CT scans for lung cancer screening may not save lives

Should smokers receive screening CT scans?

As it stands, there’s no evidence that screening patients with either chest x-rays or CT scans save lives, but a large, federally-funded study should yield some answers in the next year or so.

Recently, however, there’s data suggesting that screening chest CT scans for lung cancer gives a lot of false positives. Needless to say, these false positives are magnified with CT scans versus a conventional x-ray:

Among those who received CT scans, 21% had a false positive after one scan and 33% after two scans. For those who received chest X-rays, 9% had a false positive after one and 15% had a false positive after two. More than half of those with a positive finding had a follow-up scan or chest X-ray. About 7% in the CT scan group and 4% in the chest X-ray group had an unnecessary invasive medical procedure, typically bronchoscopy.

As David Leonhardt wrote in the New York Times, arguments like these are “soulless.” One anecdote of life-saving early detection wipes out rigorous data that suggests adverse complications from unnecessary testing.

If you don’t believe me, consider the firestorm that erupted after the USPSTF modified their breast cancer screening guidelines.

There will always be a subset of the population who believes that more testing means better medicine. It’s up to doctors and health reformers to convince patients otherwise, and warn them of the potential complications stemming from unnecessary tests.

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