Breast cancer develops in the milk-producing glands in the breast, or the passages or ducts that deliver milk to the nipples.
If left untreated, some breast cancers can spread into the surrounding tissue and other parts of the body
What are the symptoms?
Symptoms that may indicate breast cancer include:
A lump or thickening in the breast or armpit
A change in the size, shape or feel of the breast
Changes in the skin of the breast, such as dimpling, puckering or redness
Nipple changes, such as an unusual discharge or change in the direction of the nipple
Changes around the nipple, such as an unusual rash or sore area
Unusual pain or discomfort
Who''s affected?
About one in nine women in the UK gets breast cancer at some point. It''s the most common cancer in the UK.
Breast cancer can occur in men , but is much rarer.
What are the risk factors?
Age - about 80 per cent of women who are diagnosed with breast cancer are over 50 and half of those are over 60
The contraceptive pill - although the level of risk returns to normal after a woman stops taking it
Starting your periods early in life or having a late menopause
A family history of breast cancer
Being overweight after the menopause
Alcohol - the more a woman drinks each day the greater the risk
Hormone replacement therapy (HRT) with the risk increasing the longer it''s taken, but within five years of stopping HRT the risk returns to normal
This risk is reduced by having children at a younger age. The more children a woman has also lowers the risk.
Breastfeeding also reduces the risk.
Genetic factors
About five to ten per cent of breast cancer cases are inherited as a dominant condition.
Mutations in two particular genes have been linked to the disease. These genes, known as BRCA1 and BRCA2, account for about ten per cent of inherited breast cancers. They''re also associated with an increased risk of ovarian cancer.
Mutations of the TP53 tumour-suppressor gene are associated with an increased risk of developing breast cancer.
With most non-inherited breast cancers, genetics also plays a part, but probably through mutations that develop later in life.
People with a strong family history of breast cancer (those with several close relatives who''ve had it, or a mother or sister who developed the disease before the age of 50 or before the menopause) may be offered an assessment of their risk and genetic
screening using a blood test, if appropriate.
How is it diagnosed?
Most cases are picked up when a woman notices a lump in her breast or through routine screening with mammography. Nine out of ten lumps aren''t dangerous, but they should be checked.
Being breast aware, reporting any changes and, for women aged between 50 and 70, attending NHS mammogram screenings help to identify breast cancer early. Women with a strong family history may be offered screening before 50.
The incidence of breast cancer appears to be rising, probably due to better screening. Fortunately, cure rates are also rising. During the past decade, deaths from breast cancer have fallen by 20 per cent.
What''s the treatment?
Treatment for breast cancer includes surgery, radiotherapy, chemotherapy, biological therapy and hormone therapy (for example, tamoxifen).
Emotional support for the individual and their family is important.