Low-Dose Computed Tomography Screening in Relatives With a Family History of Lung Cancer

BACKGROUND The role of family history of lung cancer (LCFH) in screening using low-dose computed tomography (LDCT) has not been prospectively investigated and with long-term follow-up. METHODS A multicenter prospective study with up to three rounds of annual LDCT screening was conducted to determine the detection rate of LC in asymptomatic first or second-degree relatives of LCFH. RESULTS From 2007 to 2011, there were 1,102 participants enrolled, including 805 and 297 from simplex (SF) and multiplex families (MF), respectively (54.2% female, and 70.0% never-smokers). Last follow-up date was May 05, 2021. The overall LC detection rate was 4.5% (50/1102). The detection rate in MF was 9.4% (19/202) and 4.4% (4/91) in never-smokers and who smoked, respectively. The corresponding rates for SF were 3.7% (21/569) and 2.7% (6/223), respectively. Of them, 68.0% and 22.0% of cases with stage I and IV diseases, respectively. LC diagnoses within a 3-year interval from initial screening were younger, higher detection rate, and more stage I disease; thereafter, more stage III/IV disease and 66.7% (16/24) with negative or semi-positive nodules in initial CT scans. Within the 6-year interval, only maternal (modified rate ratio [RR]=4.46, 95% confidence interval [CI]=2.32–8.56) or maternal relative history of LC (modified RR=5.41, 95% CI=2.84–10.30) increased the risk of LC. CONCLUSION LCFH is a risk factor for LC, more in MF history, never-smokers, younger adults, and those with maternal relatives with LC. Randomized controlled trials are needed to confirm mortality benefit of LDCT screening in those with LCFH.