Is it safe for endoscopic piecemeal mucosal resection in treating large sessile colorectal polyps?

Endoscopic resection of large sessile colorectal polyps is increasingly used as an alternative to surgery, but remains challenging because of its technical difficulty, the high risk of complications such as bleeding or perforation, and the possibility of coexisting malignancy.

This research, lead by Dr Sohn DK and his colleagues at the National Cancer Centre, Korea, demonstrated the safety of endoscopic piecemeal resection (EPMR) for large sessile colorectal polyps and the research has recently been published on June 14, 2010 in the World Journal of Gastroenterology. The authors included a large number of polyps with significant numbers of malignancies and were able to demonstrate that relapse was low in patients with benign polyps after endoscopic resection.

The research group enrolled 47 patients with 50 large sessile polyps (2 cm or greater in diameter) who underwent EPMR using a submucosal saline injection technique and observed them during follow-up examinations over a median period of 37 months. They showed that 12% of patients had procedure-related minor bleeding. No perforations were observed. Recurrence was identified in 5 cases (12.2%). The significant finding of this research is that the incidence of recurrence after EPMR in malignant lesions was higher than that in benign lesions (33.3% vs 3.1%).

It is still difficult to explain the reason why the incidence of recurrence after EPMR in malignant lesions was higher than that in benign lesions. However, the authors suggested that the endoscopist should try to remove all cancer cells completely because microscopic residual cancer cells after EPMR can cause recurrences. They also suggested that EPMR should be applied carefully in malignant polyps, and close follow-up endoscopic examinations are necessary for early detection of recurrence.