Mutation Any change in the DNA (see Deoxyribonucleic
acid) of a cell. Mutations may be caused by mistakes during
cell proliferation or by exposure to DNA-damaging agents
in the environment. Mutations can be harmful, beneficial,
or have no effect. If they occur in cells that make eggs or
sperm, they can be inherited; if mutations occur in other
types of cells, they are not inherited. Certain mutations
may lead to cancer or other diseases.
Nanotechnology Science, engineering, and technology
conducted at the nanoscale, which is about 1 to 100
nanometers; for comparison, a sheet of paper is about
100,000 nanometers thick. Nanotechnology can be used
in all other fields of science, such as chemistry, biology,
physics, materials science, and engineering.
National Cancer Institute (NCI) The largest of the 27
research-focused institutes and centers of the National
Institutes of Health. The NCI coordinates the National
Cancer Program, which conducts and supports research,
training, health information dissemination, and other
programs with respect to the cause, diagnosis, prevention,
and treatment of cancer; rehabilitation from cancer; and
the continuing care of cancer patients and their families.
Neuroendocrine tumors Rare types of cancer that form
from cells that release hormones into the blood in response
to a signal from the nervous system. Neuroendocrine
tumors can occur anywhere in the body, although most
frequently they arise in the lungs, appendix, small intestine,
rectum, and pancreas.
Noncommunicable diseases Diseases that are not
passed from person to person, such as diabetes, cancer,
and cardiovascular disease. Also called chronic disease.
Non–small cell lung cancer (NSCLC) A group of lung
cancers that are named for the kinds of cells found in the
cancer and how the cells look under a microscope. The
three main types of NSCLC are squamous cell carcinoma,
large cell carcinoma, and adenocarcinoma. NSCLC is the
most common kind of lung cancer.
Oncology The branch of medicine that focuses on cancer
diagnosis and treatment.
Oncolytic virus A virus that can preferentially infect
and lyse (break down) cancer cells. Oncolytic viruses
can occur naturally or can be made in the laboratory by
changing other viruses.
Pancreatic cancer A group of cancers that start in cells of
the pancreas, an organ located behind the stomach. Most
pancreatic cancers begin in cells that make the digestive
fluids, and the most common of these cancers are called
adenocarcinomas. Cancers that arise in the pancreatic cells
that help control blood sugar levels are called pancreatic
neuroendocrine tumors (see Neuroendocrine tumors).
Precision cancer medicine The tailoring of treatments
to the individual characteristics—in particular, the
genetics—of each patient and her or his cancer. Also called
personalized cancer medicine, molecularly based cancer
medicine, individualized cancer medicine, tailored cancer
medicine, and genetic cancer medicine.
Polyp A benign growth that protrudes from a mucous
membrane, most typically associated with the colon.
Prevalence The number or percentage of people alive
on a certain date in a population who previously had a
diagnosis of a particular disease. It includes new and
preexisting cases, and it is a function of both past incidence
Programmed death- 1 (PD- 1) A protein on the surface
of immune cells called T cells (see T cell). When PD- 1
attaches to programmed death-ligand 1 (PD-L1) on other
cells (see Programmed death-ligand 1), it sends signals
into the T cells to tell them to slow down and stop acting
aggressively. Thus, PD- 1 acts as an immune checkpoint
protein or brake.
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-1b and T cell).
Proteasome A large protein complex found inside cells.
It helps destroy other proteins when they are no longer
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