SAN DIEGOEffective screening for colorectal cancer requires
ongoing testing and follow-up. Robert E. Schoen, MD, MPH, of the
University of Pittsburgh, reported that adherence with sigmoidoscopy
is outstandingabout 86% of eligible subjects returned for a
follow-up exam at 3 years. However, a negative experience with
screening flexible sigmoidoscopy can keep patients from repeating the
procedure. He discussed the findings at an American
Gastroenterological Association research forum held during Digestive
Dr. Schoen and his colleagues measured compliance with repeat
screening sigmoidoscopy and the factors affecting compliance in the
Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial.
PLCO is an NCI community-based randomized clinical trial with
10 US screening centers, Dr. Schoen said. It offers periodic
multimodality cancer screening, including flexible
sigmoidoscopy. In the initial years of the trial, sigmoidoscopy
was offered at 3-year intervals.
Of the more than 10,000 subjects between the ages of 60 and 74 who
had undergone a baseline flexible sigmoidoscopy examination and were
eligible for a repeat examination, 8,804 (86.6%) accepted when the
repeat exam was offered 3 years later, he reported.
The study showed that 1,360 people refused to repeat the
sigmoidoscopy exam or did not show up for the clinic visit for their
repeat exam. Those most likely to refuse were women (18.3%),
non-Hispanic blacks (21.7%), current smokers (21.8%), and people with
technically inadequate baseline sigmoidoscopy exams (26.8%).
The researchers found that age and education were neither strongly
nor consistently associated with refusing the repeat screening procedure.
We found that one reason for a high refusal rate is patient
discomfort, Dr. Schoen said. An inadequate exam the first
time that was associated with pain was more likely to lead to
nonadherence 3 years later. Further research should be done to
generalize results to community settings and test interventions to
encourage repeat screenings.