Glossary Terms

Additional cancer treatment given after the primary treatment to lower the risk that the cancer will come back. Adjuvant therapy may include chemotherapy, radiation therapy, hormone therapy, targeted therapy, or biological therapy.

Cancer that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.

An operation to remove the breast cancer but not the breast itself. Types of breast-conserving surgery include lumpectomy (removal of the lump), quadrantectomy (removal of one quarter, or quadrant, of the breast), and segmental mastectomy (removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor). Also called breast-sparing surgery.

Treatment with drugs that kill cancer cells.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Treatment that adds, blocks, or removes hormones. For certain conditions (such as diabetes or menopause), hormones are given to adjust low hormone levels. To slow or stop the growth of certain cancers (such as prostate and breast cancer), synthetic hormones or other drugs may be given to block the body’s natural hormones. Sometimes surgery is needed to remove the gland that makes a certain hormone. Also called endocrine therapy, hormonal therapy, and hormone treatment.

Surgery to remove abnormal tissue or cancer from the breast and a small amount of normal tissue around it. It is a type of breast-sparing surgery.

Surgery for breast cancer in which the breast, most or all of the lymph nodes under the arm, and the lining over the chest muscles are removed. Sometimes the surgeon also removes part of the chest wall muscles.

The removal of cancer as well as some of the breast tissue around the tumor. The lining over the chest muscles below the tumor may also be removed. Usually one or more of the lymph nodes under the arm are also taken out. Also called segmental mastectomy.

The use of high-energy radiation from x-rays, gamma rays, neutrons, protons, and other sources to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external-beam radiation therapy), or it may come from radioactive material placed in the body near cancer cells (internal radiation therapy). Systemic radiation therapy uses a radioactive substance, such as a radiolabeled monoclonal antibody, that travels in the blood to tissues throughout the body. Also called irradiation and radiotherapy.

The removal of cancer as well as some of the breast tissue around the tumor. The lining over the chest muscles below the tumor may also be removed. Usually one or more of the lymph nodes under the arm are also taken out. Also called partial mastectomy.

The extent of a cancer in the body. Staging is usually based on the size of the tumor, whether lymph nodes contain cancer, and whether the cancer has spread from the original site to other parts of the body.

Stage I breast cancer is divided into stages IA and IB. In stage IA, the tumor is 2 centimeters or smaller and has not spread outside the breast. In stage IB, (1) no tumor is found in the breast, but small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes; or (2) the tumor is 2 centimeters or smaller and small clusters of cancer cells (larger than 0.2 millimeter but not larger than 2 millimeters) are found in the lymph nodes.

Stage II breast cancer is divided into stages IIA and IIB. In stage IIA, (1) no tumor is found in the breast, but cancer is found in the axillary (under the arm) lymph nodes; or (2) the tumor is 2 centimeters or smaller and has spread to the axillary lymph nodes; or (3) the tumor is larger than 2 centimeters but not larger than 5 centimeters and has not spread to the axillary lymph nodes. In stage IIB, the tumor is (1) larger than 2 centimeters but not larger than 5 centimeters and has spread to the axillary lymph nodes; or (2) larger than 5 centimeters but has not spread to the axillary lymph nodes.

Stage III breast cancer is divided into stages IIIA, IIIB, and IIIC. In stage IIIA, (1) no tumor is found in the breast, but cancer is found in axillary (under the arm) lymph nodes that are attached to each other or to other structures, or cancer may be found in lymph nodes near the breastbone; or (2) the tumor is 2 centimeters or smaller and cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or the cancer may have spread to lymph nodes near the breastbone; or (3) the tumor is larger than 2 centimeters but not larger than 5 centimeters and cancer has spread to axillary lymph nodes that are attached to each other or to other structures, or cancer may have spread to lymph nodes near the breastbone; or (4) the tumor is larger than 5 centimeters and cancer has spread to axillary lymph nodes that may be attached to each other or to other structures, or the cancer may have spread to lymph nodes near the breastbone. In stage IIIB, the tumor may be any size and cancer (1) has spread to the chest wall and/or the skin of the breast; and (2) may have spread to axillary lymph nodes that may be attached to each other or to other structures, or the cancer may have spread to lymph nodes near the breastbone. In stage IIIC, there may be no sign of cancer in the breast or the tumor may be any size and may have spread to the chest wall and/or the skin of the breast. Also, cancer (1) has spread to lymph nodes above or below the collarbone, and (2) may have spread to axillary lymph nodes or to lymph nodes near the breastbone. In operable stage IIIC, the cancer is found (1) in ten or more axillary lymph nodes; or (2) in the lymph nodes below the collarbone; or (3) is found in axillary lymph nodes and in lymph nodes near the breastbone. In inoperable stage IIIC, the cancer has spread to the lymph nodes above the collarbone.

Cancer has spread to other organs of the body, most often the bones, lungs, liver, or brain.

A procedure to remove or repair a part of the body or to find out whether disease is present. An operation.