Molecular profile in body fluids in subjects enrolled in a randomised trial for lung cancer screening: Perspectives of integrated strategies for early diagnosis

The aim of this study was to evaluate the diagnostic value of a grid of molecular genetic markers detectable in sputum and plasma samples of individuals enrolled in a lung cancer screening program with low-dose CT. Subjects enrolled in the baseline screening round of the ITALUNG (randomised) screening trial were invited to provide biological specimens for molecular analysis (1356 subjects out of 1406). We included 98 subjects in this analysis. There was a highly statistically significant difference between proportion of subjects with a negative baseline CT screening test who were positive to allelic imbalance, and those with a non-calcified nodule (NCN greater than or equal to 5 mm), the reason of recall for all suspects at CT Scan (χ2: 22.9; P < 0.0001). Allelic imbalance showed good performance for screening of NCN ≥5 mm. In subjects recalled for NCN ≥5 mm, LOH, K-ras mutations and high levels of free plasma DNA (>5 ng/ml plasma) might be important to support clinical decision making for further follow-up and repeated screening. This study, embedded in an early diagnosis randomised trial, suggests that a multi-screening approach integrating imaging technique and a biomolecular marker panel is worth of further investigation.