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
Papanicolaou or PAP test - A test of a sample of cells taken from a woman’s
cervix. The test is used to look for changes in the cells of the cervix that show
cervical cancer or conditions that may develop into cancer. It is the best tool to
detect precancerous conditions and hidden, small tumors that may ultimately
develop into cervical cancer.
Pancreatic neuroendocrine tumor - A rare cancer that forms in the islets of
Langerhans cells (a type of cell found in the pancreas). Also called islet cell
Philadelphia chromosome - An abnormality of chromosome 22 in which part
of chromosome 9 is transferred to it. Bone marrow cells that contain the
Philadelphia chromosome are often found in chronic myelogenous leukemia.
Polyp - A benign growth that protrudes from a mucous membrane.
Positron emission tomography (PET) - A procedure in which a small amount
of radioactive dye (sugar) is injected into a vein, and a scanner is used to make
detailed, computerized pictures of areas inside the body where the dye travels;
also called PET scan. Because cancer cells often use more glucose than normal
cells, when combined with a radioactive glucose (sugar) called FDG, the
pictures can be used to find cancer cells in the body, including
micrometastases; this type of procedure is called FDG-PET.
Prevalence - the number or percent of people alive on a certain date in a
population who previously had a diagnosis of the disease. It includes new
(incidence) and pre-existing cases, and is a function of both past incidence and
Prostatic Specific Antigen (PSA) - An enzyme secreted by the prostate gland,
increased levels of which are found in the blood of patients with cancer of the
Protein - A molecule made up of amino acids that are needed for the body to
function properly. Proteins are the basis of body structures, such as skin and
hair, and of substances such as enzymes, cytokines, and antibodies.
Radiation - Energy released in the form of particle or electromagnetic waves.
Common sources of radiation include radon gas, cosmic rays from outer space,
medical x-rays, and energy given off by a radioisotope (unstable form of a
chemical element that releases radiation as it breaks down and becomes more
Radiotherapy - The use of high-energy radiation from x-rays, gamma rays,
neutrons, protons, and other sources to kill cancer cells and shrink tumors.
Radiation may come from a machine outside the body (external-beam radiation
therapy), or it may come from radioactive material placed in the body near
cancer cells (internal radiation therapy). Systemic radiotherapy uses a
radioactive substance, such as a radiolabeled monoclonal antibody, that travels
in the blood to tissues throughout the body; also called irradiation and radiation
Renal cell carcinoma - The most common type of kidney cancer. It begins in
the lining of the renal tubules in the kidney. The renal tubules filter the blood
and produce urine. Also called hypernephroma, renal cell adenocarcinoma, and
renal cell cancer.
Rheumatoid arthritis (RA) - An autoimmune disease that causes pain,
swelling, and stiffness in the joints, and may cause severe joint damage, loss of
function, and disability. The disease may last from months to a lifetime, and
symptoms may improve and worsen over time. Some cancer therapeutics are
now routinely used for the treatment of RA.
Signaling pathway/signaling network - A group of molecules in a cell that
work together to control one or more cell functions, such as cell division or cell
death. After the first molecule in a pathway receives a signal, it activates
another molecule. This process is repeated until the last molecule is activated
and the cell function involved is carried out. Abnormal activation of signaling
pathways can lead to cancer, and drugs are being developed to block these
pathways. This may help block cancer cell growth and kill cancer cells.
Stereotactic radiosurgery - A type of external radiation therapy that uses
special equipment to position the patient and precisely give a single large dose
of radiation to a tumor. It is used to treat brain tumors and other brain disorders
that cannot be treated by regular surgery. It is also being studied in the
treatment of other types of cancer. Also called radiation surgery, radiosurgery,
and stereotaxic radiosurgery.
Surrogate endpoint - A biomarker intended to substitute for a clinical
endpoint (see Endpoint). Surrogate markers are used when the primary
endpoint is undesired (e.g., death), or when the number of events is very small,
thus making it impractical to conduct a clinical trial to gather a statistically
significant number of endpoints. The FDA and other regulatory agencies will
often accept evidence from clinical trials that show a direct clinical benefit to
The Cancer Genome Atlas (TCGA) - A project to catalogue genetic mutations
responsible for cancer, started in 2005. The goal of the project is to provide
systematic, comprehensive genomic characterization and sequence analysis of
different types of human cancers.
Tumor - An abnormal mass of tissue that results when cells divide more than
they should or do not die when they should. Tumors may be benign (not cancer),
or malignant (cancer); also called neoplasm.
Tumor microenvironment - The normal cells, molecules, and blood vessels
that surround and feed a tumor cell. A tumor can change its microenvironment,
and the microenvironment can affect how a tumor grows and spreads.
Tumor suppressor gene - A type of gene that makes a protein called a tumor
suppressor protein that helps control cell growth. Mutations (changes in DNA) in
tumor suppressor genes may lead to cancer;also called an antioncogene.
Vaccine - A substance or group of substances meant to cause the immune
system to respond to a tumor or to microorganisms, such as bacteria or viruses.
A vaccine can help the body recognize and destroy cancer cells or
Vaccine/Immunotherapy - A type of treatment that uses a substance or group
of substances to stimulate the immune system to destroy a tumor or infectious
microorganisms such as bacteria or viruses.