Evidence is insufficient to support lung cancer screening with low-dose computed tomography in the Medicare population, members of the Medicare Evidence Development and Coverage Advisory Committee said at a meeting on April 30.
Specifically, the MEDCAC advisers said that, on average, they had low confidence there is adequate evidence that the benefits outweigh the harms of lung cancer screening with low-dose computed tomography (LDCT) in the Medicare population.
Dr. Rita Redberg
The Centers for Medicare & Medicaid Services accepted two formal requests to initiate a national coverage analysis on lung cancer screening with LDCT, which the U.S. Preventive Services Task Force gave a grade B recommendation for people at high risk for lung cancer based on age and smoking history.
"I think it’s almost impossible to extrapolate to the Medicare population the expected results that we would get when I feel it’s our obligation to first do no harm. I didn’t hear that the evidence is there to support benefit beyond harm," said Dr. Curtis Mock, national medical director of UnitedHealthcare Medicare & Retirement.
Most of the MEDCAC advisers said that they were not satisfied by the Medicare-population data in the National Lung Screening Trial (NLST). That study of more than 50,000 asymptomatic adults, aged 55-74 years, showed a 16% reduction in lung cancer mortality and a 6.7% reduction in all-cause mortality when patients were screened using LDCT (N. Engl. J. Med. 2013;368:1980-91). One cancer death was averted for every 320 patients screened, and one death from all causes was prevented in every 219 patients screened.
But Medicare-eligible patients – those aged 65-74 years – represented about 25% of patients in the trial, less than the nearly 36% NLST-eligible in the U.S. population.
"I am concerned that we don’t really have a lot of data in the Medicare population, certainly not in the 75-80 [year-old age group], particularly on the harms in the age group that was included in NLST," said Dr. Rita Redberg, MEDCAC chair and professor of medicine at the University of California, San Francisco.
Dr. Redberg also highlighted the additional health complications with Medicare-age patients.
"Surgical mortality increases as one gets older, and the benefits of early detection tend to disappear as you get older because there are more competing causes of death," she said.
The MEDCAC advisers also noted that they were not confident that the harms of lung cancer screening with LDCT (average effective dose of 1.5 mSv) would be minimized if implemented in the Medicare population.
"The harm I worry about will be the intervention of this test on people for which we know nothing about the benefits and harms," said Dr. Allan Fendrick, professor in the department of internal medicine at the University of Michigan, Ann Arbor.
Similarly, Dr. Harry Burke, associate professor at the Uniformed Services University of the Health Sciences in Bethesda, Md., said, "I think the low positive predictive value drives harm. Whether you can balance that harm with the benefit is a very difficult business."
Lastly, the advisors said that they strongly believe there are clinically significant evidence gaps when using LDCT for lung cancer screening in the Medicare population outside a clinical trial.
"The most important gap that I see is based on totality of the data – both from this large NLST trial but also high-quality publications from other trials – to be able to come up with a cohort where we would have much higher confidence that the benefits outweigh the harms than other subgroups," said MEDCAC vice chair Dr. Art Sedrakyan, director of the Patient Centered Comparative Outcomes Research Program at Cornell University, New York.
CMS will take the expert panel’s recommendations into consideration as it develops its national coverage decision for lung cancer screening with LDCT, which it plans to issue by mid-November, followed by a 30-day public comment period.