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Breast cancer is a malignant tumor that starts from cells of the breast. A malignant tumor is a group of cancer cells that may grow into (invade) surrounding tissues or spread (metastasize) to distant areas of the body.The breast tissue covers an area larger than just the breast. It extends up to the collarbone and from the armpit across to the breastbone in the centre of the chest. The breasts sit on the chest muscles that cover the ribs. Each breast is made of glands, ducts (thin tubes) and fatty tissue. Lobules are groups of glands that can produce milk. Milk flows from the lobules through a network of ducts to the nipple. The nipple is in the centre of a darker area of skin called the areola. Fatty tissue fills the spaces between the lobules and ducts and protects them.
A woman’s breasts may feel different at different times of her menstrual cycle, sometimes becoming lumpy just before her period. Breast tissue also changes with age. Breast tissue in younger women is mostly made of glands and milk ducts, but older women’s breasts are made up mostly of fatty tissue.
Types of breast cancer
There are several different types of breast cancer, which can develop in different parts of the breast. The most common is known as ductal breast cancer, which develops in the cells that line the breast ducts. Ductal breast cancer accounts for about 80% of all cases of breast cancer.
Other less common types of breast cancer include lobular breast cancer, which develops in the cells that line the milk-producing lobules, inflammatory breast cancer and Paget's disease of the breast. Breast cancer can spread to other parts of the body, such as the liver, bones or lymph nodes (small glands that remove bacteria from the body).
To understand breast cancer, it helps to have some basic knowledge about the normal structure of the breasts. The female breast is made up mainly of lobules (milk-producing glands), ducts (tiny tubes that carry the milk from the lobules to the nipple), and stroma (fatty tissue and connective tissue surrounding the ducts and lobules, blood vessels, and lymphatic vessels).
The lymph system is important to understand because it is one of the ways in which breast cancers can spread. This system has several parts.
Lymph nodes are small, bean-shaped collections of immune system cells (cells that are important in fighting infections) that are connected by lymphatic vessels. Lymphatic vessels are like small veins, except that they carry a clear fluid called lymph (instead of blood) away from the breast. Lymph contains tissue fluid and waste products, as well as immune system cells. Breast cancer cells can enter lymphatic vessels and begin to grow in lymph nodes.
Breast cancer is the most common malignancy affecting women in North America and Europe. Close to 200,000 cases of breast cancer were diagnosed in the United States in 2001. Breast cancer is the second leading cause of cancer death in American women behind lung cancer. The lifetime risk of any particular woman getting breast cancer is about 1 in 8 although the lifetime risk of dying from breast cancer is much lower at 1 in 28. Men are also at risk for development of breast cancer, although this risk is much lower than it is for women.
Breast self-exam should be part of your monthly health care routine, and you should visit your doctor if you experience breast changes. If you're over 40 or at a high risk for the disease, you should also have an annual mammogram and physical exam by a doctor. The earlier breast cancer is found and diagnosed, the better your chances of beating it.
The actual process of diagnosis can take weeks and involve many different kinds of tests. Waiting for results can feel like a lifetime. The uncertainty stinks. But once you understand your own unique “big picture,” you can make better decisions. You and your doctors can formulate a treatment plan tailored just for you.
General Breast Cancer Terms |
