About Breast Cancer

When abnormal cells multiply and form a cancer that is located in tissues of the breast, it is called breast cancer. Usually, breast cancer occurs in the ducts that carry milk to the nipple, or in the lobules, the small sacs that produce milk. Breast cancer is defined as either non-invasive or invasive.

Non-invasive breast cancer

Non-invasive breast cancer, also called carcinoma in situ, is cancer that is confined to the ducts or lobules in the breast. It usually does not have the potential to spread outside of these areas. The most common type of noninvasive breast cancer is ductal carcinoma in situ (DCIS). Lobular carcinoma in situ (LCIS) is not a true cancer, but a marker of increased risk of developing breast cancer later. For this reason, women with LCIS are encouraged to have a physical exam once or twice a year, along with a yearly mammogram.

Invasive breast cancer

Invasive breast cancer has the potential to spread to lymph nodes and other organs in the body, such as the liver, lungs or bone.

Ductal carcinoma

The most common type of invasive or infiltrating breast cancer is ductal carcinoma, which accounts for about 80 percent of all breast cancers. This cancer begins in the ducts that carry milk to the nipple.

Lobular carcinoma

Another form of invasive breast cancer is lobular carcinoma. This cancer begins in the milk-producing glands in the breast. It accounts for 10-15 percent of all invasive breast cancers.

Medullary carcinoma

Medullary carcinoma is a form of ductal carcinoma that accounts for about 5 percent of all breast cancers. This cancer has several unique features, including the larger size of its cancer cells and the presence of immune system cells on the perimeter of the tumor. Women with this cancer have a better prognosis than do women with either ductal or lobular carcinoma.

Colloid carcinoma

Colloid carcinoma is a rare type of ductal carcinoma that begins in the mucous cells lining the ducts. Women with this cancer have a better prognosis than do women with either ductal or lobular carcinoma.

Tubular carcinoma

Tubular carcinoma is a form of ductal carcinoma that accounts for about 2 percent of all breast cancers. Women with this cancer have a better prognosis than do women with either ductal or lobular carcinoma.

Inflammatory breast cancer

Inflammatory breast cancer accounts for about 1 percent of all invasive breast cancers. With this type of cancer the skin of the breast appears red due to cancer cells within the lymphatic channels in the skin. The skin also may feel warm and may appear to have the texture of an orange peel. Inflammatory breast cancer is an advanced type of breast cancer.

Source: American Cancer Society