Comparison of performance of two Stool DNA Tests and a Faecal Immunochemical Test in Detecting Colorectal Neoplasm: a Multicentre Diagnostic Study

Background:

The most widely used noninvasive screening tests for colorectal cancer are fecal occult blood tests. Stool DNA test was developed in recent years. However, direct comparative analyses of these tests within the same population are still sparse.

Methods:

A total of 2,842 participants who visited outpatient clinics or cancer screening centers were enrolled. Stool DNA test-I (KRAS, BMP3, NDRG4, and hemoglobin immunochemical tests), stool DNA test-II (SDC2 and SFRP2 tests), and fecal immunochemical test (FIT) alone were performed and colonoscopy was used as the gold standard among 2,240 participants. Forty-two and 302 participants had colorectal cancer and advanced adenomas (AA), respectively.

Results:

The sensitivity for colorectal cancer of stool DNA test-I, -II, and FIT was 90.5%, 92.9%, and 81.0%, respectively. The sensitivity for advanced neoplasm (AN; colorectal cancer plus AA) of stool DNA test-I, -II, and FIT was 34.9%, 42.2%, and 25.9%, respectively. The specificity of stool DNA test-I, -II, and FIT was 91.4%, 93.3%, and 96.8%, respectively, among those with negative results on colonoscopy. When the specificity of FIT was adjusted to match that of stool DNA tests by changing the threshold, no significant difference was seen in the sensitivities among the three tests for detecting colorectal cancer. For AN, the sensitivity of FIT was higher than DNA test-I and similar to DNA test-II under the same specificities.

Conclusions:

There was no significant advantage of the two stool DNA tests compared with FIT in detecting colorectal cancer or AN in this study.

Impact:

Our findings do not support extensive use of stool DNA tests instead of FIT.