If you have suspected breast cancer, either because of your symptoms or because your mammogram has shown an abnormality, you'll be referred to a specialist breast cancer clinic for further tests.
If you have symptoms and have been referred to a specialist breast unit by your GP, you'll probably be invited to have a mammogram, which is an X-ray of your breasts. You may also need an ultrasound scan.
If your cancer was detected through the NHS Breast Screening Programme, you may need another mammogram or ultrasound scan.
Your doctor may suggest that you only have a breast ultrasound scan if you're under the age of 35. This is because younger women have denser breasts, which means a mammogram isn't as effective as ultrasound in detecting cancer.
Ultrasound uses high-frequency sound waves to produce an image of the inside of your breasts, showing any lumps or abnormalities.
Your breast specialist may also suggest a breast ultrasound if they need to know whether a lump in your breast is solid or contains liquid.
Read more about breast screening.
A biopsy is where a sample of tissue cells is taken from your breast and tested to see if it's cancerous.
You may also need a scan and a needle test on lymph nodes in your armpit (axilla) to see whether these are also affected.
Biopsies can be taken in different ways, and the type you have will depend on what your doctor knows about your condition.
Different methods of carrying out a biopsy are discussed below.
Needle aspiration may be used to test a sample of your breast cells for cancer or drain a small fluid-filled lump (benign cyst).
Your doctor will use a small needle to extract a sample of cells, without removing any tissue.
Needle biopsy is the most common type of biopsy. A sample of tissue is taken from a lump in your breast using a large needle.
You'll have a local anaesthetic, which means you'll be awake during the procedure, but your breast will be numb.
Your doctor may suggest that you have a guided needle biopsy, usually guided by ultrasound or X-ray, but sometimes MRI, to obtain a more precise and reliable diagnosis of cancer.
This also can distinguish it from any non-invasive change, particularly ductal carcinoma in situ (DCIS).
Vacuum-assisted biopsy, also known as mammotome biopsy, is another type of biopsy.
During the procedure, a needle is attached to a gentle suction tube, which helps to obtain the sample and clear any bleeding from the area.
If a diagnosis of breast cancer is confirmed, more tests will be needed to determine the stage and grade of the cancer, and work out the best method of treatment.
Computerised tomography (CT) scans or chest X-ray and liver ultrasound scans may be needed to check whether the cancer has spread.
An MRI scan of the breast may be needed to clarify the results or assess the extent of the condition within the breast.
If your doctor thinks the cancer could have spread to your bones, you may need a bone scan.
Before having a bone scan, a substance containing a small amount of radiation known as an isotope will be injected into a vein in your arm.
This will be absorbed into your bone if it's been affected by cancer. The affected areas of bone will show up as highlighted areas on the bone scan, which is carried out using a special camera.
You'll also need tests that show whether the cancer will respond to specific types of treatment.
The results of these tests can give your doctors a more complete picture of the type of cancer you have and how best to treat it.
The types of test you could be offered are discussed below.
In some cases, breast cancer cells can be stimulated to grow by hormones that occur naturally in your body, such as oestrogen and progesterone.
If this is the case, the cancer may be treated by stopping the effects of the hormones or by lowering the level of these hormones in your body. This is known as hormone therapy.
During a hormone receptor test, a sample of cancer cells will be taken from your breast and tested to see if they respond to either oestrogen or progesterone.
If the hormone is able to attach to the cancer cells using a hormone receptor, they're known as hormone receptor positive.
While hormones can encourage the growth of some types of breast cancer, other types are stimulated by a protein called human epidermal growth factor receptor 2 (HER2).
These types of cancer can be diagnosed using a HER2 test, and are treated with medication to block the effects of HER2. This is known as biological or targeted therapy.
When your breast cancer is diagnosed, the doctors will give it a stage. The stage describes the size of the cancer and how far it has spread, and helps to predict the outlook.
Ductal carcinoma in situ (DCIS) is sometimes described as stage 0. Other stages of breast cancer describe invasive breast cancer:
This is a simplified guide. Each stage is divided into further categories: A, B and C. If you're not sure what stage you have, ask your doctor.
The TNM staging system may also be used to describe breast cancer, as it can provide accurate information about the diagnosis:
The grade describes the appearance of the cancer cells.