What is the balance of benefits and harms for lung cancer screening with low-dose computed tomography?

After the National Lung Screening Trial (NLST)1 demonstrated improved lung cancer mortality almost a decade ago, hopes have been raised that low-dose computed tomography could be used to detect lung cancer in asymptomatic populations and improve outcomes by reducing the number of people diagnosed with advanced disease. The publication of the long-awaited Nederlands-Leuvens Longkanker Screenings Onderzoek (NELSON) trial last year2 has provided further evidence of a lung cancer mortality benefit and has provoked further calls to implement national population-based screening programmes, but the case for lung cancer screening remains controversial.