Time to Benefit for Lung Cancer Screening: A Systematic Review and Survival Meta-Analysis

Lung cancer screening with low-dose computed tomography reduces lung cancer mortality in the long term but carries immediate risks. Guidelines recommend screening persons whose life expectancy exceeds the screening test's time to benefit, defined as the time from screening initiation to first observed benefit. This study aimed to estimate the time to benefit for lung cancer screening to prevent lung cancer mortality.

Randomized controlled trials of lung cancer screening with low-dose computed tomography were identified from two prior systematic reviews and an updated search to December 3, 2023. Studies that reported lung cancer mortality were included. For each study, independent Weibull survival curves were fitted and Markov chain Monte Carlo simulations were generated to estimate the absolute risk reduction at different time points. Time to benefit was determined as the time at which absolute risk reduction thresholds (ARR=0.0005, 0.001, 0.002) were crossed. These estimates were pooled using a random-effects meta-analysis model.

A total of eight randomized controlled trials comprising 88,526 participants were included. Enrollment age ranged from age 50 to 70 years; follow-up duration ranged from 7.3 to 12.3 years. For every 1,000 persons screened, 3.4 years (95%=CI 2.2, 5.1) passed before 1 death from lung cancer was prevented (ARR=0.001). The time to prevent one lung cancer death per 2,000 persons screened (ARR=0.0005) was 2.2 years (95% CI=1.4, 3.4); per 500 persons screened (ARR=0.002), it was 5.2 years (95%=CI 3.7, 7.3).

Lung cancer screening is most appropriate for older adults at high risk of lung cancer with a life expectancy greater than 3.4 years.