P3175 - Factors Associated With False-Positive Results in Multitarget Stool DNA Test for Colorectal Cancer Screening

Akash Patel, MD¹, Adewale Ajumobi, MD, MBA, FACG^2
1Eisenhower Health, Rancho Mirage, CA; ²Eisenhower Health, University of California, Rancho Mirage, CA

Introduction: Multitarget stool DNA (Cologuard) test is commonly used for non-invasive screening of colorectal cancer (CRC). False positive (FP) results are a concern due to their associated costs and patient distress. Understanding the factors linked to FP Cologuard results is crucial for improving screening protocols. However, there is limited research in this area.

Methods: A cross-sectional study was conducted on patients with positive Cologuard results who underwent colonoscopy between January 1, 2016 and October 31, 2022 at a large community teaching hospital. A false-positive result was defined as a positive Cologuard test followed by a colonoscopy that did not reveal precancerous lesions or cancer. Data on patient demographics, body mass index (BMI), time between positive Cologuard and colonoscopy, and concurrent use of drugs including Proton Pump inhibitors (PPIs), Cyclooxygenase (COX) inhibitors, Antiplatelet agents (APAs), Oral anticoagulants (OACs), and SSRIs were collected. Binomial logistic regression was employed to identify variables associated with FP results, estimating odds ratios (ORs) and their 95% confidence intervals (CIs).

Results: The study included 312 patients with a mean age of 71.4 ± 7.4 years. The majority were over 70 years old (66.4%), female (52.9%), and non-Hispanic white (93.3%), with a mean BMI of 26.6 ± 5.0. Most patients (88.8%) underwent colonoscopy within 6 months of a positive Cologuard result. Among these patients, 115 (36.9%) had FP results. Females exhibited a significantly higher likelihood of FP results compared to males (OR, 1.67; 95% CI, 1.04-2.66). The use of COX inhibitor was associated with a substantial two-fold increase in the likelihood of FP Cologuard results compared to non-users (OR: 2.1, 95% CI: 1.13-3.91). The use of PPIs, APAs, OACs and SSRIs were not associated with false positive results. Age, (50-70 years and >70 years), wait time (< 6 months and >6 months), BMI, and hemorrhoids, were not related to FP results.

Discussion: The female gender and use of cyclooxygenase inhibitors are associated with a false positive result in Cologuard test. Further investigation is needed to validate these results.


Disclosures:


Akash Patel, MD¹, Adewale Ajumobi, MD, MBA, FACG². P3175 - Factors Associated With False-Positive Results in Multitarget Stool DNA Test for Colorectal Cancer Screening, ACG 2023 Annual Scientific Meeting Abstracts. Vancouver, BC, Canada: American College of Gastroenterology.