Utilization of surveillance colonoscopy within 6 years after screening colonoscopy: prospective cohort study

Background: Based on the findings at screening colonoscopy different intervals apply until a next colonoscopy is recommended. For a colorectal cancer screening program to be both efficient and effective, appropriate utilization of surveillance colonoscopies is essential. Thus, we prospectively followed participants of the German screening colonoscopy program over 6 years to investigate utilization and results of surveillance colonoscopies. Methods: This study is an ancillary study to the KolosSal study, a population-based state-wide study in Saarland with long-term follow-up of > 19,000 participants of screening colonoscopy. Participants recruited in 2005 – 2007 were contacted 6 years after screening colonoscopy and requested to provide information about utilization of further colonoscopies. For all colonoscopies reported, colonoscopy and histology reports were requested from the physicians. Results: Overall, 6407 participants of screening colonoscopy were included in this analysis, 35% of whom had at least one further colonoscopy in the following 6 years. Participants with no polyps or hyperplastic polyps only, with non-advanced and with advanced adenomas detected at screening colonoscopy had further colonoscopies in 22%, 56% and 61% of cases, respectively. Among patients with no adenoma findings at screening, only 3 – 4% had advanced neoplasms at a subsequent colonoscopy as validated by medical records. If surveillance colonoscopy was used earlier than recommended among patients with non-advanced adenomas (up to 3 years after screening colonoscopy) and advanced adenomas (year 1) detected at screening, advanced neoplasms were detected in 4% and 21%, respectively. Conclusion: This study suggests a high level of non-adherence to the guidelines for surveillance after colonoscopy in Germany, including overuse among patients with no adenoma findings at screening and underuse among higher risk participants with advanced adenomas detected at screening.