2832 Real Life Impact of Physician Awareness of a Positive Stool DNA Test on Subsequent Colonoscopy Outcome in Colorectal Cancer Screening

Abstract

INTRODUCTION: A recent study that included 244 subjects has looked into clinical outcome of colonoscopy based on the physician’s awareness of the positive result. That study showed significant differences in colonoscopy findings. We present a larger real-life study on the impact of physician awareness of a positive stool DNA test on colonoscopy results. METHODS: Chart review of 1413 patients who had a positive stool DNA followed by documented subsequent colonoscopy was done. Attention was made to the indication of the procedure in the colonoscopy report. A total of 5 patients were excluded, 3 of them had unknown indication and 2 of them had a finding of “other carcinoma” aside from adenocarcinoma. Index lesions were recorded and patients were divided in 2 groups. Group 1 included patient who had indication of “stool DNA testing” or its equivalent, while group 2 included all the other indications assuming that the provider was not aware of the positive stool DNA testing. Advanced adenoma was defined as an adenoma that is larger than 10 mm or had high risk features such as villous transformation or high grade dysplasia. Nonadvanced adenoma was defined as an adenoma that is smaller than 10 mm and had no high risk features. Statistical analysis with Chi-square was done to compare the proportions. A P-value < 0.05 was considered to be statistically significant. RESULTS: Out of the 1408 patients included in the analysis, 979 (70%) patients had an indication of “stool DNA testing” or its equivalent while 429 (30%) had another indication. Results of group 1 and group 2 were as follows. “Adenocarcinoma” was found in 1.84% vs. 1.4% respectively (P = 0.56). “Advanced adenoma” was found in 24.82% vs. 21.21% respectively (P = 0.14). “10 mm adenoma” was found in 7.25% vs. 6.99% respectively (P = 0.86). Non advanced adenoma was found in 28.7% vs. 31.24% respectively (P = 0.57). Finally, no adenomas were found in 37.39% vs. 39.16% respectively (P = 0.33). CONCLUSION: Following a positive stool DNA test, 1 out of 3 colonoscopies are done without the physician’s awareness of the positive result. Fortunately, there was no difference in the outcome of colonoscopy whether the physician was aware of the positive result or not.