How can we better identify patients with rectal bleeding who are at high risk of colorectal cancer? An observational study

Abstract

Purpose: Rectal bleeding is a common symptom of colorectal cancer. In this paper, we describe and evaluate the operation of a central access and triage system for patients with rectal bleeding, which uses a “high-risk”/ “low-risk” designation based on the referring doctor’s subjective designation and a 10-item symptom checklist. Methods: A total of 1846 patients, referred between February 1, 2016, and December 31, 2018, were included. Exclusion criteria were the following: incorrect patient identification number, duplicate records, and pre-diagnosed gastrointestinal cancer. Data was obtained by chart review. Sensitivity, specificity, and positive and negative predictive values were calculated for each item on the symptom checklist. Results: Eight hundred seventy-nine (48%) patients received endoscopy, and 37 (2%) were found to have cancer. Five hundred eighty-two (32%) patients were deemed high-risk. Twenty-nine (78%) of the patients with cancer were in the high-risk group. Patients in the high-risk group had a higher incidence of cancer (5.0% vs 0.6%, p < 0.001) and shorter waits to endoscopy (201 vs 292 days). Patients designated as high-risk by the referring physician had a relative risk of 22.3 compared to those designated as low-risk. Patients deemed high-risk by the symptom checklist had a relative risk of 3.5 compared to low-risk patients. Conclusion: Our system stratified 29/37 (78%) of the patients found to have cancer as high-risk. A total of 8/37 (22%) patients with cancer were deemed low-risk. Our research has identified two variables (weight loss and anemia) which have been added to our referral symptom checklist. This study helped us identify areas for refinement of our triage system. These findings are of interest to physicians who treat colorectal cancer.