WASHINGTON—People who have had adenomas removed during colonoscopy are returning for surveillance colonoscopies more frequently than recommended by current guidelines, according to a community-based study presented at Digestive Disease Week 2007 (abstract 269). But the study also found that some patients with advanced adenomas were not receiving surveillance colonoscopies as often as recommended. "There is an element of both underutilization and overutilization," said Robert E. Schoen, MD, MPH, professor of medicine and epidemiology at the University of Pittsburgh.
Previous surveys have suggested that physicians, particularly surgeons and primary care physicians, recommend surveillance colonoscopy more often than recommended, but this is the first study to measure actual use in relation to histologic findings in a community-based cohort, Dr. Schoen said. Subjects were part of the Prostate, Lung, Colorectal, and Ovarian (PLCO) screening trial. All had received an initial sigmoidoscopy as part of the PLCO; subsequent colonoscopy and surveillance were left up to the patients and their physicians.
Dr. Schoen and his colleagues sampled four groups: those with advanced adenomas (1,350), nonadvanced adenomas (1,046), hyperplastic polyps (724), and no polyps (554). They used a telephone questionnaire to obtain data on surveillance colonoscopies, and then verified the data from medical records.
The findings showed that many patients with advanced adenomas were not receiving follow-up colonoscopies at 3 years, as recommended by the US Multi-Society Task Force on Colorectal Cancer. Five years after the initial colonoscopy with polyp removal, only 63% had had one or more surveillance colonoscopies. After 10 years, the figure was 83%. Those with advanced adenomas who did not have repeat colonoscopies were more likely to be older (age 70 to 74) at the time of the baseline exam and less likely to have a family history of colorectal cancer.
The task force guidelines for follow-up of nonadvanced adenomas—polyps less than 1 cm without villous features or high-grade dysplasia—call for a repeat colonoscopy in 5 to 10 years. Among PLCO subjects with nonadvanced adenomas at baseline, about 46% had received one follow-up colonoscopy in that period. However, surveillance was often more frequent: 20% of those with nonadvanced adenomas had received two or more colonoscopies at 7 years.
Even among participants with no adenomas at baseline (hyperplastic polyps or no polyps), 40% had a repeat colonoscopy within 5 years, and 15% had two or more in 7 years. Screening guidelines generally recommend colonoscopy every 10 years for average-risk individuals age 50 and older. "Viewed through the lens of current guidelines for people without adenomas, what we see in the community is certainly much greater than what is recommended," Dr. Schoen said.
