Macrobiotics (Macrobiotic Diet)
A diet that includes mostly vegetarian and organic foods. A macrobiotic diet is a type of integrative or complementary therapy.
Magnetic Resonance Imaging (see MRI)
Malignant
Cancerous.
Mammary Duct (Milk Duct, Duct)
A canal that carries milk from the lobules to a nipple opening during breastfeeding.
Mammary Duct Ectasia
A benign (not cancer) breast condition in which a milk duct under the nipple widens and thickens. This can cause the milk duct to become swollen with fluid build-up inside it. There are usually no symptoms, but sometimes there may be a thick nipple discharge or redness or tenderness of the nipple. No treatment is needed if the woman is not having symptoms (burning, pain, or itching in the nipple area).
Mammary Glands
The breast glands that produce milk.
Mammogram
An X-ray image of the breast.
Margin
The edge or border of the tissue removed in cancer surgery. The margin is described as negative or clean when the pathologist finds no cancer cells at the edge of the tissue, suggesting that all of the cancer has been removed. The margin is described as positive or involved when the pathologist finds cancer cells at the edge of the tissue, suggesting that all of the cancer has not been removed.
Mastectomy
Surgery to remove part or all of the breast. There are different types of mastectomy that differ in the amount of tissue and lymph nodes removed.
Mastitis
An inflammation (swelling) of the breast usually occurring during breastfeeding. Symptoms include pain, nipple discharge, fever, redness and hardness over an area of the breast.
Mean
A statistics term. The average value in a set of measurements. The mean is the sum of a set of numbers divided by how many numbers are in the set.
Mean Survival Time
The average length of time from either the date of diagnosis or the start of treatment for a disease, such as cancer, that patients diagnosed with the disease are still alive. In a clinical trial, measuring mean survival is one way to see how well a new treatment works.
Medical Oncologist
A doctor who has special training in diagnosing and treating cancer in adults using chemotherapy, hormonal therapy, biological therapy, and targeted therapy. A medical oncologist often is the main health care provider for someone who has cancer. A medical oncologist also gives supportive care and may coordinate treatment given by other specialists.
Menarche
The first menstrual period.
Menopausal Hormone Therapy (Postmenopausal Hormone Use, Hormone Replacement Therapy)
The use of hormone pills containing estrogen (with or without progestin) to help relieve symptoms of menopause. Symptoms may include hot flashes, night sweats, vaginal dryness, sleep problems, mood swings, and thinning of the bones. Menopausal hormone therapy is given to replace the natural hormones that are no longer made by the body. It can also be given to woman who went through early menopause due to cancer treatment. Also called MHT.
Menopause
The time of life when a woman’s ovaries stop producing hormones and menstrual periods stop. Natural menopause usually occurs around age 50. A woman is said to be in menopause when she hasn’t had a period for 12 months in a row. Symptoms of menopause include hot flashes, mood swings, night sweats, vaginal dryness, trouble concentrating, and infertility.
Metabolized
The chemical process when drugs and food are broken down by the body.
Metastasis
The spread of cancer cells from the place where they first formed to another part of the body. In metastasis, cancer cells break away from the original (primary) tumor, travel through the blood or lymph system, and form a new tumor in other organs or tissues of the body. The new, metastatic tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the lung, the cancer cells in the lung are breast cancer cells, not lung cancer cells.
Microcalcifications
Tiny calcium deposits in the breast that may be seen on a mammogram. They are a sign of changes in the breast that may or may not be related to breast cancer.
Microvascular Surgery
Surgery that involves connecting small blood vessels to each other.
Modified Radical Mastectomy
Surgical removal of the breast, the lining of the chest muscles and some of the lymph nodes in the underarm area. Used to treat early and locally advanced breast cancer.
Molecular Breast Imaging (see Nuclear Medicine Imaging of the Breast in N)
Monoclonal Antibodies
A type of protein that is made in the laboratory and can bind to certain targets in the body, such as antigens on the surface of cancer cells. There are many kinds of monoclonal antibodies, and each monoclonal antibody is made so that it binds to only one antigen. Monoclonal antibodies are being used in the diagnosis and treatment of many diseases, including some types of cancer. They can be used alone or to carry drugs, toxins, or radioactive substances directly to cancer cells.
Mortality Rate
Number of deaths in a given group of people over a certain period of time.
MRI (Magnetic Resonance Imaging)
An imaging technique that uses a strong magnet connected to a computer to take detailed pictures of organs or soft tissues in the body that are hard to see using other imaging tests.
Multifocal Breast Cancer
Breast cancer in which there is more than one tumor, all of the tumors were created from one original tumor. The tumors are likely to be in the same section (or quadrant) of the breast.
Multimodality Therapy
Use of two or more treatment methods (such as surgery, radiation therapy, chemotherapy, hormone therapy and targeted therapy) in combination or one after the other to get the best results.