An initial measurement taken at an early point in time to represent a beginning condition. It is used as a point of comparison to look for changes over time. For example, the size of a tumor will be measured before treatment (baseline) and then afterward to see if the treatment had an effect.

In medicine, treatment that experts agree is appropriate, accepted and widely used. Healthcare providers are obligated to provide best practice treatments. Also called standard of care and standard therapy.

A medicine put on the skin to help repair damaged skin. It may be used to treat the redness, burning and peeling caused by radiation therapy.

Cancer that occurs in both breasts.

A preventative (prophylactic) surgery to remove both breasts, in order to reduce the risk of developing breast cancer.

A method of learning to voluntarily control certain body functions such as heartbeat, blood pressure and muscle tension with the help of a special machine. This method can help control pain.

The removal of cells or tissues for examination by a pathologist. The pathologist may study the tissue under a microscope or perform other tests on the cells or tissue. There are many different types of biopsy procedures. The most common types include: (1) incisional biopsy, in which only a sample of tissue is removed; (2) excisional biopsy, in which an entire lump or suspicious area is removed; and (3) needle biopsy, in which a sample of tissue or fluid is removed with a needle. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

Treatment to boost or restore the ability of the immune system to fight cancer, infections and other diseases. Also used to lessen certain side effects that may be caused by some cancer treatments. Monoclonal antibodies, growth factors and vaccines are used in biotherapy and may have a direct antitumor effect.

The necrosis (death) of bone tissue caused by treatment with a bisphosphonate (a medicine or substance used to treat osteoporosis, bone pain caused by some types of cancer, and high blood calcium). It commonly occurs in the jaw bones. There may be pain, swelling and infection in the areas of necrosis.

A test to check the number of red blood cells, white blood cells and platelets in a sample of blood. Also called CBC and complete blood count.

The use of medicines to create openings between cells in the blood-brain barrier. The blood-brain barrier is a protective network of blood vessels and tissue that protects the brain from harmful substances, but can also prevent anticancer medicines from reaching the brain. Once the barrier is opened, anticancer medicines may be infused into an artery that goes to the brain, in order to treat brain tumors. Also called BBBD.

A licensed pharmacist with special training in how to design, give, monitor and change chemotherapy. Also called BCOP and oncology pharmacy specialist.

A measure that relates body weight to height. BMI is sometimes used to measure total body fat and whether a person is a healthy weight. Excess body fat is linked to an increased risk of some diseases including heart disease and some cancers. Also called BMI.

A measure of the amount of minerals, mostly calcium and phosphorous, contained in a certain volume of bone. Bone density measurements are used to diagnose osteoporosis, a condition marked by decreased bone mass, to see how well osteoporosis treatments are working and to predict how likely the bones are to break. Low bone density can occur in individuals treated for cancer. Also called BMD, bone mass and bone mineral density.

An imaging test that measures bone density (the amount of bone mineral contained in a certain volume of bone) by passing X-rays with two different energy levels through the bone. It is used to diagnose osteoporosis (decrease in bone mass and density). Also called BMD scan, DEXA, DEXA scan, dual energy X-ray absorptiometric scan, dual X-ray absorptiometry and DXA.

A radioactive substance that is given through a vein, and collects in bone cells and in tumor cells that have spread to the bone. It kills cancer cells by giving off low-level radiation.

Cancer that has spread from the original (primary) tumor to the brain.

A gene on chromosome 13 that normally helps to suppress cell growth. A person who inherits certain mutations, or changes, in a BRCA2 gene has a higher risk of getting breast, ovarian, prostate and other types of cancer.

Also called stage 0 breast carcinoma in situ. There are two types of breast carcinoma in situ: ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). DCIS is a noninvasive condition in which abnormal cells are found in the lining of a breast duct, a tube that carries milk to the nipple. The abnormal cells have not spread outside the duct to other tissues in the breast. In some cases, DCIS may become invasive cancer and spread to other tissues, although it is not known how to predict which lesions will become invasive cancer. LCIS is a condition in which abnormal cells are found in the breast lobules, small sections of tissue involved with making milk. This condition seldom becomes invasive cancer; however, having LCIS in one breast increases the risk of developing breast cancer in either breast.

A method used to examine the lining of the breast ducts to look for abnormal tissue. A very thin, flexible, lighted tube attached to a camera is inserted through the nipple, and threaded into the breast ducts deep in the breast. Tissue and fluid samples may be removed during the procedure.

A section of the breast that contains the lobules, the glands that make milk.

Surgery to rebuild the shape of the breast after a mastectomy.

Also called breast-sparing surgery. A surgery 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).