Why is the sDNA re-testing interval described as “uncertain”?

There are currently no observational data upon which to base a recommendation for appropriate screening intervals. Although the manufacturer of the currently available commercial test recommends a 5-year interval for routine screening, such an interval was judged by the committee to be appropriate only for a test that has very high sensitivity for both cancer and adenomatous polyps – a standard that has not been documented for sDNA testing. In the only large population study of sDNA completed to date, the sDNA test had better performance than the comparison gFOBT for the detection of cancer and advanced adenomas, but the detection rate still was not dissimilar to that of a high sensitivity gFOBT or FIT, for which current repeat testing recommendations range between 1 and 2 years.