S350 Are Primary Care Providers Accurately Ordering Cologuard in the Community Setting?

Abstract

Introduction: Colon cancer screening saves lives, and colonoscopy remains the gold standard test. Cologuard (CG), a non-invasive multi-target stool DNA + Fecal Immunohistochemical Test, is 92% sensitive for colon cancer detection, but only 42.4% sensitive for advanced adenoma detection, thus limiting its preventive role. CG is indicated as a screening test for asymptomatic patients without colon cancer risk factors, and is increasingly ordered by primary care providers (PCPs). It is unknown if PCPs are ordering CG according to approved indications. To determine if referring PCPs in our community are ordering the CG test in accordance with approved indications. Methods: Our practice has a wide network of referring providers with multiple offices. This prospective study enrolled all patients referred to our practice with a positive CG test from December 2020 to June 2021. Clinical information was obtained from medical records. Patients responded to a questionnaire asking: (1) Did you see blood in your stool or observe blood from your rectum, and (2) Did you have a stool test showing blood before your CG test? The colonoscopy results were recorded and the data was analyzed. Results: 81 patients (28M:53F) with a positive CG test were enrolled, with a median age 62 years (96.3% patients >50 years old). 9% of the study population self-identified as African-Americans. 54/81 (66.7%) of patients had >1 adenomatous polyp or colon cancer (n=3) on colonoscopy, and specifically 16% (13/81) had advanced adenomatous polyps/mass. 33.3% (27/81) of patients had either a hyperplastic polyp or a normal colonoscopy. The false positive rate for CG in this study was 33.3%. 16% (13/81) of patients who were prescribed a CG test had blood present in stool, and of these 13 patients, 12 reported overt bleeding prior to being prescribed CG. Conclusion: This study reveals that our community-based PCPs are incorrectly ordering CG as a screening test, and specifically, are unaware that overt bleeding is a contraindication for CG testing. 15% of patients initially reported overt bleeding prior to CG testing, and this contributed to the elevated false positive rate observed in our study (33.3%) compared to the accepted false positive rate of 12% for comparable patients. The cost of CG is $500-600 and widespread erroneous testing leads to increased healthcare cost. This study highlights an opportunity for PCP education, and suggests similar regional analysis should be conducted.