Impact of lung cancer screening with low-dose chest computed tomography on an older population: a retrospective cohort study

BACKGROUND: The older population is at high risk of lung cancer (LC). However, the importance of lung cancer screening (LCS) in this population is rarely investigated. Herein, we evaluated the effect of LCS with low-dose computed tomography (LDCT) in the older population. METHODS: This retrospective cohort study was conducted in a single center and included patients aged 70–80 years who had undergone LCS with LDCT. They were categorized into the early 70s (70–74 years) and late 70s (75–80 years) groups based on their age. Using propensity score matching, the control group included patients with non-screening-detected LC from an LC cohort. LC detection, characteristics, and treatment were compared between the early and late 70s groups and between screening-detected LC and non-screening-detected LC. RESULTS: The study included 1,281 participants who underwent LDCT for LCS, of whom 1,020 were in their early 70s and 261 in their late 70s. Among the screening groups, 87.7% of the patients were ever-smokers. The overall LC detection rate was 2.8%. Interestingly, the LC detection rate in the late 70s group was similar to that in the early 70s group (3.4% vs. 2.7%, P=0.485). Furthermore, the incidence of LC was 6.1 cases and 8.3 cases per 1,000 person-years in the early 70s and late 70s groups, respectively (P=0.428). When comparing LC characteristics, patients with screening-detected LC showed a higher proportion of stage I LC (52.8% vs. 30.6%, P=0.010) and a lower proportion of stage IV LC (19.4% vs. 42.2%, P=0.010) than those with non-screening-detected LC. Moreover, 80.6% of patients with screening-detected LC received appropriate tumor reduction treatment based on the cancer stage. CONCLUSIONS: In the older population, LCS using LDCT showed remarkable detection of LC, with a higher proportion of cases detected at an early stage.