Background: This study aimed to determine the diagnostic yield of colonoscopy 1 year after colorectal cancer (CRC) resection based on whether the index colonoscopy was performed by the operating surgeon.
Methods: All patients undergoing surgery for colorectal cancer by two colon and rectal surgeons at a university hospital from 1991 to 2005 were identified from the tumor registry. Those patients with a complete preoperative colonoscopy by any physician and a 1-year follow-up examination by the operating surgeon were selected for the study population. Family history of colorectal cancer, tumor location, endoscopist, presence of synchronous neoplasms, and findings of 1-year colonoscopy were recorded. Fisher's exact test was used to compare the probability of finding any adenoma, advanced adenoma, or invasive cancer based on the index endoscopist.
Results: Of the 719 patients who underwent resection during the study period, 432 met the inclusion criteria. The index colonoscopy for 117 of these patients (27.1%) was performed by one of the two surgeons. Overall, 10 patients (2.3%) had a "new" cancer diagnosed at 1 year, and 1 patient (0.2%) had a local recurrence. Patients whose index colonoscopy was performed by their operating surgeon appeared less likely to have an advanced lesion found at 1 year (5.1% vs 11.4%; p = 0.06). The index colonoscopy for 9 of the 10 of cancers found at 1 year was not performed by the operating surgeon.
Conclusions: Colonoscopy 1 year after CRC resection is clearly justified. An index colonoscopy by the operating surgeon eliminates a "handoff" and may diminish the incidence of high-risk lesions at 1 year.