Blood based biomarkers beyond genomics for lung cancer screening

A major contributing factor to high mortality in lung cancer is that most cases are diagnosed at advanced stages with limited benefits from currently available therapies, hence the interest in implementing screening strategies to detect lung cancer at an early stage. The findings from the National Lung Screening Trial (NLST) study, which demonstrated a 20% reduction in lung cancer mortality with low-dose CT (LDCT) screening of subjects aged 55–74 years with a 30-pack-year smoking history, have generated interest in lung cancer screening (1). Based on these findings the US Preventive Services Task Force recommended LDCT screening of subjects that meet the NLST criteria. However the adoption of lung cancer screening has been quite modest and a cautious approach to screening has been advocated (2). Concerns about the high percentage of false positives and potential health hazards resulting from exposure to radiation with repeat LDCTs as well as concern about the fact that a majority of subjects destined to be diagnosed with lung cancer are currently not eligible for screening have heightened the need to identify subjects at risk for developing lung cancer that do not meet current eligibility criteria. Biomarkers offer the potential for precision medicine across the cancer continuum from risk assessment to early detection and tumor classification (3). For lung cancer in particular, approaches in which a biomarker based initial screen is followed by LDCT or in which a biomarker test is combined with LDCT have merit for early detection applications (4,5)