The U.S. Preventive Services Task Force is comparing the effectiveness of CT scans for colorectal cancer along with other alternatives to the standard colonoscopy, in the first step to getting Medicare and private insurers to cover new screenings for the nation's second-leading cause of cancer death.
In a draft research plan for colorectal cancer screening, open for public comment until Feb. 5, the task force outlined its goals to probe and compare the effectiveness of several methods available today: colonoscopies, flexible sigmoidoscopy (an examination of the lower part of the colon), CT colonography, fecal screening (including DNA tests) and blood screening.
While the influential USPSTF has recommended fecal occult blood testing, sigmoidoscopy or colonoscopy for adults over 50 since 2008 as a "Grade A" service that insurers have to cover mostly in-full, the task force previously found insufficient evidence for CT colonography and fecal DNA tests and declined to suggest coverage for them.
Now, the task force is reconsidering its stance on those screenings after new studies and technology advances, and as a new wave of Americans age into retirement and find themselves more susceptible to the disease.
Colonoscopies are still considered the "gold standard" for colon cancer screening, able to detect and remove precancerous lesions, and helping contribute to the 90 percent five-year survival rate for early stage cancers. But the invasiveness of the procedures and the potential for complications -- with an adverse event rate as high as 2.8 per 1,000 procedures -- may be discouraging people from getting screened.
With the USPSTF is taking a fresh look at screening options, one alternative that's gained some support is CT colonography or "virtual colonoscopies." President Obama was screened with a CT colonography after he turned 50, and the American College of Radiology, the Multi-Society Task Force on Colorectal Cancer and Colon Cancer Alliance have supported expanding the option.
A dearth of availability for colonoscopy alternatives has attracted some entrepreneurs, like Mark Baumel, MD, who founded Colon Health Centers of America to offer CT colonography as a "one stop shop" service with gastroenterology practices who take colon CT scans and perform same-day removal of any polyps found in patients.
Medicare, however, does not pay for CT colonography, after a lengthy review in 2009 found that the evidence of its benefits and harms (from radiation or missed polyps) was inconclusive.
At the time, as CMS noted, private health plans varied in their coverage of CT colonography, with Cigna and Kaiser Permanente offering coverage and Aetna and Anthem covering it only for diagnostics or in the absence of colonoscopy. The Blue Cross Blue Shield Association, which was reviewing the evidence at the time of Medicare's decision, ended up giving the go-ahead for coverage through its Technology Evaluation Center.
The USPSTF's study is likely to revive those debates over CT colonography and other alternatives, as a number of biotech firms have been trying to develop new non-invasive screenings, such as stool sample tests, genetic tests and blood biomarker tests. .
For all of the different options, the USPSTF is studying two main issues: the "test performance characteristics" for detecting colorectal cancer, advanced adenomas (benign tumors), and adenomatous polyps; and the adverse effects as they vary across subpopulations.
The task force is also hoping to use the study to get a more comprehensive window into colon cancer screening and the disease generally, proposing to examine overall screening rates across the different tests for different subpopulations, the likelihood of progression or regression of small adenomas (benign tumors), and the distribution of lesions in the colon.