NEWS

UNC-RTI studies show colon screening cuts cancer cases, deaths, is cost-effective

By DAVID WILLIAMSON
UNC News Services

CHAPEL HILL -- The U.S. Preventive Services Task Force, in its strongest ever recommendation for colorectal cancer screening, today (July 15) urged that all adults age 50 and over get screened for the disease, the nation’s second leading cause of cancer deaths. Various screening tests are available, making it possible for patients and their clinicians to decide which test is most appropriate for each individual.

The task force based its conclusion on two reports from a research team led by Dr. Michael Pignone of the University of North Carolina at Chapel Hill. The Evidence-based Practice Center at RTI International and UNC, which is under contract to the Agency for Healthcare Research and Quality, issued the reports.

As part of its analysis, the task force also reviewed the studies regarding cost-effectiveness and found that colorectal cancer screening was very cost-effective, especially when compared with other mass cancer screening efforts such as mammography.

Cancer screening tests reduce deaths from colorectal cancer and also can cut the number of new cases by alerting doctors to remove intestinal polyps that might become malignant, the new UNC and RTI studies conclude. Several screening methods appear to be effective, but the best one cannot be determined yet because of insufficient information from clinical research, scientists say.

The work involved systematically collecting and analyzing data from all relevant research found on colorectal cancer screening between 1966 and September 2001. Investigators relied chiefly on online medical databases such as MEDLINE, hand searches, various other publications and medical experts to identify the studies.

Results appear in the July 16 issue of Annals of Internal Medicine, a medical journal, and coincide with release of the task force recommendation. The task force is a panel of independent experts, mostly university faculty members.

"Cancer of the colon or rectum claims close to 57,000 lives every year," said Pignone, assistant professor of medicine at the UNC School of Medicine. "For that reason, it is important that we know and share with the public what’s known about the best ways to guard against it."

Effective tests include flexible sigmoidoscopy and colonoscopy, which involve doctors visually inspecting the inside of the lower intestines with lighted tubes, and fecal occult blood tests, said Pignone, a fellow at UNC’s Cecil G. Sheps Center for Health Services Research and a member of the UNC Lineberger Comprehensive Cancer Center. The fecal occult blood test requires patients to collect a tiny stool specimen at home and mail it to a laboratory for analysis. Another method, barium enema, also might be effective, he said, but that has not been confirmed.

"The bottom line is that we found increasingly good evidence to support the different methods of screening including fecal occult blood screening," the physician said.

Colorectal cancer screening was very cost effective when compared with not doing the tests, he and his colleagues found. Overall, the cost for each year of life saved was between $10,000 and $20,000, which is significantly less than costs associated with each year of life saved by mammography and treatment of moderate hypertension.

"The second major point from this second study was that there was no clear form of screening that was most cost-effective, at least so far as we could determine with the available data," Pignone said. "Colonoscopy is the single most accurate test at any given time, but our findings about which test was most effective were mixed since colonoscopy is done less frequently than sigmoidoscopy and fecal occult blood tests. Also with colonoscopy, the complication rate is higher, and one out of every 1,000 to 2,000 tests leads to perforation of the colon. Since 95 percent of people will never develop colon cancer, those people are only at risk for the complications."

Co-authors of the new research report on screening include Drs. Melissa Rich of UNC; Steven M. Teutsch of Merck & Co.; task force chair Alfred O. Berg of the University of Washington, Seattle, and Kathleen N. Lohr, a chief scientist at RTI International, adjunct professor at UNC and head of the Evidence-Based Practice Center.

Co-authors of the report on screening’s cost-effectiveness are Drs. Somnath Saha of the Oregon Health & Science University, Tom Hoerger of RTI and Jeanne Mandelblatt of Georgetown University Medical Center.

Like the other 11 AHRQ Evidence-based Practice Centers in the United States and Canada, the RTI-UNC team reviews all relevant information on selected health topics to provide guidance for medical decisions.

RTI International is an independent, nonprofit research organization dedicated to improving health and other human concerns. More information is available on RTI at http://www.rti.org/epc and on the U.S. Preventive Services Task Force at http://www.preventiveservices.ahrq.gov.

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Note: Pignone can be paged at (919) 216-1710. His e-mail address is pignone@email.unc.edu.

UNC News Services Contact: David Williamson, (919) 962-8596
AHRQ Contact: Barbara Najar, (301) 594-9881
RTI Contact: Jill Miller Denning, (919) 541-7044