WASHINGTON — Physicians don't seem to be doing such a good job of adhering to recommendations for colonoscopy surveillance, following some patients too often and not following others often enough, Dr. Robert E. Schoen reported at the annual Digestive Disease Week.
Dr. Schoen, a professor of medicine and epidemiology at the University of Pittsburgh, and his colleagues looked at surveillance colonoscopy records for 3,607 participants (60% men, 93% white) in the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial. All of the patients had an abnormal screening flexible sigmoidoscopy and then underwent diagnostic colonoscopy within 1 year.
At 5 years' follow-up, only 63% of the patients with advanced adenoma had undergone a surveillance colonoscopy. At 10 years, 83% had had a follow-up colonoscopy. On the other side of the spectrum, 40% of those with no polyps had undergone a surveillance colonoscopy at 5 years; that number rose to 64% at 10 years. (See box.)
“There is an element of both underutilization and overutilization,” Dr. Schoen said. According to recommendations by the U.S. Multi-Society Task Force on Colorectal Cancer and the American Cancer Society, patients with two or fewer small (less than 1-cm) tubular adenomas with only low-grade dysplasia should have their next follow-up colonoscopy in 5–10 years. Patients with small rectal hyperplastic polyps should be considered to have normal colonoscopies and should have their next follow-up colonoscopy in 10 years. Patients with 3–10 adenomas, any adenoma 1 cm or larger, any adenoma with villous features, or high-grade dysplasia should have a follow-up colonoscopy in 3 years (Gastroenterology 2006;130:1872–85.)
In the PLCO trial, patients who had an abnormal flexible sigmoidoscopy were referred to their primary care physician for a decision regarding further testing. Colonoscopies were performed by community-based physicians, not trial investigators. Likewise, surveillance decisions were made by community-based physicians.
For this study, patients were interviewed over the telephone. They were reminded of their baseline colonoscopy findings and asked about follow-up surveillance colonoscopy. Medical records were used to confirm reported colonoscopies. There were at least 5 years of follow-up data after the baseline colonoscopy, with a median of 9 years.
At baseline colonoscopy, 37% of the patients had advanced adenoma, 28% had a nonadvanced adenoma, 20% had hyperplastic polyps or another benign mucosal abnormality, and 15% had no polyps.
At 7 years, 34% of those with advanced adenoma, 20% of those with nonadvanced adenoma, 15% of those with benign polyps or abnormalities, and 15% of those with no polyps had at least two follow-up colonoscopies.
Patients aged 70–74 with an advanced adenoma had an odds ratio of 1.6 for not getting a follow-up colonoscopy, compared with younger patients with an advanced adenoma.
Participants in the PLCO trial were recruited through 10 regional centers across the United States. Individuals were asymptomatic upon enrollment. The study involved 154,942 people aged 55–74 years at entry, and more than 65,000 individuals had a flexible sigmoidoscopy.
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