pigmented tissues, such as the eye (uveal melanoma) or the
intestines (mucosal melanoma).
Metastasis The spread of cancer from one part of the
body to another. A tumor formed by cells that have
spread is called a “metastatic tumor” or a “metastasis.” The
metastatic tumor contains cells that are like those in the
original (primary) tumor. The plural form of metastasis is
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 or 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.
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.
Neuroblastoma A type of cancer that arises from immature
nerve cells, most frequently those in the adrenal gland,
but also those in the abdomen, chest, or near the spine.
Neuroblastoma most often occurs in children younger than
Non-Hodgkin lymphoma A term for a large group of cancers
that arise in B cells or T cells (see T cell). Non-Hodgkin
lymphomas can be aggressive (fast-growing) or indolent
(slow-growing) types. B-cell non-Hodgkin lymphomas
include Burkitt lymphoma, diffuse large B-cell lymphoma,
and mantle cell lymphoma. Anaplastic large cell lymphoma
is one example of a T-cell non-Hodgkin lymphoma (see
Anaplastic large cell lymphoma).
Non–small cell lung carcinoma (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 non–small cell lung cancer are
squamous cell carcinoma, large cell carcinoma, and
adenocarcinoma. Non–small cell lung cancer 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
Ovarian cancer Cancer that arises in tissues of the ovary
(one of a pair of female reproductive glands in which the
ova, or eggs, are formed). The most common types of
ovarian cancer are ovarian epithelial carcinomas, which
form from cells on the surface of the ovary, and malignant
germ cell tumors, which form from egg cells.
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
Patient-reported outcome A report on the status of a
patient’s health condition that comes directly from the
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 percent 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 and survival.
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 immune
cells, 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.
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.