Latest lung cancer screening stories need to reflect on harms as well as benefits

The following is a guest post from Harold DeMonaco, one of our expert editors on HealthNewsReview.org and Director of the Innovation Support Center at the Massachusetts General Hospital.

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When I went to my IGoogle homepage today I noticed a story on yet another lung cancer screening article.  The story, in Oncology Nurse Advisor but from the HealthDay news service, has a rather provocative headline, “Insurers should screen older smokers for lung cancer”. The story reviewed a recently published study in Health Affairs that is likely to ignite the debate over routine screening for lung cancer yet again.  Here are the conclusions from the authors of this well constructed Health Affairs study using actuarial data:

“Our results suggest that commercial insurers should consider lung cancer screening of high-risk individuals to be high-value coverage and provide it as a benefit to people who are at least fifty years old and have a smoking history of thirty pack-years or more. We also believe that payers and patients should demand screening from high-quality, low-cost providers, thus helping set an example of efficient system innovation.”

The authors provide some interesting numbers to back up their conclusion.  Of the 18 million or so smokers who fall into their eligibility criteria, they showed a potential for an additional 130,000 additional survivors of lung cancer due to early detection.  It’s hard to argue that saving this many lives is not important.  But the study does not look into the negative aspects of the double edged sword that is lung cancer screening.  While we are constantly berated for being anti-screening, it is important for people to understand what the risks and benefits are for any medical procedure including screenings.

The National Cancer Institute (NCI) previously funded a large study to determine whether screening with low-dose CT, as compared with chest radiography, would reduce mortality from lung cancer among high-risk smokers. The results of the earlier study were published in August 2011 and generated a good deal of discussion in the media.  The NCI sponsored study was done in a somewhat different group of long term smokers but there are sufficient similarities for the data to be useful here.  The positive rate related to spiral CT scans was 24.2% or about one out of every four people scanned had a positive finding.  That would amount to 4,320,000 positive findings if extrapolated to the 18 million smokers discussed in the actuarial study.  But 94.6% of these positive results were false positives.  That means that 4,086,720 people screened would have a false positive result.  All would likely suffer from some degree of angst. Of those with false positive findings, 0.06% had a major complication possibly related to subsequent invasive procedures in the NCI sponsored study.  That amounts to 108,000 people who would have a serious adverse event related to a procedure due to a false positive test result.  Those events need to be considered when thinking about the 130,000 potential lives saved through screening.

Few medical procedures are without risk and each should be viewed as a double edged sword.  Benefits as well as risks need to be considered.  Reporting on just the benefits provides readers with only half the story.