Looking for sputum biomarkers in lung cancer secondary prevention: where are we now?

Secondary prevention (i.e., early detection) is fundamental to enlarge the window of opportunity for potentially curative treatments in lung cancer patients. The National Lung Screening Trial (NLST) demonstrated that lowdose computed tomography (LDCT)-based screening of high-risk individuals is an effective strategy, leading to 20% relative reduction in lung cancer-specific mortality (1). Despite this clinical benefit, the widespread employment of this screening approach has one major limitation: only less than 4% of LDCT-detected lung nodules are malignant (1). The high false-positive rate would result in anxiety and fear for the patients and their family, and unnecessary invasive procedures with subsequent unbearable medical expenses. Thus, it is imperative to develop additional interventions that might be used alone or, more realistically, to enhance the cost-effectiveness of LDCT-based identification of early-stage lung cancers.