Lung Cancer Screening with Low-Dose CT: a Meta-Analysis.
BACKGROUND
Randomized controlled trials have evaluated the efficacy of low-dose CT (LDCT) lung cancer screening on lung cancer (LC) outcomes.


OBJECTIVE
Meta-analyze LDCT lung cancer screening trials.


METHODS
We identified studies by searching PubMed, Google Scholar, the Cochrane Registry, ClinicalTrials.gov , and reference lists from retrieved publications. We abstracted data on study design features, stage I LC diagnoses, LC and overall mortality, false positive results, harm from invasive diagnostic procedures, overdiagnosis, and significant incidental findings. We assessed study quality using the Cochrane risk-of-bias tool. We used random-effects models to calculate relative risks and assessed effect modulators with subgroup analyses and meta-regression.


RESULTS
We identified 9 studies that enrolled 96,559 subjects. The risk of bias across studies was judged to be low. Overall, LDCT screening significantly increased the detection of stage I LC, RR = 2.93 (95% CI, 2.16-3.98), I2 = 19%, and reduced LC mortality, RR = 0.84 (95% CI, 0.75-0.93), I2 = 0%. The number needed to screen to prevent an LC death was 265. Women had a lower risk of LC death (RR = 0.69, 95% CI, 0.40-1.21) than men (RR = 0.86, 95% CI, 0.66-1.13), p value for interaction = 0.11. LDCT screening did not reduce overall mortality, RR = 0.96 (95% CI, 0.91-1.01), I2 = 0%. The pooled false positive rate was 8% (95% CI, 4-18); subjects with false positive results had < 1 in 1000 risk of major complications following invasive diagnostic procedures. The most valid estimates for overdiagnosis and significant incidental findings were 8.9% and 7.5%, respectively.


DISCUSSION
LDCT screening significantly reduced LC mortality, though not overall mortality, with women appearing to benefit more than men. The estimated risks for false positive results, screening complications, overdiagnosis, and incidental findings were low. Long-term survival data were available only for North American and European studies limiting generalizability.
['Hoffman|Richard M|RM|http://orcid.org/0000-0002-4714-7726', 'Atallah|Rami P|RP|', 'Struble|Roger D|RD|', 'Badgett|Robert G|RG|']
D055088:Early Detection of Cancer D005260:Female D006801:Humans D008175:Lung Neoplasms D008297:Male D008403:Mass Screening D000069342:Medical Overuse D014057:Tomography, X-Ray Computed
lung cancer screening meta-analysis mortality low-dose computed tomography lung neoplasms