About
Breast cancer is cancer arising in breast tissue. Cancer is simply a group of abnormal cells that have abnormal growth patterns.
Facts
- Most breast lumps - more than 90% - are discovered by women themselves.
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Eight out of ten breast lumps are not cancerous, but only a health professional can make that diagnosis.
- Breast cancer is the most common type of cancer in women with the exception of nonmelanoma skin cancers. It is the second leading cause of death by cancer in women, following only lung cancer.
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Although breast cancer is primarily a disease of women, almost 1% of breast cancers occur in men.
- A woman has a lifetime risk of developing invasive breast cancer of about one in eight, or 13%.
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Women over the age of 35, those who have a family history of breast cancer, and those who have had cancer in one breast have a greater risk of developing breast cancer.
- The earlier cancers are discovered, the greater the success of treatment.
- Death rates from breast cancer have been gradually declining and continue to decline. These decreases are likely due both to increased awareness, screening and improved treatment methods.
Types of Breast Cancer
- The breasts are made of fat, glands, and connective (fibrous) tissue. The breast has several lobes, which are divided into lobules that end in the milk glands. Tiny ducts run from the many tiny glands, connect together, and end in the nipple. These ducts are where 80% of breast cancers occur. This condition is called ductal cancer.
- Cancer developing in the lobules is termed lobular cancer. About 10-15% of breast cancers are of this type.
- Other less common types of breast cancer include inflammatory breast cancer, medullary cancer, phyllodes tumor, angiosarcoma, mucinous (colloid) carcinoma, mixed tumors, and a type of cancer involving the nipple termed Paget's disease.
- Non invasive changes, called in situ changes, are common. In situ is Latin for "in place" or "in site" and means that the changes haven't spread from where they started. When these in situ changes occur in the ducts, they are called ductal carcinoma in situ (DCIS). DCIS may be identified on routine mammography. When in situ changes happen in the lobules, it is called lobular carcinoma in situ (LCIS). When cancers spread into the surrounding tissues, they are termed infiltrating cancers. Cancers spreading from the ducts into adjacent spaces are termed infiltrating ductal carcinomas.
- Cancers spreading from the lobules are infiltrating lobular carcinomas.
- The most serious cancers are metastatic cancers. Metastasis means that the cancer has spread from the place where it started into other tissues distant from the original tumor site. The most common place for breast cancer to metastasize is into the lymph nodes under the arm or above the collarbone on the same side as the cancer. Other common sites of breast cancer metastasis are the brain, the bones, and the liver.