Quick facts

• Breast cancer is the most common cancer in women in the UK.
• A breast lump is the first symptom in 9 out of 10 breast cancers.
• Breast cancer can affect men. We have a separate guide for men with breast cancer .
• Treatment for breast cancer may include a combination of surgery, radiotherapy, chemotherapy, drugs to block hormones or their effects on cancer cells (hormonal therapies), and a drug called Herceptin® (trastuzumab).
• The type of treatment you have will depend on many factors, including the size of the tumour and whether you have had your menopause.

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

• Ductal carcinoma in situ (DCIS)
• Lobular carcinoma in situ (LCIS)
• Invasive breast cancer
• Related conditions
• Rarer types of breast cancer

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.

• Invasive ductal breast cancer occurs when the cells that line the duct have become cancerous and have spread into the surrounding breast tissue. It is the most common type of breast cancer; between 70-80% (7 to 8 out of every 10) of all breast cancers are this type.
  
  
• Invasive lobular breast cancer develops from the cells that line the lobes of the breast. They have a different appearance to ductal cancers and have a particular pattern of spread in the surrounding breast tissue. Approximately 10% (1 in 10) of breast cancers are this type.
  
  
• Inflammatory breast cancer is a rare type of breast cancer in which the cancer cells block the tiny channels (lymph vessels) in the skin and tissues of the breast. This causes the breast to become swollen, red and inflamed. The breast may also feel warm and tender to the touch. Chemotherapy is usually the first treatment, often followed by a combination of radiotherapy , hormonal therapy and surgery . About 1 to 2% (1 to 2 in every 100) of all breast cancers are inflammatory breast cancer.

Note: A separate factsheet is available for inflammatory breast cancer.

Related conditions

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:

• 'Ductal' means the cancer cells developed in the ducts, the tubes that carry milk to the nipple.
• 'Lobular' means the cancer cells began in the lobes or lobules, where milk is produced.
• 'In situ' means the cancer cells are completely contained within the ducts or lobes.
• 'Invasive' means the cancer has spread from the ducts or lobes into the surrounding breast tissue.
• A 'carcinoma' is a type of cancer (except when mentioned in the context of LCIS, above).

Rarer types of breast cancer

There are a number of rarer types of breast cancer such as:

• medullary breast cancer
• mucinous breast cancer
• tubular breast cancer

Your doctor or nurse, can give you more information about these rarer types of breast cancer.

Breast cancer causes and risk factors

Overview

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.

Risk factors

A personal history of breast cancer or certain breast diseases

• Women who have had breast cancer before are at a greater risk of developing a new breast cancer.
• Certain types of benign breast disease – lobular carcinoma in situ (LCIS) or atypical hyperplasia – are associated with an increased risk of breast cancer.

Hormonal factors

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.

• Women who are taking combined hormone replacement therapy (HRT), or have recently taken it, have a slightly increased risk of breast cancer. Younger women who take HRT because they have had an early menopause or have had their ovaries removed do not have an increased risk of breast cancer until after the age of 50.
• Women who are taking the contraceptive pill, or have recently taken it, have a very slightly increased risk of developing breast cancer.
• Women who don't have children are slightly more likely to develop breast cancer than women who have children.
• Women who have never breastfed are slightly more likely to develop breast cancer than women who have breastfed for more than a year.
• Women who start their periods at a young age (early puberty) or have a late menopause have a slightly higher risk of breast cancer.

Lifestyle

• Drinking more than two units of alcohol a day over many years can increase the risk. A unit of alcohol is half a pint of normal strength lager or beer, a small glass (125ml) of wine, or a single measure (25ml) of spirit.
• Being overweight, once you have had your menopause, can increase the risk of breast cancer.

Genetics

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.

Breast self-awareness

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.