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.

Cancer detection rate

A measure of how many participants who underwent screening are confirmed to have cancer. This is calculated by dividing the number of confirmed cases by the total number of participants who underwent screening and is expressed as a percentage.1

Cancer registry

A population-based information system for collecting and storing data on the burden of cancer in a population. Registries record data such as incidence, mortality, proportion of people diagnosed at each stage of the disease and type of treatment they recieved.2


Substances which can lead to an increased risk of cancer by inducing genetic changes to exposed cells, altering how they grow and behave.3 Carcinogens can be naturally occurring (e.g. radon) or produced by different industries (e.g. asbestos, tobacco). See also ‘Asbestos’

Care pathway

A systematic process of best practice for healthcare professionals to follow when providing care to a person with lung cancer. Care pathways also map out the ‘path’ an individual can expect to follow through a healthcare system, including screening, diagnosis, treatment and rehabilitation.4

Chest X-ray

A chest X-ray uses a very small dose of ionising radiation to produce medical images of inside the chest. Scans can be used to evaluate the lungs, heart and chest wall. They can also be used to help diagnose and monitor treatment for a variety of lung conditions, including lung cancer.5

Chronic obstructive pulmonary disease (COPD)

A group of chronic conditions that cause breathing difficulties due to inflammation or scar tissue in the lungs, for example, emphysema and chronic bronchitis.6

Cohort study

A study where participants are recruited and observed based on shared common characteristics (e.g. occupation, age) to understand potential changes in disease burden or the outcome of an intervention (e.g. lung cancer screening) over a long period of time.7 See also ‘Prospective study’ and ‘Retrospective study’

Computed tomography (CT)

Computed tomography (CT) is a non-invasive medical imaging technique that uses a computer and an X-ray to create detailed images (slices) of the inside of the body. These images can be used to diagnose diseases, guide further tests or treatments, and monitor conditions over time.8 See also ‘Low-dose computed tomography’

Computer-aided detection (CADe)

A class of computer systems used to support healthcare professionals to evaluate medical images of an individual undergoing screening. CADe systems can locate and interpret potential nodules to indicate whether they may be cancerous. If the system concludes that a scan may be positive for lung cancer, the person will be referred for a follow-up.9-11 See also ‘Artificial intelligence’, ‘Computer-aided diagnosis’, ‘Early detection’, ‘False positive’ and ‘Nodule’

Computer-aided diagnosis (CADx)

A class of computer systems that provide a ‘second opinion’ on a medical imaging procedure. CADx systems are used after a person has received a positive screening result and is attending a follow-up appointment, or when they first seek medical care for potential symptoms of lung cancer.9-11 See also ‘Artificial intelligence’, ‘Computer-aided detection’, ‘Early diagnosis’, ‘False positive’ and ‘Nodule’

Cost-effectiveness analysis (CEA)

CEA studies are a type of economic evaluation that aid decision-makers in understanding how to allocate resources for health services. They model potential costs of implementing an intervention (e.g. lung cancer screening) or a new treatment for lung cancer against evidence of potential benefits (e.g. the number of quality-adjusted life years gained) and forecast overall change over a long period of time.12 See also ‘Health technology assessment’ and ‘Quality-adjusted life year (QALY)’

Clinical trials

Clinical trials are formal studies conducted in humans to evaluate the impact of an intervention, for example, lung cancer screening.13 Clinical trials are used to compare a new approach to one that is already in use or to no intervention. See also ‘Randomised controlled trial’


  1. Lehman CD, Arao RF, Sprague BL, et al. 2017. National performance benchmarks for modern screening digital mammography: Update from the Breast Cancer Surveillance Consortium. Radiology 283(1): 49-58

  2. Global Lung Cancer Coalition. 2022. Glossary. Available from: [Accessed 04/03/22]

  3. National Human Genome Research Institute. Carcinogen. Available from: [Accessed 08/04/22]

  4. Centre for Policy on Ageing. The effectiveness of care pathways in health and social care. [Updated 01/05/14]. Available from: [Accessed 27/04/22]

  5. Chest X-ray (Radiography) [Updated 15/06/2020]. Available from: [Accessed 04/03/22]

  6. Center for Disease Control. Chronic Obstructive Pulmonary Disease (COPD). [Updated 22/02/2021]. Available from: [Accessed 04/03/2022]

  7. Barrett D, Noble H. 2019. What are cohort studies? Evidence Based Nursing 22(4): 95

  8. NHS. CT scan. [Updated 18/08/21]. Available from: [Accessed 30/03/22]

  9. Choi HK, Wang X, Mazzone PJ. 2020. Artificial intelligence as a diagnostic tool for lung nodule evaluation. Journal of Medical Artificial Intelligence 3: 16

  10. Oudkerk M, Liu S, Heuvelmans M, et al. 2020. Lung cancer LDCT screening and mortality reduction — evidence, pitfalls and future perspectives. Nature Reviews: Clinical Oncology: 10.1038/s41571-020-00432-6:

  11. Firmino M, Angelo G, Morais H, et al. 2016. Computer-aided detection (CADe) and diagnosis (CADx) system for lung cancer with likelihood of malignancy. BioMedical Engineering OnLine 15(1): 2

  12. Sanders GD, Maciejewski ML, Basu A. 2019. Overview of cost-effectiveness analysis. Jama Guide to Statistics and Methods 321(14): 1400-01

  13. National Institute on Aging. What are clinical trials and studies? [Updated 09/04/20]. Available from: [Accessed 30/03/22]