The definitions below are provided with the kind consent of Macmillan Cancer Support. They are presented in alphabetical order A-Z.

Abdomen is the part of your body with your stomach, bowel and other parts of the digestive system. It is often called your tummy.

Adjuvant therapy is treatment given after your main cancer treatment. For example, your main treatment may be an operation to remove the cancer. You may then have chemotherapy as an adjuvant therapy to reduce the risk of the cancer coming back.

Advance care planning is planning ahead for how you want to be cared for.

Alopecia is hair loss. It can happen to the hair on your head, eyebrows, eyelashes, and other areas of the body. Hair loss can be a side effect of some cancer treatments, such as chemotherapy. Your healthcare team will talk to you about how to reduce the chance of this happening. They can also help you get a wig if you want one.

Anaemia is when you have a low number of red blood cells in your blood. This can make you feel tired and breathless.

Anaesthetic is a drug that makes people more comfortable during a medical procedure. A general anaesthetic puts a person to sleep for a while. A local anaesthetic numbs a part of the body so the person cannot feel anything.

Benign tumour is a lump in the body that is not cancer. Benign tumours usually grow slowly and do not spread to other parts of the body.

Biopsy is when your doctor takes a small sample of tissue from your body and looks at it under a microscope. This is to see if the cells are cancerous or not.

Blood count is a routine blood test to measure the number of red blood cells, white blood cells and platelets in your blood. It is also called a full blood count (FBC).

Carcinogen is a substance which can cause cancer, such as radiation or the chemicals in cigarettes.

Carcinoma is a type of cancer that starts in epithelial cells. These cells cover the outside of our body and our organs. Most cancers are carcinomas.

Carcinoma in situ is a group of abnormal cells that have stayed in the place where they began. They have not spread. They may become a cancer and grow into nearby tissue.

Carer’s assessment is a chance to talk to your local council or social services department about what help you need if you are caring for someone. If you care for someone aged over 18, you have the right to a carer’s assessment and support. For more information, contact your local council in England, Wales and Scotland, or your Health and Social Care Board in Northern Ireland. You can also contact Carers UK.

Central line is a long, hollow tube made from silicone rubber. The line is put into one of the veins in your chest. It can be used to give chemotherapy treatment and other medicines. It can also be used to take samples of your blood for testing. A Hickman® line is a type of central line.

Chemotherapy is the use of anti-cancer (cytotoxic) drugs to destroy cancer cells, including leukaemia and lymphoma. It can be given alone or with other treatments.

Complementary therapy is the use of other treatments in addition to conventional medical treatments. Examples include acupuncture and meditation.

Consent is agreeing to have treatment. The doctor will usually ask you to sign a form before you have treatment to say that you give your permission. No medical treatment can be given without your consent.

CT scan (computerised tomography scan) is a scan that uses x-rays to build a three-dimensional picture of the inside of the body. This scan usually takes 10 to 30 minutes and is painless.

Cytotoxic means toxic to cells. See chemotherapy.

Diagnosis is a description of the illness a person has.

Diarrhoea is having frequent or watery bowel movements (poo). It can sometimes be a symptom of cancer or a side effect of some cancer treatments.

Drip is a way of giving fluids or drugs such as chemotherapy into a vein. It is also called an intravenous (IV) infusion.

Fatigue is when you feel extremely tired most, or all, of the time. Cancer and some of its treatments can cause fatigue.

Fertility is the ability to have children.

Fine needle aspiration is a test that uses a thin needle to take a small sample of cells from your body to be examined.

Grade is a way for doctors to describe the growth of a cancer.

Histology is the study of cells. Doctors look at cells under a microscope to see if they are normal or not. If there are cancer cells, they look to see what type of cancer it is. It is sometimes also called histopathology.

Hormonal therapy is a treatment that can change the amount or action of certain hormones in the body. This can slow or stop cancer cells from growing.

Hormones are substances produced naturally in the body. They act as chemical messengers and influence the growth and activity of cells.

Immune system is your body’s natural defence system. It helps protect against infection and disease. See lymphatic system.

Incontinence is when you have trouble controlling your bladder or your bowel.

Inoperable is when cancer cannot be removed by an operation. It might mean cancer has spread to a part of the body where an operation is not possible or too risky.

Intramuscular injection (IM) is an injection into a muscle.

Intravenous (IV) is when a drug or fluid is given into one of your veins.

Leukaemia is a cancer of the white blood cells. White blood cells fight and prevent infection.

Local therapy is a treatment, for example, radiotherapy and surgery, which only affects a particular area of your body.

Lymph is a fluid that flows around your lymphatic system.

Lymphatic system is what helps protect us from infection and disease. It also drains lymph fluid from tissues in the body before returning it to the blood. The lymphatic system is made up of fine tubes called lymphatic vessels. They connect to groups of lymph nodes throughout the body.

Lymphoedema is swelling in a part of the body. It develops because of a build-up of fluid in the body’s tissues. This happens when the lymphatic system, which normally drains the fluid away, is not working properly. It can happen in any part of the body but is most likely to affect an arm or a leg.

Lymphoma is a cancer of the lymphatic system.

Lymph nodes (lymph glands) are part of the lymphatic system. They are small and bean-shaped. They filter germs (bacteria)  and disease from the lymph fluid.

Malignant tumour is a lump in the body that is cancer. Malignant tumours can spread to different parts of the body.

Metastasis is when the cancer has spread from one part of the body to another. Cancer that has spread is sometimes called a metastatic disease or secondary cancer.

MRI scan (magnetic resonance imaging scan) is a scan that uses magnetism to build up a detailed picture of areas of your body.

Multidisciplinary team (MDT) is a group of health and social care professionals who work together to manage your treatment and care.

Nausea is feeling sick.

Negative result means something could not be found. For example, a negative lymph node biopsy means that cancer cells were not found in the lymph nodes.

Neo-adjuvant therapy is treatment given before the main treatment. For example, you might have chemotherapy before surgery to shrink the tumour and make surgery easier or more effective.

Oedema is the build-up of fluid in the body. It causes swelling.

Oncology is the medical speciality that deals with cancer.

Orally is when you take something by mouth. For example, taking a tablet.

Outpatient is when you go into hospital for an appointment and leave on the same day. Outpatients do not stay in hospital overnight.

Paediatrics is the medical speciality that deals with children.

Palliative care is treatment that is given to help improve quality of life when the cancer cannot be cured. Palliative treatment aims to meet the physical, spiritual, psychological and social needs of a person with cancer.

Pathology is the study and diagnosis of disease.

PET scan (positron emission tomography scan) is a test that measures the activity of cells in different parts of the body. It can be used to find out more about a cancer and see if it has spread to other parts of the body.

PICC line is a long, thin, flexible tube. It is put into a vein just above the bend in your elbow. It is used to give chemotherapy or other treatments. It usually stays in until treatment finishes.

Platelet is a type of cell found in your blood. Platelets help your blood to clot to help stop bleeding. Chemotherapy can reduce the number of platelets in your blood for a time, making you more likely to have bleeding and bruising.

Portacath is a long, thin tube that is put in under the skin to give chemotherapy and other drugs. The tube is connected to a small box under the skin.

Positive result means something has been found. For example, a positive lymph node biopsy means that cancer cells were found in the lymph nodes.

Pre-med (pre-medication) is a medication that you may be given before a test or treatment. For example, you may have a pre-med before having chemotherapy to help stop you feeling sick.

Primary cancer is a cancer that starts in one area of the body. Most cancers are primary cancers.

Prognosis is the likely outcome of a disease. The prognosis gives an idea of how long a person might live.

Progression (or progressed) means that the cancer is still growing, or has continued to spread.

Prosthesis is an artificial body part. A prosthesis is used if that part of the body has been removed. It helps with mobility and appearance.

Pump is something that may be used to give you chemotherapy or fluids. The pump makes sure that the right amounts are given over the right amount of time. Some pumps are small and can be taken home so that you do not have to stay in hospital.

Radiology is the use of imaging such as x-rays and scans to help diagnose cancer.

Radiotherapy uses high-energy x-rays to destroy cancer cells while doing as little harm as possible to normal cells. It can help to shrink and control cancer and relieve symptoms.

Recurrence is when cancer has come back. If it comes back to the same area of the body, it is called local recurrence. If it has spread to other parts of the body, it is called distant recurrence.

Remission is when treatment is controlling the cancer or has made it temporarily disappear, but it may not have been cured.

Secondary cancers (or secondaries) are where the primary cancer has spread to another part of the body. See metastasis.

Stage is a way for doctors to describe cancer. It means the extent of cancer. This usually means how big it is and whether it has spread from where it first started.

Subcutaneous injection (SC) is an injection given into the layer of fat under your skin.

Surgery is an operation, often to remove something (such as cancer) from the body.

Systemic therapy is a treatment that treats the whole body. For example, chemotherapy.

Targeted therapy (or biological therapy) is a treatment that interferes with cell processes that cause the cancer to grow.

Therapy is another word for treatment.

Terminal is when no more treatment can be given to control the cancer. It may mean that someone should prepare for the end of life.

Tissue is the way your cells line up next to each other to form part of your body. For example, breast cells line up next to each other to make breast tissue.

Treatment cycle is the time between one round of treatment until the next one starts.

Tumour is a group of cells that are growing in an abnormal way. Tumours can be made up of cells that are not cancerous (benign) or cancerous (malignant).

Tumour markers are proteins produced by some types of cancer. They are found in the blood. They can sometimes help doctors to diagnose the cancer, or see how well treatments are working.

Ultrasound scan is a scan that uses sound waves to create a picture of the inside of your body.

X-ray scan is a way to take pictures of the inside of your body. It can show breaks or problems with your bones and joints. It can also show changes to other body tissues and organs, such as the lungs or breasts.