P-32

A radioactive form of the element phosphorus used in the treatment of cancer.

p-glycoprotein

A protein that pumps substances out of cells. Cancer cells that have too much p-glycoprotein may not be killed by anticancer drugs.

p-value

A term in statistics. It helps show whether a difference found between groups that are being compared is due to chance. A small p-value usually means that the difference between groups is not due to chance alone, but is due to some other factor, such as a treatment one of the groups received. A large p-value usually means that the difference between groups is probably due to chance alone.

P30 Cancer Center Support Grant

Funds awarded to certain U.S. institutions by the National Cancer Institute (NCI) for them to become cancer centers in the United States, based on scientific merit. The funds help the cancer centers improve the way they are run and develop new ways to prevent, diagnose, and treat cancer. To receive the award, one goal of the cancer center must be to turn clinical and basic research into better health care. Also called CCSG.

p53 gene

A tumor suppressor gene that normally inhibits the growth of tumors. This gene is altered in many types of cancer.

PA

A health professional who is licensed to do certain medical procedures under the guidance of a doctor. A PA may take medical histories, do physical exams, take blood and urine samples, care for wounds, and give injections and immunizations. Also called physician assistant.

PABA

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Bacteria that live in the intestines need PABA to survive. PABA is found in grains and foods from animals. It is being studied as a radiosensitizer (a substance that makes tumor cells more sensitive to radiation therapy) and in the treatment of certain skin disorders. Also called aminobenzoic acid and para-aminobenzoic acid.

pacemaker

An electronic device that is implanted in the body to monitor heart rate and rhythm. It gives the heart electrical stimulation when it does not beat normally. It runs on batteries and has long, thin wires that connect it to the heart. Also called artificial pacemaker and cardiac pacemaker.

Pacific valerian

A plant whose roots are used as a sedative and to treat certain medical conditions. It is being studied as a way to improve sleep in cancer patients undergoing treatment. Also called garden heliotrope, garden valerian, Indian valerian, Mexican valerian, valerian, Valeriana officinalis, and Valerianae radix.

pack year

A way to measure the amount a person has smoked over a long period of time. It is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. For example, 1 pack year is equal to smoking 1 pack per day for 1 year, or 2 packs per day for half a year, and so on.

paclitaxel

A drug used to treat breast cancer, ovarian cancer, and AIDS-related Kaposi sarcoma. It is also used together with another drug to treat non-small cell lung cancer. Paclitaxel is also being studied in the treatment of other types of cancer. It blocks cell growth by stopping cell division and may kill cancer cells. It is a type of antimitotic agent. Also called Taxol.

paclitaxel albumin-stabilized nanoparticle formulation

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. Paclitaxel albumin-stabilized nanoparticle formulation is a type of mitotic inhibitor. Also called ABI-007, Abraxane, nanoparticle paclitaxel, and protein-bound paclitaxel.

paclitaxel liposome

A form of the anticancer drug paclitaxel that is contained in very tiny, fat-like particles. It may have fewer side effects and work better than paclitaxel. It is being studied in the treatment of several types of cancer. Paclitaxel liposome blocks the ability of cells to divide and may kill cancer cells. It is a type of mitotic inhibitor and a type of antimicrotubule agent. Also called LEP-ETU, liposomal paclitaxel, LipoTaxen, and PNU-93914.

paclitaxel poliglumex

A form of the anticancer drug paclitaxel combined with a protein called poliglumex that may have fewer side effects and work better than paclitaxel. It is being studied in the treatment of breast cancer, ovarian cancer, lung cancer, and other types of cancer. It belongs to the family of drugs called mitotic inhibitors. Also called CT-2103, paclitaxel polyglutamate, and Xyotax.

paclitaxel polyglutamate

A form of the anticancer drug paclitaxel combined with a protein called poliglumex that may have fewer side effects and work better than paclitaxel. It is being studied in the treatment of breast cancer, ovarian cancer, lung cancer, and other types of cancer. It belongs to the family of drugs called mitotic inhibitors. Also called CT-2103, paclitaxel poliglumex, and Xyotax.

paclitaxel-loaded polymeric micelle

A form of the anticancer drug paclitaxel used to treat breast cancer, ovarian cancer, and AIDS-related Kaposi sarcoma. It is also used with another drug to treat non-small cell lung cancer. Paclitaxel is mixed with very tiny particles of a substance that makes it easier to dissolve in water. This allows higher doses of paclitaxel to be given. It is a type of antimitotic agent.

Paget disease of bone

A chronic condition in which both the breakdown and regrowth of bone are increased. Paget disease of bone occurs most frequently in the pelvic and leg bones, skull, and lower spine. It is most common in older individuals, and may lead to bone pain, deformities, and fractures. Also called osteitis deformans.

Paget disease of the nipple

A form of breast cancer in which the tumor grows from ducts beneath the nipple onto the surface of the nipple. Symptoms commonly include itching and burning and an eczema-like condition around the nipple, sometimes accompanied by oozing or bleeding.

PAH

A type of chemical formed when coal, oil, gas, garbage, tobacco, meat, and other substances are burned. These chemicals are also made for use in many products, including coal tar, creosote, roofing tar, pesticides, mothballs, dandruff shampoos, and some medicines. Being exposed to one of these chemicals over a long time may cause cancer. Also called polycyclic aromatic hydrocarbon.

pain threshold

The point at which a person becomes aware of pain.

PALA

A substance that is being studied for its ability to increase the effectiveness of the anticancer drug fluorouracil.

palate

The roof of the mouth. The front portion is bony (hard palate), and the back portion is muscular (soft palate).

palatine uvula

The soft flap of tissue that hangs down at the back of the mouth (at the edge of the soft palate). Also called uvula.

palifermin

A form of keratinocyte growth factor (KGF) that is made in the laboratory. KGF stimulates the growth of cells that line the surface of the mouth and intestinal tract. Palifermin is used to prevent and treat oral mucositis (mouth sores) caused by high-dose chemotherapy and radiation therapy in leukemia and lymphoma. It is also being studied in the prevention and treatment of oral mucositis and dysphagia (difficulty swallowing) in other types of cancer. Palifermin is a type of recombinant human keratinocyte growth factor. Also called Kepivance.

palliation

Relief of symptoms and suffering caused by cancer and other life-threatening diseases. Palliation helps a patient feel more comfortable and improves the quality of life, but does not cure the disease.

palliative care

Care given to improve the quality of life of patients who have a serious or life-threatening disease. The goal of palliative care is to prevent or treat as early as possible the symptoms of a disease, side effects caused by treatment of a disease, and psychological, social, and spiritual problems related to a disease or its treatment. Also called comfort care, supportive care, and symptom management.

palliative therapy

Treatment given to relieve the symptoms and reduce the suffering caused by cancer and other life-threatening diseases. Palliative cancer therapies are given together with other cancer treatments, from the time of diagnosis, through treatment, survivorship, recurrent or advanced disease, and at the end of life.

palmar-plantar erythrodysesthesia

A condition marked by pain, swelling, numbness, tingling, or redness of the hands or feet. It sometimes occurs as a side effect of certain anticancer drugs. Also called hand-foot syndrome.

palonosetron

The active ingredient in a drug used to treat nausea and vomiting caused by cancer treatment. Palonosetron is a type of serotonin receptor antagonist and a type of antiemetic.

palonosetron hydrochloride

A drug used to treat nausea and vomiting caused by cancer treatment. It is a type of serotonin receptor antagonist and a type of antiemetic. Also called Aloxi.

palpable disease

A term used to describe cancer that can be felt by touch, usually present in lymph nodes, skin, or other organs of the body such as the liver or colon.

palpation

Examination by pressing on the surface of the body to feel the organs or tissues underneath.

palpitation

A rapid or irregular heartbeat that a person can feel.

pamidronate

A drug that is used to treat hypercalcemia (too much calcium in the blood) and cancer that has spread to the bones. It belongs to the family of drugs called bisphosphonates.

panacea

A cure-all.

Pancoast tumor

A type of lung cancer that begins in the upper part of a lung and spreads to nearby tissues such as the ribs and vertebrae. Most Pancoast tumors are non-small cell cancers. Also called pulmonary sulcus tumor.

pancreas

A glandular organ located in the abdomen. It makes pancreatic juices, which contain enzymes that aid in digestion, and it produces several hormones, including insulin. The pancreas is surrounded by the stomach, intestines, and other organs.

pancreatectomy

Surgery to remove all or part of the pancreas. In a total pancreatectomy, part of the stomach, part of the small intestine, the common bile duct, gallbladder, spleen, and nearby lymph nodes also are removed.

pancreatic

Having to do with the pancreas.

pancreatic cancer

A disease in which malignant (cancer) cells are found in the tissues of the pancreas. Also called exocrine cancer.

pancreatic duct

Part of a system of ducts in the pancreas. Pancreatic juices containing enzymes are released into these ducts and flow into the small intestine.

pancreatic endocrine cancer

A rare cancer that forms in the islets of Langerhans cells (a type of cell found in the pancreas). Also called islet cell carcinoma.

pancreatic enzyme

A protein secreted by the pancreas that aids in the digestion of food.

pancreatic function test

A test used to help diagnose problems in the pancreas, such as gastrinomas and pancreatitis. It measures the ability of the pancreas to respond to the hormone secretin (a hormone that causes other substances to be released by the stomach, liver, and pancreas). Secretin is given to the patient by a tube put through the nose or throat into the small intestine and stomach or by injection into a vein. After a certain amount of time, samples are taken to be sent to a laboratory for testing. It is a type of pancreatic function test. Also called secretin stimulation test.

pancreatic insulin-producing tumor

An abnormal mass that grows in the beta cells of the pancreas that make insulin. Pancreatic insulin-producing tumors are usually benign (not cancer). They secrete insulin and are the most common cause of low blood sugar caused by having too much insulin in the body. Also called beta cell neoplasm, beta cell tumor of the pancreas, and insulinoma.

pancreatic juice

Fluid made by the pancreas. Pancreatic juices contain proteins called enzymes that aid in digestion.

pancreatic polypeptide

A small protein made by the pancreas that helps control the release of other substances made by the pancreas. The amount of pancreatic polypeptide in the blood increases after a person eats. It may also increase with age, and in certain diseases, such as diabetes and pancreatic cancer. Also called PP.

pancreatitis

Inflammation of the pancreas. Chronic pancreatitis may cause diabetes and problems with digestion. Pain is the primary symptom.

panic

Sudden extreme anxiety or fear that may cause irrational thoughts or actions. Panic may include rapid heart rate, flushing (a hot, red face), sweating, and trouble breathing.

panitumumab

A human monoclonal antibody that is being used to treat colorectal cancer that has spread to other parts of the body. It is used in patients whose disease has not gotten better during or after treatment with other anticancer drugs. It is also being studied in the treatment of other types of cancer. Monoclonal antibodies are made in the laboratory and can locate and bind to substances in the body, including cancer cells. Panitumumab binds to the epidermal growth factor receptor (EGFR) and may block tumor cell growth. Also called ABX-EGF and Vectibix.

panobinostat

A drug being studied in the treatment of cancer. It blocks enzymes needed for cells to grow and divide and may kill cancer cells. Panobinostat may also prevent the growth of new blood vessels that tumors need to grow. It is a type of histone deacetylase inhibitor and a type of antiangiogenesis agent. Also called Faridak and LBH589.

pantothenic acid

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Pantothenic acid helps some enzymes use foods and make many substances used in the body and protects cells against damage from peroxides. It is found in almost all plant and animal foods. Pantothenic acid is water-soluble (can dissolve in water) and must be taken in every day. Also called vitamin B5.

PANVAC-V

A cancer vaccine made with a form of vaccinia virus that does not cause disease in humans. It is being studied in the treatment of some types of cancer. The virus is changed in the laboratory to make human proteins, including the tumor markers called CEA and MUC-1, that may help immune cells in the body kill tumor cells. Also called inalimarev and recombinant vaccinia-CEA-MUC-1-TRICOM vaccine.

PAP

An enzyme produced by the prostate. It may be found in increased amounts in men who have prostate cancer. Also called prostatic acid phosphatase.

Pap smear

A procedure in which cells are scraped from the cervix for examination under a microscope. It is used to detect cancer and changes that may lead to cancer. A Pap smear can also show conditions, such as infection or inflammation, that are not cancer. Also called Pap test and Papanicolaou test.

Pap test

A procedure in which cells are scraped from the cervix for examination under a microscope. It is used to detect cancer and changes that may lead to cancer. A Pap test can also show conditions, such as infection or inflammation, that are not cancer. Also called Pap smear and Papanicolaou test.

Papanicolaou test

A procedure in which cells are scraped from the cervix for examination under a microscope. It is used to detect cancer and changes that may lead to cancer. A Papanicolaou test can also show conditions, such as infection or inflammation, that are not cancer. Also called Pap smear and Pap test.

papillary dermis

The thin top layer of the dermis (the inner layer of the skin). The papillary dermis has connective tissue and blood vessels that give nutrients to the epidermis (the outer layer of the skin) and that help control the temperature of the skin.

papillary serous carcinoma

An aggressive cancer that usually affects the uterus/endometrium, peritoneum, or ovary.

papillary thyroid cancer

Cancer that forms in follicular cells in the thyroid and grows in small finger-like shapes. It grows slowly, is more common in women than in men, and often occurs before age 45. It is the most common type of thyroid cancer.

papillary tumor

A tumor shaped like a small mushroom, with its stem attached to the epithelial layer (inner lining) of an organ.

papillary-reticular dermal interface

The layer of the skin between the papillary dermis (the thin top layer of the dermis) and the reticular dermis (the thick bottom layer of the dermis). The dermis is the layer of skin below the epidermis (the outer layer of the skin).

papilledema

Swelling around the optic disk, the area where the optic nerve (the nerve that carries messages from the eye to the brain) enters the eyeball. Papilledema occurs when increased brain pressure caused by tumors or other problems results in swelling of the optic nerve.

PAR-101

A substance being studied in the treatment of diarrhea caused by infection with Clostridium difficile (a type of bacteria that can grow without oxygen) in cancer patients. PAR-101 is a type of antibiotic. Also called OPT-80 and tiacumicin B.

para-aminobenzoic acid

A nutrient in the vitamin B complex that the body needs in small amounts to function and stay healthy. Bacteria that live in the intestines need para-aminobenzoic acid to survive. Para-aminobenzoic acid is found in grains and foods from animals. It is being studied as a radiosensitizer (a substance that makes tumor cells more sensitive to radiation therapy) and in the treatment of certain skin disorders. Also called aminobenzoic acid and PABA.

paracentesis

A procedure in which a thin needle or tube is put into the abdomen to remove fluid from the peritoneal cavity (the space within the abdomen that contains the intestines, the stomach, and the liver).

paraganglia

A collection of cells that came from embryonic nervous tissue, and are found near the adrenal glands and some blood vessels and nerves. Most paraganglia secrete epinephrine and norepinephrine.

paraganglioma

A rare, usually benign tumor that develops from cells of the paraganglia. Paraganglia are a collection of cells that came from embryonic nervous tissue, and are found near the adrenal glands and some blood vessels and nerves. Paragangliomas that develop in the adrenal gland are called pheochromocytomas. Those that develop outside of the adrenal glands near blood vessels or nerves are called glomus tumors or chemodectomas.

parageusia

A bad taste in the mouth. Also called dysgeusia.

paralysis

Loss of ability to move all or part of the body.

paralytic ileus

A condition in which the muscles of the intestines do not allow food to pass through, resulting in a blocked intestine. Paralytic ileus may be caused by surgery, inflammation, and certain drugs.

paramyxovirus

A type of virus that has hemagglutinin-neuraminidase proteins in the outer coat and RNA as the genetic material. Measles (rubeola) virus, mumps virus, and Newcastle disease virus are paramyxoviruses.

paranasal sinus

One of many small hollow spaces in the bones around the nose. Paranasal sinuses are named after the bones that contain them: frontal (the lower forehead), maxillary (cheekbones), ethmoid (beside the upper nose), and sphenoid (behind the nose). The paranasal sinuses open into the nasal cavity (space inside the nose) and are lined with cells that make mucus to keep the nose from drying out during breathing.

paranasal sinus and nasal cavity cancer

Cancer that forms in tissues of the paranasal sinuses (small hollow spaces in the bones around the nose) or nasal cavity (the inside of the nose). The most common type of paranasal sinus and nasal cavity cancer is squamous cell carcinoma (cancer that begins in flat cells lining these tissues and cavities).

paraneoplastic syndrome

A group of symptoms that may develop when substances released by some cancer cells disrupt the normal function of surrounding cells and tissue.

paranoia

A mental disorder in which a person has an extreme fear and distrust of others. A paranoid person may have delusions that people are trying to harm him or her.

Paraplatin

A drug that is used to treat advanced ovarian cancer that has never been treated or symptoms of ovarian cancer that has come back after treatment with other anticancer drugs. It is also used with other drugs to treat advanced, metastatic, or recurrent non-small cell lung cancer and is being studied in the treatment of other types of cancer. Paraplatin is a form of the anticancer drug cisplatin and causes fewer side effects in patients. It attaches to DNA in cells and may kill cancer cells. It is a type of platinum compound. Also called carboplatin.

parasite

An animal or plant that gets nutrients by living on or in an organism of another species. A complete parasite gets all of its nutrients from the host organism, but a semi-parasite gets only some of its nutrients from the host.

parasitic

Having to do with or being a parasite (an animal or plant that gets nutrients by living on or in an organism of another species).

parasomnia

An abnormal disruption of sleep, such as sleep walking, sleep talking, nightmares, bedwetting, sleep apnea (problems with breathing that cause loud snoring), or nighttime seizures.

parasympathetic nervous system

The part of the nervous system that slows the heart, dilates blood vessels, decreases pupil size, increases digestive juices, and relaxes muscles in the gastrointestinal tract.

parathormone

A substance made by the parathyroid gland that helps the body store and use calcium. A higher-than-normal amount of parathormone causes high levels of calcium in the blood and may be a sign of disease. Also called parathyrin, parathyroid hormone, and PTH.

parathyrin

A substance made by the parathyroid gland that helps the body store and use calcium. A higher-than-normal amount of parathyrin causes high levels of calcium in the blood and may be a sign of disease. Also called parathormone, parathyroid hormone, and PTH.

parathyroid cancer

A rare cancer that forms in tissues of one or more of the parathyroid glands (four pea-sized glands in the neck that make parathyroid hormone, which helps the body store and use calcium).

parathyroid gland

One of four pea-sized glands found on the surface of the thyroid. The parathyroid hormone made by these glands increases the calcium level in the blood.

parathyroid hormone

A substance made by the parathyroid gland that helps the body store and use calcium. A higher-than-normal amount of parathyroid hormone causes high levels of calcium in the blood and may be a sign of disease. Also called parathormone, parathyrin, and PTH.

parathyroidectomy

Surgery to remove one or more parathyroid glands (four pea-sized organs found on the thyroid).

parenchyma

The essential or functional elements of an organ.

parenteral nutrition

A form of nutrition that is delivered into a vein. Parenteral nutrition does not use the digestive system. It may be given to people who are unable to absorb nutrients through the intestinal tract because of vomiting that won't stop, severe diarrhea, or intestinal disease. It may also be given to those undergoing high-dose chemotherapy or radiation and bone marrow transplantation. It is possible to give all of the protein, calories, vitamins and minerals a person needs using parenteral nutrition. Also called hyperalimentation, total parenteral nutrition, and TPN.

paresthesia

An abnormal touch sensation, such as burning or prickling, that occurs without an outside stimulus.

paricalcitol

A substance that is being used to treat overactive parathyroid glands in patients with kidney failure. It is also being studied in the treatment of cancer. Paricalcitol belongs to the family of drugs called vitamin D analogs.

parietal cell vagotomy

Surgery to cut the parts of the vagus nerve that cause gastric acid to be made in the stomach. It is done to treat stomach ulcers or other conditions in which the stomach makes too much acid.

parietal pericardium

The outer layer of the pericardium, which is a thin sac of tissue that surrounds the heart.

parietal peritoneum

The layers of tissue that line the abdominal wall and the pelvic cavity.

Parkinson disease

A progressive disorder of the nervous system marked by muscle tremors, muscle rigidity, decreased mobility, stooped posture, slow voluntary movements, and a mask-like facial expression.

parotid gland cancer

Cancer that forms in a parotid gland, the largest of the salivary glands, which make saliva and release it into the mouth. There are 2 parotid glands, one in front of and just below each ear. Most salivary gland tumors begin in parotid glands.

parotidectomy

Surgery to remove all or part of the parotid gland (a large salivary gland located in front of and just below the ear). In a radical parotidectomy, the entire gland is removed.

paroxetine hydrochloride

A drug used to treat depression and anxiety disorders. It is a type of selective serotonin reuptake inhibitor (SSRI). Also called Paxil.

paroxysmal nocturnal hemoglobinuria

A rare disorder in which red blood cells are easily destroyed by certain immune system proteins. Symptoms include blood clots, and red or brownish urine in the morning. Aplastic anemia (decreased production of blood cells) may lead to PNH, and people with PNH are at increased risk of acute myelogenous leukemia. Also called PNH.

PARP

A type of enzyme involved in many functions of the cell, including the repair of DNA damage. DNA damage may be caused by normal cell actions, UV light, some anticancer drugs, and radiation used to treat cancer. Inhibitors of one enzyme, PARP-1, are being studied in the treatment of cancer. Also called poly (ADP-ribose) polymerase.