Postcolonoscopy Colorectal Cancer in a Referral Center for Colorectal Cancer: Prevalence and Risk Factors

BACKGROUND AND AIMS: Colonoscopy is effective to detect and remove colorectal lesions. However, after a negative colonoscopy, cancers could be detected during the interval follow-up. This study was designed to identify characteristics and risk factors for postcolonoscopy colorectal cancer – interval type. METHODS: Medical records of individuals who were newly diagnosed with colorectal cancer between January 2018 and December 2019 were reviewed. Clinical, demographic, and endoscopic variables were analyzed. Those with the diagnosis of colorectal cancer between two consecutive colonoscopies performed within the appropriated surveillance range were considered to have postcolonoscopy colorectal cancer – interval type. A comparison between the group of patients with non-postcolonoscopy colorectal cancer – interval type and the group of patients with postcolonoscopy colorectal cancer – interval type was then performed. RESULTS: During the study period, 491 patients were newly diagnosed with colorectal cancer. Among them, 61 (12.4%) had postcolonoscopy colorectal cancer – interval subtype. Postcolonoscopy colorectal cancer – interval type was three times more prevalent on the proximal colon (p = 0.014) and was associated with the presence of two or more cardiovascular risk factors (aOR = 4.25; p = 0.016), cholecystectomy in the past (aOR = 10.09; p = 0.019), and family history of colorectal cancer on a first-degree relative (aOR = 4.25; p = 0.006). Moreover, isolated cardiovascular risk factors revealed a protective effect for the absence of all cardiovascular risk factors (aOR = 20; p = 0.034). The ROC curve associated with the multivariate model revealed a predictive power of 77.8% (p < 0.001). CONCLUSIONS: Postcolonoscopy colorectal cancer – interval type is more common in the proximal colon and in patients with a family history (first-degree relative) of colorectal cancer, two or more cardiovascular risk factors, and a history of cholecystectomy. All of these are easily detectable in clinical practice and may be of extreme importance in the control of postcolonoscopy colorectal cancer in the near future.