False-positive results from computed-tomography (CT) scans were a cause for concern in the 2011 US National Lung Screening Trial (see Nature 513, S4–S6; 2014). But false-positives have now been cut significantly owing to improved imaging technology and more-refined screening protocols (see B. J. McKee et al. J. Am. Coll. Radiol. http://dx.doi.org/10.1016/j.jacr.2014.08.002; 2014).

Contrary to your implication, an actuarial analysis indicates that CT lung scanning is cost-effective (see B. Pyenson et al. Am. Health Drug Benefits 7, 272–282; 2014) in the US population covered by the health-insurance programme Medicare. Most members screened are aged over 65.

The study finds that the average monthly cost of CT lung scanning per Medicare member is just US$1 (the equivalent screening cost for breast and colorectal cancers is $2.50 and $1.40, respectively). This latest cost–benefit analysis is consistent with other peer-reviewed research proving that lung-cancer screening is cost-effective for Medicare and for private payers too.

As James Mulshine, a translational-medicine specialist at Rush University in Chicago, Illinois, pointed out in a 2010 Lung Cancer Alliance statement, through screening, “we have the opportunity to realize the greatest single reduction of cancer mortality in the history of the war on cancer” (see go.nature.com/vs2smt).