What interval between colorectal cancer resection and first surveillance colonoscopy? An audit of practice and yield

Colonoscopic follow-up after colorectal cancer resection (CRC) is recommended to screen for anastomotic recurrence and metachronous neoplasia, although guidelines vary in the timings of the first investigation. We aimed to quantify current practice and yield of neoplasia at first colonoscopy in relation to time from original resection.

We conducted a retrospective case note study of all CRCs treated with curative intent within our hospital between two time periods: 2001-2003 and 2006-2007. Variables collected were the extent of preoperative luminal imaging, tumour site, procedure, timing and findings of initial colonoscopy, postoperative CT findings and mortality. The first follow-up colonoscopy findings including neoplasia formation and recurrence rates were matched with rates of complete preoperative luminal imaging. Two-year and 5-year outcomes were sought.

A total of 863 patients underwent CRC with curative intent within these two time periods (518 vs 345). Colonoscopic follow-up rates by 2 years were 32.8%vs 54.1%. Within the first cohort 63.5% of patients underwent colonoscopy by 5 years. Significant volumes of neoplasia and resectable recurrences were found before 2 years within these groups. Earlier detection of recurrent malignancy was associated with an improved patient outcome. Complete preoperative screening of the bowel was not associated with a lower incidence of neoplasia at first postoperative colonoscopy.

Our study demonstrates significant colonoscopic detection rates of neoplasia within 2 years of CRC. Patient outcomes were improved with earlier detection. We would therefore suggest an interval of no more than 2 years between resection and first surveillance colonoscopy.