A retrospective study of colonoscopic surveillance in the elderly.

Background: Aotearoa New Zealand (AoNZ) guidelines suggest surveillance colonoscopy should be carefully considered after age 75. The authors noted a cluster of patients presenting in their 8th and 9th decade of life with a new colorectal cancer (CRC) having previously been declined surveillance colonoscopy.

Methods: A 7-year retrospective analysis was performed of patients who underwent a colonoscopy aged between 71 and 75 years in the period between 2006 and 2012. Kaplan-Meier graphs were created with survival measured from the time of index colonoscopy. Log rank tests were used to determine any difference in survival distribution. Relative risk (RR) was calculated, and 95% confidence intervals (CI) reported.

Results: A total of 623 patients met inclusion criteria; 461 (74%) had no indication for surveillance colonoscopy and 162 (26%) had an indication. Of the 162 patients with an indication, 91 (56.2%) underwent surveillance colonoscopies after the age of 75. Twenty-three (3.7%) patients were diagnosed with a new CRC. Eighteen (78.2%) patients diagnosed with a new CRC underwent surgery. The median survival overall was 12.9 years (95% CI 12.2-13.5). This did not differ between patients with (13.1, 95% CI 12.1-14.1) or without (12.6, 95% CI 11.2-14.0) an indication for surveillance.

Conclusion: This study found one quarter of patients who had a colonoscopy between the ages of 71-75 had an indication for surveillance colonoscopy. Most patients with a new CRC underwent surgery. This study suggests it may be appropriate to update the AoNZ guidelines and consider adopting a risk stratification tool to aid decision making.