This information is about primary breast cancer (stages 1-3). We also have information on breast cancer that has spread to other parts of the body or come back after treatment (secondary breast cancer ).
About breast cancer
About the breasts
The breasts are made up of fat, connective tissue and glandular tissue. They have lobes, where breast milk is made, and ducts, which connect the lobes to the nipple.
A woman's breasts are rarely the same size as each other, and may feel different at different times of the menstrual cycle, sometimes becoming lumpy just before a period.
Under the skin, an area of breast tissue extends into the armpit (axilla). The armpits also contain a collection of lymph nodes (lymph glands), which are part of the lymphatic system.
There are also lymph nodes just beside the breastbone and behind the collarbones.
Types of breast cancer and related conditions
There are different types of breast cancer. They are usually named after the types of cells from which it is thought the cancer has developed. Most breast cancers start in the cells lining the ducts (the channels in the breast that carry milk to the nipple) and spread into the surrounding breast tissue. This is known as invasive ductal breast cancer. There are other, less common types of breast cancer. Knowing the exact type of cancer helps the doctors to decide on the most appropriate treatment.
Learn more about these types and related conditions, including how they are diagnosed and treated, by clicking on the links below.
Ductal carcinoma in situ (DCIS): (separate factsheet available)
DCIS is a condition in which breast cancer cells have developed within some of the breast ducts (the channels in the breast that carry milk to the nipple). The abnormal cells are completely contained within the ducts and have not spread into the surrounding breast tissue. Because the cancer cells have not spread outside of the ducts, DCIS is sometimes referred to as pre-cancerous, pre-invasive, non-invasive, or intraductal cancer.
Lobular carcinoma in situ (LCIS) : (separate factsheet available)
LCIS means that there are changes to the cells lining the lobules (where milk is produced) of the breast. It is not cancer, but it means there is a small increase in the risk of developing breast cancer later. Most women with LCIS will never develop breast cancer or need treatment, but doctors usually will recommend regular breast examinations so that any changes can be recognised early if they do occur.
Invasive breast cancer :
If cancer cells have spread beyond the lining of the ducts or lobules into the surrounding breast tissue, it is called invasive breast cancer.
Note: A separate factsheet is available for inflammatory breast cancer.
Paget's disease of the breast : (separate factsheet available)
Paget's disease of the breast is a change in the skin of the nipple that usually first appears as a scaly, red rash. Some women may notice an itching or burning sensation, and there may be oozing or bleeding from the nipple or the darker area surrounding it (areola). About 9 in 10 women with Paget's disease of the breast will have an underlying breast cancer. Treatment will depend on whether or not cancer is present, the type of tumour and how much of the breast is affected.
Making sense of medical terms
The types of breast cancer are named according to the place the cancer started, and whether it has spread into the breast tissue:
Rarer types of breast cancer
There are a number of rarer types of breast cancer such as:
Your doctor or nurse, can give you more information about these rarer types of breast cancer.
Breast cancer causes and risk factors
About 44,000 people in the UK each year are diagnosed with breast cancer. The causes of breast cancer are not yet completely understood, but it is known that some factors (known as risk factors) may increase a woman's risk of developing the disease. The risk of developing breast cancer is very small in young women and increases as women get older. Eight out of ten (80%) breast cancers occur in women over the age of 50. Other risk factors include being overweight, having a significant family history of breast cancer, using hormone replacement therapy after the age of 50 or taking the contraceptive pill.
This booklet is for women with breast cancer. We also have information about breast cancer in men.
A personal history of breast cancer or certain breast diseases
As the female hormone oestrogen can affect the development of breast cancer, exposure to oestrogen (without any breaks) over a long period can increase the risk. The following risk factors are related to oestrogen exposure.
A very small number – between 5–10% (1 in 20 – 1 in 10) – of breast cancers are thought to be related to faulty genes that run in families. The two main genes linked to breast cancer are BRCA1 and BRCA2. If you have a strong family history of breast or ovarian cancer, it is possible that you have inherited a faulty cancer gene. But keep in mind that breast cancer is the most common cancer in women in the UK, so even if you have one or even two elderly family members with breast cancer, it is unlikely that you carry one of these gene changes (mutations).
If you are worried about your breast cancer risk, we have more detailed information on breast cancer risk factors and cancer genetics.
Early detection and screening
The earlier a breast cancer is diagnosed and treated, the better the chance of successful treatment. By checking your breasts regularly for lumps and other changes, you can improve your chances of finding breast cancer at an early, curable stage. Women in the UK at higher risk of developing breast cancer because of their age or family history are eligible for regular breast screening as part of a national screening programme.
It's important to become familiar with how your breasts normally feel at different times of the month. You'll then be able to pick up any changes in your breasts that aren't normal for you. If you are concerned about anything unusual in your breasts, you can make an appointment with your GP.
UK National Breast Screening Programme: (this is for information only).
In the UK, all women between the ages of 50 and 70 (64 in Northern Ireland) are offered mammograms (breast x-rays) every three years, as part of a national breast screening programme. Women over the age of 70 can ask to continue with three-yearly mammograms.
Women may be eligible for regular screening at a younger age if they are at higher risk of developing breast cancer because of their family history. If you have a close relative with breast cancer, you can discuss with your GP whether you should have regular screening before the age of 50.
What is screening?
Screening is testing to detect cancer early, before symptoms are noticed, or to find changes that could develop into cancer later if left untreated.