1. Goldstraw et al. J Thorac Oncol 2007 Why should we want to screen? Survival (years)

2. Why should we want to screen? Localised Regional spread Distant spread When diagnosis is based on symptoms When diagnosis is based on screening Stage shift !

3. National lung screening trial (NLST) Inclusion criteria -Age 55-74 years -Smoking history ≥30PY, active or stopped less than 15 years ago Exclusion criteria -History of lung cancer -Other prior cancer in past 5 years -Chest CT less than 18 months ago -Unexplained weight loss (>15lb in past year) -Metallic implants or devices in chest or back -Home oxygen supplementation -Pneumonia treated with antibiotics in past 12 weeks Aberle et al. N Engl J Med 2011

4. -53’454 subjects randomised to one of two groups: -Low dose CT -Chest X-ray -3 screening rounds at annual intervals -Non-calcified nodules ≥4mm in CT or any size in X-ray were referred for diagnostic work-up -Primary outcome: lung cancer related mortality National lung screening trial (NLST) Aberle et al. N Engl J Med 2011

5. National lung screening trial (NLST)

6. Aberle et al. N Engl J Med 2011 National lung screening trial (NLST)

7. Kovalchik et al. N Engl J Med 2013 National lung screening trial (NLST)

8. Kovalchik et al. N Engl J Med 2013 National lung screening trial (NLST)

9. Lung cancer screening trials Boiselle, JAMA 2013

10. Screening recommendations Boiselle, JAMA 2013

11. Open issues -Is one positive trial enough evidence? -Was there overdiagnosis in the NSLT? -Will other populations at risk of lung cancer benefit from CT screening? -Screening of a large, at-risk population possible? -How many screening rounds? -Cost effectiveness? -«side effects» of screening (i.e.radiation exposure)

12. Conclusions Lung cancer is a lethal disease associated with substantial medical and economic burden. NLST: lung cancer screening may reduce mortality considerably. Possible advantage of LDCT screening has to be balanced against the potential of inducing harm. Many issues are not yet resolved: i.e. overdiagnosis, number of screening rounds, study population, cost-efficacy. Further evidence and information is needed, before lung cancer screening can be recommended in Switzerland.