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.


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.1

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.2 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.2 See alsoOpportunistic screening’ and ‘Targeted screening’


A scenario where screening identifies cancerous nodules or lesions that will never cause any symptoms.3 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.4 See also ‘False positive’ and ‘Nodule’


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

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

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

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