Breast Cancer

Breast cancer is a type of cancer where cells in the breast tissue divide and grow without the normal control. About 80 percent of breast cancers originate in the mammary ducts, while about 20 percent arise in the lobules [5]. Cancerous tumors in the breast usually grow very slowly so that by the time one is large enough to be felt as a lump, it may have been growing for as long as ten years.

The majority (over 75%) of breast cancers begin in the (milk) ducts within the breast; the next most common site is the lobules - the glandular tissue that makes milk. Most breast cancers are slow-growing and by the time a lump can be felt, it may have been growing for 5 or 10 years. Early breast cancer usually has no symptoms and the earlier a tumor is found, the better the chance of survival. For these reasons it is extremely important for women to be screened regularly by mammography or ultrasound since they may identify a cancerous tumor before it can be felt. In addition, if a lump or thickening can be felt, it is vital to seek a medical evaluation right away.