M proteins: Antibodies or parts of antibodies found in unusually large amounts in the blood or urine of people with multiple myeloma.
Macrophage: A type of white blood cell that surrounds and kills microorganisms, removes dead cells, and stimulates the action of other immune system cells.
Mafosfamide: A form of cyclophosphamide that can be administered as an intrathecal infusion. Mafosfamide is being studied as an anticancer drug; it belongs to the family of drugs called alkylating agents.
MAGE-3: A gene found in some types of tumors.
Magnetic resonance imaging (mag-NET-ik REZ-o-nans IM-a-jing): MRI. A procedure in which a magnet linked to a computer is used to create detailed pictures of areas inside the body.
Maintenance therapy: Treatment that is given to help a primary (original) treatment keep working. Maintenance therapy is often given to help keep cancer in remission.
Malabsorption syndrome: A group of symptoms such as gas, bloating, abdominal pain, and diarrhea resulting from the body's inability to properly absorb nutrients.
Malignancy: A cancerous tumor that can invade and destroy nearby tissue and spread to other parts of the body.
Malignant (ma-LIG-nant): Cancerous; a growth with a tendency to invade and destroy nearby tissue and spread to other parts of the body.
Malignant ascites: A condition in which fluid containing cancer cells collects in the abdomen.
Malignant fibrous histiocytoma: Characterized by a tumor developing in soft tissue or bone.
Malignant meningioma: A rare, quickly growing tumor that occurs in the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.
Malignant mesothelioma: A rare type of cancer in which malignant cells are found in the sac lining the chest or abdomen. Exposure to airborne asbestos particles increases one's risk of developing malignant mesothelioma.
MALT lymphoma: Mucosa-associated lymphoid tissue lymphoma. A type of cancer that arises in cells in mucosal tissue that are involved in antibody production.
Mammogram (MAM-o-gram): An x-ray of the breast.
Mammography (mam-OG-ra-fee): The use of x-rays to create a picture of the breast.
Mantle field (MAN-tul): The area of the neck, chest, and lymph nodes in the armpit that are exposed to radiation.
Marimastat: An anticancer drug that belongs to the family of drugs called angiogenesis inhibitors. Marimastat is a matrix metalloproteinase inhibitor.
Marker: A diagnostic indication that disease may develop.
Mastectomy (mas-TEK-toe-mee): Surgery to remove the breast (or as much of the breast tissue as possible).
Matrix metalloproteinase: A member of a group of enzymes that can break down proteins, such as collagen, that are normally found in the spaces between cells in tissues (i.e., extracellular matrix proteins). Because these enzymes need zinc or calcium atoms to work properly, they are called metalloproteinases. Matrix metalloproteinases are involved in wound healing, angiogenesis, and tumor cell metastasis.
MDL 101,731: A drug that belongs to a family of drugs called ribonucleotide reductase inhibitors.
Measurable disease: A tumor that can be accurately measured in size. This information can be used to judge response to treatment.
Mec: A tumor that can be accurately measured in size. This information can be used to judge response to treatment.
Medial supraclavicular lymph nodes: Lymph nodes located above the collar bone and between the center of the body and a line drawn through the nipple to the shoulder.
Median: A statistics term. The middle value in a set of measurements.
Median survival time: The point in time from either diagnosis or treatment at which half of the patients with a given disease are found to be, or expected to be, still alive. In a clinical trial, median survival time is one way to measure how effective a treatment is.