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Abdomen

Area of the body below the ribs and lungs and above the hip bones. Contains many of the body organs: stomach, small and large bowel, pancreas, liver, spleen, kidneys.

Abnormal smear

Cervical smear test showing evidence of precursor lesions in the cervix. Women who have an abnormal smear need further tests and in some cases treatment to remove the abnormal cells. An abnormal smear result does not mean that you have cancer.

Abscess

A swollen area within the body tissue, containing an accumulation of pus (dead white blood cells). Forms due to local bacterial infection.

Absolute risk

Likelihood of an event occurring in the population under study in a given time period.

Acquired immunodeficiency syndrome (AIDS)

Serious chronic disease caused by infection with a virus called the human immunodeficiency virus (HIV). The virus weakens the immune system making the patient vulnerable to infection, certain cancers and other disorders.

Acute

A disease of short duration that is typically severe. Often contrasted with chronic.

Acute lymphoblastic leukaemia (ALL)

Type of leukaemia in which too many immature lymphocyte white blood cells are produced. Acute leukaemia can progress very quickly, if untreated. The main type of leukaemia in children but can also affect adults.

Acute myeloid leukaemia (AML)

Type of leukaemia in which the body produces too many granulocyte or monocyte precursor cells (types of white blood cells collectively known as 'myeloid' cells). Acute leukaemia can progress very quickly, if untreated.

Acute non-lymphocytic leukaemia

The term for any acute leukaemia that does not involve lymphocyte white blood cells. Includes acute myeloid leukaemia, the most common form.

Adenocarcinoma

A cancer of glandular tissue. For example, an adenocarcinoma of the lung is a cancer of the mucus-secreting cells that line the airways.

Adenoma

A benign tumour formed from glandular structures in epithelial tissue.

Adenomatus polyp

A benign growth in the bowel, which may later develop into cancer.

Adenomavirus

A group of viruses that cause respiratory tract and eye infections. Adenoviruses used in gene therapy are altered to carry a specific tumor-fighting gene.

Adhesion molecules

Molecules found at the cell surface, which help bind a cell to its neighbours or to the extracellular matrix. See also cell adhesion.

Adipose tissue

Body tissue used for the storage of fat.

Adjuvant therapy

A treatment given in addition to the main treatment (for example, chemotherapy as well as surgery) to try to prevent a cancer from coming back.

Adrenal gland

Small glands near the kidneys that make the hormone adrenaline.

Adult T-cell leukaemia

A rare, rapidly progressing form of leukaemia caused by a virus called human T-cell leukemia virus.

Aetiology

Study of the causes of disease.

Age-specific rate

A measure of how common something is in a certain age group. So, for instance, with cancer incidence it is the number of people diagnosed with cancer at a certain age in a certain year, divided by the population of that age group and in that year X 100,000.

Age-standardised rate

Age-standardisation adjusts rates to take into account how many old or young people are in the population being looked at. When rates are age-standardised, you know that differences in the rates over time or between geographical areas do not simply reflect variations in the age structure of the populations. This is important when looking at cancer rates because cancer is a disease that predominantly affects the elderly. So if cancer rates are not age-standardised, a higher rate in one country is likely to reflect the fact that it has a greater proportion of older people.

Alimentary canal

The passage along which food passes through the body from mouth to anus during digestion.

Amino acid

The building blocks of proteins, the ‘doing’ molecules of a cell. A protein is made of long chains of amino acids joined together and folded up in a very precise way. There are twenty different types of amino acid, all with different chemical properties. The jobs a protein is able to carry out are determined by the order the amino acids are joined together in. This order is determined, in turn, by the order of the bases on the gene that makes it.

Anastrozole (Arimidex)

A drug used to treat breast cancer. It works by blocking the production of the female sex hormone oestrogen.

Androgen

A hormone, such as testosterone, that is responsible for the development of male characteristics. Androgens can also encourage the growth of certain cancers, such as prostate cancer.

Androgen-ablation therapy

A type of hormone treatment for cancer, where the purpose is to remove or reduce (ablate) the amount of androgen present in the body.

Angiogenesis

The process by which new blood vessels grow. Cancers can attract new blood vessels to grow towards them to supply them with oxygen and nutrients. Scientists are developing new cancer drugs that block this process in order to starve the tumour.

Anovulatory cycle

Mestruation in which ovulation does not occur.

Antiangiogenic

Something that blocks the process of angiogenesis. For example, antiangiogenic drugs to help treat cancer.

Antibody

Proteins found in the blood, produced by specialised white blood cells called 'B-cells'. B-cells make antibodies when the body recognises that something foreign (unfamiliar) is present, for example infecting bacteria. The antibodies attach themselves to these invaders, which are then destroyed. Scientists can now make synthetic antibodies (sometimes called 'monoclonal antibodies') in the lab, and use them to diagnose and treat disease.

Anticarcinogenic

Something that prevents or delays the development of cancer.

Antioxidant

A substance that prevents a chemical process called oxidation. This is when oxygen molecules join with another chemical. Oxidation damage to body cells can cause genetic mutations that can lead to cancer. So antioxidants may help to prevent cancer from developing.

Anus

The opening at the end of the alimentary canal through which excrement leaves the body.

Apoptosis

(Also called 'cell suicide' or 'programmed cell death'). Normal cells automatically kill themselves by apoptosis once they have reproduced about 60 times. This helps prevent cancer, by killing off older cells that have accumulated more damage to their DNA. Cancer cells have usually developed the ability to bypass apoptosis, and can carry on dividing.

Appendix

The tube shaped sac opening into the lower end of the large intestine. It is small and has no known function.

Aquired immunodeficiency syndrome (AIDS)

A serious disease caused by infection with a virus called the human immunodeficiency virus (HIV). The virus weakens the immune system making the patient vunerable to infection, certain cancers and other disorders.

Aromatase inhibitors

Type of anticancer drug that works by blocking the action of an enzyme called aromatase. Aromatase is involved in the production of oestrogens, so aromatase inhibitors help lower the amount of oestrogen in the body. This can block the growth of tumours that require oestrogen, for example some breast cancers.

Artefact

Something observed during an investigation that is not a true phenomenon, but occurs as a result of the preparative or investigative procedure.

Asbestos

A highly heat-resistant fibrous silicate mineral that can be woven into fabrics, and is used in brake linings and other fire-resistant and insulating materials. The danger to health caused by breathing in highly carcinogenic asbestos particles has lead to a more stringent control of its use. Exposure to asbestos can cause severe fibrosis and mesothelioma.

Ascending colon

The first main part of the large intestine, which passes upwards from the caecum on the right hand side of the abdomen.

Astrocyte

A star shaped 'glial' cell of the central nervous system.

Astrocytoma

A type of brain tumour that develops from astrocytes. It is the most common type of glioma.

Asymptomatic

Having no symptoms of disease.

Atom

The tiny particles of which matter is composed. They consist of a central nucleus made up of positively charged protons and chargeless neutrons, surrounded by a cloud of negatively charged electrons.

Atypia

Cells that look different from normal cells. A diagnosis does NOT mean you have cancer. But it may mean you are at increased risk of developing cancer.

Atypical hyperplasia

Benign but abnormal cells. It is the only form of benign breast disease that is a risk factor for breast cancer. A woman diagnosed with atypical hyperplasia will probably have the affected area removed, and may be invited for more frequent breast screening.

Autologous

Cells or tissues obtained from the same individual.

Average

An amount, standard, level or rate regarded as usual or ordinary. The average can be represented using the mean, median or mode.

Avoidable deaths

The number of avoidable deaths is defined as the number of deaths attributable to cancer within five years of diagnosis that would be avoided if patients had the same five-year relative survival as patients in the most affluent category.