The Physiology of Breast Cancer

At the Breast Specialty of Baton Rouge, we feel that it is important to educate our patients about every aspect of their illness. Keeping informed can help many people better cope with having cancer. Firstly, we would like to discuss a little bit about the physiology of the breast and how cancer can affect it.

A woman’s breast is made up of 15-20 lobes. And each lobe is made up of smaller sections, called lobules, inside of which are tiny groups of milk-producing glands. After a baby is born, the body begins to allow that breast milk to flow from the lobes, through thin ducts to the nipple. Fibrous tissue and fat fill the spaces between the lobules and ducts.

The cancer will usually begin in the cells that line the duct flowing from the lobes to the nipple. This is call ductal carcinoma. About 7 of every 10 women with breast cancer have ductal carcinoma, it is the most common form of breast cancer.

The second most common type is lobular carcinoma. This cancer begins in the lobule of the breast. About 1 in every 10 women with cancer has lobular carcinoma. There are cases of both occurring at once and there are also less common types of breast cancer.

Normal cells, the building blocks of tissues and organs, grow and divide to form new cells when needed. Old or damaged cells should die and the new cells would take their place. Cancer occurs when this process goes wrong and either new cells form when they are not needed, and old or damaged cells don’t die, as they should. The build up of extra cells form a mass called lump, growth, or tumor. There are two types of tumors: benign and malignant. Benign tumors

• are usually not harmful;

• don’t spread to other parts of the body;

• and can be removed without usually growing back.

Malignant tumors, on the other hand,

• can be life threatening;

• can invade or spread to other parts of the body;

• often can be removed but sometimes grow back.

It is also important to note that when breast cancer cells spread to other parts of the body (using blood or lymph vessels), the new tumor has the same kind of abnormal cells and the same name as the origination. For example, if breast cancer cells spread to the lungs, it is not call lung cancer. The disease is metastatic breast cancer; the cancer cells in the lung are actually breast cancer and are treated as breast cancer.