THURSDAY, June 17 (HealthDay News) -- Getting surveillance colonoscopies every one to two years instead of every two to three years is associated with a reduced risk of colorectal cancer (CRC) for members of families with Lynch syndrome, according to a study in the June issue of Gastroenterology.

Hans F.A. Vasen, M.D., of the Leiden University Medical Centre in the Netherlands, and colleagues tracked CRC incidence during 1995 to 2008 in 205 Lynch syndrome families who had mutations in one of the mismatch repair genes (745 mutation carriers). Forty-six families (344 individuals) without the genetic condition were also followed.

In a mean follow-up of 7.2 years, the researchers found that 33 of the Lynch syndrome patients under surveillance developed CRC, compared to 6 individuals in a mean 7.0 years of follow-up among the non-Lynch syndrome families. Of the 33 Lynch syndrome patients with CRC, 13 had an interval of more than two years from their previous colonoscopy to CRC detection. Of the remaining 20 patients who had colonoscopies within the two-year interval, 90 percent had localized tumors. The researchers concluded that, for members of Lynch syndrome families over 10 years of follow-up, colonoscopy intervals of one to two years result in a cumulative CRC risk of 6 percent and an advanced CRC risk of 0.6 percent.

"With surveillance intervals of one to two years, members of families with Lynch syndrome have a lower risk of developing CRC than with surveillance intervals of two to three years. Because of the low risk of CRC in non-Lynch syndrome families, a less intensive surveillance protocol can be recommended," the authors write.

Abstract
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