Use of low-dose CT for early lung cancer screening: A systematic review and meta-analysis

Objectives: Recent studies have demonstrated that low-dose computer tomography (LDCT) screening in place of X-ray screening for lung cancer could reduce relative mortality in heavy smokers by 20%. The aim of this study was to conduct a systematic review and meta-analysis for the performance of LDCT in lung cancer screening and to evaluate the potential benefits and harms of implementing such a screening program in Taiwan. Methods: We searched electronic databases (MEDLINE, EMBASE and Cochrane library) for studies on LDCT screening (1996 to 2014) and conducted meta-analyses of sensitivity, specificity, and positive predictive values (PPV). We also undertook meta-regression to examine the impact of study characteristics on LDCT screening. Results: Only 5 studies provided sufficient information for a meta-analysis of sensitivity (87.43%, 95% Confidence Interval [CI]: 72.79 to 94.77%) and specificity (96.45%, 95% CI: 80.39% to 99.44%). Twenty-one studies provided information for a meta-analysis of PPV (6.4%, 95% CI: 4.8 to 8.2%). Conclusions: Several studies from Western countries recommended the use of LDCT screening for lung cancer in high risk populations, especially for heavy smokers. However, the low PPV of LDCT was seldom discussed. Those false positive cases may suffer from mental stress and harm from unnecessary invasive interventions. Given the low smoking prevalence in Taiwan, implementing LDCT for population screening in lung cancer could represent a significant challenge.