In info point 8 of the COPD module, we presented the 2016 Canadian Task Force on Preventive Health Care recommendation for lung cancer screening with a low dose CT scan for a duration of 3 years. This was based on the most robust RCT data available at the time, including the National Lung Screening Trial (NLST) 2 that enrolled ≥50000 persons, aged between 55 and 74 with a ≥30 pack year history of smoking. This trial demonstrated a 20% reduction in lung cancer mortality and a 6.7% reduction in all-cause mortality for 3 rounds of annual LDCT screening versus annual chest X-rays.
A member noted that lung cancer screening programs across Canada vary from this both in terms of admission criteria for screening and duration of screening, with most programs continuing beyond 3 years. Evidence for the optimal duration, and the impact of expanding the population screened is an area of ongoing research. An interesting review of the rationale for the Ontario lung cancer screening criteria can be found here: https://www.nejm.org/doi/full/10.1056/NEJMoa1211776.