Risk Factors Associated with Colorectal Cancer in Octogenarians Can Help Stratify the Need for Colonoscopy

Abstract

Objective Colonoscopy is increasingly performed in octogenarians for the detection of colorectal cancer (CRC), but its benefits may be outweighed by its risks. The aim of the present study was to identify the risk factors for CRC in octogenarians presenting for colonoscopy to help stratify the need for this procedure. Methods A retrospective analysis of 434 patients aged ≥ 80 years referred for a colonoscopy between January 2018 and December 2019. Comparisons were made between those with and without CRC and advanced adenoma (AA). The primary endpoint was to identify the clinical variables predictive of CRC and AA, and the secondary endpoints were complications and death 30 days after the procedure. Results Colonoscopy was performed in 434 octogenarians, predominantly for symptoms, with CRC in 65 (15.0%) patients. Iron deficiency was associated with a higher risk of having CRC identified on colonoscopy (odds ratio [OR]: 2.33; 95% confidence interval [95%CI] = 1.36-4.00), but not symptoms such as bleeding, weight loss, or diarrhea. A colonoscopy in the last 10 years was protective, with a lower risk of CRC (OR: 0.45; 95%CI = 0.22-0.93). Patients with both normal iron stores and a colonoscopy within 10 years had a 92.5% chance of not having CRC. No variables were predictive of AA. Patients with complications, including death, were older and more likely to have underlying cardiorespiratory disease. Conclusion Iron status and colonoscopy within 10 years can be used to predict the risk of CRC in octogenarians. Those with low predicted risk, especially if older and with cardiorespiratory disease, should be considered for non-invasive tests, such as computed tomography (CT) colonography, over colonoscopy.