A rational approach to CT lung cancer screening

Recently, a family physician colleague asked me to explain why the Affordable Care Act requires private health insurers to provide first-dollar coverage for preventive services that the U.S. Preventive Services Task Force assigns an “A” or “B” (recommended) rating, but allows public insurers (Medicare and Medicaid) to determine if and how they will cover these services.

Until recently, the question hadn’t come up, since Medicare has agreed to cover pretty much every screening test or preventive medication deemed by the USPSTF as being effective (or, as the Task Force would say, benefits outweigh harms). Low-dose CT (LDCT) screening for lung cancer in heavy smokers over age 55 is the first case to highlight the implications of this legislative leeway; given a “B” rating by the USPSTF last December, this test was nonetheless rejected by Medicare’s Evidence Development and Coverage Advisory Committee (MEDCAC) at its April 30 meeting for having insufficient evidence to convince them that seniors would actually benefit from it.

If Medicare follows MEDCAC’s lead and declines to cover LDCT scans, a 64 year-old with a greater than 30 pack-year smoking history and any private health insurance plan will be able to receive lung cancer screening for free, while a 65 year-old with the same medical history and Medicare coverage will need to pay $300 or more out of pocket or skip the test. That outcome would make sense to neither patients nor physicians, and unsurprisingly, the American College of Radiology released a strongly worded statement as soon as the MEDCAC decision was announced, reaffirming its support for “full national coverage of these lifesaving exams.”

Outraged radiologists can rest easy. The politics of this situation mean that Medicare will likely override the advice of its advisory committee, regardless of what science says. 44 senators have already sent a letter to CMS Administrator Marilyn Tavenner urging that LDCT be covered as soon as possible. Medicare expects to release its coverage determination in November, around the time of the midterm elections, and as readers of this blog recall from the 2010 midterms, the current administration has a record of disregarding inconvenient evidence from federal health agencies when control of Congress is at stake.

I and many others who are familiar with the evidence (including the American Academy of Family Physicians) believe that the Task Force overreached in declaring lung cancer screening to be beneficial based on a single abbreviated randomized trial that focused more on the benefits of screening than the physical, psychological, and financial harms (described further in a recent JAMA Internal Medicine paper) that result from the screening cascade. Even when screenings are “free,” subsequent diagnostic tests and treatments are not. Further, the USPSTF extrapolated from data on 3 years of LDCT scans to recommend that screening continue annually for up to 25 years in smokers who don’t quit, and extended the upper age limit for screening 6 years beyond anyone in the trial (from age 74 to 80). What’s the long-term risk of developing cancer from the additional radiation of 20 or more LDCTs, plus several additional full-dose chest CTs precipitated by a 96 percent false positive rate? How many more biopsy-related and surgical complications will occur in practice than in the trial? No one really knows, and that’s why I worry.

An editorial published in the Annals of Internal Medicine makes a good argument for a middle ground between screening only seniors who can afford it and the roughly 9 million Americans who are potentially eligible for the test: “For CMS to offer coverage of LDCT screening only when it is done in facilities that are certified as comprehensive, patient-centered programs designed to maximize benefits and minimize harms.” It would be nice if these conditions were met at every institution that offered screening tests to seniors, but unfortunately, many providers are more interested in maximizing profits than improving health outcomes. For LDCT, a screening test for which the jury is still very much out, this proposed policy offers a rational way forward.

Kenneth Lin is a family physician who blogs at Common Sense Family Doctor

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