The glossary explains some of the words used across this website and covers some key cancer and research terms, which primarily focus on lung cancer.


The external review of a health service against pre-defined performance standards. If achieved, it demonstrates that facility provides high-quality services.1


A substance that is added to a medicine to increase the efficacy of, or modify, other ingredients.2

Advanced lung cancer

Advanced lung cancer describes how cancerous cells that initially started growing in the lung have now spread to nearby tissues, lymph nodes or other organs in the body. Treatment can be given to help shrink the tumour, slow the growth of cancer cells or relieve symptoms,3 but advanced lung cancer is not usually curable.4 See also ‘Early stage lung cancer’, ‘Metastatic lung cancer’ and ‘Stage’


A third-party who helps patients throughout their treatment to ensure the patient receives equal and fair treatment, the patient is fully aware of their rights and are able to make informed decisions, and the patient’s voice and views are listened to and respected.5

Age-standardised rate (ASR)

A method that enables comparison of the burden of a disease between several populations. Using an ASR reduces the bias that may occur from comparing incidence and mortality rates for populations with different ages by accounting for the effect that age may have on the rate of diseases in a population. This enables other factors besides age to be explored as the potential explanation for a difference in cancer risk between populations.6 See also ‘Incidence’ and ‘Prevalence’

Anaplastic lymphoma kinase gene (ALK gene)

A biomarker that, when mutated, can increase the growth of cancer cells. Testing for the ALK gene in tumour tissue can help to plan cancer treatment. It can be treated with medication that blocks the biomarker action, thus slowing cancer growth.7 See also ‘biomarker’

Artificial intelligence (AI)

AI (e.g. machine learning, deep learning and neural networks) has several potential uses in lung cancer, such as improving the efficiency of screening or supporting healthcare professionals to make decisions.8-11 See also ‘Computer-aided detection’


A naturally occurring mineral used in construction materials, automotive parts and textiles. If products containing asbestos are disturbed, tiny fibres are released into the air – inhaling these can cause scarring, inflammation, and cancer of the lung and surrounding tissues.12 See also ‘Carcinogens’

As low as reasonably achievable (ALARA)

The guiding principle of radiation safety. It means avoiding all exposure to radiation, regardless of dose, that does not have a direct benefit. This can be achieved by using the three basic protective measures: minimising time exposed, increasing the distance from a radioactive source, and using shielding measures to reduce radiation exposure.13


Lung cancer is considered asymptomatic if a patient has no noticeable symptoms that are usually associated with the disease, such as a chronic cough, weight loss and chest pain.14 See also ‘Symptoms’