Lung Cancer Screening by Low-Dose CT Scan: Baseline Results of a French Prospective Study

Lung cancer mortality has been found to decrease significantly with low-dose (LD) computed tomographic (CT) screening among current or former smokers. However, such a screening program is not implemented in France. This study assessed the feasibility of a lung cancer screening program using LD CT scan in a French administrative territory. We report here the results of the first screening round.

DEP KP80 was a single-arm prospective study initiated in May 2016. Participants aged 55 to 74 years, current or former smokers of ≥ 30 pack-years, were recruited. An annual LD CT scan was scheduled. Our algorithms considered nodules < 5 mm as negative findings and nodules > 10 mm as positive; for intermediate nodules between 5 and 10 mm, 3-month CT scan with doubling time measurement was recommended. All general practitioners, pulmonologists, and radiologists from the Somme department were solicited to participate. Subjects were selected by general practitioners or pulmonologists who checked the inclusion criteria and prescribed the CT scan.

Over a 2.5-year period, 1307 subjects were recruited. Screening was negative in 733 cases (77.2%), positive in 54 (5.7%), and indeterminate in 162 (17.1%). After the 3-month scans, 57 subjects screened positive: 26 patients exhibited 31 lung cancers (67.7% of stage 0 to I), of whom 76.9% underwent surgical resection, and 29 had no cancer (false-positive rate = 3.1%). The prevalence of lung cancer was 2.7%.

This study demonstrated the feasibility of organized lung cancer screening using LD CT scan within a real-life context in the general population.