Words to Know

nerve block

A procedure in which medicine is injected directly into or around a nerve or into the spine to block pain.

neurocognitive

Having to do with the ability to think and reason. This includes the ability to concentrate, remember things, process information, learn, speak and understand.

neurologic

Having to do with nerves or the nervous system.

neuropathy

Also called peripheral neuropathy. A nerve problem that causes pain, numbness, tingling, swelling, or muscle weakness in different parts of the body. It usually begins in the hands or feet and gets worse over time. Neuropathy may be caused by physical injury, infection, toxic substances, disease (such as cancer, diabetes, kidney failure, or malnutrition), or medicines, including anticancer agents.

neurotoxicity

The tendency of some treatments to cause damage to the nervous system.

neurotoxin

A substance that is poisonous to nerve tissue.

neutropenia

A condition in which there is a lower-than-normal number of neutrophils (a type of white blood cell).

NIH

A federal agency in the U.S. that conducts biomedical research in its own labs; supports the research of non-Federal scientists in universities, medical schools, hospitals, and research institutions throughout the country and abroad; helps in the training of research investigators; and fosters communication of medical information. Access the NIH Web site at http://www.nih.gov. Also called National Institutes of Health.

nipple

In anatomy, the small raised area in the center of the breast through which milk can flow to the outside.

nipple discharge

Fluid that is not milk coming from the nipple.

nitrosourea

An anticancer medicine that can cross the blood-brain barrier. Carmustine and lomustine are nitrosoureas.

NMRI

Also called magnetic resonance imaging, MRI, nuclear magnetic resonance imaging. A procedure in which radio waves and a powerful magnet linked to a computer are used to create detailed pictures of areas inside the body. These pictures can show the difference between healthy and diseased tissue. NMRI makes better images of organs and soft tissue than other scanning techniques, such as computed tomography (CT) or X-ray. NMRI is especially useful for imaging the breast tissue, brain, spine, the soft tissue of joints, and the inside of bones.

node-negative

Breast cancer that has not spread to the lymph nodes.

node-positive

Breast cancer that has spread to the lymph nodes.

nodule

A growth or lump that may be malignant (cancerous) or benign (noncancerous).

nonblinded

Describes a clinical trial or other experiment in which the researchers know what treatments are being given to each study subject or experimental group. If human subjects are involved, they know what treatments they are receiving.

nonconsecutive case series

A clinical study that includes some, but not all, of the eligible participants identified by the researchers during the study registration period. This type of study does not usually have a control group.

noninvasive

Breast cancer that stays inside the ducts or the lobules of the breast. An example of a noninvasive breast cancer is ductal carcinoma in situ, a very early type of cancer where breast cancer cells are located in the milk ducts. Because these cells cannot spread at this stage, DCIS is considered noninvasive breast cancer. In some cases, DCIS may become invasive cancer if it is not removed, although doctors are still learning how to predict which DCIS will become invasive. The term 'noninvasive' in general use, in medicine, describes a procedure that does not require inserting an instrument through the skin or into a body opening.

nonmalignant

Also called benign. Not cancerous. Nonmalignant tumors may grow larger but do not spread to other parts of the body.

nonmetastatic

Breast cancer that has not spread from the primary site (place where it started) to other places in the body, such as the lymph nodes.