The NEJM has an article an editorial on CT screening for lung cancer. The article notes:
The rate of adherence to screening was more than 90%. The rate of positive screening tests was 24.2% with low-dose CT and 6.9% with radiography over all three rounds. A total of 96.4% of the positive screening results in the low-dose CT group and 94.5% in the radiography group were false positive results. The incidence of lung cancer was 645 cases per 100,000 person-years (1060 cancers) in the low-dose CT group, as compared with 572 cases per 100,000 person-years (941 cancers) in the radiography group
The rate of death was reduced by 6.7%.
The editorial noted:
The NLST results show that three annual rounds of low-dose CT screening reduce mortality from lung cancer, and that the rate of death associated with diagnostic procedures is low.
And:
According to the authors, 7 million U.S. adults meet the entry criteria for the NLST,1 and an estimated 94 million U.S. adults are current or former smokers. With either target population, a national screening program of annual low-dose CT would be very expensive, which is why I agree with the authors that policy makers should wait for more information before endorsing lung-cancer screening programs.
Medicynical Note: This screening is quite costly even without considering the costs of sorting out the false positives. There is a question whether any system of care, much less one that is bankrupting a nation, can afford such a screening program. Would, for example, some of the funds be better employed in education about the hazards of smoking and smoking cessation.
Medicynic 
New study shows a 15% rate of pneumothorax in folks getting lung nodules biopsied … 6% requiring a chest tube.
Multiply times the 95% false positive rate of 25,000 scans (or 50,000,000 if it’s rolled out?) Number needed to screen of 320 in a high-high-risk population, which number will go way higher when lower-risk people are screened as would seem likely.
So, I’m not recommending my ex-heavy smoking family member get a chest CT. At least not till things are more clear. Would you?
Source:
http://www.pulmccm.org/main/category/lung-cancer-review/
Agree. It’s fascinating in the U.S. we like to thing money is no object. We’re awaiting cost effectiveness data which should be published in the near future. If you haven’t already seen it you might check this http://www.nejm.org/doi/full/10.1056/NEJMe1103776.