Breast cancer is the most common type of cancer in the UK. Most women diagnosed with breast cancer are over 50, but younger women can also get breast cancer.
About one in eight women are diagnosed with breast cancer during their lifetime. There’s a good chance of recovery if it’s detected in its early stages.
For this reason, it’s vital that women check their breasts regularly for any changes and always get any changes examined by their GP.
In rare cases, men can also be diagnosed with breast cancer. Read about breast cancer in men.
Symptoms of breast cancer
Breast cancer can have a number of symptoms, but the first noticeable symptom is usually a lump or area of thickened breast tissue.
Most breast lumps aren’t cancerous, but it’s always best to have them checked by your doctor.
You should also see your GP if you notice any of the following:
- a change in the size or shape of one or both breasts
- discharge from either of your nipples, which may be streaked with blood
- a lump or swelling in either of your armpits
- dimpling on the skin of your breasts
- a rash on or around your nipple
- a change in the appearance of your nipple, such as becoming sunken into your breast
Breast pain isn’t usually a symptom of breast cancer.
Causes of breast cancer
The exact causes of breast cancer aren’t fully understood. However, there are certain factors known to increase the risk of breast cancer.
- age – the risk increases as you get older
- a family history of breast cancer
- a previous diagnosis of breast cancer
- a previous benign breast lump
- being tall, overweight or obese
- excessive use of alcohol
Diagnosing breast cancer
After examining your breasts, your GP may refer you to a specialist breast cancer clinic for further tests. This might include breast screening (mammography) or a biopsy.
Tests at the breast cancer clinic
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.
Mammogram and breast ultrasound
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.
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.
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
Further tests for breast cancer
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.
Scans and X-rays
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.
Tests to determine specific types of treatment
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
Stage and grade of breast cancer
Stage of breast cancer
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:
- stage is – the tumour is “in situ” and there’s no evidence of invasion (pre-invasive)
- stage 1 – the tumour measures less than 2cm and the lymph nodes in the armpit aren’t affected; there are no signs that the cancer has spread elsewhere in the body
- stage 2 – the tumour measures 2-5cm, the lymph nodes in the armpit are affected, or both; there are no signs that the cancer has spread elsewhere in the body
- stage 3 – the tumour measures 2-5cm and may be attached to structures in the breast, such as skin or surrounding tissues, and the lymph nodes in the armpit are affected; there are no signs that the cancer has spread elsewhere in the body
- stage 4 – the tumour is of any size and the cancer has spread to other parts of the body (metastasis)
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.
TNM staging system
The TNM staging system may also be used to describe breast cancer, as it can provide accurate information about the diagnosis:
- T – the size of the tumour
- N – whether the cancer has spread to the lymph nodes
- M – whether the cancer has spread to other parts of the body
Grade of breast cancer
The grade describes the appearance of the cancer cells.
- low grade (G1) – the cells, although abnormal, appear to be growing slowly
- medium grade (G2) – the cells look more abnormal than low-grade cells
- high grade (G3) – the cells look even more abnormal and are more likely to grow quickly
Types of breast cancer
There are several different types of breast cancer, which can develop in different parts of the breast.
Breast cancer is often divided into:
- non-invasive breast cancer (carcinoma in situ) – found in the ducts of the breast (ductal carcinoma in situ, DCIS) and hasn’t developed the ability to spread outside the breast. It’s usually found during a mammogram and rarely shows as a breast lump.
- invasive breast cancer – usually develops in the cells that line the breast ducts (invasive ductal breast cancer) and is the most common type of breast cancer. It can spread outside the breast, although this doesn’t necessarily mean it has spread.
Other less common types of breast cancer include:
- invasive (and pre-invasive) lobular breast cancer
- inflammatory breast cancer
- Paget’s disease of the breast
It’s possible for breast cancer to spread to other parts of the body, usually through the bloodstream or the axillary lymph nodes. These are small lymphatic glands that filter bacteria and cells from the mammary gland.
If this happens, it’s known as secondary, or metastatic, breast cancer.
Treating breast cancer
If cancer is detected at an early stage, it can be treated before it spreads to nearby parts of the body.
Breast cancer is treated using a combination of:
Surgery is usually the first type of treatment you’ll have, followed by chemotherapy or radiotherapy or, in some cases, hormone or biological treatments.
The type of surgery and the treatment you have afterwards will depend on the type of breast cancer you have. Your doctor will discuss the best treatment plan with you.
In a small proportion of women, breast cancer is discovered after it’s spread to other parts of the body (metastatic breast cancer).
Secondary cancer, also called advanced or metastatic cancer, isn’t curable, so the aim of treatment is to achieve remission (symptom relief).