Adenocarcinoma: A type of cancer that arises from tissues that secrete fluids and that may occur in various organs including the prostate.


Alteration: Any change in the DNA sequence of a cell. Alterations occur when a mistake happens during cell division or as a result of exposure to a DNA-damaging agent in the environment. Certain alterations increase the risk for cancer or other diseases.


Androgen: A hormone that promotes the development and maintenance of male sexual characteristics and may also promote the growth of prostate cancer cells.


Androgen deprivation therapy (ADT): A treatment approach for prostate cancer that suppresses the production of or blocks the action of male hormones to stop the growth of prostate cancer cells. This may be achieved by surgical removal of the testicles (surgical castration) or by administration of medications called antiandrogens (chemical castration).


AR-therapy: Next-generation hormonal therapies, such as abiraterone acetate and enzalutamide, which target the androgen-receptor signaling pathway.


Ataxia telangiectasia mutation (ATM): A genetic alteration that results in ataxia telangiectasia syndrome, which is associated with an increased risk for certain types of cancer including prostate cancer.


Biomarker: Biomarkers are substances such as genetic material (DNA) and proteins found in blood and tumor tissue that might show if a cancer patient will respond or not respond to a treatment.


BRCA1 and BRCA2: Tumor suppressor genes involved in hereditary cancers including prostate cancer. [Ariel Study Glossary]


Chemotherapy: A drug treatment that uses powerful chemicals to kill rapidly dividing and fast-growing cancer cells.


Clinical trial: A type of research study that tests how well new medications work for the screening, prevention, diagnosis, or treatment of a disease, such as cancer.


Deoxyribonucleic acid (DNA): Molecules found inside cells that carry genetic information; damage to DNA may cause certain types of cancer. DNA is made up of four building blocks called nucleotides: adenine (A), thymine (T), guanine (G), and cytosine (C). The nucleotides attach to each other (A with T, and G with C) to form chemical bonds called base pairs, which connect the two DNA strands. Based on how these nucleotides bond together, the two strands of DNA twist into the shape of a spiral ladder called a helix. DNA is found inside the nucleus of a cell where it forms the chromosomes. Genes are short pieces of DNA that carry specific genetic information.


Disease burden: The intensity or severity of a disease and the impact on quality and duration of life.


Double-blind: The design of a clinical research study is “double-blind” when neither the participant nor the study physician knows whether the participant is receiving study drug or control (another treatment or, in some cases, placebo).


Gleason score: Since prostate cancers often have areas with different grades, a grade is assigned to the 2 areas that make up most of the cancer. These 2 grades are added to yield the Gleason score (also called the Gleason sum). The first number assigned is the grade that is most common in the tumor. For example, if the Gleason score is written as 3+4=7, it means most of the tumor is grade 3 and less is grade 4 and they are added for a Gleason score of 7. The highest a Gleason score can be is 10. The higher the Gleason score, the more likely it is that your cancer will grow and spread quickly.


Grade: A system for classifying cancer cells based on how abnormal they appear when examined under a microscope.


Homologous recombination deficiency (HRD) test: A genetic testing method that detects deficiency in a DNA repair process known as homologous recombination (HR) that can be used to determine if treatment with  poly (ADP-ribose) polymerase (PARP) inhibitors may be an effective treatment option. The test may be performed using a blood test or tissue sample.


Lymph nodes: Small gland-like structures that are part of the network of lymph tissues found throughout the body that help the body fight infection and disease.


Metastatic castration-resistant prostate cancer (mCRPC): Prostate cancer that has spread to other parts of the body outside of the prostate gland and keeps growing despite maintaining very low levels of testosterone in the body.


Open-label:  A type of clinical trial in which both the researchers and participants know which treatment is being administered.


Poly (ADP-ribose) polymerase (PARP): A type of enzyme involved in many functions of the cell, including the repair of DNA damage. In cancer treatment, blocking PARP may help keep cancer cells from repairing their damaged DNA, causing them to die. PARP inhibitors are a type of targeted cancer therapy.

Placebo: An inactive substance or treatment that looks the same as, and is given the same way as, an active drug or treatment being tested. The effects of the active drug or treatment are compared to the effects of the placebo.


Prostate-specific antigen (PSA): A protein produced in the prostate that can be measured in the blood. There are normally small amounts of PSA detectable. Increased levels can be used to identify the potential presence of prostate cancer and determine if prostate cancer has recurred or is progressing.


Radiotherapy: The use of high-energy radiation to kill cancer cells. Radiation may come from a machine outside the body (external-beam radiation therapy), radioactive material placed in the body near cancer cells (internal radiation therapy or brachytherapy), or by injection into the bloodstream where it travels to specific tissues.


Randomized clinical trial: A study in which people are allocated at random (by chance alone) to receive one of two or more clinical interventions. One of these interventions is the standard of comparison or control. The control may be a standard of care medicine, a placebo (“sugar pill”), or no intervention at all.