Medical Terms Glossary
Common terms you may see in clinical trial eligibility criteria, explained in plain language.
47 terms covering clinical trial eligibility, cancer treatments, and related medical concepts.
A
- Absolute Neutrophil Count (ANC)
- A blood test that measures infection-fighting white blood cells.
- Adjuvant Therapy
- Treatment given after surgery to reduce the risk of cancer returning.
- Adequate Organ Function
- Your heart, liver, kidneys, and bone marrow are working well enough for treatment.
- AST / ALT
- Blood tests used to check liver function.
- Autoimmune Disease
- A condition where the immune system attacks the body, such as lupus or rheumatoid arthritis.
B
- Biomarker
- A measurable sign in the body, such as a gene mutation, that provides information about cancer.
C
- CAR-T Therapy
- A treatment where a patient's immune cells are modified to better attack cancer.
- Chemotherapy
- Drugs that kill fast-growing cells, including cancer cells.
- Clinical Trial
- A research study in people that tests new treatments to see if they are safe and effective.
- CNS Metastases
- Cancer that has spread to the brain or spinal cord.
- Complete Response
- Cancer disappears on scans.
- Creatinine
- A blood test used to check kidney function.
E
- ECOG Performance Status
- A scale (0–5) that describes how well a person can perform daily activities.
- Eligibility Criteria
- The rules that determine who can or cannot join a clinical trial.
- Exclusion Criteria
- The conditions that prevent someone from joining a trial.
H
- Hemoglobin
- A measure of red blood cells that carry oxygen.
- Histologically Confirmed
- Cancer diagnosis confirmed by examining tissue under a microscope.
- Hormone Therapy
- Treatment that blocks or lowers hormones that help certain cancers grow.
I
- Immunotherapy
- Treatment that helps the immune system find and attack cancer.
- Inclusion Criteria
- The conditions you must meet to join a trial.
- Investigational Drug
- A treatment that is still being studied and not yet approved for general use.
L
- Locally Advanced
- Cancer that has spread nearby but not to distant parts of the body.
M
- Metastatic
- Cancer that has spread to other parts of the body.
- MSI-High
- A change in tumor DNA that may make cancer more responsive to immunotherapy.
- Mutation
- A change in a gene that may affect how cancer grows or responds to treatment.
N
- Neoadjuvant Therapy
- Treatment given before surgery.
O
- Overall Survival (OS)
- How long patients live after starting treatment.
P
- Partial Response
- Cancer shrinks but does not completely disappear.
- PD-1 / PD-L1
- Proteins involved in the immune system that some immunotherapy drugs target.
- Phase I Trial
- The first stage of testing a new treatment in people, mainly focused on safety and dosage.
- Phase II Trial
- A study that tests whether a treatment works for a specific cancer and continues safety evaluation.
- Phase III Trial
- A study that compares a new treatment to the current standard treatment.
- Placebo
- An inactive treatment that looks like the real treatment but has no active drug.
- Platelet Count
- A blood test that measures cells that help with clotting.
- Prior Lines of Therapy
- The number of different treatment regimens a patient has received.
- Progressive Disease
- Cancer that is growing or spreading despite treatment.
- Progression-Free Survival (PFS)
- How long patients live without the cancer getting worse.
R
- Radiation Therapy
- High-energy rays used to kill cancer cells.
- Randomized
- Participants are assigned by chance to different treatment groups.
- Recurrent
- Cancer that has returned after treatment.
- Refractory
- Cancer that did not respond to treatment.
- Relapsed
- Cancer that responded to treatment but later came back.
S
- Stable Disease
- Cancer does not significantly grow or shrink.
- Standard of Care
- The current best-known treatment for a condition.
T
- Targeted Therapy
- Drugs that specifically attack certain features of cancer cells.
- Treatment-Naïve
- Has not received prior treatment for this condition.
W
- Washout Period
- A required waiting period between stopping one treatment and starting another.