What is ALK+ NSCLC?

Header image

There are two types of lung cancer: small cell, and non-small cell.

Non-small cell lung cancer (often abbreviated to NSCLC) is the most common type of lung cancer. It accounts for around 85% of all lung cancers, and consists of several sub-types, depending on where in the lungs the cancer starts growing:1,2    

A diagram showing the three different types of non-small cell lung cancer and where they each start developing within the lungs

1. Adenocarcinoma

This type of cancer can affect people who used to smoke and people who haven’t smoked before. It starts in the cells that make mucus in your lungs and often starts growing on the outer edges of the lungs (but can be found further in too).1

2. Squamous cell carcinoma

This type is often linked to people who have a history of smoking. They tend to grow on the cells that line the tubes that carry air into your lungs (the bronchi).1

3. Undifferentiated, or large cell, carcinoma

This is the rarest type of NSCLC. Large cell tumours spread early and can start anywhere in the lungs.1

ALK+ NSCLC is a subtype of NSCLC. Learn more about what having ALK+ NSCLC means here.

If your NSCLC has spread to other parts of your body your doctor might describe it as “advanced”.

What causes ALK+ NSCLC?

While smoking and being exposed to second-hand smoke are some of the most well-known causes of lung cancer,3 people who develop ALK+ NSCLC often have never smoked, or may have only lightly smoked, in the past.4,5

Developing lung cancer when you have little or no smoking history can be extremely frustrating, and you might find yourself looking for answers as to why you have developed lung cancer at all.

There are a number of other factors (summarised below) that are thought to be associated with the development of NSCLCs, however it is important to note that for some people there may be no obvious cause as to why they have developed ALK+ NSCLC.


Exposure to inhaled or ingested substances such as:

  • Asbestos6
  • Arsenic6
  • Non-tobacco smoke (e.g. burning buildings, wildfires which may contain traces of metals and other carcinogenic substances)6
  • Diesel exhaust6
  • Metals such as chromium, beryllium and nickel (you might be exposed to these if you work with car engines, or around smelting or welding for example)6
  • Atmospheric pollutants7

Radiation exposure from:

  • X-rays, CT scans8
  • Radiotherapy to the chest area9
  • Radon exposure10
  • Exposure to radioactive fallout11


Family history

Family history/genetics:

  • Although inheritance is not guaranteed, people with a family history of lung cancer are more likely to develop it than people without12    
HIV infection

HIV infection:

  • People with HIV are up to three times more likely to develop lung cancer than those without the infection13,14
ALKAnaplastic lymphoma kinase
NSCLCNon-small cell lung cancer

  1. American Cancer Society. What is Non-Small Cell Lung Cancer? 2016. Available from https://www.cancer.org/cancer/non-small-cell-lung-cancer/about/what-is-non-small-cell-lung-cancer.html. Last accessed July 2019.
  2. World Health Organization (WHO). WHO Classification of Tumours: Pathology and Genetics of Tumours of the Lung, Pleura, Thymus and Heart. Third edition, Volume 10. Chapter 1, WHO Press. 2004.
  3. National Comprehensive Cancer Network (NCCN). NCCN Clinical Practice Guideline in Oncology: Non-Small Cell Lung Cancer, Version 2. 2019. 2018.
  4. Gridelli C et al. Cancer Treat Rev 2014; 40(2): 300–306.
  5. Perez CA et al. Lung Cancer 2014; 84(2): 110–115.
  6. Field RW, Withers BL. Clin Chest Med 2012; 33(4): 10.1016/j.ccm.2012.07.001.
  7. World Health Organization (WHO). Ambient (outdoor) air quality and health. 2018. Available from: http://www.who.int/en/news-room/fact-sheets/detail/ambient-(outdoor)-air-quality-and-health. Last accessed July 2019.
  8. Berrington de González A et al. J Med Screen 2008; 15(3): 153–158.
  9. Friedman DL et al. J Natl Cancer Inst 2010; 102(14): 1083–1095.
  10. American Cancer Society. Radon and Cancer. 2015. Available from: https://www.cancer.org/cancer/cancer-causes/radiation-exposure/radon.html. Last accessed July 2019.
  11. Shimizu Y et al. Radiat Res 1990; 121(2): 120–141.
  12. Schwartz AG & Ruckdeschel JC. Am J Respir Crit Care Med 2005; 173(1): 16–22.
  13. Shiels MS et al. J Acquir Immune Defic Syndr 2009; 52(5): 611–622.
  14. Winstone TA et al. Chest 2013; 143(2): 305–314.