Glossary of Terms
A Reader-Requested Roadmap of the MissionGBM Abbreviations and Acronyms
UPDATED: 21-Jun-2024
Life Science researchers and clinicians share a couple of things in common with the military – namely, that we love our abbreviations and acronyms for words and phrases that are often used. But sometimes we get so wound up in our work that we forget that our shorthand is not familiar to the broader audience. Many thanks to the MissionGBM readership for requesting a Glossary of Terms.
So, without further ado, we humbly post the MissionGBM “Jubilie” Glossary. You might want to bookmark this evergreen page for future reference. Please send us any additional items that you would like to see added to this Glossary.
ADL – Activities of Daily Living. Activities that an independent adult typically performs on a daily basis – shopping, preparing meals, personal hygiene, dressing, taking medications, managing money, using the telephone, email or computer, for example.
AE – Adverse Event. Adverse Event is the term that we use in therapeutics development to describe unwanted side effects of treatment. AEs come in five (5) Grades:
Grade 1 – Mild; asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated.
Grade 2 – Moderate; minimal or local, non-invasive intervention likely necessary an can be delivered on an out-patient basis; May interfere with some ADL.
Grade 3 – Severe or medically significant, but not immediately life-threatening; Hospitalization required and significant limitation of ADL.
Grade 4 – Life-threatening consequences; urgent intervention in a skilled medical facility is necessary.
Grade 5 – Death
BBB – Blood-Brain Barrier. The Blood-Brain Barrier is a selective semi-permeable membrane between the blood and the interstitium of the brain, allowing cerebral blood vessels to regulate molecule and ion movement between the blood and the brain.
Bx – Biopsy. A procedure whereby biological material from a tumor is sampled for subsequent tumor biological analysis and profiling. Biopsies can take the form of either a direct tissue retrieval or liquid biopsy (LBx) of circulating tumor fragments/cells.
“Cold” Tumor. A tumor that is not likely to trigger a strong immune response and respond to immunotherapy because the degree of immunosuppression in the TME is elevated. Most often the case with brain tumors. Opposite of a “Hot” tumor.
CR – Complete Response. As defined by RANO Criteria for brain cancers: Disappearance of all enhancing disease, which is stable for at least four (4) weeks. Stable or improved T2-FLAIR on MRI. No new lesions detected. Clinically, discontinued or reduced corticosteroid use with documented clinical stability or improvement.
DIPG - Diffuse Intrinsic Pontine’s Glioma. A rare, fast-growing tumor that forms in cells called glial cells in a part of the brain stem called the pons. DIPGs tend to spread to nearby tissue and other parts of the brain stem, are hard to treat, and have a poor prognosis. They usually occur in children. See here for further information.
DMG - Diffuse Midline Glioma. A primary central nervous system (CNS) tumor that forms in the brain or spinal column, and is typically found in the central area of the brain (see here). DMGs are very challenging to treat because they often involve or are proximal to critical brain executive function areas rendering the tumors difficult or impossible to address with conventional therapies (e.g. RT, surgery).
ecDNA – Extrachromosmal DNA. Small circles of DNA that do not reside on chromosomes, and do not follow the normal rules of Mendelian inheritance. ecDNA is increasingly being recognized as critically important to the neoplastic transformation process in early cancer cells. In addition, many of the most pathological oncogenes and immunosuppressive genes have been recently been discovered to reside on ecDNA (see here and here).
Furball. Otherwise known as a dogfight both in aerial combat (see here)…and when you realize that you must stare down brain cancer in the biggest fight of your life. Fight’s On!
FUS – Focused Ultrasound. A broad set of biophysical techniques that harness ultrasonic energy of varying frequency, power and energy to affect a therapeutic objective, including tissue ablation, transient opening of the BBB to permit enhanced drug delivery, or retrieval of circulating biomolecules for analysis (see here).
GoC – Goals of Care. A super-important plan for the things that each individual patient wants to achieve from brain cancer therapy (see here). We cannot stress three things enough: (1) GoC discussions must involve the entire Care Team, and should be considered as evergreen; (2) it is not realistic to have a goal of curing cancer; and (3) failure to soberly consider GoC is a sure fire way create unnecessary strife in your family and Care Team. As we say, “Denial is not just a river in Africa”.
HGG – High Grade Glioma. Primary brain tumors of glial cells pathologically graded at Grade 3 or 4 according to the 2021 World Health Organization Classification of Tumors of the Central Nervous System (see here). If a lowercase “p” precedes HGG (e.g. pHGG), then the tumor has been found in a pediatric patient.
“Hot” Tumor. A tumor that is likely to trigger a strong immune response and respond to immunotherapy. Opposite of a “Cold” tumor, which is most often the natural state in brain tumors.
IDH – Isocitrate Dehydrogenase. IDH is a naturally occurring enzyme found in a cell’s metabolic pathways. When IDH becomes mutated, it alters its biochemical reaction products in a manner that can lead to cancer neogenesis. IDH is the most frequently mutated metabolic gene in human malignant cancer (see here).
Incurious. Not interested in knowing the current research or best available #Data, or not wanting to discover or try anything new (see here). A word frequently attached to the patient experience at some large brain tumor centers.
irAE – Immune-Related Adverse Event. An AE resulting from undesirable action of the immune system on otherwise healthy tissue in a patient, usually as a result of an immunotherapy protocol. Examples include, dermatitis, thyroiditis, colitis, pneumonitis, pancreatitis, hepatitis or hypophysitis.
irEC – Immune-Related Enterocolitis. An irAE occurring in the colon and manifesting as confirmed colitis.
KPS – Karnofsky Performance Status. A standardized scale used to measure the ability of cancer patients to perform ordinary tasks. See here for further information.
LGG – Low Grade Glioma. Primary brain tumors of glial cells pathologically graded at Grade 1 or 2 according to the 2021 World Health Organization Classification of Tumors of the Central Nervous System (see here). If a lowercase “p” precedes LGG (e.g. pLGG), then the tumor has been found in a pediatric patient.
LITT – Laser Interstitial Thermal Therapy. A minimally invasive neuro-surgical procedure employing heat from laser pulses to destroy selected abnormal tissue.
Metastases or Mets. Cancer originating outside the brain that has spread (metastasized) to the brain. Brain metastases tend to have very different molecular and genetic profiles than those observed for primary brain cancers. Some cancers (e.g. non-small cell lung cancer) have up to a 20% probability of metastasizing to the brain.
MGBM – MissionGBM. Self-explanatory.
MGMT. A naturally-occurring enzyme that is designed to repair DNA damage created by the action of alkylating agents (like temozolomide) by removing the appended alkyl moieties. The activity level of MGMT is influenced by the methylation status of its genetic promoter sequence. uMGMT – means that the promoter is unmethylated, and therefore, MGMT actively removes appended alkyl moieties largely rendering ineffective the action of drugs such as TMZ. mMGMT – means that the promoter is methylated, and therefore, MGMT is relatively inactive at removing appended alkyl moieties largely rendering effective the action of drugs such as TMZ. In HGGs, about two-thirds of cases have a uMGMT status while roughly one-third of cases display a mMGMT status.
MoA – Mechanism of Action. The biological or biophysical sequence of steps by which a drug or medical device renders its therapeutic activity.
ndGBM. Newly diagnosed GBM
NO – Neuro-Oncology or Neuro-Oncologist. Self-explanatory. In the case of a physician, someone who has likely been trained in medical residency as a Neurologist, and then receives 1-2 years of Neuro-Oncology indoctrination during a post-residency fellowship.
NSGY – Neurosurgery. Self-explanatory.
OR – Objective Response. A documented Partial or Complete Response resulting from a defined treatment protocol.
ORR – Objective Response Rate. The percentage of people in a treatment group or study who obtain a documented Objective Response.
OS – Overall Survival. The length of time from either the date of diagnosis or the start of treatment for a disease that patients diagnosed with the disease are still alive. mOS refers to the median OS for a group of patients under observation in a study.
PD – Progressive Disease. As defined by RANO Criteria for brain cancers: Twenty-five percent (25%) or more increase in enhancing lesions despite stable or increasing steroid dose. Increase in T2-FLAIR on MRI not attributable to non-tumor causes. Any new lesions detected. Deterioration of clinical conditions not attributable to non-tumor causes, and not due to decreased steroid utilization.
PFS – Progression Free Survival. The length of time during and after the treatment of a disease that a patient lives with the disease, but it does not get worse. mPFS refers to the median PFS for a group of patients under observation in a study.
PR – Partial Response. As defined by RANO Criteria for brain cancers: Fifty percent (50%) or more decrease of all measurable enhancing lesions, which is stable for at least four (4) weeks. Stable or improved T2-FLAIR on MRI. No new lesions detected. Clinically, discontinued or reduced corticosteroid use with documented clinical stability or improvement.
Pseudo-Progression. Pseudo-progression is a phenomenon in which an initial increase in tumor size is observed or new lesions appear, followed by a decrease in tumor burden; this phenomenon can benefit patients receiving immunotherapy but often leads to premature discontinuation of treatment owing to the false judgment of progression. Can be tricky to diagnose even for the most experienced neuro-radiologists in the absence of a biopsy of the lesions noted on MRI.
Pseudo-Response. Pseudo-response is marked by an apparent significant decrease in radiological presentation of the tumor after initiation of a therapeutic intervention, which is subsequently found to result from radiological influences unrelated to true therapeutic effect on the tumor. Pseudo-response is often seen after administration of bevacizumab (Avastin®) or certain corticosteroids.
QoL – Quality of Life. Each individual patient defines her/his path through life, including the acceptable level of inconveniences, AEs and neurological compromise.
Quackfoolery. Medical treatment based on unsupported beliefs instead of actual science- or evidence-based information. Beware! - A source of widespread pollution on cable TV channels and social media. See here for further information.
RANO Criteria. The Response Assessment in Neuro-Oncology (RANO) criteria was created to permit standardization of imaging interpretation used to assess brain tumors and the response to treatments thereof (see here).
RCT - Randomized Control Trial. A clinical trial design that randomly assigns patients, who have met the study Inclusion and Exclusion criteria, to either the Treatment or Control arms without regard to individual patient characteristics. Going further, RCTs can be designed such that all parties involved with the trial do not know the assignment and treatment status of the patient. A well-designed RCT is considered the Gold Standard of modern clinical development.
rGBM. Recurrent GBM
RT – Radiation Therapy. A set of therapeutic procedures that uses energetic external beams or loco-regional radioisotopes to damage target tissue, and force them to die or generate a strong immunological response.
SAE – Serious Adverse Event. An AE that is assessed at Grade 3 and above.
SD – Stable Disease. As defined by RANO Criteria for brain cancers: Does not qualify for Complete Response, Partial Response or Progression. Stable, non-enhancing T2-FLAIR on MRI. Stable or reduced corticosteroid use compared to baseline. Clinically stable.
SoC – Standard of Care. The baseline treatment regimen that almost all brain cancer patients initially receive following diagnosis. For newly diagnosed High Grade Glioma patients (GBM; Grade 3-4 Astrocytomas, Diffuse Midline Gliomas), SoC is typically some form of chemo-radiation therapy following neuro-surgical resection.
TME – Tumor Micro-Environment. The biological conditions found within a tumor at the cellular or molecular level.
TMZ – Temozolomide. An old, modestly brain-penetrant DNA alkylating agent that is the workhorse of most SoC treatment regimens in many brain cancer cases.
TTF - Tumor Treating Fields. A novel anti-cancer therapeutic technique that uses low power alternating electrical fields to disrupt cellular biophysical processes, resulting in dyskinesis and a whole host of sequelae that can be harnessed to produce some rather compelling clinical results under the proper circumstances (see here).
Tx – Therapeutic or Therapeutic Regimen. Shorthand for the specific therapeutic protocol used to treat disease.
WTF – Whiskey Tango Foxtrot. Useful phrase/question that can be uttered in a variety of situations such as (1) when dealing with your health insurance plan; (2) when one realizes that your NO is not willing to discuss alternative treatments, and will not say why; or (3) what you might say on the radio when you begin to “gray out” because you are pulling 5Gs trying to break lag and get a clear shot on the Six of your opponent in a multi-circle furball.