Piecemeal mucosectomy, submucosal dissection or transanal microsurgery for large colorectal neoplasm

Although smaller colonic polyps are removed by snare polypectomy or Endoscopic Mucosal Resection (EMR), there is evidence from the British Bowel Cancer Screening Programme that many larger lesions are referred for surgical resection. There is, however, a significant morbidity and mortality attached to surgery, with 30 day mortality rates varying between 1% and 8% [1]. In addition, surgery is expensive. In the UK, the surgical treatment of colonic lesions accounts for more hospital in-patient expenditure than for cancer at any other site. In contrast to surgical resection, endoscopic resection allows colonic lesions to be removed with a minimum of cost, morbidity and mortality [2-4]. The recognition and removal of precancerous lesions are important to reduce the risk of subsequent colorectal cancer [5]. Furthermore, many likely early colonic cancers are considered for removal by endoscopic resection such as EMR or Endoscopic Submucosal Dissection (ESD) [6]. EMR is now a well-established technique for the treatment of colorectal neoplasms with minimal invasiveness [7, 8, 2]. However, it entails a high frequency of local recurrence after piecemeal EMR for large lesions [9, 10]. ESD was conceived in Japan with the aim to avoid this problem, allowing en bloc resection of larger colorectal lesions. Despite its longer procedure time and higher complication rate, ESD results in a higher en bloc resection rate compared with conventional or piecemeal EMR [11-13]. ESD for colorectal lesions is not yet fully established as a standard therapeutic method for colorectal lesions worldwide. In this review we discuss the therapeutic strategies available to manage non-polypoid early cancer of the colon and rectum, with particular regard to differences in Eastern and Western practice.