Programmed death-ligand 1 (PD-L1) A protein on the surface
of many cell types, including some tumor cells. When it attaches to
PD- 1 on the surface of T cells, it sends signals into the T cells to tell
them to slow down and stop acting aggressively (see Programmed
death- 1 and T cell).
Prostate cancer A form of cancer that starts in tissues of the prostate
(a gland in the male reproductive system found below the bladder and
in front of the rectum). In men, it is the most frequently diagnosed
cancer and the second most common cause of death from cancer.
Prostate-specific antigen (PSA) A protein secreted by the prostate
gland, increased levels of which are found in the blood of patients with
cancer of the prostate.
Protein A molecule made up of amino acids that is needed for the
body to function properly.
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 stable).
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 therapy.
Receptor A protein in a cell that attaches to specific molecules,
such as hormones, from outside the cell, in a lock-and-key manner,
producing a specific effect on the cell—for example, initiating cell
proliferation. Receptors are most commonly found spanning the
membrane surrounding a cell but can be located within cells.
Signaling pathway/signaling network A group of molecules in a
cell that work together to control one or more cell functions, such as
cell proliferation or cell death. After the first molecule in a pathway
receives a signal, it alters the activity of 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.
These drugs may help prevent cancer cell growth and kill cancer cells.
Soft tissue sarcoma A group of cancers that arise in soft tissues
of the body such as the muscles, tendons, fat, blood vessels, lymph
vessels, nerves, and tissues around joints. Both children and adults
can develop soft tissue sarcomas. Rhabdomyosarcoma is the most
common type of soft tissue sarcoma in children, while gastrointestinal
stromal tumors are the most common in adults.
Standard of care The intervention or interventions generally
provided for a certain type of patient, illness, or clinical circumstance.
The intervention is typically supported by evidence and/or expert
consensus as providing the best outcomes for the given circumstance.
T cell A type of immune cell that protects the body from invading
microorganisms and other foreign substances and that destroys infected
and malignant cells. A T cell is a type of white blood cell. Also called
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 cells, molecules, and blood
vessels that surround and feed a cancer cell. A cancer can change
its microenvironment, and the microenvironment can affect how a
tumor grows and spreads.
Urothelial carcinoma The most common type of bladder cancer.
It begins in urothelial cells that line the inside of the bladder. These
cells are able to change shape and stretch when the bladder is full.
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 microorganisms.
This list contains some of the specialized terms pertinent to the
AACR Cancer Progress Report 2017.