Biomarkers in lung cancer screening: the importance of study design

In most randomised controlled trials of low radiation dose computed tomography (LDCT) screening for lung cancer, eligibility has been determined by age and tobacco smoking criteria [1, 2]. A number of multivariable risk prediction models have been developed that are more sensitive and specific, but are still heavily dependent on smoking and age [3]. Some have been used successfully in trials and pilot programmes and have yielded higher detection rates, although they may also select people with more comorbidities [4-6]. Using biomarkers to select people for lung cancer screening is an important area for research because it offers the possibility to identify those at high risk who are not eligible for screening by conventional criteria, while avoiding further investigation in those who do not have malignant disease. This means that the impact of the intervention as a whole could be greater (more lives saved) and harms, due to the screening of low-risk people or those without cancer, could be avoided. Two biomarkers intended for use in lung screening are presented in this issue of the European Respiratory Journal.