CT lung cancer screening gets low-confidence vote from MEDCAC panel

Low dose CT (LDCT) screening for high-risk individuals received a low-confidence recommendation from the Medicare Evidence Development and Coverage Advisory Committee (MEDCAC) Wednesday, calling into question whether Medicare will end up covering these screening exams.

The panel's low-confidence recommendation clearly is at odds with the United States Preventive Services Task Force (USPSTF) decision in December to recommend screening. The USPSTF made its recommendation based mainly on the results of the National Lung Screening Trial (NLST)  that showed a 20 percent mortality benefit from LDCT compared to screening with chest x-ray.

The idea that Medicare should cover low-dose CT lung cancer screening received plenty of support from clinicians and other advocates at Wednesday's meeting. For instance, Ella Kazerooni, chair of the American College of Radiology Committee on Lung Cancer screening, told the panel that the ACR endorsed the USPSTF recommendation and that there is definitive evidence that screening with low dose CT can be done safely, with little harm and low radiation exposure.

"Our practitioners are ready and willing and able to perform lung cancer CT screening safely," she said. "Many of them ... are already doing this in practice and they're doing it safely."

Others, though, were more cautious.

Doug Campos-Outcalt, M.D., of the University of Arizona College of Medicine in Phoenix, and a member of the American Academy of Family Physicians, told the panel that while "we [AAFP] rarely disagree with the USPSTF, we did disagree with them on lung cancer screening." According to Campos-Outcalt, AAFP would have given LDCT lung cancer screening an "I" rating, representing "insufficient evidence."

AAFP's reservations included concerns that the conditions of the National Lung Screening Trial could not be replicated in community settings, and that LDCT lung cancer screening probably would result in fewer benefits and more harms when introduced in that setting.

Many of the panel members clearly were concerned about the potential harms associated with the exam, despite the mortality benefit.

Steven H. Woolf, M.D., director of the Center on Society and Health at Virginia Commonwealth University, related that he had served on the USPSTF for 16 years, adding that "in my day, looking at the evidence presented, this would not have received a 'B' recommendation; it probably would have received an 'I' recommendation."

Woolf was troubled by the fact that the USPSTF made its recommendation based on one trial--the NLST.

"We've never relied on a single trial to set national policy on cancer screening," he said.

Added Curtis Mock, M.D., senior medical direct and vice president Medicare Advantage, UnitedHealthcare Medicare & Retirement: "It is almost impossible to extrapolate to the Medicare population the expected results we would expect to get when I feel it is our first obligation to do no harm. I didn't find it. I thought I would today, but I didn't hear that the evidence is there to support benefit beyond harm."

The panelists were asked to vote on three questions on a scale of 1 to 5, with 1 representing no or low confidence and 5 representing high confidence. The questions and mean scores included: 

  • How confident are you that there is adequate evidence to determine if the benefits outweigh the harms of lung cancer screening with low-dose CT? (2.2222)
  • How confident are you that the harms of lung cancer screening with low-dose CT if implemented in the Medicare population will be minimized? (2.3333)
  • How confident are that that clinically significant evidence gaps remain regarding the use of low-dose CT for lung cancer screening in the Medicare population outside a clinical trial? (4.4444)

MEDCAC plans on publishing its proposed recommendations in November.