National Cancer Institute NCI Cancer Bulletin: A Trusted Source for Cancer Research News
February 9, 2010 • Volume 7 / Number 3

Special Report

Experts Recommend Steps to Increase Colorectal Cancer Screening in Primary Care

Enhancing Use and Quality of Colorectal Cancer Screening logo

Nearly 50,000 people die of colorectal cancer (CRC) each year in the United States, a rate second only to lung cancer deaths. Evidence shows that screening for CRC can reduce mortality and that CRC can be prevented by identifying and removing precancerous lesions known as adenomatous polyps. Guidelines recommend regular screening for adults older than age 50 who are at average risk, yet “screening is underused,” concluded an independent panel of experts at an NIH State-of-the-Science conference last week.

“We recognize that some people may find colorectal cancer screening tests to be unpleasant and time consuming,” said Dr. Donald Steinwachs of Johns Hopkins University, who chaired the 13-member panel. But “we need to find ways to encourage more people to get these important tests.”

Though CRC screening for this target group has approximately doubled in the decade ending in 2008, to about 55 percent, “millions of eligible people are not screened by any method,” the panel stressed in a draft conference statement. Many scientists at the conference believe rates in the United States should approach 80 percent, and the 13-member panel identified six strategies to achieve this goal.

“One of the strengths of CRC screening is that options are available,” said Dr. Carrie Klabunde, chair of the conference planning committee and an epidemiologist in the Health Services and Economics Branch in NCI’s Division of Cancer Control and Population Sciences. Nearly all of the recent increase in screening rates was driven by greater use of colonoscopy after Medicare began to cover the test in 2001.

Taking the Campaign to Primary Care Practices in the United States

“Many of the screening issues identified by the panel, indeed most preventive services delivered in the United States, occur within the context of the routine medical practices of primary care physicians,” said Dr. Klabunde. “And a shortage is looming, since they now comprise less than a third of U.S. physicians and their number is declining.”

Beyond CRC screening, “primary care physicians are faced with an expanding list of preventive services they are expected to deliver, yet the time to do so is woefully inadequate,” she explained. “This is why it is so important to identify effective and efficient ways to deliver the recommended CRC screening tests to eligible adults.”

Over the last 5 years, NCI has joined together with the Agency for Healthcare Research and Quality to fund research that might improve the delivery of preventive services. From a number of different projects and published studies, they applied a “New Model of Primary Care Delivery” to colorectal cancer screening. An article describing the model, published in the Journal of General Internal Medicine in 2007, outlined strategies for enhancing delivery of colorectal cancer screening in primary care, including fostering a team approach, developing relevant information systems, involving patients in decisions, monitoring the performance of the practice, enhancing reimbursement, and providing training. Many of these themes were discussed during last week’s State-of-the-Science conference.

At the conference, proponents of colonoscopy and its virtual counterpart, computed tomography (CT) colonography, promoted these two options, despite the fact that achieving high rates of screening solely with colonoscopy or CT colonography appears unlikely given the current lack of capacity and number of trained providers. Also, CT colonography is not covered by Medicare, nor is it currently recommended by the U.S. Preventive Services Task Force (USPSTF), one of two major groups that have issued guidelines on colorectal cancer screening. The USPSTF does not recommend colonoscopy over other screening options (including fecal occult blood testing (FOBT), sigmoidoscopy, and barium enema), while guidelines from the U.S. Multi-Society Task Force on Colorectal Cancer and the American Cancer Society state that tests providing a full structural examination of the colon are preferred over other tests.

“Not only do we lack randomized, controlled trial data to warrant such a preference,” Dr. Klabunde explained, but there is evidence that other screening options that use colonoscopy as a diagnostic follow-up test can play a role in systems that achieve high screening rates. The panel heard some of this evidence from the Veterans Health Administration, Kaiser Permanente of Northern California, and the National Health Service in Great Britain at the conference. And a newer version of the FOBT, the fecal immunochemical test, has shown promise in detecting colorectal cancer while minimizing patient burden by not requiring dietary or medication restrictions prior to screening.

Each screening method may have its place, depending on patient preferences, provider capacity, and access to and availability of services; those issues are addressed by two of the panel’s six recommendations:

  • Eliminate financial barriers to colorectal cancer screening and appropriate follow up
  • Conduct research to assess the effectiveness of tailoring programs to match the characteristics and preferences of target population groups to increase colorectal cancer screening

The panel found that the most important factors associated with being screened are having insurance coverage and access to a regular health care provider. They also emphasized the need for targeted strategies for specific subgroups that have below-average screening rates. For example, Hispanics are less likely to be screened than non-Hispanic whites.

“In the United States, we really need to look more carefully at the context where most people would get screened,” said Dr. Klabunde, referring to the office practices of primary care physicians. Two of the panel’s recommendations focus on this care setting:

  • Conduct studies to determine the comparative effectiveness of the various colorectal cancer screening methods in usual practice settings
  • Widely implement interventions that have proven effective at increasing colorectal cancer screening, including patient reminder systems and one-on-one interactions with providers, educators, or navigators

The conference was sponsored by the NIH Office of Medical Applications of Research and NCI, along with other NIH and Department of Health and Human Services agencies. The independent panel included experts in the fields of cancer surveillance, health services research, community-based research, informed decision-making, access to care, health care policy, health communication, health economics, health disparities, epidemiology, statistics, thoracic radiology, internal medicine, gastroenterology, public health, end-of-life care, and a public representative.

An evidence report on enhancing the use and quality of CRC screening that was developed for the panel is available online.

Addison Greenwood