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.

Occupational Therapist

A healthcare professional who uses activity to promote good mental health, assist recovery and help people achieve important personal outcomes. They provide holistic support to patients to help them improve their ability to do everyday tasks.1 See also ‘holistic’


Medical doctor specialising in the treatment of people with cancer. For example, medical oncologists specialise in the treatment of cancer using medicines (e.g. chemotherapy and immunotherapy) and thoracic oncologists specifically treat cancers that develop in the chest, including lung cancer.2

Opportunistic screening

Opportunistic screening happens when someone either requests a screening test or is offered one by a healthcare professional during a routine check-up. Unlike an organised programme, opportunistic screening is not systematically offered to all people that might be eligible for screening in a population.3 See alsoOrganised screening’ and ‘Targeted screening’

Organised screening

Inviting a clearly defined group of people to attend screening following a common protocol, so all participants are offered the same services, information and support. Large numbers of people are often invited to take part in organised screening. Outcomes may be monitored by a centralised third party to ensure they are of a high standard.3 See alsoOpportunistic screening’ and ‘Targeted screening’

Out-of-pocket costs

Direct payments for healthcare. This can include fully self-funded care, as well as contributions to government-funded care and co-payments on health insurance.4 See also ‘co-payment’


A scenario where screening identifies cancerous nodules or lesions that will never cause any symptoms.5 These cancers may stop growing or go away on their own. The consequences of overdiagnosis include the possibility of individuals being referred for treatment or further tests that are unnecessary.6 See also ‘False positive’ and ‘Nodule’


  1. Royal College of Occupational Therapists. 2023. About occupational therapy. Available from: [Accessed 10/08/2023]

  2. Types of oncologists.  Available from: [Accessed 12/04/22]

  3. National Screening Unit: New Zealand Ministry of Health. Organised and opportunistic screening. [Updated 05/12/14].  Available from: [Accessed 30/03/22]

  4. Office for National Statistics. 2023. Healthcare expenditure, UK Health Accounts: 2021. Available from: [Accessed 03/08/2023]

  5. National Cancer Institute. NCI Dictionary of Cancer Terms.  Available from: [Accessed 04/03/22]

  6. World Health Organization. 2020. WHO report on cancer: setting priorities, investing wisely and providing care for all. Geneva: WHO