Characteristics of lung nodules detected by low-dose CT scan: results from the French lung cancer screening study DEP KP80

<bold>Introduction:</bold> DEP KP80 was a real-life prospective study assessing the efficacy of lung cancer screening using low-dose CT scan (LDCT) <bold>Objectives:</bold> To compare the scanographic characteristics and profiles of participants with benign and malignant nodules detected during a lung cancer screening program. Patients and Methods: The DEP KP80 study included participants aged 55 to 74 years, active smokers or having quit smoking for less than 15 years, with a smoking habit of at least 30 pack-years. A total of 1,711 annual LDCT screenings were performed during the three rounds. <bold>Results:</bold> Overall, 1,050 nodules were detected in 408 of the 1,029 participants screened (39.6%). Mean age was 61.9±5.3 years and 65.9% were men. Moreover, 86.4% of nodules were solid, 9.1% were ground-glass, and 4.5% were mixed. Regarding their location, 45% of nodules were in the upper lobes, 12.9% in the middle lobe, and 42.1% in the lower lobes. They measured less than 4mm in 42.5%, between 5 and 10 mm in 46.9%, and over 10mm in 10.6% of cases. Nodules were malignant in 43 of the 408 participants (10.5%). In multivariate analysis, multiple nodules were predictive of benignity, a diameter >10mm was predictive of cancer, and a location in the upper lobes was a risk factor at the limit of significance (p=0.06). No significant differences were found regarding age, sex, or nodule density. <bold>Conclusion:</bold> This analysis of a real-life lung cancer screening study highlighted that isolated supra-centimetric lung nodules located in the upper lobes and detected by LDCT should be considered malignant until proven otherwise.