Incomplete resection increases risk for future, advanced neoplasia in colorectal polyps
In patients with colorectal neoplastic polyps, colon segments with complete resection compared with those after incomplete resection had a statistically significantly greater risk for future neoplasia and advanced neoplasia.
“Because resection sites were not marked in the study, we assessed metachronous neoplasia in colon segments in which a polyp was removed,” Heiko Pohl, MD, from the department of gastroenterology, Veterans Affairs Medical Center, in Vermont, and colleagues wrote in Annals of Internal Medicine. “We hypothesized that if incomplete resection contributes to post colonoscopy [colorectal cancer (CRC)], then segments in which a polyp was incompletely removed should have a higher risk for metachronous neoplasia vs. segments in which polyps were completely removed. Therefore, the primary aim of the study was to compare the rate of neoplasia in segments with prior incomplete resection vs. the rate of neoplasia in segments with prior complete resection.”
Pohl and colleagues performed an observational study of 233 patients who participated in the Complete Adenoma Resection study who had resection of a 5- to 20-mm neoplastic polyp, had a documented complete or incomplete resection and had a surveillance examination. Of these patients, 166 had at least one surveillance examination. Investigators measured segment metachronous neoplasia and then compared it between segments with a prior incomplete polyp resection (incomplete segments) and those with a prior complete resection (complete segments), accounting for clustering of segments within patients. The median time to surveillance in incomplete resection was shorter compared with complete resection (17 vs. 45 months).
Investigators found a greater risk for any metachronous neoplasia was noted in segments with incomplete compared with complete resection (52% vs. 23%; risk difference [RD], 28% [95% CI, 9%-47%]).
“Incomplete segments also had a greater number of neoplastic polyps (mean, 0.8 vs. 0.3; RD, 0.50 [CI, 0.1-0.9]) and greater risk for advanced neoplasia (18% vs. 3%; RD, 15% [CI, 1%-29%]),” Pohl and colleagues wrote.
According to researchers, incomplete resection was a significant independent factor correlated with metachronous neoplasia (OR, 3 [CI, 1.12-8.17]).
“The study found a greater risk for any neoplasia and of advanced neoplasia in segments after incomplete resection compared with segments with a prior complete resection,” the authors wrote. “The direct evidence from this study strongly supports the hypothesis that residual neoplasia from incompletely removed polyps is a likely contributor to neoplasia recurrence and, by extension, interval CRC. The results highlight the critical importance of polyp resection technique in efforts to improve colonoscopy quality. Further work to improve polypectomy technique through training and quality assurance type monitoring is warranted.”