breast cancer
In medicine, cancer of the breast. It is usually diagnosed following the detection of a painless lump in the breast (either through self-examination or mammography). Other, less common symptoms, include changes in the shape or texture of the breast and discharge from the nipple. It is the commonest cancer amongst women: there are 28,000 new cases of breast cancer in Britain each year and 185,700 in the USA.
Treatment
If the tumour is caught early, only it and the immediate surrounding tissue needs removing, in a process called lumpectomy, usually accompanied by radiotherapy. In more advanced cases a
mastectomy is performed. Chemotherapy or hormone-blocking drugs (such as
tamoxifen) may also accompany either procedure. The average survival rate after 5 years was 83.2% in 1996. According to UK epidemiologists in May 2000, deaths from breast cancer had fallen by 25% since the late 1980s. The decline was attributed to early detection and surgery and the use of the drug tamoxifen.
Risk factors
Possible risk factors include a family history of breast cancer (mutations in the genes
BRCA1 and
BRCA2 were found to cause more than 50% of inherited breast cancer cases, in the 1990s); childlessness or late childbearing; early onset of menstruation and late menopause.
| US Medicare patients are more likely to have breast cancer diagnosed at an early stage if they belong to a health maintenance organization (HMO), according to research published in February 1999 in the Journal of the American Medical Association. |
