Accrual: The process of enrolling patients in a clinical research study (trial), or the number of patients already enrolled in a trial or anticipated to enroll in a trial.

Acute: A sudden onset of symptoms or disease.

Alkylating Agent: A chemotherapeutic agent such as melphalan or cyclophosphamide. Alkylating refers to the way in which these agents cross-link the DNA of myeloma cells and block cell division.

Allogeneic: See "Bone Marrow Transplant."

Amyloidosis: A condition in which myeloma light chains (Bence Jones proteins) are deposited in tissues and organs throughout the body. This occurs more commonly with lambda versus kappa Bence Jones proteins. In patients with amyloidosis, the light chain proteins bind to certain tissues such as heart, nerves and kidney rather than being excreted out of the body through the kidneys.

Analgesic: Any drug that relieves pain. Aspirin and acetaminophen are mild analgesics.

Analog: A chemical compound that is structurally similar to another but differs slightly in composition.

Anemia: A decrease in the normal number of red blood cells, usually below 10G% with over 13-14G% being normal. Myeloma in the bone marrow blocks red cell production causing shortness of breath, weakness and tiredness.

Anesthesia: Loss of feeling or awareness. Local anesthesia causes loss of feeling in a part of the body. General anesthesia puts the person to sleep.

Angiogenesis: Blood vessel formation, which usually accompanies the growth of malignant tissue, including myeloma.

Angiogenesis inhibitors: Compounds that attempt to cut off the blood supply to tumors.

Antibiotics: Drugs used to treat infection.

Antibody: A protein produced by certain white blood cells to fight infection and disease in the form of antigens such as bacteria, viruses, toxins, or tumors. Each antibody can bind only to a specific antigen. The purpose of this binding is to help destroy the antigen. Antibodies can work in several ways, depending on the nature of the antigen. Some antibodies disable antigens directly. Others make the antigen more vulnerable to destruction by white blood cells.

Antiemetic agent: A drug that prevents or controls nausea and vomiting.

Antifungal agent: A drug used to treat fungal infections.

Antigen: Any foreign substance (such as a bacteria, virus, or toxin) that, when introduced into the body, causes the immune system to produce natural antibodies.

Antineoplastic agent: A drug that prevents, kills, or blocks the growth and spread of cancer cells.

Appendicular skeleton: The long bones (i.e. arms and legs) which are attached to spine, chest and pelvis.

Apoptosis: A normal cellular process involving a genetically programmed series of events leading to the death of a cell.

Aspiration: The process of removing fluid or tissue, or both, from a specific area.

Asymptomatic myeloma: Myeloma that presents no signs or symptoms of disease. Also called indolent, smoldering, or early myeloma.

Axial Skeleton: The skull, spine, and pelvis region of the skeleton.

B cells: White blood cells that develop into plasma cells in the bone marrow and are the source of antibodies. Also known as B lymphocytes.

Basophil: A type of white blood cell. Basophils are granulocytes.

Bence Jones: A myeloma protein present in urine. The amount of Bence Jones protein is expressed in terms of G per 24 hours. Normally a very small amount of protein ( <0.1G/24h) can be present in the urine, but this is albumin rather than Bence Jones protein. The presence of any Bence Jones protein is abnormal.

Benign: Not cancerous; does not invade nearby tissue or spread to other parts of the body. MGUS is a benign condition.

Beta 2 Microglobulin (b2M): A small protein found in the blood. High levels occur in patients with active myeloma. Low or normal levels occur in patients with early myeloma and/or inactive disease. Approximately 10% of patients have myeloma that does not produce b2M. For these patients, b2M testing cannot be used to monitor the disease. At the time of relapse, b2M can increase before there is any change in the myeloma protein level. Therefore, 90% of the time, b2M is very useful for determining disease activity.

Biological response modifiers (BRMs): Substances that stimulate the body's response to infection and disease. The body naturally produces small amounts of these substances. Scientists can produce some of them in the laboratory in large amounts and use them in cancer treatment.

Biopsy: The removal of a sample of tissue for microscopic examination to aid in diagnosis.

Bisphosphonate: A type of drug that binds to the surface of bone where it is being resorbed (eaten into) and protects against osteoclast activity.

Blood cells: Minute structures produced in the bone marrow; they consist of red blood cells, white blood cells, and platelets.

Blood count: The number of red blood cells, white blood cells, and platelets in a sample of blood.

Bone marrow: The soft, spongy tissue in the center of bones that produces white blood cells, red blood cells, and platelets.

Bone marrow aspiration: The removal, by a needle, of a sample of fluid and cells from the bone marrow for examination under a microscope.

Bone marrow biopsy: The removal, by a needle, of a sample of tissue from the bone. The cells are checked to see whether they are cancerous. If cancerous plasma cells are found, the pathologist estimates how much of the bone marrow is affected. Bone marrow biopsy is usually done at the same time as bone marrow aspiration.

Bone marrow donor: A person who donates healthy bone marrow to a patient who has had high-dose cancer treatment. The patient is given the donor's healthy marrow during a bone marrow transplant

Bone marrow transplantation: See "Transplantation."

Bone remodeling: The normal coordination (coupling) between osteoclast cells (which resorb or destroy bone) and osteoblast cells (which create new bone matrix) to maintain a balanced state of bone production and destruction.

Bone scan: A technique to create images of bones on a computer screen to indicate areas of injury, disease, or healing. A small amount of radio-active material is injected into a vein and travels through the bloodstream. It collects in the bones, especially in abnormal areas of the bones, and is detected by a scanner. This is a valuable test to determine if cancer has spread to the bone, if anticancer therapy has been successful, and if affected bony areas are healing. Also known as "bone scintigraphy."

BUN (Blood Urea Nitrogen): A measure of the urea level in the blood. Urea is cleared by the kidney. BUN is a laboratory blood test to assess how well the kidney is functioning. Diseases, such as myeloma, which compromise kidney function, frequently lead to increased levels of BUN.