New endoscopic technique improves chances of complete removal of large early colorectal cancers
"This new, advanced technique, although technically challenging, is particularly useful for the removal of larger precancerous and early cancerous tumours," Prof. Nakajima said. "By removing these tumours in one piece, which we can now do using ESD, we can effectively cure the cancer."
Endoscopic resection in early colorectal cancer
Colorectal cancer (CRC) continues to impose a significant burden worldwide despite the widespread availability of endoscopic polyp removal. Early CRC may be treated by endoscopic techniques without requiring surgery if the cancer has not spread to the lymph nodes. Conventional endoscopic resection (removal) techniques, including endoscopic mucosal resection (EMR) and polypectomy, are internationally-accepted minimally invasive treatments for CRC. However, according to Prof. Nakajima, if the tumour is larger than 20mm, it becomes increasingly difficult to remove as a single piece (i.e. en-bloc resection).
"We can remove these tumours in a piecemeal manner, but studies have shown that this is associated with a 20% risk of tumour recurrence," he explained. "The new technique was therefore developed that was based on EMR, but that used an endoscopic knife to remove larger lesions in a single piece."
ESD: how it works
ESD was first developed in Japan during the early 2000s. The technique involves the injection of a fluid underneath the tumour lesion to separate it from the deeper tissues and elevate the area for removal. An endoscopic knife is then used to cut away the cancerous tissue in a single piece, allowing the size and shape of the resection to be controlled. The main disadvantages of the technique are that it takes longer to perform than EMR and initial studies suggest that it is associated with a higher risk of perforation.
ESD in colorectal cancer: the clinical evidence
The first studies to assess the use of ESD in colorectal cancer were published last year.2,3 These studies confirmed that ESD was associated with a higher en-bloc resection rate and the removal of larger areas of tissue than EMR and confirmed the technical feasibility of using the procedure in specialised treatment centres.
The latest results of a large, prospective, multicentre study involving 18 specialised centres in Japan - presented for the first time at the UEGW 2011 meeting and selected as one of the top five congress abstracts1 - confirmed that ESD was far more likely to achieve en-bloc resection (95% vs. 56%; P<0.01) than conventional endoscopic resection techniques (including EMR), particularly for lesions >40 mm. Procedure times were longer for ESD than for conventional techniques (96 minutes vs. 18 minutes), however, complication rates were low and comparable for both types of procedure in the current study. This prospective study is still on-going to evaluate the recurrence rate at one year after initial treatment in both groups.
"This large, prospective study has confirmed the advantages of ESD over other endoscopic resection techniques, enabling very high cure rates in early colorectal cancer," said Prof. Nakajima. "This technique is emerging as the standard treatment for early CRC in Japan, particularly for patients with larger lesions, and we hope that other countries will soon follow our lead."
1. Nakajima T, Tanaka S, Saito Y. Prospective multicenter study on endoscopic treatment of large early colorectal neoplasia conducted by Colorectal Endoscopic Resection
Standardization Implementation Working Group of Japanese Society for Cancer of the Colon and Rectum. Abstract presented at the UEGW 2011, Stockholm, Sweden.
Endoscopy 2011; 43 (Suppl I) A1.
2. Saito Y, Fukuzawa M, Matsuda T, et al. Clinical outcome of endoscopic submucosal dissection versus endoscopic mucosal resection of large colorectal tumors as
determined by curative resection. Surg Endosc 2010; 24: 343-352.
3. Saito Y, Uraoka T, Yamaguchi Y, et al. A prospective, multicenter study of 1111 colorectal endoscopic submucosal dissections (with video). Gastrointest Endosc 2010;