Breast Cancer Prevention (PDQ®)
Cancer Information Summaries « English « Patients « B
General Information About Breast Cancer
Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts. Anatomy of the breast, showing lymph nodes and lymph vessels.
Each breast also has blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. Lymph vessels lead to organs called lymph nodes. Lymph nodes are small bean-shaped structures that are found throughout the body. They filter lymph and store white blood cells that help fight infection and disease. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.
Breast cancer is the second most common type of cancer in American women.
Women in the United States get breast cancer more than any other type of cancer except skin cancer. The number of new cases has increased every year over the last 30 years. Breast cancer is second to lung cancer as a cause of cancer death in American women. However, deaths from breast cancer have decreased a little bit every year for the past several years. Breast cancer also occurs in men, but the number of new cases is small.
Finding and treating breast cancer early may prevent death from breast cancer. Screening tests may be used to help find breast cancer. See the PDQ summary on Screening for Breast Cancer for more information.
This record was last updated on November 13th, 2008.
About the PDQ Cancer Information Summaries from the National Cancer Institute
PDQ (Physician Data Query) is a comprehensive cancer database published by the National Cancer Institute (NCI), which is part of the National Institutes of Health (NIH). It contains peer-reviewed summaries on cancer treatment, screening, prevention, genetics, and supportive care, and complementary and alternative medicine; a registry of cancer clinical trials; and directories of physicians, professionals who provide genetics services, and organizations that provide cancer care.
The PDQ Cancer Information Summaries are peer reviewed and updated monthly by six editorial boards comprised of specialists in adult treatment, pediatric treatment, supportive care, screening and prevention, genetics, and complementary and alternative medicine. The Boards review current literature from more than 70 biomedical journals, evaluate its relevance, and synthesize it into clear summaries. Many of the summaries are also available in Spanish.
Linked medical terms appearing on this page are added by Healia to help readers find more information and are not part of the original PDQ document.