Incompletely Resected Polyps Associated With Subsequent Neoplasia and Advanced Neoplasia in Observational Study

Interval cancers are thought to result primarily from missed lesions, with a smaller component in the 10% to 30% range arising from incomplete polyp resection. The evidence for the latter is from the occurrence of interval cancer in the same segment from which a polyp previously was resected. 

The current study attempts to provide observational evidence that incomplete resection is, in fact, associated with subsequent neoplasia. The authors performed a retrospective assessment of the Complete Adenoma REsection (CARE) study that had demonstrated variable efficacy between endoscopists in the resection of 5- to 20-mm polyps. Patients from the CARE study were followed to examine the risk of neoplasia in colon segments according to whether polyps had been completely or incompletely resected. The original determination of complete resection had been made by biopsy of resection margins immediately after finishing an apparent complete resection. 

There were 166 patients with follow-up colonoscopy involving 33 colon segments with a prior incomplete resection and 181 segments with a previous complete resection. The risk of any metachronous neoplasm was greater in segments with a prior incomplete resection versus complete resection (52% vs 23%). Segments with incomplete resection also had a higher mean number of neoplasms (0.8 vs 0.3) and a higher risk of advanced neoplasia (18% vs 3%). In a multivariate analysis, incomplete resection was the strongest predictor of metachronous neoplasia with an odds ratio of 3.0.