Eight studies (n=19,107) were included in the review. None of the studies were RCTs; all were prospective cohort studies (two with same patient comparisons and six without controls).
Detection rate of lung cancer: for seven of the studies, the detected prevalence rate for lung cancer using CT ranged from 0.4 to 2.7%. Age and smoking history were associated with increased prevalence.
Two studies compared CT with chest radiography. Both reported that CT detected more lung cancers: 27 and 13 for CT versus 7 and 5, respectively, for chest radiography.
Stage of cancer at detection: in the CT screening studies, there were 119 stage I or II lung cancer cases, and 18 stage III or IV lung cancer cases (including small-cell lung cancer cases).
Lung cancer mortality and overall mortality: the data on disease-specific and overall mortality were incomplete.
Screening-related morbidity and mortality: no screening-related deaths were reported.
Histology of detected lung cancers: the CT screening trials predominantly detected adenocarcinoma (80%). Only 12% of squamous cell carcinoma and 8% of other subtypes were reported.
Detection rate of suspicious abnormalities (noncalcified pulmonary nodules): the rate for noncalcified pulmonary nodules ranged from 5 to 51%, with the smallest detectable lesions below 3 mm. The positive predictive values (proportion of lung cancers among those with suspicious lesions) of CT scanning for lung cancer was variable (0.02 to 0.12).