N-acetyl-L-cysteine

A drug usually used to reduce the thickness of mucus and ease its removal. It is also used to reverse the toxicity of high doses of acetaminophen. Also called acetylcysteine and N-acetylcysteine.

N-acetylcysteine

A drug usually used to reduce the thickness of mucus and ease its removal. It is also used to reverse the toxicity of high doses of acetaminophen. Also called acetylcysteine and N-acetyl-L-cysteine.

N-acetyldinaline

A substance that is being studied as an anticancer drug in the treatment of non-small cell lung cancer. Also called CI-994.

N-benzoyl-staurosporine

A substance that is being studied in the treatment of leukemia. It belongs to the family of drugs called protein kinase inhibitors. Also called midostaurin and PKC412.

N-butyl-N-(4-hydroxybutyl) nitrosamine

A substance that is used in cancer research to cause bladder tumors in laboratory animals. This is done to test new diets, drugs, and procedures for use in cancer prevention and treatment.

NaCl

Chemical abbreviation for sodium chloride (table salt).

naloxone

A substance that is being studied as a treatment for constipation caused by narcotic medications. It belongs to the family of drugs called narcotic antagonists.

naltrexone

A drug that blocks the action of opiates (drugs used to treat pain). It may be used in the treatment of intravenous opiate addiction or alcohol dependence. Naltrexone is also being studied in the treatment of breast cancer. It may block the effects of the hormone estrogen, which causes some breast cancer cells to grow, or block the blood flow to tumors. It is a type of opiate antagonist. Also called naltrexone hydrochloride, ReVia, and Vivitrol.

naltrexone hydrochloride

A drug that blocks the action of opiates (drugs used to treat pain). It may be used in the treatment of intravenous opiate addiction or alcohol dependence. Naltrexone hydrochloride is also being studied in the treatment of breast cancer. It may block the effects of the hormone estrogen, which causes some breast cancer cells to grow, or block the blood flow to tumors. It is a type of opiate antagonist. Also called naltrexone, ReVia, and Vivitrol.

Namenda

A drug used to treat dementia caused by Alzheimer disease. It is also being studied in the treatment of side effects from whole-brain radiation therapy for cancer and other conditions. Namenda blocks the uptake of calcium by certain brain cells and decreases their activity. It is a type of N-methyl-D-asparatate (NMDA) receptor antagonist. Also called memantine hydrochloride.

nanogram

A measure of weight. One nanogram weighs a billion times less than one gram, and almost a trillion-times less than a pound.

nanometer

A measure of length in the metric system. A nanometer is one billionth of a meter. An average human hair is about 60,000 nanometers thick. Nanometers are used to measure wavelengths of light and distances between atoms in molecules.

nanomole

The amount of a substance equal to a billionth of a mole (a measure of the amount of a substance). Also called nM.

nanoparticle

A particle of that is smaller than 100 nanometers (one-billionth of a meter). In medicine, nanoparticles can be used to carry antibodies, drugs, imaging agents, or other substances to certain parts of the body. Nanoparticles are being studied in the detection, diagnosis, and treatment of cancer.

nanoparticle paclitaxel

A drug used to treat breast cancer that has spread or that has come back within 6 months after chemotherapy. It is also being studied in the treatment of newly diagnosed breast cancer and other types of cancer. Nanoparticle paclitaxel is a type of mitotic inhibitor. Also called ABI-007, Abraxane, paclitaxel albumin-stabilized nanoparticle formulation, and protein-bound paclitaxel.

nanoprobe

A device that uses x-rays instead of visible light to form images of very small structures, such as the insides of blood vessels and cells. It can be used to study processes such as angiogenesis (growth of blood vessels). The term nanoprobe is also used to describe very small particles that can be used in the detection, diagnosis, and treatment of cancer.

nanotechnology

The field of research that deals with the engineering and creation of things from materials that are less than 100 nanometers (one-billionth of a meter) in size, especially single atoms or molecules. Nanotechnology is being studied in the detection, diagnosis, and treatment of cancer.

Naprosyn

A drug used to treat mild pain and the symptoms of arthritis and several other conditions. It is also being studied in the treatment of bone pain in patients with cancer. Naprosyn stops the body from making substances that cause pain and inflammation. It is a type of nonsteroidal anti-inflammatory drug (NSAID) and a type of cyclooxygenase inhibitor. Also called naproxen.

naproxen

A drug used to treat mild pain and the symptoms of arthritis and several other conditions. It is also being studied in the treatment of bone pain in patients with cancer. Naproxen stops the body from making substances that cause pain and inflammation. It is a type of nonsteroidal anti-inflammatory drug (NSAID) and a type of cyclooxygenase inhibitor. Also called Naprosyn.

narcotic

A substance used to treat moderate to severe pain. Narcotics are like opiates such as morphine and codeine, but are not made from opium. They bind to opioid receptors in the central nervous system. Narcotics are now called opioids.

Naropin

A drug used to control pain and to cause a temporary loss of feeling in one part of the body, during and after surgery. It is also being studied for pain control after cancer surgery. It is a type of local anesthetic. Also called ropivacaine and ropivacaine hydrochloride.

nasal

By or having to do with the nose.

nasogastric

Describes the passage from the nose to the stomach. For example, a nasogastric tube is inserted through the nose, down the throat and esophagus, and into the stomach.

nasogastric tube

A tube that is inserted through the nose, down the throat and esophagus, and into the stomach. It can be used to give drugs, liquids, and liquid food, or used to remove substances from the stomach. Giving food through a nasogastric tube is a type of enteral nutrition. Also called gastric feeding tube and NG tube.

Nasonex

A drug that is used in a cream to treat certain skin conditions and in a nasal spray to treat sinus problems caused by allergies. It is being studied as a way to treat inflammation of the skin caused by radiation therapy. Nasonex is a type of corticosteroid. Also called Elocon, mometasone, and mometasone furoate.

nasopharyngeal cancer

Cancer that forms in tissues of the nasopharynx (upper part of the throat behind the nose). Most nasopharyngeal cancers are squamous cell carcinomas (cancer that begins in flat cells lining the nasopharynx).

nasopharynx

The upper part of the throat behind the nose. An opening on each side of the nasopharynx leads into the ear.

nasoscope

A thin tube-like instrument used to examine the inside of the nose. A nasoscope has a light and a lens for viewing and may have a tool to remove tissue. Also called rhinoscope.

nasoscopy

Examination of the inside of the nose using a nasoscope (or rhinoscope). A nasoscope is a thin, tube-like instrument with a light and a lens for viewing. It may also have a tool to remove tissue to be checked under a microscope for signs of disease. Also called rhinoscopy.

National Cancer Institute

The National Cancer Institute, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. The National Cancer Institute conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the National Cancer Institute Web site at http://www.cancer.gov. Also called NCI.

National Center for Complementary and Alternative Medicine

A federal agency that uses science to explore complementary and alternative medicine (CAM) practices, trains CAM researchers, and provides authoritative information about CAM to professionals and the public. NCCAM awards grants for research projects, training, and career development in CAM; sponsors conferences, educational programs, and exhibits; studies ways to use proven CAM practices along with conventional medical practice; and supports adding CAM to medical, dental, and nursing school programs. NCCAM is part of the National Institutes of Health. Also called NCCAM.

National Institutes of Health

A federal agency in the U.S. that conducts biomedical research in its own laboratories; 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 National Institutes of Health Web site at http://www.nih.gov. Also called NIH.

natural history study

A study that follows a group of people over time who have, or are at risk of developing, a specific medical condition or disease. A natural history study collects health information in order to understand how the medical condition or disease develops and how to treat it.

natural killer cell

A type of immune cell that has granules (small particles) with enzymes that can kill tumor cells or cells infected with a virus. A natural killer cell is a type of white blood cell. Also called NK cell and NK-LGL.

natural killer-cell large granular lymphocyte leukemia

A type of leukemia in which large natural killer (NK) cells (a type of white blood cell) that contain granules (small particles) are found in the blood. It is a chronic disease that may last for a long time and get worse. Also called NK-LGL leukemia and NK-LGLL.

naturopathy

A system of disease prevention and treatment that avoids drugs and surgery. Naturopathy is based on the use of natural agents such as air, water, light, heat, and massage to help the body heal itself. It also uses herbal products, nutrition, acupuncture, and aromatherapy as forms of treatment.

nausea

A feeling of sickness or discomfort in the stomach that may come with an urge to vomit. Nausea is a side effect of some types of cancer therapy.

Navelbine

A drug used to treat advanced non-small cell lung cancer. It blocks cell growth by stopping cell division and may cause cancer cells to die. It is a type of vinca alkaloid and a type of antimitotic agent. Also called vinorelbine tartrate.

navitoclax

A substance being studied in the treatment of lymphomas and other types of cancer. It blocks some of the enzymes that keep cancer cells from dying. It is a type of Bcl-2 family inhibitor. Also called ABT-263.

NB1011

A substance that is being studied for its ability to make cancer cells respond to drugs to which they have become resistant. It is a type of nucleoside analog.

NBI-3001

A substance being studied in the treatment of cancer. It is made by combining interleukin-4 with a bacterial toxin. NBI-3001 is a type of recombinant chimeric protein. Also called interleukin-4 PE38KDEL cytotoxin and interleukin-4 PE38KDEL immunotoxin.

NCCAM

A federal agency that uses science to explore complementary and alternative medicine (CAM) practices, trains CAM researchers, and provides authoritative information about CAM to professionals and the public. NCCAM awards grants for research projects, training, and career development in CAM; sponsors conferences, educational programs, and exhibits; studies ways to use proven CAM practices along with conventional medical practice; and supports adding CAM to medical, dental, and nursing school programs. NCCAM is part of the National Institutes of Health. Also called National Center for Complementary and Alternative Medicine.

NCI

NCI, part of the National Institutes of Health of the United States Department of Health and Human Services, is the Federal Government's principal agency for cancer research. It conducts, coordinates, and funds cancer research, training, health information dissemination, and other programs with respect to the cause, diagnosis, prevention, and treatment of cancer. Access the NCI Web site at http://www.cancer.gov. Also called National Cancer Institute.

NCI clinical trials cooperative group

A group of researchers, cancer centers, and community doctors who are involved in studies of new cancer treatment, prevention, early detection, quality of life, and rehabilitation. Clinical trials carried out by cooperative groups are sponsored by the National Cancer Institute (NCI), and large numbers of patients take part in many locations. Examples include the Radiation Therapy Oncology Group (RTOG), Gynecologic Oncology Group (GOG), and Children's Oncology Group (COG).

NCX 4016

A substance being studied in the prevention of colorectal cancer. It is a form of aspirin that gives off nitric oxide gas and is less irritating to the lining of the stomach than plain aspirin. It is a type of nonsteroidal anti-inflammatory drug (NSAID). Also called nitric oxide-releasing acetylsalicylic acid derivative.

NDGA

A drug put on the skin to treat growths caused by sun exposure. A form of NDGA that is taken by mouth is being studied in the treatment of prostate cancer. NDGA is an antioxidant, and it may block certain enzymes needed for tumor growth. Also called Actinex, masoprocol, and nordihydroguaiaretic acid.

NDV

Newcastle disease virus. A bird virus that is being studied in the treatment of cancer. It may be used to kill cancer cells directly, or it may be given as a cancer vaccine to stimulate the body's immune system. NDV is a type of biological response modifier and vaccine therapy. Also called Newcastle disease virus.

nebulizer

A device used to turn liquid into a fine spray.

neck dissection

Surgery to remove lymph nodes and other tissues in the neck.

necrosis

Refers to the death of living tissues.

needle biopsy

The removal of tissue or fluid with a needle for examination under a microscope. When a wide needle is used, the procedure is called a core biopsy. When a thin needle is used, the procedure is called a fine-needle aspiration biopsy.

needle localization

A procedure used to mark a small area of abnormal tissue so it can be removed by surgery. An imaging device is used to guide a thin wire with a hook at the end through a hollow needle to place the wire in or around the abnormal area. Once the wire is in the right place, the needle is removed and the wire is left in place so the doctor will know where the abnormal tissue is. The wire is removed when a biopsy is done. Also called needle/wire localization and wire localization.

needle-localized biopsy

A procedure to mark and remove abnormal tissue when the doctor cannot feel a lump. An imaging device is used to guide a thin wire with a hook on the end through a hollow needle to place the wire in or around the abnormal area. Once the wire is in the right place, the needle is removed and the wire is left in so the doctor will know where the abnormal tissue is. The wire is removed at the time the biopsy is done.

needle/wire localization

A procedure used to mark a small area of abnormal tissue so it can be removed by surgery. An imaging device is used to guide a thin wire with a hook at the end through a hollow needle to place the wire in or around the abnormal area. Once the wire is in the right place, the needle is removed and the wire is left in place so the doctor will know where the abnormal tissue is. The wire is removed when a biopsy is done. Also called needle localization and wire localization.

needling

In acupuncture, the insertion of a thin needle into a specific place on the body to unlock qi (vital energy). The needle may be twirled, moved up and down at different speeds and depths, heated, or charged with a low electric current.

nefazodone

A drug used to treat depression. It belongs to the family of drugs called antidepressant agents. Also called Serzone.

negative axillary lymph node

A lymph node in the armpit that is free of cancer.

negative test result

A test result that does not show the specific disease, condition, or biomarker for which the test is being done.

nelarabine

A drug used to treat certain types of T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). It belongs to the family of drugs called antimetabolites. Also called 506U78 and Arranon.

nelfinavir mesylate

A drug that interferes with the ability of a virus to make copies of itself.

neoadjuvant therapy

Treatment given as a first step to shrink a tumor before the main treatment, which is usually surgery, is given. Examples of neoadjuvant therapy include chemotherapy, radiation therapy, and hormone therapy. It is a type of induction therapy.

neoplasia

Abnormal and uncontrolled cell growth.

neoplasm

An abnormal mass of tissue that results when cells divide more than they should or do not die when they should. Neoplasms may be benign (not cancer), or malignant (cancer). Also called tumor.

neoplastic meningitis

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 meningeal metastasis.

nephrectomy

Surgery to remove a kidney or part of a kidney. In a partial nephrectomy, part of one kidney or a tumor is removed, but not an entire kidney. In a simple nephrectomy, one kidney is removed. In a radical nephrectomy, an entire kidney, nearby adrenal gland and lymph nodes, and other surrounding tissue are removed. In a bilateral nephrectomy, both kidneys are removed.

nephrologist

A doctor who specializes in diagnosing and treating kidney disease.

nephrostomy

Surgery to make an opening from the outside of the body to the renal pelvis (part of the kidney that collects urine). This may be done to drain urine from a blocked kidney or blocked ureter into a bag outside the body. It may also be done to look at the kidney using an endoscope (thin, lighted tube attached to a camera), to place anticancer drugs directly into the kidney, or to remove kidney stones.

nephrotomogram

A series of x-rays of the kidneys. The x-rays are taken from different angles and show the kidneys clearly, without the shadows of the organs around them.

nephrotoxic

Poisonous or damaging to the kidney.

nephroureterectomy

Surgery to remove a kidney and its ureter. Also called ureteronephrectomy.

nerve

A bundle of fibers that receives and sends messages between the body and the brain. The messages are sent by chemical and electrical changes in the cells that make up the nerves.

nerve block

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

nerve cell

A type of cell that receives and sends messages from the body to the brain and back to the body. The messages are sent by a weak electrical current. Also called neuron.

nerve grafting

Replacing a damaged nerve with a section of a healthy nerve that has been removed from another part of the body. This procedure is being studied in the prevention of erectile dysfunction in men having surgery for prostate cancer.

nerve growth factor

A protein made by the body that causes certain nerve cells to grow and helps keep them alive.

nerve-sparing radical prostatectomy

Surgery to remove the prostate in which an attempt is made to save the nerves that help cause penile erections.

nerve-sparing surgery

A type of surgery that attempts to save the nerves near the tissues being removed.

nervous system

The organized network of nerve tissue in the body. It includes the central nervous system (the brain and spinal cord), the peripheral nervous system (nerves that extend from the spinal cord to the rest of the body), and other nerve tissue.

Neulasta

A drug used to increase numbers of white blood cells in patients who are receiving chemotherapy. It is a type of colony-stimulating factor. Also called filgrastim-SD/01 and pegfilgrastim.

Neumega

A drug used to increase the number of blood cells, especially platelets, in some cancer patients receiving chemotherapy. Neumega is a form of interleukin-11 (a cytokine normally made by support cells in the bone marrow) that is made in the laboratory. It is a type of biological response modifier. Also called oprelvekin, recombinant human interleukin-11, and rhIL-11.

neural

Having to do with nerves or the nervous system, including the brain and the spinal cord.

neuro-oncologist

A doctor who specializes in diagnosing and treating brain tumors and other tumors of the nervous system.

neurobehavioral

Having to do with the way the brain affects emotion, behavior, and learning. Some cancers or their treatment may cause neurobehavioral problems.

neuroblastoma

Cancer that arises in immature nerve cells and affects mostly infants and children.

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.

neuroectodermal tumor

A tumor of the central or peripheral nervous system.

neuroendocrine

Having to do with the interactions between the nervous system and the endocrine system. Neuroendocrine describes certain cells that release hormones into the blood in response to stimulation of the nervous system.

neuroendocrine carcinoma of the skin

A rare type of cancer that forms on or just beneath the skin, usually in parts of the body that have been exposed to the sun. It is most common in older people and in people with weakened immune systems. Also called Merkel cell cancer, Merkel cell carcinoma, and trabecular cancer.

neuroendocrine tumor

A tumor that forms from cells that release hormones in response to a signal from the nervous system. Some examples of neuroendocrine tumors are carcinoid tumors, islet cell tumors, medullary thyroid carcinomas, pheochromocytomas, and neuroendocrine carcinomas of the skin (Merkel cell cancer). These tumors may secrete higher-than-normal amounts of hormones, which can cause many different symptoms.

neuroepithelial

Having to do with tissue made up of sensory cells, such as tissue found in the ear, nose, and tongue.

neurofeedback

A treatment being studied to improve brain function in certain brain disorders and in patients treated with chemotherapy for breast cancer. Sensors are placed on a person's head, which allows brain activity to be shown as patterns on a computer screen. A beep or a tone may be used as a reward to a person for changing certain brain activities. Neurofeedback may help cancer patients deal with the stress and mental side effects of chemotherapy. Also called EEG biofeedback.

neurofibroma

A benign tumor that develops from the cells and tissues that cover nerves.

neurofibromatosis type 1

A rare genetic condition that causes brown spots and tumors on the skin, freckling in skin areas not exposed to the sun, tumors on the nerves, and developmental changes in the nervous system, muscles, bone, and skin. Also called NF1.

neurofibromatosis type 2

A genetic condition in which tumors form on the nerves of the inner ear and cause loss of hearing and balance. Tumors may also occur in the brain and on nerves in the skull and spinal cord, and may cause loss of speech, eye movement, and the ability to swallow. Also called acoustic neurofibromatosis and NF2.

neuroglia

Any of the cells that hold nerve cells in place and help them work the way they should. The types of neuroglia include oligodendrocytes, astrocytes, microglia, and ependymal cells. Also called glial cell.

neuroleptic agent

A type of drug used to treat symptoms of psychosis. These include hallucinations (sights, sounds, smells, tastes, or touches that a person believes to be real but are not real), delusions (false beliefs), and dementia (loss of the ability to think, remember, learn, make decisions, and solve problems). Most neuroleptic agents block the action of certain chemicals in the nervous system. Also called antipsychotic and antipsychotic agent.

neuroleptic malignant syndrome

A life-threatening condition that may be caused by certain drugs used to treat mental illness, nausea, or vomiting. Symptoms include high fever, sweating, unstable blood pressure, confusion, and stiffness. Also called NMS.

neurologic

Having to do with nerves or the nervous system.

neurological exam

A series of questions and tests to check brain, spinal cord, and nerve function. The exam checks a person's mental status, coordination, ability to walk, and how well the muscles, sensory systems, and deep tendon reflexes work.

neurologist

A doctor who specializes in the diagnosis and treatment of disorders of the nervous system.