The appropriate interval for endoscopic rescreening after a negative colonoscopic examination is uncertain.
Dr Thomas Imperiale and colleagues from Indianapolis, USA identified persons with no adenomas on baseline screening colonoscopy who returned at 5 years for follow-up colonoscopy.
Findings were categorized according to the most advanced lesion present.
These ranged from no polyp, a hyperplastic polyp, to a tubular adenoma less than 1 cm in diameter, to an advanced adenoma or cancer.
Baseline screening colonoscopy had identified 2,436 persons with no adenomas, of which 52% were re-screened about 5 years later.
|One or more adenomas were found in 16%|
|New England Journal of Medicine|
The mean age of this group at baseline was 57 years, and 57% of its members were men.
The research team found no cancers on rescreening.
One or more adenomas were found in 16%.
A total of 19 advanced adenomas, of which 10 were distal to the splenic flexure, were found in 1% of patients.
The risk of an advanced adenoma did not differ significantly between persons with no polyps at baseline and those with hyperplastic polyps at baseline.
The team found that men were more likely than women to have any adenoma and to have an advanced adenoma.
Dr Imperiale’s team concluded, “Among persons with no colorectal neoplasia on initial screening colonoscopy, the 5-year risk of colorectal cancer is extremely low.”
“The risk of advanced adenoma is also low, although it is higher among men than among women.”
“Our findings support a rescreening interval of 5 years or longer after a normal colonoscopic examination.”