P-30 protein: An anticancer drug that may inhibit cancer cell growth.

P-32: A radioactive form of phosphorus used in the treatment of cancer.

P-value: A statistics term. A measure of probability that a difference between groups during an experiment happened by chance. For example, a p-value of .01 (p = .01) means there is a 1 in 100 chance the result occurred by chance. The lower the p-value, the more likely it is that the difference between groups was caused by treatment.

P53 gene: The p53 GENE like the Rb gene, is a tumor suppressor gene, i.e., its activity stops the formation of tumors. If a person inherits only one functional copy of the p53 gene from their parents, they are predisposed to cancer and usually develop several independent tumors in a variety of tissues in early adulthood. This condition is rare, and is known as Li-Fraumeni syndrome.

Paclitaxel: An anticancer drug that belongs to the family of drugs called mitotic inhibitors.

Paget's 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.

PALA: An anticancer drug that is being studied to increase the effectiveness of the chemotherapy drug fluorouracil.

Palate (PAL-et): The roof of the mouth. The front portion is bony (hard palate), and the back portion is ion is muscular (soft palate).

Palliative therapy: Treatment given to relieve symptoms caused by advanced cancer. Palliative therapy does not alter the course of a disease but improves the quality of life.

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

Pamidronate: A drug that belongs to the family of drugs called bisphosphonates. Pamidronate is used as treatment for abnormally high levels of calcium in the blood.

Panacea: A remedy for all disease or ills; cure-all. In Greek mythology, Panacea was the goddess of healing.

Pancoast tumor: Non-small cell lung cancer that originates in the upper portion of the lung and extends to other nearby tissues such as the ribs and vertebrae. Also called a pulmonary sulcus tumor.

Pancreas: A fish-shaped spongy grayish-pink organ about 6 inches (15 cm) long that stretches across the back of the abdomen, behind the stomach. The head of the pancreas is on the right side of the abdomen and is connected to the duodenum (the first section of the small intestine). The narrow end of the pancreas, called the tail, extends to the left side of the body.

Pancreatectomy (pan-kree-a-TEK-toe- mee): Surgery to remove the pancreas. In a total pancreatectomy, a portion of the stomach, the duodenum, common bile duct, gallbladder, spleen, and nearby lymph nodes also are removed.

Pancreatic: Having to do with the pancreas.

Pancreatic enzymes: A group of proteins secreted by the pancreas which aid in the digestion of food.

Pancreapancreatic juices: Fluids made by the pancreas. Pancreatic juices contain proteins called enzymes that aid in digestion.

Pap test: The collection of cells from the cervix for examination under a microscope. It is used to detect changes that may be cancer or may lead to cancer, and can show noncancerous conditions, such as infection or inflammation. Also called a Pap smear.

Papillary tumor (PAP-ih-lar-ee TOO-mer): A tumor shaped like a small mushroom, with its stem attached to the epithelial layer (inner lining) of an organ.

Papilledema (pap-il-eh-DEE-ma): Swelling around the optic disk.

Paracentesis: Insertion of a thin needle or tube into the abdomen to remove fluid from the peritoneal cavity.

Parageusia: The medical term for a bad taste in the mouth. One common form of parageusia is a metallic taste of food.

Paralysis (pa-RAL-ih-sis): Loss of ability to move all or part of the body.

Paraneoplastic syndrome (paire (pair-a-nee-o-PLAS-tik): A group of symptoms that may develop when substances released by some cancer cells disrupt the normal function of surrounding cells and tissue.

Parasite: An animal or a plant that lives on or in an organism of another species and gets at least some of its nutrition from that other organism.

Parasitic: Having to do with or being a parasite. A parasite is an animal or a plant that lives on or in an organism of another species and gets at least some of its nutrients from it.