Background & Aims: Endoscopic surveillance after curative colorectal cancer (CRC) resection is routine. However, there is controversy whether the 1-year interval between preoperative and postoperative colonoscopy is justified owing to improved colonoscopy standards. We aimed to assess the yield of surveillance colonoscopies 1 year after CRC surgery. Methods: We performed a retrospective cohort study of 572 patients (54.9% male; mean age, 66.2 ± 9.9 y), who underwent curative surgical resection of a first CRC from June 2013 through April 2016 in the Northwest region of The Netherlands. Patients were included if a complete clearing colonoscopy was performed before surgery and the interval between the preoperative and postoperative colonoscopy was 12 months (range, 6–20 mo), conforming to Dutch guidelines. The primary outcome of the study was the yield of CRC at the surveillance colonoscopy performed 1 year after curative resection. A secondary outcome was the yield of advanced neoplasia. Results: After a mean surveillance interval of 13.7 months (±2.8 mo), 10 of 572 patients (1.7%; 95% CI, 0.7%–2.8%) received a diagnosis of CRC. Of these, 5 CRCs were apparently metachronous cancers (3 were stage III or IV) and 5 were recurrences at the anastomosis (1 was stage IV). In 11.4% of patients (95% CI, 8.9%–13.8%), advanced neoplasia was detected at the 1-year follow-up colonoscopy. Synchronous advanced neoplasia at baseline colonoscopy was a risk factor for detection of advanced neoplasia at the follow-up colonoscopy (odds ratio, 2.2; 95% CI, 1.3–3.8; P ≤ .01). Conclusions: Despite high colonoscopy quality, the yield of CRC at surveillance colonoscopy 1 year after CRC resection was 1.7%. These were metachronous CRCs and recurrences, often of advanced stage. The high yield justifies the recommendation of a 1-year surveillance interval after surgical CRC resection.

Colon Cancer, Detection, Prevention, Treatment,
Clinical Gastroenterology and Hepatology
Department of Public Health

van Lanschot, M.C.J. (Meta C.J.), van Leerdam, M.E, Lansdorp-Vogelaar, I, Doets, S. (Sharon), Nagtegaal, I.D, Schreurs, H.W. (Hermien W.), … van Berkel, A.-M. (2019). Yield of Surveillance Colonoscopies 1 Year After Curative Surgical Colorectal Cancer Resections. Clinical Gastroenterology and Hepatology, 17(11), 2285–2293. doi:10.1016/j.cgh.2019.02.026