One-fifth of LDCT detected lung cancers are indolent

Researchers used data from the National Lung Screening Trial (NLST), a randomised trial comparing screening using LDCT versus chest radiography (CXR) among 53,452 people considered at high risk for lung cancer. Patients were considered high risk if they had smoked an equivalent of a pack of cigarettes a day for 30 years and were observed for 6.4 years.

In this study, researchers estimated the number of excess cancer diagnoses in the LDCT arm of the NLST compared to the CXR arm and found that the probability that a lung cancer by LDCT screening would result in overdiagnosis was 18.5%. 

Earlier this year, US government advisers recommended annual screening for people aged 55–79 with a history of smoking a packet of cigarettes a day for 30 years following another study using from the NLST which found screening with LDCT was associated with significant reductions in lung cancer (20%) and all-cause (6.7%) mortality.

Local experts however,