Background:
Multitarget stool DNA (mt-sDNA) screening has increased rapidly since simultaneous approval by the U.S. Food and
Drug Administration and Centers for Medicare and Medicaid Services in 2014, whereas CT colonography screening remains underused and is not covered by Centers for Medicare and Medicaid Services.
Purpose:
To report postapproval clinical experience with mt-sDNA screening for colorectal cancer (CRC) and compare results with
CT colonography screening at the same center.
Materials and Methods:
In this retrospective cohort study, asymptomatic adults underwent clinical mt-sDNA screening during a 5-year
interval (2014–2019). Electronic medical records were searched to verify test results and document subsequent optical colonoscopy
and histopathologic findings. A similar analysis was performed for CT colonography screening during a 15-year interval (2004–
2019), with consideration of thresholds for positivity of both 6-mm and 10-mm polyp sizes. x2
or two-sample t tests were used for
group comparisons.
Results: A total of 3987 asymptomatic adult patients (mean age, 64 years 6 9 [standard deviation]; 2567 women) underwent
mt-sDNA screening and 9656 patients (mean age, 57 years 6 8; 5200 women) underwent CT colonography. Test-positive rates
for mt-sDNA and for 6-mm- and 10-mm-threshold CT colonography were 15.2%, 16.4%, and 6.7%, respectively. Optical
colonoscopy follow-up rates for positive results of mt-sDNA and 6-mm- and 10-mm-threshold CT colonography were 13.1%,
12.3%, and 5.9%, respectively. Positive predictive values (PPVs) for any neoplasm 6 mm or greater, advanced neoplasia, and CRC
for mt-sDNA were 54.2%, 22.7%, and 1.9% respectively; for 6-mm-threshold CT colonography, PPVs were 76.8%, 44.3%, and
2.7%; for 10-mm-threshold CT colonography, PPVs were 84.5%, 75.2%, and 5.2%, respectively (P , .001 for mt-sDNA vs CT
colonography for all except 6-mm CRC at CT colonography). For mt-sDNA versus 6-mm-threshold CT colonography, overall
detection rates for advanced neoplasia were 2.7% and 5.0%, respectively (P , .001); corresponding detection rates for CRC were
0.23% and 0.31%, respectively (P = .43).
Conclusion:
The detection rates of advanced neoplasia at CT colonography screening were greater than those of multitarget stool
DNA. Detection rates were similar for colorectal cancer.
