BETHESDA, MD—A panel of outside professionals meeting under the auspices of the National Institutes of Health here has issued a state-of-the-science conference report calling for increased efforts to screen more Americans for colorectal cancer.
The panel, which was not asked to evaluate or compare the effectiveness of various colorectal cancer screening options, concluded that although overall screening rates for American adults over age 50 (the target screening population) increased from 20%-30% in 1997 to almost 55% 11 years later, the cutoff for the analysis, that those rates are still much too low and that screening is underused.
The analysis also found that screening rates are far higher in integrated health systems such as the Department of Veterans Affairs (80%) and Kaiser Permanente (75% in the Medicare population) than in the general population.
Given the availability of colorectal cancer screening methods and the recommendations on periodic screening by expert groups such as the US Preventive Services Task Force (USPSTF) and the American Cancer Society, “this is lower than what all of us would expect,” said panel chair Donald Steinwachs, PhD, Professor and Interim Director of the Johns Hopkins Institute for Policy Studies and Director of Hopkins' Health Services Research and Development Center in the Bloomberg School of Public Health.
Asked in an interview if it is fair to say that the nation is not fully applying what is already known, Dr. Steinwachs said yes. “We have research evidence [on ways to increase screening] that is not being used,” he said. “That's true of a lot of health care interventions.”
The panel recommended widely implementing proven strategies to increase colorectal cancer screening, including patient reminder systems and one-on-one office visits with health care providers. Dr. Steinwachs said that one of the most striking findings to emerge from research presented to the panel was the importance of a physician telling a patient that he or she needed screening. According to a study from the federal Agency for Healthcare Research and Quality (AHRQ), some 95% of primary care physicians routinely recommend colonoscopy screening to patients age 50 and older who are at average risk for colorectal cancer.
Eliminating Financial Barriers
The panel called for “eliminating financial barriers to colorectal cancer screening and appropriate follow-up.” Dr. Steinwachs noted that another marked finding to emerge from the conference was the key role played by having no health insurance or having insurance that does not completely cover screening. Patients with good insurance coverage are much more likely to be screened.
On an up note, the panel said that the Centers for Disease Control and Prevention recently launched a new program—similar to its breast and cervical cancer screening program—to bring colorectal cancer screening to the uninsured and underinsured.
In July 2001, Medicare began coverage for screening colonoscopies, and the panel found that this screening method is the most widely used test today. Annual fecal occult blood testing (FOBT), flexible sigmoidoscopy, and double-contrast barium enema have decreased as colonoscopy has increased.
Computed tomography colonography (CTC, the so-called virtual colonoscopy) is newer, is used less frequently, is currently not covered by Medicare and is not recommended as a screening method by the USPSTF although it is by the ACS.
In an invited presentation at the conference, C. Daniel Johnson, MD, Professor of Radiology at the Mayo Clinic in Scottsdale, Arizona, said that CTC has come of age as a viable colorectal cancer screening tool. “Education and testing can result in high levels of examination performance,” he said
Dr. Steinwachs said the panel recognized that preparing for and having a colonoscopy is time-consuming and unpleasant to many patients, but he stressed that the technique can effectively prevent and detect colon cancer.
Panel member Lawrence S. Friedman, MD, Professor of Medicine at Harvard Medical School and Tufts University School of Medicine, said there are good reasons colonoscopy has emerged as the dominant US screening method. “It's one-stop shopping,” said Dr. Friedman, who is also Chair of the Department of Medicine at Newton-Wellesley Hospital.
“You can get screened and treated in one intervention,” he added, pointing out that if an adenomatous polyp is found on screening, it can be snipped off.
Although FOBT is the only screening method for which randomized clinical trials have shown evidence of reduced mortality from colorectal cancer, Dr. Friedman said the downside is that patients need to have FOBT screening every year. He also pointed out that if the FOBT result is positive, the patient will end up having a colonoscopy anyway.
Calling CT colonography “another acceptable alternative,” Dr. Friedman emphasized that patients' inclination toward a particular screening method should be taken into account. “People have different preferences, and one of the goals should be to match preferences of people with the test itself,” said Dr. Friedman.
Dr. Steinwachs agreed: “People ought to be informed about all the options for being screened,” he said.
‘Risk Very Low in Good Hands'
In its report, the panel recognized that colonoscopy screening carries risks, particularly the risk of perforation of the colon. But this risk is “very low in good hands,” said panel member Leonard E. Egede, MD, Professor of Medicine and Director of the Center for Health Disparities Research at the Medical University of South Carolina.
He said an unintended consequence of colonoscopy could be extra-colonic findings, such as an aneurysm found in a male smoker. Such a consequence could be good or bad, depending on whether the incidental finding leads to needed treatment or needless follow-up tests, he said.
No Central Registry
Currently a central US registry to track colorectal cancer screening does not exist, with available data coming from various sources. But the data clearly show that there has been a slow, upward trend in screening since 1997. Thus the panel recognized that if US colorectal screening rates do increase dramatically, it could strain existing capacity, including facilities and trained health professionals.
The panel recommended research to track trends in colorectal screening, including development of an infrastructure similar to that of the Breast Cancer Surveillance Consortium, and stated that “Expanding high-quality endoscopy training to more providers, including nonphysicians, may be warranted.”
This last point is somewhat controversial, judging from negative and/or skeptical audience comments at NIH after Dr. Steinwachs read the panel's report aloud. Asked for this article about the negative reactions to using nonphysician endoscopists to do colorectal cancer screening, Dr. Steinwachs said, “There is such variation in access that we have to think creatively about providing services.” He pointed out that back in the 1970s there was a lot of resistance to the use of physician assistants and nurse practitioners on the part of physicians, and now they are valued members in health care delivery.