Types of Breast Cancer
The breast is composed of two main types of tissues: glandular tissues and stromal (supporting) tissues. Glandular tissues house the lobules (milk-producing glands) and the ducts (the milk passages) while stromal tissues include fatty and fibrous connective tissues of the breast. The breast is also made up of lymphatic tissue, which is immune system tissue that removes cellular fluids and waste.
There are several types of tumors that may develop within different areas of the breast. Most are benign, such as fibrocystic changes which may feel lumpy and can cause breast swelling and pain but do not spread and are not life threatening. Malignant tumors are usually hard, painless lumps with irregular edges but some rare cancers are tender, soft and rounded. The most common types of breast cancer are listed below:
Lobular carcinoma in situ (LCIS, lobular neoplasia) is a sharp increase in the number of cells within the lobules of the breast. The term, "in situ," refers to cancer that has not spread past the area where it initially developed. Many physicians do not classify LCIS as breast cancer, but it does increase a woman's risk of developing cancer later in life. Ductal carcinoma in situ (DCIS) is breast cancer at the earliest stage and is confined to the ducts with almost 100% chance of being cured. Infiltrating (invasive) ductal carcinoma (IDC) starts in a duct and penetrates the wall of the duct, invading the fatty tissue of the breast and possibly other regions of the body. IDC is the most common type of breast cancer accounting for nearly 80% of cases. Infiltrating (invasive) lobular carcinoma (ILC) begins in the lobules of the breast but often spreads to other regions of the body. ILC accounts for 10% to 15% of breast cancers.
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Related informational links:
American Cancer Society
American Cancer Society Clinical Trials Matching Service
National Cancer Institute Breast Cancer
CancerNet - A service of the National Cancer Institute
National Breast Cancer Awareness Month
Breast Cancer Net
New York Times - Breast Cancer News
CancerTrack - Tracking cancer online
Mamm Magazine online
Health Central
Breast Cancer Society of Canada