Words to Know

medullary breast carcinoma

A rare type of breast cancer that often can be treated successfully. It is marked by lymphocytes (a type of white blood cell) in and around the tumor that can be seen when viewed under a microscope.

mega-voltage linear accelerator

Also called linac, linear accelerator, and MeV linear accelerator. A machine that uses electricity to form a stream of fast-moving subatomic particles. This creates high-energy radiation that may be used to treat breast cancer.


Also called Megace. A medicine used to block estrogen and suppress the effects of estrogen and androgens. It is used to treat breast and endometrial cancer, and is also used to improve appetite in individuals with breast cancer. Megace belongs to the group of hormones called progestins.


Also called Alkeran. A medicine that is being studied in the treatment of cancer, including breast cancer. It is used to treat multiple myeloma and ovarian epithelial cancer. It belongs to the family of medicines called alkylating agents.

meningeal metastasis

A serious problem that may occur in cancer in which cancer cells spread from the original (primary) tumor to the meninges, thin layers of tissue that cover and protect the brain and spinal cord. It can happen in many types of cancer, but is the most common in melanoma, breast, lung and gastrointestinal cancer. The cancer may cause the meninges to be inflamed. Also called carcinomatous meningitis, leptomeningeal carcinoma, leptomeningeal metastasis, meningeal carcinomatosis and neoplastic meningitis.


The time of life when a woman's ovaries stop producing hormones and her 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.


Abnormally heavy menstrual bleeding.

menstrual cycle

The monthly cycle of hormonal changes from the beginning of one menstrual period to the beginning of the next.

menstrual period

The periodic discharge of blood and tissue from the uterus. From puberty until menopause, menstruation occurs about every 28 days when a woman is not pregnant.


Periodic discharge of blood and tissue from the uterus. From puberty until menopause, menstruation occurs about every 28 days when a woman is not pregnant.

mental health counselor

A specialist trained to help individuals and their families communicate about emotional and personal matters. A mental health counselor may also help counseling participants work through issues that help determine the pros and cons of various decisions.

mental health

A person's overall psychological and emotional condition. Good mental health is a state of well-being in which a person is able to cope with everyday events, think clearly, be responsible, meet challenges and have good relationships with others.

meperidine hydrochloride

Also called Demerol. A prescription medicine used to treat moderate to severe pain. It binds to opioid receptors in the central nervous system. Meperidine hydrochloride is a type of analgesic agent and a type of opioid.


In traditional Chinese medicine, one of 20 channels that form a network through which qi or chi (the body's vital energy) flows and that connect the body's acupuncture sites.


A medicine that helps protect the kidneys and bladder from the toxic effects of anticancer medicines such as ifosfamide and cyclophosphamide.


A process that analyzes data from different studies done about the same subject. The results of a meta-analysis are usually stronger than the results of any study by itself.


Having to do with metal. Some breast cancer treatments may change the sense of taste and cause foods to have a metallic taste.


Surgery to remove one or more metastases - tumors formed from cells that have spread from the primary tumor. When all metastases are removed, it is called a complete metastasectomy.


The spread of cancer from one part of the body to another. A tumor formed by cells that have spread is called a 'metastatic tumor' or a 'metastasis.' The metastatic tumor contains cells that are like those in the original (primary) tumor. The plural form of metastasis is metastases.


To spread from one part of the body to another. When cancer cells metastasize and form secondary tumors, the cells in the metastatic tumor are like those in the original (primary) tumor.