Stool DNA testing for early detection of colorectal cancer: systematic review using the HTA Core Model(®) for Rapid Relative Effectiveness Assessment

BACKGROUND: Stool DNA testing for early detection of colorectal cancer (CRC) is a non-invasive technology with the potential to supplement established CRC screening tests. The aim of this health technology assessment was to evaluate effectiveness and safety of currently CE-marked stool DNA tests, compared to other CRC tests in CRC screening strategies in an asymptomatic screening population. METHODS: The assessment was carried out following the guidelines of the European Network for Health Technology Assessment (EUnetHTA). This included a systematic literature search in MED-LINE, Cochrane and EMBASE in 2018. Manufacturers were asked to provide additional data. Five patient interviews helped assessing potential ethical or social aspects and patients’ experiences and preferences. We assessed the risk of bias using QUADAS-2, and the quality of the body of evidence using GRADE. RESULTS: We identified three test accuracy studies, two of which investigated a multitarget stool DNA test (Cologuard(®), compared fecal immunochemical test (FIT)) and one a combined DNA stool assay (ColoAlert(®), compared to guaiac-based fecal occult blood test (gFOBT), Pyruvate Kinase Isoenzyme Type M2 (M2-PK) and combined gFOBT/M2-PK). We found five published surveys on patient satisfaction. No primary study investigating screening effects on CRC incidence or on overall mortality was found. Both stool DNA tests showed in direct comparison higher sensitivity for the detection of CRC and (advanced) adenoma compared to FIT, or gFOBT, respectively, but had lower specificity. However, these comparative results may depend on the exact type of FIT used. The reported test failure rates were higher for stool DNA testing than for FIT. The certainty of evidence was moderate to high for Cologuard(®) studies, and low to very low for the ColoAlert(®) study which refers to a former version of the product and yielded no direct evidence on the test accuracy for ad-vanced versus non-advanced adenoma. CONCLUSIONS: ColoAlert(®) is the only stool DNA test currently sold in Europe and is available at a lower price than Cologuard(®), but reliable evidence is lacking. A screening study including the current product version of ColoAlert(®) and suitable comparators would, therefore, help evaluate the effectiveness of this screening option in a European context.