Glossary
Being diagnosed with cancer can feel like having to learn a whole new language. Here you can find definitions for words your doctor is likely to use.
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
A
Adjuvant therapy: – Additional treatment given to reduce the chance of the cancer returning.
Adoptive Cell Therapy – A type of immunotherapy in which immune cells – such as T cells or NK cells – are collected from a patient or donor, modified or expanded in a laboratory, and then given back to the patient to help the immune system fight cancer.
Amputation – The removal of a limb or extremity part with surgery.
Angiogenesis – The process by which new blood vessels form. Tumours can trigger angiogenesis to obtain the blood supply they need to grow, making this process a key target in some cancer treatments.
Anti-angiogenic therapy – Treatment designed to block the formation of new blood vessels that feed a tumour. Drugs such as sorafenib and regorafenib work in this way and are being studied in osteosarcoma.
Antibody – Part of the immune system which recognises things that do not belong in the body and sticks to them including cancer cells.
Antigen – A marker on the surface of a cell that is recognised as ‘foreign’ by the immune system.
B
Biopsy – A medical procedure that involves removing a small amount of tissue from the body which is then examined under a microscope.
Biomarker – A molecule in the body that can indicate a specific condition or process in the body.
Bispecific antibody – An engineered antibody designed to bind to two different targets at the same time for example, a cancer cell marker and an immune cell helping to bring immune cells into direct contact with tumour cells to destroy them.
C
Cancer – A disease where cells divide and grow uncontrollably and can spread to other areas of the body.
Cannula – A flexible tube that is inserted into a vein with a small needle, which can then be used to deliver medication.
CAR-NK cell therapy – A type of immunotherapy in which natural killer (NK) cells are genetically engineered with a chimeric antigen receptor (CAR) to better recognise and destroy cancer cells. Being studied in osteosarcoma as an alternative to CAR-T cell therapy.
CAR-T cell therapy (Chimeric Antigen Receptor T cell therapy) – A type of immunotherapy in which a patient’s own T cells (a type of immune cell) are removed, genetically modified in a laboratory to carry a special receptor that recognises cancer cells, and then returned to the patient. The modified cells can then seek out and attack cancer cells.
CD47 – A protein found on the surface of some cancer cells that acts as a ‘do not eat me’ signal, helping tumour cells avoid being destroyed by the immune system. Drugs targeting CD47 are being investigated in osteosarcoma.
Central line – A flexible tube that is inserted into larger veins in the chest. This can stay in place for weeks/months and can be used to give medications and for blood tests.
Central Nervous System – The brain and spinal cord.
Checkpoint inhibitor – See Immune checkpoint inhibitor.
Cisplatin – A chemotherapy drug used as part of the standard treatment regimen for osteosarcoma. It works by damaging the DNA of cancer cells, preventing them from dividing.
Cisplatin, Doxorubicin, Methotrexate, Ifosfamide – The four chemotherapy drugs most commonly used in osteosarcoma treatment, often given in combination. See individual entries for each drug.
Compassionate Use Programme– Drugs that are not currently licensed for osteosarcoma but can be given when no other treatments are working.
Complete Response – When a cancer disappears completely after treatment.
CTLA-4 – A protein on the surface of immune cells that acts as a brake on the immune response. Some checkpoint inhibitor drugs block CTLA-4 to help the immune system become more active against cancer cells.
D
Dendritic cell vaccine – A type of cancer vaccine in which a patient’s own dendritic cells (cells that help train the immune system) are exposed to tumour material in a laboratory, then returned to the patient to help the immune system recognise and attack cancer cells.
DNA – The molecule that contains the genetic information that makes you the person you are.
Dose Escalation Study – A trial where the dose of a drug is increased until the highest safe dose is found.
Doxorubicin – A chemotherapy drug (also known as adriamycin) commonly used in the treatment of osteosarcoma. It works by interfering with cancer cell DNA to stop cells from dividing.
E
Enzyme – Molecules in the body that speed up chemical reactions.
Exclusion Criteria – A list of features that determine who can’t join a clinical trial.
Expanded access – Drugs that are not currently licensed for osteosarcoma but can be given when no other treatments are working.
F
Fertility – The ability to have children.
First-line Therapy – The first choice of treatment.
G
Gene therapy – A treatment approach that involves altering or replacing faulty genes, or introducing new genetic material into cells, to treat or prevent disease. In osteosarcoma research, gene therapy is being explored to improve how cancer cells respond to treatment.
Genomic profiling – A test that examines a tumour’s DNA to identify specific genetic mutations or alterations. The results can help doctors understand what is driving the cancer and identify targeted therapy options that may be effective for that individual patient.
Grade – How quickly cancer cells are growing and dividing.
H
Histology – The study of cells and tissues under a microscope. In osteosarcoma, histology helps confirm the diagnosis and subtype.
Histological response – How much of the tumour has been destroyed by chemotherapy when examined after surgery.
I
Ifosfamide – A chemotherapy drug used in osteosarcoma treatment, often given in combination with other chemotherapy agents. It works by damaging the DNA of rapidly dividing cancer cells.
IGF-1R (Insulin-like Growth Factor 1 Receptor) – A protein found on the surface of some cancer cells that promotes their growth and survival. Drugs that block IGF-1R are being studied as a targeted therapy approach in osteosarcoma.
Immune system – A system in the body that fights infection.
Immunocompromised – A person who is more susceptible to getting an infection. This can be due to a disease or treatment.
Immunosuppressed – A person who is more susceptible to getting an infection. This can be due to a disease or treatment.
Immune checkpoint inhibitor – A type of drug that blocks proteins (called checkpoints) that prevent the immune system from attacking cancer cells. By releasing these brakes, checkpoint inhibitors help the immune system recognise and destroy tumour cells. Common targets include PD-1, PD-L1, and CTLA-4.
Immune evasion – The ability of cancer cells to avoid being recognised and destroyed by the immune system. Understanding immune evasion is important in developing new immunotherapy treatments for osteosarcoma.
Inclusion Criteria – A list of features that determine who can join a clinical trial.
Infusion – A fluid such as a medication given into a vein.
Inhibitor – A drug that blocks or reduces the function of a particular protein.
Inpatient – When a person stays in hospital while receiving treatment.
Intravenous – Medication which is given into a vein.
L
Limb-sparing surgery – Surgery to remove a bone tumour while preserving the affected limb. The removed bone is typically replaced with a metal implant (endoprosthesis) or bone graft. This is now the most common surgical approach for osteosarcoma where possible, as an alternative to amputation.
Local – Cancer that is only located at the site where it first developed.
M
Maintenance Therapy – Treatment that is given to prevent cancer from either progressing or coming back.
Malignant– Another word to describe cancer cells: cells that grow and divide uncontrollably and can spread to other areas of the body.
MAP – The standard chemotherapy combination used in osteosarcoma, made up of methotrexate, doxorubicin and cisplatin.
Metastasis – Cancer cells have spread from the site where they developed to other parts of the body.
Methotrexate – A chemotherapy drug used in high doses as part of the standard treatment for osteosarcoma. It works by interfering with the production of DNA in rapidly dividing cancer cells.
mTOR pathway – A cellular signalling pathway that regulates cell growth and division. It is overactive in some cancers, making it a target for drugs called mTOR inhibitors, which are being studied in osteosarcoma.
Multidisciplinary Team – A group of medical professionals who meet to plan a person’s treatment.
N
Natural killer (NK) cells – A type of immune cell that can recognise and destroy cancer cells and cells infected by viruses without needing prior exposure to them. NK cells are being studied as a basis for new immunotherapy approaches in osteosarcoma.
Neoantigen vaccine – A personalised cancer vaccine designed to target unique mutations found in a patient’s tumour. By training the immune system to recognise these specific cancer-cell markers, neoantigen vaccines aim to trigger an immune attack on the tumour.
Neo-Adjuvant Therapy – Treatment given to shrink the tumour before the main treatment (usually surgery).
Neutropenic – Low white blood cell count.
O
Oncologist – A doctor who specialises in cancer.
Oncolytic virotherapy – A treatment approach that uses viruses specially designed or selected to infect and destroy cancer cells while leaving healthy cells unharmed. These viruses can also stimulate the immune system to attack the tumour.
Orthopaedic Surgeon – A doctor who specialises in treating bone-related conditions.
Outpatient – When a person receives treatment from a hospital but does not stay overnight.
P
Paediatric – To do with children.
Paediatrician – Doctors that manage conditions affecting children.
Palliative – Treatments or care designed to help manage the symptoms of a condition but not cure it.
Phase – The different stages of clinical trials that must be done to investigate a new drug. Phase 1 is the first stage while phase 4 is the final stage. Read more about the phases here.
Partial Response – When a tumour gets smaller after treatment but does not completely disappear.
PD-1 (Programmed Cell Death Protein 1) – A protein on the surface of T cells (immune cells) that acts as a brake on the immune system. Some cancers exploit PD-1 to avoid immune attack. Checkpoint inhibitor drugs that block PD-1 are being studied in osteosarcoma.
PD-L1 (Programmed Death Ligand 1) – A protein found on the surface of some cancer cells that binds to PD-1 on immune cells, switching off the immune response. PD-L1 levels in a tumour are sometimes measured to help predict whether checkpoint inhibitor drugs may be effective.
Placebo – An inactive treatment that is given during a clinical trial and compared with the drug of interest to see how effective the drug is. The placebo drug will resemble the active drug so participants in the trial do not know which drug they are receiving, which could affect the results. You will not be given a placebo on its own if you need active treatment for your osteosarcoma.
Platelets – Cells in the blood that help to stop bleeding.
Post-operative – After surgery
Precision medicine – An approach to treatment that uses information about a patient’s individual genes, environment, and lifestyle to tailor therapies specifically to them. In osteosarcoma, this may involve genomic profiling to identify targeted treatments most likely to be effective for that patient’s tumour.
Progression Free Survival – Length of time a person lives with cancer but it does not get worse.
Prophylaxis – Treatment given to prevent something from happening.
Prosthetic – A device designed to replace a missing body part.
Protein – Found in cells and needed for the development, growth and function of our bodies.
Pulmonary Metastasis – Cancer cells that have spread to the lungs.
R
Receptor tyrosine kinase (RTK) – A type of protein on the surface of cells that helps to regulate cell growth and division. Some RTKs are overactive in osteosarcoma, and drugs called RTK inhibitors are being studied as a targeted treatment.
Recurrent – Cancer that is treated but then comes back.
Refractory – Cancer that does not respond to treatment.
Regorafenib – A targeted therapy drug that blocks several proteins involved in tumour growth and blood vessel formation. It is being investigated in clinical trials as a treatment for recurrent or refractory osteosarcoma.
Relapse – Cancer that is treated but then comes back.
Remission – When there is no more evidence of cancer in a person’s body.
Resection – The surgical removal of tumours.
S
Sorafenib – A targeted therapy drug that works by blocking proteins involved in tumour growth and the formation of new blood vessels. It is being studied in osteosarcoma, particularly in recurrent or treatment-resistant cases.
Stable Disease – Cancer that is neither going away nor progressing.
Stage – A way to characterize the size and spread of cancer and help to guide treatment.
Study Type – There are different types of trials that are done to answer different types of questions. Read more about the study types here.
Systemic – Affecting the whole body.
T
T cells – A type of white blood cell that plays a central role in the immune response. T cells can recognise and destroy abnormal cells, including cancer cells, and are the basis of several immunotherapy approaches being studied in osteosarcoma.
Targeted therapy – Treatment that is designed to interfere with specific molecules or genetic mutations involved in the growth and spread of cancer, rather than affecting all rapidly dividing cells as conventional chemotherapy does. Targeted therapies aim to be more precise and may have fewer side effects.
TIM-3 – A protein found on the surface of some immune cells that acts as an immune checkpoint, dampening the immune response. It is being investigated as a potential target for new checkpoint inhibitor drugs in osteosarcoma.
Tissue – An organised group of cells that act together to perform a function.
Tumour – A mass of cells that are growing where they shouldn’t be. Tumours can be benign or malignant. Benign tumours do not spread to other parts of the body whereas malignant tumours are cancerous and have the potential to spread.
Tumour microenvironment (TME) – The area immediately surrounding a tumour, including the blood vessels, immune cells, and other cells and molecules that interact with cancer cells. In osteosarcoma, the TME is often immunosuppressive – meaning it suppresses the immune system – which can make immunotherapy less effective. Understanding and modifying the TME is a key area of research.
Tumour-associated macrophages (TAMs) – A type of immune cell found within and around tumours. In osteosarcoma, TAMs often promote tumour growth rather than attacking it, and targeting them is being explored as a possible treatment strategy.
Tyrosine kinase inhibitor (TKI) – A type of targeted therapy drug that blocks tyrosine kinase proteins, which are involved in signalling pathways that drive cancer cell growth. Several TKIs are being studied in osteosarcoma, including sorafenib and regorafenib.