Further evidence to support the safety and efficacy of endoscopic mucosal resection for Paris type 0-II, Is and laterally spreading tumors of the colorectum in Western cohorts

We read the paper by Bories et al. with great interest [1]. In this prospective study, 52 colorectal lesions in 50 patients were treated with endoscopic mucosal resection (EMR) using the lift-and-cut technique described by Deyhle et al. [2]. Preresection staging was carried out using the Hitachi U33 endoscopic ultrasound (EUS) probe in the rectum, with colonic lesions being assessed clinically using the non-lifting sign described by Uno and Munakata [3] as indicative of T2 disease. Complications occurred in 9.6 % of the patients, with recurrent disease observed in 15 % of the group after a mean follow-up period of 17.3 months.

However, the authors conclude that data concerning EMR are sparse in Western publications. We would like to share our experience of EMR with the French group, as we feel their comparison with the retrospective data series reported by Ahmad et al. [4] is no longer up to date, in view of more recently published manuscripts. Importantly, the largest series of prospective EMR procedures to date was reported by the Sheffield group in 2004 [5].

We have previously reported on the safety and efficacy of EMR for endoluminal treatment of Paris type 0-II and Is colorectal lesions staged before resection using high-magnification chromoscopic colonoscopy (HMCC) [5] [6]. In this prospective study of 599 lesions, 254 lesions (40 %; excluding hyperplasia/metaplasia) met the criteria for flat morphology (Paris 0-II), with 374 (60 %) being sessile. High-grade dysplasia (HGD) was observed in 23 % of the Paris type 0-II lesions, in comparison with 9 % of the Paris Is lesions (P < 0.001). Complete resection was achieved in 96 % of the resections, with perforation and bleeding occurring in 0.2 % and 2 %, respectively.

Our group also reported the largest prospective evaluation of HMCC for in vivo differentiation between nonneoplastic noninvasive, neoplastic noninvasive, and neoplastic invasive characteristics of Paris type 0-II lesions using standardized morphological, pit-pattern, and histopathological criteria [7]. In this prospective study of 1008 Paris 0-II lesions, the sensitivity and specificity rates of HMCC for distinguishing between nonneoplastic and neoplastic lesions were 98 % and 92 %, respectively, with a specificity of 98 % for differentiation of neoplastic invasive lesions using the Kudo type V pit-pattern criteria.

Using the modified Nagata criteria in HMCC, we subsequently described the endoscopic morphological assessment of the submucosal invasive depth and associated lymph-node disease in Paris type 0-II colorectal lesions [8]. In this prospective study of 850 patients with 51 lesions (demonstrable with an index Paris 0-II lesion with type V pit criteria), 97 % of the lesions were correctly assessed as having sm2+ invasion using the pit types Vn(B) and Vn(C) as clinical indicators of invasive disease. We concluded that using the Nagata criteria, the in vivo staging of submucosal depth in Paris 0-II lesions was as sensitive as conventional 7.5-MHz EUS, but with a tendency to overstage lesions; a low overall specificity therefore limits the clinical use of the technique.

Using the combined 12.5/20-MHz miniprobe high-frequency EUS through-the-scope catheter (Olympus UM2/3R), we subsequently demonstrated that high-frequency EUS was superior to HMCC alone for differentiating T1/T2 disease, with a high positive predictive value for deep submucosal invasion (with associated lymph-node dissections being carried out in 15 % of this group) [9]. HMCC is also useful in predicting the completeness of the vertical and horizontal resection margins after EMR, which can help stratify patients who are at high risk of recurrent disease or those requiring adjunctive extended EMR or adjuvant argon plasma ablation [10]. In our series of 684 lesions treated with EMR, the sensitivity of HMCC for predicting remnant tissue in the lateral and vertical resection planes was 79 % and 80 %, respectively, with the specificity for both margins being 97 %.

Finally, a report on EMR of laterally spreading tumors (both the G and NG types) with a 24-month surveillance period after resection was also published by our group recently [11]. The overall “cure” rate for both morphologies of laterally spreading tumor was 96 % after the 24-month follow-up period. Local recurrent disease was detected in 17 % of the patients (10 of 52), in all cases within 6 months of the index resection (on the basis of the Higaki criteria). Eight of these patients underwent a second-stage extended EMR, with no residual disease being found at the 24-month follow-up examination. In addition, using a combination of HMCC and 20-MHz EUS staging, the accuracy was 100 %. Extended EMR in the rectum using combined 12.5/20-MHz EUS for stage T0/T1 tumors was also described by our group in a prospective study in which the overall endoscopic “cure” rate after a median follow-up period of 16 months was 98 % [12].

In conclusion, EMR of the colorectum is a safe and effective resection technique that has now been well described in Western cohorts. Appropriate patient selection is essential. Preresection assessment using chromoscopy, magnification, and preferably high-frequency EUS is desirable. Further advanced endoscopic training and education are mandatory for the success of this technique.

Competing interests: None

References

• 1 Bories E, Pesenti C, Monges G. et al . Endoscopic mucosal resection for advanced sessile adenoma and early-stage colorectal carcinoma.  Endoscopy. 2006;  38 231-235
• 2 Deyhle P, Largader F, Jenny S, Fumagalli I. A method for endoscopic electroresection of sessile colonic polyps.  Endoscopy. 1973;  5 38-40
• 3 Uno Y, Munakata A. The non-lifting sign of invasive colon cancer.  Gastrointest Endosc. 1994;  40 485-489
• 4 Ahmad N A, Kochman M L, Long W B. et al . Efficacy, safety, and clinical outcomes of endoscopic mucosal resection: a study of 101 cases.  Gastrointest Endosc. 2002;  55 390-396
• 5 Hurlstone D P, Cross S S, Adam I. et al . An evaluation of colorectal endoscopic mucosal resection using high-magnification chromoscopic colonoscopy: a prospective study of 1000 colonoscopies.  Endoscopy. 2004;  36 491-498
• 6 . The Paris endoscopic classification of superficial neoplastic lesions: esophagus, stomach, and colon: November 30 to December 1, 2002.  Gastrointest Endosc. 2003;  58 (6 Suppl) S3-43
• 7 Hurlstone D P, Cross S S, Adam I. et al . Efficacy of high magnification chromoscopic colonoscopy for the diagnosis of neoplasia in flat and depressed lesions of the colorectum: a prospective analysis.  Gut. 2004;  53 284-290
• 8 Hurlstone D P, Cross S S, Adam I. et al . Endoscopic morphological anticipation of submucosal invasion in flat and depressed colorectal lesions: clinical implications and subtype analysis of the Kudo type V pit pattern using high-magnification-chromoscopic colonoscopy.  Colorectal Dis. 2004;  6 369-375
• 9 Hurlstone D P, Brown S, Cross S S. et al . High magnification chromoscopic colonoscopy or high frequency 20 MHz mini probe endoscopic ultrasound staging for early colorectal neoplasia: a comparative prospective analysis.  Gut. 2005;  54 1585-1589
• 10 Hurlstone D P, Cross S S, Brown S. et al . A prospective evaluation of high-magnification chromoscopic colonoscopy in predicting completeness of EMR.  Gastrointest Endosc. 2004;  59 642-650
• 11 Hurlstone D P, Sanders D S, Cross S S. et al . Colonoscopic resection of lateral spreading tumours: a prospective analysis of endoscopic mucosal resection.  Gut. 2004;  53 1334-1339
• 12 Hurlstone D P, Sanders D S, Cross S S. et al . A prospective analysis of extended endoscopic mucosal resection for large rectal villous adenomas: an alternative technique to transanal endoscopic microsurgery.  Colorectal Dis. 2005;  7 339-344