Screening for lung cancer: A systematic review of overdiagnosis and its implications

Low-dose computed tomography (LDCT) screening is increasingly used for early lung cancer detection targeted to high-risk populations. Quantifying overdiagnosis, its potential harms, and economic consequences is important. We assessed the magnitude, harms, and economic impact of lung cancer overdiagnosis from LDCT screening in high-risk populations. We synthesized evidence from eight randomized trials involving 84,660 participants. LDCT may increase overdiagnosis compared to no screening (relative risk [RR] 1.05; 222 additional cases per 100 000 people screened; low certainty). Compared to chest x-ray (CXR), LDCT likely slightly increases overdiagnosis (RR 1.01; 63 additional cases per 100 000 people screened; moderate certainty). The proportion of overdiagnosed cancers is 0.07 (7000 more lung cancers overdiagnosed per 100 000 lung cancers detected; low certainty) when compared to no screening, and 0.01 compared to CXR (1000 more lung cancers overdiagnosed per 100 000 lung cancers detected; moderate certainty). In terms of cost, LDCT resulted in an additional societal burden of €2,026,422.00 per 100 000 individuals screened compared to no screening. The magnitude of overdiagnosis in LDCT screening is likely low compared to CXR.