A recent meta-analysis has found that endoscopy is much more effective than faecal tests for detecting advanced neoplasia, which mitigates the increased participation rate of faecal testing.

To be effective, screening tests for colorectal cancer (CRC) must balance accuracy with population attendance. “Low participation rates dilute the intrinsic efficacy of CRC screening tests, reducing the overall yield for advanced neoplasia in a population setting,” explains Cesare Hassan, lead author of the meta-analysis.

Hassan and co-workers included 14 studies with a total of 197,910 participants in their meta-analysis. They analysed data for detection rates and adherence to the screening programmes.

The researchers found that endoscopy-based screening had a 33% lower participation rate than screening that used faecal tests. However, endoscopy had a threefold higher detection rate of advanced neoplasia than faecal tests. In addition, the new immunochemical faecal occult blood test was found to be superior to the guaiac-based faecal occult blood test for both accuracy and participation. “Our study clearly shows that the superior accuracy of endoscopy compared with faecal tests minimizes any impact of participation rate in determining the detection rate of advanced neoplasia in a screening setting,” says Hassan.

The authors note several factors that their analysis did not account for. For example, the studies included one round of faecal tests, whereas repeated rounds every 1–2 years are recommended, which could increase the accuracy of these tests. New, less invasive tests could prove to be superior to current endoscopy strategies.