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.

Targeted screening

A strategy in which people who are considered to be at high risk of lung cancer are invited to take part in screening.1 See also ‘Organised screening’ and ‘Risk prediction model’

TNM system

A system for classifying cancer called the tumour, node and metastasis (TNM) system. It groups cancers into three domains involving both letters and numbers:2
  • T: the size of the primary tumour
  • N: whether the cancer has spread to the lymph nodes
  • M: whether the tumour has metastasised, either nearby or to distant parts of the body.
For example, a small cancer that has only spread to the lymph nodes may be classified as T2 N1 M0, whereas more advanced cancer that has spread significantly may be classified as T4 N3 M1.3 See also ‘Stage’


Treatment for lung cancer varies depending on its type and stage at diagnosis. People with non-small-cell lung cancer can be treated with surgery, chemotherapy, radiation therapy, targeted therapy or a combination of these treatments.4 People with small-cell lung cancer are usually treated with radiation therapy and chemotherapy.5 6 Treatment for lung cancer is constantly evolving, so please refer to your latest national guidelines for more information. See also ‘Stage’ and ‘Surgical resection’


  1. Marcus PM, Freedman AN, Khoury MJ. 2015. Targeted cancer screening in average-risk individuals. American Journal of Preventive Medicine 49(5): 765-71

  2. Goldstraw P, Chansky K, Crowley J, et al. 2016. The IASLC lung cancer staging project: proposals for revision of the TNM stage groupings in the forthcoming (eighth) edition of the TNM classification for lung cancer. Journal of Thoracic Oncology 11(1): 39-51

  3. Cancer Research UK. Stages of cancer. [Updated 07/07/20].  Available from: [Accessed 12/04/22]

  4. Zappa C, Mousa SA. 2016. Non-small cell lung cancer: current treatment and future advances. Translational lung cancer research 5(3): 288-300

  5. Rudin CM, Brambilla E, Faivre-Finn C, et al. 2021. Small-cell lung cancer. Nature Reviews Disease Primers 7(1): 3

  6. enters for Disease Control and Prevention. How is lung cancer diagnosed and treated? [Updated 18/10/21]. Available from: [Accessed 30/03/22]