Slides last updated: October 2013

Relative contribution of risk factors to lung cancer burden 1. Alberg AJ & Samet JM, Epidemiology of Lung Cancer. Chest 2003; 123:21s-49s 2. American Lung Association. Lung Cancer Fact Sheet. Available online: cancer/resources/facts-figures/lung-cancer-fact- sheet.html#Other_Causes, accessed on 15/09/ Cancer Research UK. Lung Cancer Risk Factors. Available online: accessed on 15/09/2013 8% Asbestos % Radon exposure 2,3 2% Outdoor air pollution 1 Population attributable risk Impact of exposure likelihood of exposure = 85% Cigarette smoking % Occupational exposure to carcinogens 1-3

Tobacco use is the most important risk factor 1 1.American Cancer Society. Cancer Statistics Atlanta: American Cancer Society, Inc. Higher rates of smoking are associated with higher rates of lung cancer. A decrease in the prevalence of smoking in many countries since the 1950s has led to lower rates of lung cancer incidence and mortality, albeit with a lag of several decades. Trends in Tobacco Use and Lung Cancer Death Rates* in the US

Tobacco blend/filtering may affect distribution of NSCLC subtypes 1 1. Hoffmann D, Djordjevic MV, & Hoffman I. Preventative Medicine 1997:26, 427–434 lower levels of polynuclear aromatic hydrocarbons… higher levels of tobacco- specific N-nitrosamines… The advent and increased popularity of filtered cigarettes has also led to a change in the distribution of lung cancer subtypes. Filters, along with newer tobacco blends, give rise to: …and potentially to decreasing incidence of squamous cell carcinoma… …and potentially to increasing incidence of adenocarcinoma Filters also tend to lead smokers to inhale smoke more deeply and retain smoke in the lungs longer, delivering higher doses of carcinogens to the peripheries of the lungs

Exposure to asbestos increases the risk of developing lung cancer, mesothelioma and other non-malignant lung disorders 2 Exposure to asbestos coupled with smoking increases the risk to a greater extent than the separate components added together 2 Radon exposure, especially when combined with tobacco smoking, can lead to increased risk of lung cancer 1 Studies in Europe and USA have found that the risk of lung cancer increased by 8.9% and 11% respectively per 100Bq/m 3 increase in radon gas 1,3 Radon and asbestos exposure are also important risk factors 1. Darby S, Hill D Auvinen A et al. BMJ 2005;330: Erren TC, Jacobsen M & Piekarski C. Epidemiology 1999;10:405– Krewski D, Lubin JH, Zielinski JM et al. Epidemiology 2005;16:

Other risk factors include indoor air pollution and alcohol A diet high in fresh, beta-carotene-rich fruit and vegetables shows some evidence of decreasing lung cancer risk. However, beta carotene given as a supplement was shown to increase lung cancer risk and mortality 3 There is evidence that those who consume alcohol in high amounts (more than three drinks per day) have increased lung cancer risks, although it is difficult to control for the confounding effect of smoking in studies 4 1. Hosgood HD, Boffetta P, Greenland S, et al. Environ Health Perspect 2010; 118:1743– Lam WK, White NW & Chan-Yeung MM. Int J Tuberc Lung Dis 2004;8:1045– Omenn GS, Goodman GE, Thornquist MD, et al. NEJM 1996;334: Bandera EV, Freudenheim JL & Vena JE. Cancer Epidemiol Biomarkers Prev 2001;10: Indoor air pollution is a known lung cancer risk factor 1,2 Wood burning Coal burning Cooking oil fumes

Hereditary factors can play a role 1. Coté ML, Liu M, Bonassi S, et al. European Journal of Cancer 2012;48: Pray L. Nature Education 2008;1(1) Having a first-degree relative with lung cancer can be a risk factor for developing the disease 1 There are several genes that are potentially implicated in familial lung cancer, one of which codes for nicotinic acetylcholine receptors 2 Mutations to this receptor could increase lung cancer risk from 14% in smokers overall to 20-23% in smokers with the mutation 2