Diagnostic biomarkers: A biomarker used to help identify and diagnose conditions. High glucose levels are a diagnostic biomarker for diabetes.

Discovery research: Experiments with genes, cells, animals, or people to find a new or improved understanding of an action, health behavior, process, technique, technology, or model to improve care.

Disparity (See cancer disparity and health disparity)

Epidemiology: The study of the occurrence, distribution, and possible causes of diseases (like cancer) in a group of people.  

Epigenetic age/epigenetic aging (see biologic age)

Epigenetic changes (see epigenetics)

Epigenetic mark (see epigenetics)

Epigenetic signature (see epigenetics)

Epigenetics/epigenetic changes (also known as epigenetic marks or signatures): The study or process of how a person’s behaviors (like diet and exercise) and environment (like toxins, healthy or unhealthy stress management, and draining or inspiring school/work environments) can cause changes that add or remove special marks on a gene’s DNA that affect the way your genes work and how active they are. 

Epigenetic changes affect how your body reads a DNA sequence but doesn’t change the sequence as genetic changes do. Specifically, epigenetic changes, turn genes “on” and “off.” Different genes are more active in some cells than in others. Even within a certain cell, some genes are active at some times and inactive at others. Epigenetics has a strong influence on how a person develops and can alter individual traits.

Behaviors that may change epigenetic patterns/marks:

• Alcohol consumption
• Environmental pollutants
• Nutrition/diet
• Obesity
• Physical activity
• Psychological Stress
• Smoking
• Working habits (like working night shifts)

Some epigenetic changes increase your risk of developing cancer and other health conditions. It may be easier for scientists to find and remove bad epigenetic marks, though, compared to fixing a hardcopy genetic mutation. For example, reversing epigenetic changes may reveal a potential target for new treatments. 

Other helpful things to know about epigenetics: 

• Epigenetic modifications are heritable and can be passed between generations.
  
• Epigenetic changes may be reversible (unlike genetic changes). 
  
• Your epigenetics change throughout your life. 
  
• Epigenetics explains how early experiences can have lifelong impacts.
  
• Young brains are particularly sensitive to epigenetic changes.
  
• Epigenetics explains how people with identical DNA can have dramatically different looks and behaviors (phenotypic differences).
  

Epigenome: A collection of chemical marks that accumulate on a gene’s DNA as the body develops (also known as epigenetic marks or epigenetic signatures). Known as the epigenome, this collection of marks “tells” the gene what to do, where to do it, and when to do it.

Etiology: The study of the causes of a disease. There are many possible causes of cancer. Research is showing that both genetics (genes passed on from your parents) and lifestyle (including exposures to carcinogens) are major factors involved in the development of many cancers. See also carcinogen, gene.

Experimental study: When researchers introduce an intervention and study the effects. Randomized controlled trials are a type of experimental study. Unlike correlational research where a scientist looks for associations among naturally occurring variables, in experimental studies, the researcher may introduce a change and then monitor its effects. 

Federal Poverty Line (FPL): The income level that’s used to set eligibility limits for several programs and benefits in the United States. It’s published each year by the US Department of Health and Human Services. These programs include Medicaid, Children’s Health Insurance Program (CHIP), Supplemental Nutrition Assistance Program (SNAP), Supplemental Nutrition Program for Women, Infants, and Children (WIC), and other “welfare” programs.

FPL (see Federal poverty line) 

Functional precision medicine: A pre-clinical research platform where scientists use live tumor cells taken from patients to identify new drugs, including the identification of biomarkers to personalize the use of these drugs.

Gene editing (see CRISPR)

Gene expression: The process of the body turning encoded information in a gene into a function. For instance, a gene may have the code for making a certain protein. When the gene is “expressed,” a protein is made. Proteins dictate a cell’s function. 

The term gene expression communicates how many, how often, and when proteins are created from the instructions within the genes. Some researchers describe gene expression as volume control. Epigenetic changes affect gene expression to turn genes “on” and “off” (compared genetic changes can alter which protein is made, but not how much or when). 

Genetic changes (see genetic mutation)

Genetic mutations (also known as genetic variants and genetic changes): Permanent changes in the DNA sequence of a gene are called gene mutations. Some scientists think that “gene variant” is a more accurate term because changes in DNA do not always lead to disease. Sometimes the terms are used as synonyms.

Genetic predisposition or genetic susceptibility: People who inherit certain changed genes that make them more likely (more disposed or more susceptible) to develop cancer are said to have a genetic predisposition to a cancer or certain types of cancer. Sometimes this is referred to as having a family cancer syndrome. But having a genetic predisposition doesn’t mean that person will develop cancer. And if they do develop cancer, it may not be caused by the inherited genetic mutation.

Genetic susceptibility (see genetic predisposition)

Genetic variants (see genetic mutations)

Genome editing (see CRISPR)

Genomics: (see human genomics)

Germline pathogenic variations: A type of mutated gene that gets passed down from a parent to child and that causes disease, such as cancer. The BRCA1 and BRCA2 mutations are examples because they are passed down by parents and increase the risk of developing several types of cancer.

Germline variations: The type of mutated gene that are passed from a parent to a child. Germline variations that cause disease are germline pathogenic variations.

Global cancer burden: An assessment of the number of cancer cases and the effects of cancer across the world. The global cancer burden may be lowered by improving cancer prevention programs, broadening cancer screening programs, expanding high-quality treatment and patient support, and prioritizing public health awareness and education campaigns in every country. See ACS Global Cancer Control Work.

Health care barriers: Factors that prevent a person from getting to (accessing) quality health care and services, which may include lack of adequate health insurance, location of health centers, available transportation, and time off from work.

Health disparity: Health disparities are usually noticeable and significant differences between population groups in regard to their health, health care, or both, in ways that are not fair or equal. Health disparities contribute to health inequalities. Differences can be in the number of people receiving care, access to nearby care, sufficient health insurance, quality of care, and more.

Such differences are preventable, as they're closely linked with economic, political, social, and/or environmental disadvantages. Health disparities may occur because of:

• Age
• Discrimination or exclusion, or both
• Disability
• Education
• Gender (or gender identity)
• Geographic location
• Income
• Literacy
• Mental health
• National origin
• Race or ethnicity
• Religion
• Sexual orientation or gender identity
• Socioeconomic status

Cancer disparities are one type of health disparity.

Health equality: Providing everyone with the same tools and resources for health care. Compare with health equity.

Health equity: The state in which everyone is able to reach their full health potential, and no one is at a disadvantage for attaining this potential on the basis of race/ethnicity, gender, health insurance coverage, disability, place of residence, or other social circumstances, such as lack of access to good jobs with fair pay, quality education and housing, safe environments, and health care.

Equity is the fair treatment, access, opportunity, and advancement for everyone while addressing needs and eliminating barriers that prevent the full participation and success of all people.

Achieving health equity requires removing obstacles to health such as poverty and discrimination, as well as their consequences, including powerlessness and lack of access to good jobs with fair pay, quality education and housing, safe environments, and health care.

Health equity is not the same as health equality. Equity acknowledges that people have different circumstances or barriers they need to overcome, often through no fault of their own. These barriers are often because of deeply rooted, longstanding inequities at all levels of society that will take an intentional effort to address in order to have equal cancer outcomes. Because of this, the tools and resources needed for health care need to be different from one person to the next.

High-thoughput sequencing (see next-generation sequencing)

Hispanic: A broad term that refers to people descended from Spanish-speaking countries or with Latin American (South America, Mexico, Central America, and certain Caribbean islands, including Cuba, Jamaica, and others.) ancestry. The term Hispanic is more commonly used in the Eastern US and is generally preferred by those of Caribbean and South American ancestry or origin. Hispanic is considered an ethnicity, as Hispanic people can be of any race. See also Latino.

Human genomics: The study of a person’s genome—a complete set of DNA, including all of its genes.

Incidence (See cancer incidence)

Interleukins: Proteins required for controlling acute inflammatory responses in the body. Interleukins are the body’s defense against “invaders,” like wounds, viruses, or diseases. 

Interleukin-6 (IL-6): A protein produced by various cells in the body to help regulate immune responses. The production of c-reactive protein (CRP) is thought to be linked with the production of IL-6. Testing the levels of interleukin-6 is a potentially useful mark of how well the immune system is functioning. Too much IL-6 has been linked with diabetes, rheumatoid arthritis, and cancer. Both physical and psychological stress can cause temporary increases in IL-6.

Internet of Everything (IoE): A 21st century digital system is an intelligent network of people, process, data, and things (objects, devices, appliances, and so forth that use implanted sensors to communicate across the network). This interconnectedness allows data from all devices to be analyzed and processed together. IoE works in sync with technologies such as artificial intelligence, machine learning, and the cloud. These processes ensure the correct information is relayed to the right destination across the network and to leverage data faster.

Internet of Things (IoT): A subset of the Internet of Everything, which includes those devices with sensors or other technology that are connected by a network and that can exchange data over the internet without human intervention. Examples of IoT devices include pacemakers, smart thermostats, home security systems, and self-driving cars.

Intervention: A program or set of activities designed to help people or populations change a particular behavior (like sitting too much or forgetting to put on sunscreen) that increases their risk for a particular disease.

In vitro: A Latin term that means grown and studied in a dish, or in the lab, compared to being grown in a living being—in vivo.

In vivo: A Latin term that means grown and studied in a living being, such as a lab mouse or human

Latino: A broad term that refers to people in the US with Latin American ancestry. Unlike Hispanic, Latino includes people from Brazil, who speak Portuguese. Latino has replaced the terms Chicano and Mexican American and is used primarily west of the Mississippi River. Like the word Hispanic, the word Latino identifies an ethnicity, as Latino people can be of any race. Latino is used for males, Latina for females, and Latinx to be gender neutral. See also Hispanic.

Longitudinal study: A research design that involves repeated observations or measurements of the same variables—such as weight, existence of a disease, like cancer, and foods eaten (diet)—over a short or long period of time—sometimes lasting decades. Researchers don't interfere with the participants' day-to-day activities but only collect qualitative and quantitative responses through surveys, interviews, or other tools. Longitudinal studies are a method of correlational research, meaning it helps scientists discover the relationship between variables in a specific population.

Machine learning: Using computer systems that are able to learn and adapt without having a specific set of instructions to follow. The way they learn is similar to how people solve problems, by analyzing and drawing inferences from patterns in data. Familiar results of machine learning include chatbots and predictive text. In cancer research, machine learning could be used to develop a tool to predict the risk of developing cancer based on a mammogram. 

Medicaid expansion: The part of the Affordable Care Act that called for increasing the number of low-income people in the United States who qualify for the health insurance coverage provided by Medicaid, a government program run by each state.

Metabolites: Small molecules that are made and stored when the body breaks down food, drugs, or its own tissue and that are affected by the environment and diseases like cancer.

Metabolomics: The study of small molecules, called metabolites, that are made and stored when the body breaks down food, drugs, or its own tissue and that are affected by the environment and diseases like cancer.

Molecular marker (see biomarker):

Monitoring biomarkers: Biomarkers that help recognize the status of disease or side effects of treatment. Tumor DNA (ctDNA) is a monitoring biomarker for certain metastatic cancers.

Mutation (see genetic mutation)

Native Hawaiian and other Pacific Islander (NHPI) groups: This umbrella term includes people with origins in any of the original peoples of Hawaii, Guam, Samoa, or other Pacific Islands.

Next-generation sequencing (also known as NGS and High-throughput sequencing): Technology that allows for simultaneous sequencing of DNA and RNA in multiple people at the same time. Compared to traditional sequencing, which determines the sequence one section at a time, next-generation sequencing in much faster, less expensive, and delivers a much larger magnitude of information. Making sense of these huge datasets requires bioinformatics and computational biology. NGS has revolutionized the field of personalized medicine (precision medicine).

NGS (see next-generation sequencing)

Observational study: When researchers observe the effect of a risk factor, diagnostic test, treatment, or other intervention without trying to change who is or isn't exposed to it.

Oncogenesis (See carcinogenesis)

Oncogenic fusion gene: A hybrid gene formed from 2 or more previously independent genes that plays a leading role in the development and progression of cancer. These hybrid, fused genes are read (transcribed) and translated as a single unit, which may lead to the production of defective proteins that cause cancer to grow and spread.

The prevalence of fusion genes varies widely across different cancers, and many fusion genes are specific to certain cancer sub-types. Rapidly and accurately identifying fusion genes can be an important part of diagnosis because specific gene fusions characterize cancer subtypes. A stratified diagnosis can predict a patient's prognosis, response to treatment, and survival.

Fusion genes are potentially excellent sites for new treatments to target. Several drugs have been successfully developed to inhibit fusion genes.

Pathogenic mutations (see pathogenic variants)

Pathogenic variants (PVs, also known as pathogenic mutations): Genetic variants or mutations that lead to disease.

Pharmacokinetics: The study of how the body interacts with medicines from the time a person takes a drug throughout its journey in the body. 

Precision medicine (also called personalized medicine): A clinical approach for medical prevention and treatment that's tailored based on a person's lifestyle, environment, and the specific genes, proteins, and other substances in their body. Precision medicine is the opposite of the one-size-fits-all approach to prevention and treatment, where an average strategy applied to everyone. A personalized approach  helps doctors and researchers more accurately predict which prevention and treatment methods will work for a specific disease in a particular person.

The 2 types of treatment most often used in precision medicine are:

• Targeted therapy, which uses medicines designed to attack a specific target on cancer cells
• Immunotherapy, which uses medicines that help the body’s immune system attack the cancer

Preclinical studies: Research that takes place before any testing in humans is done—before clinical trials. Preclinical studies may study if a drug, procedure, or treatment is likely to be useful. In the commonly used description about the research continuum, “bench to bedside,” preclinical studies are the bench—meaning they occur in a lab setting. Preclinical studies may be conducted in a test tube or cell culture (in vitro) or in animals, such as mice (in vivo).

Predictive biomarkers: Biomarkers that signal the likelihood a person has to develop a reaction after exposure to a disease, treatment, or substance in the environment. For instance, presence of the hormone ER (ER+) in a breast tumor is a predictive biomarker that tamoxifen may be an effective treatment.

Predisposition genes (see cancer-predisposition genes and genetic predisposition)

Prevalence (see cancer prevalence)

Prognostic biomarkers: Biomarkers that indicate the chances of a disease progressing or recurring. For instance, the protein HER2 is a prognostic biomarker for breast cancer.

Promoter (also known as DNA promotor): A region of DNA where transcription (copying the information in DNA to mRNA) of a gene is initiated. Promotor regions describe the direction of transcription and point out which DNA strand will be transcribed.

Promoters work with DNA regions known as enhancers to ensure a good copy of that gene. DNA bends to put the enhancer section close to the promotor section. Mutations can occur in the coding (enhancer region) or in the promotor region. Many studies suggest that DNA promotors may be the main cause of many human diseases, especially diabetes.

Prospective Cohort Study: A long, on-going (longitudinal) research study that captures and compares years of data from a group of people (cohort) to learn how specific characteristics or risk factors affect the rate of developing diseases such as cancer.  Prospective means data is collected before anyone has developed cancer. Cohort studies are a type of observational study.

Research continuum: The full scope of research—often referred to as bench to bedside. Research may start in a research lab (pre-clinical research or research at the bench), occur as part of clinical trials, be done by health care providers or within health care systems (at the bedside), and be conducted within communities.

Response biomarkers: Biomarkers that help confirm whether a prevention method or treatment worked. For instance, after vaccination, antibodies are the response biomarkers.

Safety biomarkers: Biomarkers that help identify possible toxic responses to treatment or harmful environmental exposures. For instance, creatinine is a safety biomarker for drugs that can potentially affect the kidney.

Sedentary: Sitting, reclining, or lying down while awake and expending very little energy. 

Signature marker (see biomarker)

Social determinants of health: Non-medical factors that influence health, the ability to function, risk for health problems, and quality of life. These include conditions in the environments where people are born, live, work, play, worship, and age as well as the social, economic, and political systems that shape those conditions of daily life. Social determinants of health affect educational and job opportunities, income, housing, transportation, public safety, food security, social inclusion and non-discrimination, and access to affordable health services of high quality. Social determinants of health are closely linked with health disparities.

Stroma: The cells and tissues that support and give structure to organs, glands, or other tissues in the body. It’s made mostly of connective tissue (made mostly of fibroblasts), blood vessels (lined by endothelial cells), lymphatic vessels, immune cells, and nerves.

The stroma provides nutrients to other tissues and organs, removes waste and extra fluid, and may be involved in the body's immune response, modulating inflammation levels. When stromal cells secrete growth factors, they promote tumor growth, invasion, and metastasis.

Structural racism/Systemic racism: Normalized historical, cultural, political, and institutional practices that govern society and benefit White people and disadvantage people of color. These can include housing policies, educational systems, and employment practices that reinforce and perpetuate inequities among racial groups.

Survival rate: The percentage of people who are alive at a certain time after diagnosis of a life-threatening disease, like cancer. The survival rate doesn’t determine how long a person will live after a diagnosis of cancer, but it may help people better understand how likely it is that treatment will be successful.

For cancer, it’s common to see a 5-year period after diagnosis as the marker, referred to as a 5-year survival rate. 

Survivorship: The time in a person's life from the diagnosis of cancer until death. The study of survivorship evaluates a person's quality of life, physically, mentally, and spiritually.

Susceptibility biomarker: A biomarker that signals the potential, or risk, a person has to develop a disease before they have symptoms. For instance, low-density lipoprotein (LDL) cholesterol is a susceptibility biomarker for heart disease.

Targeted therapy: Treatment that uses drugs or other substances to identify and attack a specific target on cancer cells (such as a protein) that is affecting how cancer cells grow, divide, and spread. Targeted therapies tend to affect normal cells less and therefore cause fewer side effects than other cancer treatments. Targeted therapy is the foundation of precision medicine.

TNBC (see triple-negative breast cancer)

Triple-negative breast cancer (TNBC): A subtype of breast cancer that grows faster and is more likely to spread and recur. It is more common in women younger than age 40, who are Black, or who have a BRCA1 genetic mutation. 

It’s called triple negative because the cancer cells in TNBC don’t have receptors for the hormones estrogen (ER) or progesterone (PR). Plus, TNBC cells make very little or none of the protein called HER2 (human epidermal growth factor). That means all 3 biopsy tests to check for these hormones and the HER2 protein come back "negative." 

Tumorigenesis (see carcinogenesis)

Under-represented minorities (URM) in health-related science: Racial and ethnic groups that are particularly under-represented across many career stages: African American/Black, Hispanic/Latino, American Indian and Alaska Native, Native Hawaiian and other Pacific Islander groups. The ACS Diversity in Cancer Research (DICR) program focus on racial and ethnic under-represented minorities.