A landmark study in 2011 found that screening long-term smokers for lung cancer with low-dose CT scans could save up to 12,000 lives per year, leading to guidelines from cancer and public health groups for annual screening of those at highest risk. But initial data from the first two years following the recommendation show few eligible patients are actually getting the test.
In late January, researchers from the M.D. Anderson Cancer Center in Houston reported that only 5.8 percent of eligible individuals were screened, up from 2.9 percent in 2010. In February, a separate report from the American Cancer Society concluded the screening rate was even lower, at 3.9 percent in 2015, up from 3.3 percent in 2010.
“We were a little surprised,” said Tina Shih, an economist in the M.D. Anderson department of health services research and an author of the study. “We saw a massive underuse.”
Shih cautioned that numbers reflect a period just after the guidelines went into effect and immediately following Medicare’s decision to cover the screening.
“But something I feel is alarming is we also saw people who have no business getting lung cancer screening also getting it,” she said.
The American Cancer Society guidelines call for screening individuals age 55 to 74, who are in fairly good health, have a smoking history equivalent to smoking a pack a day for 30 years and who are still smoking or have quit within the past 15 years. Guidelines from the U.S. Preventive Services Task Force extend screening until age 80.
Lung cancer kills more than 155,000 Americans each year, more than colon, breast and prostate cancers combined. Screening proponents maintain that in eligible individuals, the benefits of finding lung cancer when it is smaller and easier to treat, outweighs the risks associated with CT scans and the potential harms that can come from following up on false positives. For individuals without that extensive smoking history, however, the potential benefits are much smaller, and may not offset the risks. Nonetheless, the MD Anderson researchers saw that many patient who weren’t eligible under the guidelines had gotten the scans.
“They’re not heavy smokers or they’re not even smokers,” Shih said, “but they still go get screened.”
The data also showed some patients were getting chest X-rays to check for lung cancer, despite evidence that sort of screening is ineffective.
Screening guidelines often take years to take root. Shih said while mammography screening rates are now up at 85 percent, as recently as 1987 they were at 38 percent.
“It does take a long time for population-based screening, and in the case of lung cancer, it’s even more complicated because the eligibility criteria is so confusing.”
Central Oregon Radiology Associates and Cascade Medical Imaging offer lung cancer screening, and the St. Charles Cancer Center has helped raise awareness about the scans.
“When we did a first push for lung cancer screening, we had really high screening rates. I literally couldn’t keep up with the phone calls,” said Jessica Keegan, the cancer center’s screening coordinator. “I think now the education may not be out there and providers may not be offering it.”
The low-dose CT scans are relatively inexpensive, at between $100 to $300. More than half of those eligible for screening are either uninsured or insured by Medicaid. Another large portion are covered by Medicare.
The hospital system offers free screening to eligible patients who are uninsured or underinsured, and has had to cover the cost with St. Charles Foundation funds for some Medicare beneficiaries because of the difficulty in getting the program to pay for the scan.
Dr. Divya Sharma, medical director for Mosaic Medical and the Central Oregon Independent Physicians Association, said low screening rates may reflect confusion over the details of the guidelines and whether Medicare will pay for it.
“Patients aren’t going to get a test that they end up footing the bill for, and the providers are reluctant to order that test because they don’t know if it’s adequately covered,” she said.
Meanwhile, some electronic health records still have not embedded those guidelines in their system, so doctors don’t get an alert if one of their patients is eligible and due for screening.
“Providers need to have that experience of, gosh, they did this screening and they caught somebody with lung cancer,” Sharma said. “It’s one of those chicken and the egg situations. Because if you’re not doing a lot of screening, you have a decreased chance of finding those cases. But once you get a case, it becomes hard-wired in the provider’s mind.”
There’s evidence that uptake could be much higher if doctors told eligible patients about screening. The Veterans Health Administration recently completed a three-year lung cancer screening demonstration project in which they invited 4,246 veterans to get the test.
Nearly 58 percent agreed to be tested and 2,106 were actually screened.
Of those, 31 were diagnosed with lung cancer.
However, more than half of those screened wound up with a false-positive result, that required additional testing or procedures, but was ultimately found not to be cancer.
That was much higher than in the clinical trial that first showed lung cancer screening, and bolstered concerns that in a real world setting, screening would not save as many lives.
Editors of the JAMA Internal Medicine, in which the study was published calculated that for every 1,000 people screened, 10 would be diagnosed with potentially curable early stage lung cancer, five with incurable late stage lung cancer, 20 would undergo unnecessary invasive procedures, and 550 would experience the false alarm of a false positive.
Whether the benefits of screening outweigh the harms, the editors wrote, “remains to be adequately evaluated.”
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