The different types of breast cancer are generally sub-divided with the terms in situ, which means the tumor is confined to the part of the breast in which it started, and invasive, which means the tumor is more aggressive and can spread to other parts of the body.

Ductal carcinoma is the most common type of breast cancer. It begins in the ducts, which are thin tubes that link the other sections of the breast.

Ductal carcinoma in situ has not spread beyond the ducts. Nearly all women diagnosed at this early stage can be cured.

Invasive ductal carcinoma breaks through the duct wall to invade the fatty tissues in the breast. From there, the cancer can spread to the rest of the body by infiltrating the lymph nodes (small organs that produce immune system cells that circulate throughout the body).

Lobular carcinoma begins in the lobes or lobules (tiny sections of the breast, some of which can produce milk). It is found in both breasts more often than other types of breast cancer.

Lobular carcinoma in situ does not grow through the walls of the lobules and by itself does not usually become invasive. However, women who have it are at risk for developing other types of breast cancer.

Invasive lobular carcinoma can spread to other parts of the body. It may be harder to find by mammogram than other types of breast cancer.

Inflammatory breast cancer is a rare cancer in which the breast is red, swollen, and inflamed. The skin may appear pitted because of cancer cells blocking lymph vessels in the skin. This cancer is aggressive and should be treated promptly.

Paget’s disease forms in the ducts. If it’s limited to ductal carcinoma in situ and hasn’t invaded the rest of the breast, the outlook is excellent with mastectomy (removal of the breast).

Triple negative breast cancers don’t have the hormone receptors on their surface that most breast cancers do, and they tend to spread faster and more aggressively. These cancers are seen most often in African American women and in younger women. Chemotherapy can be effective against these cancers, but some of the other usual treatments are not, such as hormone therapy and drugs that target a protein called HER2.

Phyllodes tumors of the breast grow quickly but rarely spread to other areas of the body. Most require surgery.

Learn more about breast cancer:

• Breast Cancer Risk Assessment
• Symptoms of Breast Cancer
• Breast Cancer Stages