treatments for secondary breast cancer

If you have any questions about your treatment, don’t be afraid to ask your doctor or hospital nurse. You may like to take a close relative or friend with you to remind you of questions at the time or the answers afterwards. It often helps to make a list of the questions you want to ask and the answers that you are given.