Brain Tumor Glossary

5-ALA
5-Aminolevulinic Acid – a drug that when taken before surgery causes brain tumor cells to light up under fluorescent lighting.

Adaptive Clinical Trial
An adaptive clinical trial is a clinical trial that evaluates patients’ reactions to a drug beginning early in a clinical trial and modifies the trial in accord with those findings. The adaptation process continues throughout the trial. Modifications may include dosage, drug undergoing evaluation, patient selection criteria and “cocktail” mix. In some cases, trials have become an ongoing process that regularly adds and drops therapies and patient groups as more information is gained. The aim is to more quickly identify drugs that have a therapeutic effect and to zero in on patient populations for whom the drug is appropriate.

Anaplastic Astrocytoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Angiogenesis
Blood vessel formation, particularly the growth of new blood vessels from surrounding tissue into tumor tissue. These new vessels provide a greater blood supply to the tumor and the delivery of higher levels of oxygen and nutrients the needs to grow. The drug, Avastin, is an example of a drug that targets angiogenesis as a way to treat some malignant brain tumors, like glioblastoma.

Astrocytoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Avastin
One of the two major drugs currently approved to treat brain cancer patients, specifically recurrent glioblastoma patients. See also: angiogenesis.

Basic (or Discovery) Research
Research directed toward greater knowledge or understanding of the fundamental aspects of disease and of observable facts without specific applications towards developing a new product. It includes all scientific study and experimentation directed toward increasing fundamental knowledge and understanding in the field.

Benign
The least aggressive type of brain tumor is often called a benign brain tumor. They originate from cells within or surrounding the brain, do not contain cancer cells, grow slowly, and typically have clear borders that do not spread into other tissue. They may become quite large before causing any symptoms. If these tumors can be removed entirely, they tend not to return. Still, they can cause significant neurological symptoms depending on their size, and location near other structures in the brain. Some benign tumors can progress to become malignant.

Big Data
As biomedical tools and technologies rapidly improve, researchers are producing and analyzing an ever-expanding amount of complex biological data sets that combine vast amounts of information on tumors; this is known as ‘Big Data.’

Biomarker
A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Also called molecular marker and signature molecule.

Blood Brain Barrier
A network of blood vessels and tissue that is made up of closely spaced cells and helps keep harmful substances from reaching the brain. The blood-brain barrier lets some substances, such as water, oxygen, carbon dioxide, and general anesthetics, pass into the brain. It also keeps out bacteria and other substances, such as many anticancer drugs. Also called BBB.

Brain Tumor
A brain tumor is an abnormal growth
of tissue in the brain or central spine that can disrupt proper brain function. Doctors refer to a tumor based on where the tumor cells originated, and whether they are cancerous (malignant) or not (benign).

Brain Tumor Stem Cells
A small population of cells within the brain that have the ability to multiply and self-renew and to differentiate into a number of types of mature cells. Research is focused on identifying which cells within a brain tumor are the actual stem cells and determining their characteristics. Understanding brain tumor stem cells may lead to approaches to kill them, prevent re-growth or recurrence of brain tumors.

CED
Convection Enhanced Delivery (CED) is the delivery of drugs to the tumor through the use of catheters implanted in the tissue.

Chemotherapy
Often abbreviated as “chemo”, chemotherapy refers to chemical compounds – or drugs – that kill fast-dividing cells, like cancer cells. It is prescribed when surgery and/or radiation are not enough to remove a tumor and is used most often for treatment of malignant tumors.

Clinical Trial
A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called clinical study.

Clinical Trial Phases
A part of the clinical research process that answers specific questions about whether treatments that are being studied work and are safe. Phase 0 trials include a surgical procedure to evaluate how well the therapy is affecting the tumor tissue itself. Phase I trials test the best way to give a new treatment and the best dose. Phase II trials test whether a new treatment has an effect on the disease. Phase III trials compare the results of people taking a new treatment with the results of people taking the standard treatment. Phase IV trials are done using thousands of people after a treatment has been approved and marketed, to check for side effects that were not seen in the phase III trial.

Clinical Trial Sponsor
A person, company, institution, group, or organization that oversees or pays for a clinical trial and collects and analyzes the data. Also called trial sponsor.

Craniotomy
A surgical procedure during which a portion of the bone from the skull is removed allowing access to the brain; the bone is put back in place after the surgery.

Craniectomy
A surgical procedure to remove a portion of the skull, often performed to relieve pressure on the brain.

CT/CAT
Computed Tomography is a type of scan that uses x-rays from several angles to create a cross-sectional image of the body.

Defeat GBM
A subsidiary of the National Brain Tumor Society, Defeat GBM Research Collaborative connects leading brain tumor researchers from top cancer institutions across the globe to create a highly-focused, outcomes-driven effort. Defeat GBM aims to double the five-year survival rate of GBM patients in just five years. More info on our Defeat GBM program and progress.

Dexamethasone
A steroid often used to relieve inflammation or swelling in the brain.

DIPG
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Disease/Molecular Entity(ies)
A subtype of a condition, which is defined by a distinct functional or pathobiological mechanism. In more common terms: tumor type.

DNA Sequencing
A laboratory process used to learn the exact sequence (order) of the four building blocks, or bases, that make up DNA. Information is stored in DNA in a code made by arranging the four bases (identified by the letters A, C, G, and T) in different orders. DNA sequencing can be used to find DNA mutations (changes) that may cause diseases, such as cancer.

Drug Development Pipeline
The sequential process by which a new drug is discovered, tested, approved, and brought to market. Encompasses basic/discovery research, translational research, pre-clinical research and drug development, clinical trials, and regulatory approval. Example.

EMA
European Medicines Agency is the European equivalent of the FDA.

Endpoints
In clinical trials, an event or outcome that can be measured objectively to determine whether the intervention being studied is beneficial. The endpoints of a clinical trial are usually included in the study objectives. Some examples of endpoints are overall survival, improvements in quality of life, relief of symptoms, and disappearance of the tumor.

Epigenetics
The study of how age and exposure to environmental factors, such as diet, exercise, drugs, and chemicals, may cause changes in the way genes are switched on and off without changing the actual DNA sequence.

FDA
The U.S. Food & Drug Administration (FDA) is an agency of the United States Department of Health and Human Services. The FDA is responsible for protecting and promoting public health through the regulation and supervision of food safety, tobacco products, dietary supplements, prescription and over-the-counter pharmaceutical drugs (medications), vaccines, biopharmaceuticals, blood transfusions, medical devices, electromagnetic radiation emitting devices (ERED), cosmetics and veterinary products.

Gamma Knife (Cyber Knife)
A type of radiosurgery that uses a focused beam of gamma raysto destroy tumor cells.

Glioblastoma (GBM)
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Gene Expression
The process by which a gene is turned on in a cell to make RNA and proteins. In other words, the process by which the information from a specific gene is manifested into a biological structure or activity in the cell.

Gene Regulation
The control of gene expression.

Genomics & Proteomics
Branch of biomedical research that studies the genomes (the entire complement of DNA sequences) of a person, or of a tissue such as a specific brain tumor type. Genomic changes may include the entire set of small DNA mutations, the deletion of genes, extra copies of genes (gene amplification) or gene rearrangements relative to each other within, for example, a tumor. Genomic changes provide evidence as to which DNA alterations drive the growth of a tumor.

Genomic Sequencing
A laboratory method that is used to determine the entire genetic makeup of a specific organism or cell type. This method can be used to find changes in areas of the genome that may be important in the development of specific diseases, such as cancer.

Genomic Characterization
A laboratory method that is used to learn about all the genes in a person or in a specific cell type, and the way those genes interact with each other and with the environment. Genomic characterization may be used to find out why some people get certain diseases while others do not, or why people react in different ways to the same drug. It may also be used to help develop new ways to diagnose, treat, and prevent diseases, such as cancer. Also called genomic profiling.

Genotype
A genotype is an individual’s or a tumor’s collection of genes. The genotype is expressed when the information encoded in the genes’ DNA is used to make protein and RNA molecules. The expression of a person’s genotype contributes to the individual’s observable traits, called the phenotype; in a tumor, the expression of the tumor genotype contributes to the tumor’s traits.

Glioma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

High-Grade Gliomas
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Histology/Histopathology/Histologic Examination
The study of diseased cells and tissues using a microscope.

IDH (IDH1 and IDH2)
IDH is short for “Isocitrate dehydrogenase,” an enzyme that plays a role in the metabolism of cells. IDH has three forms, IDH1, IDH2, and IDH3. Mutated forms of IDH1 and IDH2 are often found in gliomas, typically low-grade gliomas and secondary glioblastomas (though IDH1 mutations are occasionally found in primary GBM patients, as well). These mutations, which occur early in the tumor-forming process, change the function of the enzymes, causing them to produce a metabolite called 2-hydroxyglutarate (2HG), instead of a molecule called “NADPH.” The presence of an IDH mutation in patients’ tumors is a “biomarker” for improved prognosis. This means that glioma patients that have an IDH mutation tend to live longer than patients without an IDH mutation (IDH-wide-type).

Immunotherapy
Cancer immunotherapy involves utilizing the natural immune system within a patient to help the body’s own defenses recognize, attack, and destroy tumor cells. Different approaches can include stimulating the immune system to enhance immune response, modifying immune cells, suppressing cells that dampen the immune response, viruses, and vaccines.

iMRI
intraoperative MRI is a system that allows MRI imaging to be utilized during surgery.

Low-Grade Glioma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Malignant Brain Tumors
Contain cancer cells and often do not have clear borders. They are considered to be life-threatening because they grow rapidly and invade surrounding brain tissue. Although malignant brain tumors very rarely spread to other areas of the body, they can spread throughout the brain or to the spine. These tumors can be treated with surgery, chemotherapy and radiation, but they may recur after treatment.

Medulloblastoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Meningioma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Metastatic or Secondary Brain Tumors
Begin in another part of the body and then spread to the brain. These tumors are more common than primary brain tumors and are named by the location in which they begin. They are treated based on where they originate, such as the lung, breast, colon or skin.

MGMT (often referred to as “MGMT promoter methylation” or simply “MGMT status”)
MGMT is short for “O6-alkylguanine DNA alkyltransferase.” MGMT is a gene that, when activated, provides cells with instructions to make a protein (also called MGMT) that repairs damage to DNA. For high-grade gliomas, like glioblastoma, the standard of care treatment includes the chemotherapy drug, temozolomide (brand name: Temodar). Temozolomide works by breaking a tumor cell’s DNA. Thus, if patients’ MGMT gene is active, their cells have an increased ability to undo the work of temozolomide by repairing the DNA after it’s broken by the chemotherapy. However, in some patients, the MGMT gene is “silenced” by a process called “methylation” where a chemical “tag” is placed over the spot in the DNA sequence that tells cells to read the instructions to make the MGMT protein. This tag (MGMT promoter methylation) prevents genetic machinery in the cell from reading the instructions for the DNA-repairing protein, thus allowing the effects of temozolomide to work better. As such, patients who test positive for MGMT promoter methylation tend to respond better to chemotherapy and survive longer than patients who carry unmethylated MGMT promoter DNA.

Model Systems
Model Systems: cellular and animal models are created in order to mimic the molecular, cellular, and biological characteristics of a human tumor. They are created to better understand the tumor and test therapies outside of actual humans.

Molecular Analysis
In medicine, a laboratory test that checks for certain genes, proteins, or other molecules in a sample of tissue, blood, or other body fluid. Molecular tests also check for certain changes in a gene or chromosome that may cause or affect the chance of developing a specific disease or disorder, such as cancer. A molecular test may be done with other procedures, such as biopsies, to help diagnose some types of cancer. It may also be used to help plan treatment, find out how well treatment is working, or make a prognosis. Some molecular analyses use microscopes but others use liquid-based specimens.

Molecular Diagnosis
The process of identifying a disease by studying molecules, such as proteins, DNA, and RNA, in a tissue or fluid.

Molecular Marker/Signature/Characteristic
A biological molecule found in blood, other body fluids, or tissues that is a sign of a normal or abnormal process, or of a condition or disease. A molecular marker may be used to see how well the body responds to a treatment for a disease or condition. Also called biomarker and signature molecule.

Molecular Profiling
Comprehensive molecular profiling of specific tumors identifies biological targets such as genes that allow for interventions, including targeted drug therapies that will be effective for those specific tumor types. We also believe that comprehensive molecular profiling is transforming the research landscape for some tumor types.

Mouse-model
Mice are the species of choice for modeling the complex interactions between tumor cells, a host environment, and drugs, as mouse genetics are easily manipulated. Mouse models allow investigators to better study and understand relationships between specific genetic alterations and tumors, utilize new imaging techniques, and test novel therapies.

MRI
Magnetic resonance imaging is a medical imaging technique that uses powerful magnetic fields to make detailed pictures of the inside of the body.

mTOR
Mammalian target of rapamycin (mTOR) is a protein that in humans is encoded by the MTOR gene. mTOR is a serine/threonine protein kinase that regulates cell growth, cell proliferation, cell motility, cell survival, protein synthesis, and transcription. mTOR belongs to the phosphatidylinositol 3-kinase-related kinase (PI3K) protein family. mTOR is a target in the NBTS-funded clinical trial that is part of Defeat GBM.

Nanotechnology
The field of research that deals with the engineering and creation of things from materials that are less than 100 nanometers (one-billionth of a meter) in size, especially single atoms or molecules. Nanotechnology is being studied in the detection, diagnosis, and treatment of cancer. For example, they are being engineered to deliver therapeutic agents to brain tumor cells.

NCI
The National Cancer Institute (NCI) is part of the National Institutes of Health (NIH). The NCI coordinates the U.S. National Cancer Program and conducts and supports research, training, health information dissemination, and other activities related to the causes, prevention, diagnosis, and treatment of cancer; the supportive care of cancer patients and their families; and cancer survivorship.

Neuroblastoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

NF2
Neurofibromatosis type 2 is a hereditary condition characterized by the growth of noncancerous tumors of the central nervous system.

NINDS
National Institute of Neurological Disorders and Stroke – part of the NIH, the mission of the NINDS is to reduce the burden of neurological disease.

Neurology
The branch of medicine dealing with the diagnosis and treatment of diseases of the nervous system.

Neuro-Oncology
The branch of medicine dealing with the diagnosis and treatment of brain tumors.

Neuropsychology
The study of how the structure and function of the brain relate to behavior and other psychology processes.

Neurosurgery
Surgery performed on the brain and other parts of the nervous system.

ODAC
Oncologic Drugs Advisory Committee (ODAC) is the U.S. Food and Drug Administration’s (FDA) panel that reviews and evaluates data concerning the safety and effectiveness of marketed and investigational human drug products for use in the treatment of cancer and makes appropriate recommendations to the Commissioner of Food and Drugs.

Oligodendroglioma (oligo)
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Oncogene
A gene that is a mutated (changed) form of a gene involved in normal cell growth. Oncogenes may cause the growth of cancer cells. Mutations in genes that become oncogenes can be inherited or caused by being exposed to substances in the environment that cause cancer.

Optune
(NovoTTF-100A Device) “Optune” is the brand name for a tumor-treating fields device. It is a medical device (a wearable cap connected to a battery pack in a backpack) that is applied with electrodes placed on a patient’s scalp and delivers alternating electric fields to disrupt tumor growth.

Palliative Care
Palliative care will address the symptoms of a serious illness as well as the side effects of medical therapies used to treat the illness, such as nausea, pain, anxiety, insomnia, lack of appetite and fatigue.

Pathology
A branch of medical science and clinical care primarily concerning the examination of tissues and bodily fluids in order to understand diseases, make medical diagnoses and guide clinical care.

Pathologist
A doctor who identifies diseases by studying cells and tissues under a microscope and through analysis of liquid-based specimens (e.g., blood).

Pathology Report
The description of cells and tissues made by a pathologist based on microscopic evidence, and sometimes used to make a diagnosis of a disease. If the report is based on material from surgery, it is sometimes referred to as a “surgical pathology report.”

Personalized Medicine/Precision Medicine
A form of medicine that uses information about a person’s genes, proteins, and environment to prevent, diagnose, and treat disease. In cancer, personalized medicine uses specific information about a person’s tumor to help diagnose, plan treatment, find out how well treatment is working, or make a prognosis.

PET
Positron emission tomography (PET) is a type of nuclear medicine imaging which is used to show how tissues are working.

PI
Principal Investigator (PI) is the lead researcher for a study or trial.

PIP
Pediatric Investigational Plan (PIP) is a plan that pharmaceutical companies must submit in Europe that outlines their intention to develop a pediatric equivalent of an adult therapy.

Pontine Glioma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Pilocytic Astrocytoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Primary
Whether cancerous or benign, tumors that start in cells of the brain are called primary brain tumors. Primary brain tumors may spread to other parts of the brain or to the spine, but rarely to other organs.

Proton Therapy
A type of radiation therapy that uses protons to treat cancer.

R01
The term for the standard funding vehicle the NIH uses to fund extramural research. More.

Radiation Therapy
The treatment of cancer using high energy radiation to kill tumor cells.

Radiosurgery
A type of radiation therapy that delivers a high dose of radiation to a precise location within the body.

RANO
Response Assessment in Neuro-Oncology (RANO) criteria is a set of guidelines currently used for assessing response to therapies in high-grade gliomas (the most aggressive malignant brain tumors). National Brain Tumor Society’s Clinical Trial Endpoints Initiative aims to refine this criteria so that the Industry and the FDA are comfortable in accepting imaging data based on this criteria to approve new therapies.

Resection
Surgery to remove a portion of tissue. The extent of brain tumor resection is linked to survival rates for many brain tumors.

Resistance
The ability of a tumor to be resistant and non-responsive to a certain chemotherapy, targeted therapy or radiation therapy.  This can be inherent, or be acquired after treatment.

Schwanoma
There are more than 100 types of brain and central nervous system (CNS) tumors. A detailed list of tumor types, their characteristics, symptoms, and potential treatments can be found here.

Sequencing
Sequencing is the process of analyzing a person’s biology – whether it be DNA sequencing; exome sequencing; or whole genome sequencing. Next-generation sequencing methods have greatly accelerated biological and medical research and discovery.

Signaling Pathway
Describes 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 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 block cancer cell growth and kill cancer cells.

Signal Transduction
The process by which a cell responds to substances in its environment. The binding of a substance to a molecule on the surface of a cell causes signals to be passed from one molecule to another inside the cell. These signals can affect many functions of the cell, including cell division and cell death. Cells that have permanent changes in signal transduction molecules may develop into cancer.

SPORE: Specialized Programs of Research Excellence
A cornerstone of NCI’s efforts to promote collaborative, interdisciplinary translational cancer research. SPORE grants involve both basic and clinical/applied scientists and support projects that will result in new and diverse approaches to the prevention, early detection, diagnosis and treatment of human cancers. National Brain Tumor Society is heavily involved in the brain cancer SPORE program.

Standard of Care
Treatment that is accepted by medical experts as a proper treatment for a certain type of disease and that is widely used by healthcare professionals. Also called best practice, standard medical care, and standard therapy. Standard of Care for most brain cancer patients is surgery, followed by radiation and chemotherapy (Temodar).

Subtype
Many tumors and cancer have different “subtypes” based on the specific molecular make-up of the tumor. For example, GBM has four distinct, know subtypes: neural, proneural, mesenchymal, and classical. These can be further classified by DNA methylation pattern signaling pathway activity, and clinical measures.

Survival Rate
The percentage of people in a study or treatment group who are still alive for a certain period of time after they were diagnosed with or started treatment for a disease, such as cancer. The survival rate is often stated as a five-year survival rate, which is the percentage of people in a study or treatment group who are alive five years after their diagnosis or the start of treatment. Also called overall survival rate.

Targeted Therapy
A type of treatment that uses drugs or other substances to identify and attack specific types of cancer cells with less harm to normal cells. Some targeted therapies block the action of certain enzymes, proteins, or other molecules involved in the growth and spread of cancer cells. Other types of targeted therapies help the immune system kill cancer cells or deliver toxic substances directly to cancer cells and kill them. Targeted therapy may have fewer side effects than other types of cancer treatment. Most targeted therapies are either small molecule drugs or monoclonal antibodies.

TCGA
The Cancer Genome Atlas (TCGA) is a joint effort launched in 2006 between the National Cancer Institute (NCI) and the National Human Genome Research Institute (NHGRI), to deliver researchers a better understanding of the molecular basis of cancer through the application of genome analysis and sequencing technologies. TCGA was a seminal moment in cancer research, and brain cancer research – as GBM was the first tumor type sequenced by TCGA.

Temozolomide/TMZ/Temodar
Temozolomide is a chemotherapeutic agent (chemo), that is the standard of care drug used to treat most brain cancers. It is most commonly marketed under the brand name Temodar and administered orally.

Therapeutic Target
A cellular structure, protein, or other biological component involved in the establishment, maintenance or growth of a tumor, which the interuption of could result in the halting of tumor growth.

Translational Research
A term used to describe the process by which the results of research done in the laboratory are used to develop new ways to diagnose and treat disease.

Tumorigenesis
The process of transformation of normal cells into tumor cells.

World Health Organization (WHO)
An agency of the United Nations concerned with international public health.

Xenograph Model
A type of model system in which animals are transplanted with human cancer cells.