Related Experiment Video
Updated: Jul 12, 2025
07:35
Evaluation of Colorectal Cancer Risk and Prevalence by Stool DNA Integrity Detection
Published on: June 8, 2020
7.0K
Positive Predictive Value for Multitarget Stool DNA After Bariatric and Metabolic Surgery
Derek W Ebner1, Kelli N Burger2, Brendan Broderick2
1Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, Minnesota.
Gastro Hep Advances
|October 25, 2023
Summary
Bariatric surgery does not impact the accuracy of multitarget stool DNA tests for colorectal cancer screening. This finding is crucial as obesity rates rise, increasing the need for effective screening methods.
Area of Science:
- Gastroenterology
- Oncology
- Medical Diagnostics
Background:
- Bariatric and metabolic surgery (BMS) may alter stool characteristics, potentially affecting noninvasive colorectal cancer (CRC) screening tests.
- Multitarget stool DNA (mt-sDNA) is an approved CRC screening method, but its performance in patients post-BMS is not well-established.
- Rising obesity rates are driving an increase in BMS procedures, necessitating an evaluation of mt-sDNA test efficacy in this population.
Purpose of the Study:
- To evaluate the performance of multitarget stool DNA (mt-sDNA) testing for colorectal cancer screening in patients who have undergone bariatric and metabolic surgery (BMS).
- To determine the positive predictive value (PPV) of mt-sDNA for advanced colorectal neoplasia in post-BMS patients.
Main Methods:
- A retrospective analysis of mt-sDNA results from average-risk patients with prior BMS was conducted using electronic records and an institutional BMS registry.
- Patients with a positive mt-sDNA test underwent chart review and colonoscopy for comparison with historical cohorts of patients without BMS screened by mt-sDNA and BMS patients screened by colonoscopy alone.
- The primary endpoint was the positive predictive value (PPV) for advanced colorectal neoplasia.
Main Results:
- Among 336 patients with prior BMS, 14.6% had a positive mt-sDNA test. The PPV for advanced neoplasia was 25.5% (12/47), which was statistically similar to a historical cohort without BMS (28%, P = .86).
- Follow-up colonoscopy confirmed advanced neoplasia in 25.5% of post-BMS patients with a positive mt-sDNA test.
- The rate of advanced neoplasia was higher in post-BMS patients following mt-sDNA screening compared to those screened with colonoscopy alone.
Conclusions:
- Bariatric and metabolic surgery does not appear to adversely affect the positive predictive value of multitarget stool DNA tests for colorectal cancer screening.
- The findings suggest that mt-sDNA remains a viable screening option for individuals who have undergone BMS, despite potential physiological changes.
- Further research may explore the specific mechanisms by which BMS could theoretically impact stool DNA integrity and test performance.
