Colorectal flat neoplasia

Cap-assisted EMR versus standard inject and cut EMR for treatment of large colonic laterally spreading tumors: a randomized multicenter study (with videos)

BACKGROUND AND AIMS

Piecemeal EMR of colorectal laterally spreading tumors (LSTs) >20 mm is effective. Experience is limited in the use of cap-assisted EMR (EMR-C) for resection of colonic lesions. We compared the efficacy and the safety of EMR-C for the removal of colonic LSTs ≥30 mm with "inject-and-cut" standard EMR (EMR-S).

METHODS

In this randomized trial from 4 Italian centers, 138 patients were treated with EMR-C and 102 with EMR-S. The rates of residual lesions, percentage of recurrence after 12 months, and adverse events were evaluated.

RESULTS

One hundred forty-three lesions were resected with EMR-C and 102 with EMR-S. Argon plasma coagulation (APC) was used as adjunctive treatment in 2.9% of EMR-Cs and in 22.5% of EMR-Ss (P < .001). The median time required was 20 minutes for EMR-C and 30 minutes for EMR-S (P < .001). Adverse events (AEs) occurred in 14 EMR-Cs (10.1%; 2 perforations, 11 bleeding events, and 1 stenosis) and in 22 EMR-Ss (21.6%; 1 perforation and 21 bleeding events) (P = .017). Intraprocedural AEs occurred in 3.6% of EMR-Cs and 16.7% of EMR-Ss (P = .001). Overall, residual lesions within 12 months were found to be significantly higher with EMR-S (32 patients, 31.4%) than with EMR-C (8 patients, 5.8%) (P < .001). Recurrence at follow-up colonoscopy in 12 months occurred in 7 EMR-Cs (5.1%) and 17 EMR-Ss (16.7%; P < .001).

CONCLUSIONS

The study demonstrated the feasibility and safety of EMR-C for removing large colorectal LSTs, with higher eradication rates, shorter resection time, and less use of APC when compared with EMR-S. (Clinical trial registration number: NCT03498664.).

Gene expression profiling of laterally spreading tumors

Background

Laterally spreading tumors (LSTs) are generally defined as lesions >10 mm in diameter, are characterized by lateral expansion along the luminal wall with a low vertical axis. In contrast to other forms of tumor, LSTs are generally considered to have a superficial growth pattern and the potential for malignancy. We focused on this morphological character of LSTs, and analyzed the gene expression profile of LSTs.

Methods

The expression of 168 genes in 41 colorectal tumor samples (17 LST-adenoma, 12 LST-carcinoma, 12 Ip [pedunculated type of the Paris classification)-adenoma, all of which were 10 mm or more in diameter] was analyzed by PCR array. Based on the results, we investigated the expression levels of genes up-regulated in LST-adenoma, compared to Ip-adenoma, by hierarchical and K-means clustering. To confirm the results of the array analysis, using an additional 60 samples (38 LST-adenoma, 22 Ip-adenoma), we determined the localization of the gene product by immunohistochemical staining.

Result

The expression of 129 genes differed in colorectal tumors from normal mucosa by PCR array analysis. As a result of K-means clustering, the expression levels of five genes, AKT1, BCL2L1, ERBB2, MTA2 and TNFRSF25, were found to be significantly up-regulated (p < 0.05) in LST-adenoma, compared to Ip-adenoma. Immunohistochemical analysis showed that the BCL2L1 protein was significantly and meaningfully up-regulated in LST-adenoma compared to Ip-adenoma (p = 0.010). With respect to apoptosis status in LST-Adenoma, it assumes that BCL2L1 is anti-apoptotic protein, the samples such as BCL2L1 positive and TUNEL negative, or BCL2L1 negative and TUNEL positive are consistent with the assumption. 63.2 % LST-adenoma samples were consistent with the assumption.

Conclusions

LSTs have an unusual profile of gene expression compared to other tumors and BCL2L1 might be concerned in the organization of LSTs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-015-0295-1) contains supplementary material, which is available to authorized users.

Intra-colonic administration of a polymer-bound NIRF probe for improved colorectal cancer detection during colonoscopy

There is increasing interest in the use of nanoparticle imaging probes for cancer diagnosis. However, various biological barriers limit the efficient delivery of nanoparticles to tumors following parenteral administration. We have investigated the applicability of a water-soluble polymeric imaging probe for improving the detection of gastrointestinal (GI) tumors after intra-luminal (colonic) administration. N-(2-hydroxypropyl)methacrylamide (HPMA) copolymers bearing either fluorescein-isothiocyanate (FITC) or near-infrared fluorescence (NIRF) dye (IR-783) were conjugated with EPPT1 peptide, derived from the CDR3 Vh region of a monoclonal antibody (ASM2) raised against human epithelial cancer cells, for targeting under-glycosylated mucin-1 (uMUC-1) expressed in neoplastic tissues. The targeted FITC-labeled copolymer, P-(EPPT1)-FITC, was investigated for its ability to bind human CRC cells and tissue specimens in vitro. The uMUC-1-targeted NIRF-labeled copolymer, P-(EPPT1)-IR783, was assessed for its ability to detect colonic lesions in vivo. P-(EPPT1)-FITC demonstrated superior binding to colorectal cancer (CRC) cells that over-express the uMUC-1 antigen and exhibited selectivity towards human CRC tissue specimens, as compared to adjacent normal tissues from the same patient. When applied intra-colonically, P-(EPPT1)-IR783 significantly accumulated in cancerous tissue, relative to the adjacent normal mucosa of HT29 and LS174T tumor-bearing mice, and demonstrated higher signal intensities in colonic tumors, as compared to the non-targeted P-(GG-OH)-IR783 probe (i.e., without EPPT1). We found that P-(GG-OH)-IR783 can also accumulate specifically at tumor sites. The cancer-specific uptake and retention of P-(GG-OH)-IR783 was not mediated by organic anion transporting peptides (OATPs). Our findings indicate that the polymer-bound NIRF probe can successfully detect solid tumors in the GI tract following intra-colonic administration, and could be used in conjunction with colonoscopic procedures to improve the sensitivity of colonoscopies for polyp detection.

Colorectal lateral spreading tumor subtypes: clinicopathology and outcome of endoscopic submucosal dissection

PURPOSE

This study aims to investigate the clinicopathological features of specific subtypes of laterally spreading tumor (LST) and assessed the outcome of endoscopic submucosal dissection (ESD) based upon subdifferentiation status.

METHODS

A total of 137 LSTs were present in 135 patients; 96 were granular and 41 exhibited a nongranular pattern. Granular LSTs, subdivided into homogeneous and nodular mixed, and nongranular LSTs, subdivided into flat-elevated and pseudodepressed, were retrospectively evaluated with respect to clinicopathological features and results of ESD (en bloc R0 curative resection, procedure time, complication, and recurrence rate) according to specific subtype.

RESULTS

The distribution of high-grade intraepithelial neoplasia and submucosal carcinomas was more prominent among granular nodular mixed tumors than among granular homogeneous tumors (P = 0.007), whereas there was no significant difference between nongranular pseudodepressed tumors and flat-elevated tumors. The frequency of en bloc R0 curative resection did not differ significantly among specific subtypes. For nodular mixed and pseudodepressed lesions, the median tumor size was significantly larger (P < 0.001 for each) and mean procedure time was also longer (P < 0.05 for each) than for the other two subtypes. All complications, which included three perforations, five episodes of postoperative bleeding, and one recurrence, occurred in granular nodular mixed and nongranular pseudodepressed tumors.

CONCLUSION

The risk of cancer varies with the subtypes of LSTs. ESD is an effective treatment for LSTs, however ESD is more technically demanding and carries more complications in pseudodepressed and granular mixed subtypes.

Colectomy for endoscopically unresectable polyps: how often is it cancer?

BACKGROUND

Colonoscopy has an established role in reducing the burden of colorectal cancer through early detection and removal of polyps. For endoscopically unresectable polyps, colectomy is generally indicated to prevent malignant transformation or to remove cancer already present.

OBJECTIVE

This study aimed to determine the incidence of malignancy and the factors predictive of malignancy in surgically resected benign polyps. DESIGN/PATIENTS/SETTING: This study was a retrospective chart review of patients undergoing a colectomy for a colonic polyp (no preoperative diagnosis of cancer) in 4 hospitals within the Mayo Clinic Health System.

MAIN OUTCOME MEASURES

Patient characteristics, endoscopic location and size, and preoperative and operative polyp pathology were tabulated. Correlations between these features and the finding of invasive carcinoma on surgical pathology were assessed.

RESULTS

A total of 750 patients met our inclusion criteria. Patients were predominantly male (55.2%) with an average age of 69.4 ± 9.8 years. A majority of polyps were located in the right colon (70.9%). Invasive cancer was identified in 133 patients (17.7%). Multivariate analysis revealed polyps in the left colon (adjusted OR 2.13, 95% CI (1.22-3.72)), and those with high-grade dysplasia (adjusted OR 4.60, 95% CI (2.91-7.27)) were more likely to harbor carcinoma. Age, sex, polyp dimension, and villous features were not predictive of malignancy. Of the patients with cancer, 31 (23.3%) had nodal disease.

LIMITATIONS

This study is limited by its retrospective nature, the change in terminology and technique over time, and the partially subjective nature of an endoscopically unresectable polyp.

CONCLUSIONS

The finding that polyp size and villous features do not strongly predict malignancy differs from previous endoscopic studies. This study confirms that polyps located in the left colon or with high-grade dysplasia are more likely to harbor cancer. The results of this study suggest that endoscopically unresectable polyps are best treated by radical oncologic resection.

A randomised study of hydro-jet vs. needle injection for lifting colorectal lesions prior to endoscopic resection

BACKGROUND

Submucosal lifting of lesions prior to endoscopic resection is crucial to reduce complications and improve the technical feasibility of the procedure.

AIM

To compare a self-assembled hydro-jet system vs. standard needle injection for tissue elevation prior to endoscopic resection of colorectal lesions.

METHODS

Randomised study performed at a single tertiary care institution. Consecutive patients with colonoscopic diagnosis of sessile polyps or non-polypoid lesions >5 mm or laterally spreading tumours.

OUTCOME MEASURES

successful elevation, time to proper elevation, completeness of excision, cautery damage, and general histological diagnostic quality (blinded pathologic assessment).

RESULTS

79 patients were randomised to hydro-jet (40 patients, group A) and needle (39 patients, group B) elevation. Successful elevation was achieved in 97.5% and 94.8%, respectively. Time to proper elevation was 8+/-5 s vs. 18+/-3 s (p<0.05). In group A, histology showed selective accumulation of fluid in the submucosa with intact collagen fibres. Damage to muscularis mucosa was never noted in the specimens of group A and in 7 cases of group B (p<0.01). Artefacts from "cautery effect" were very limited. Radial margins of resection could be adequately evaluated in all cases and were negative.

CONCLUSIONS

The hydro-jet system is as effective and safe as standard needle injection for tissue elevation prior to endoscopic resection of colorectal lesions, but it is significantly faster.

Flat adenomas of the large bowel: a single endoscopist study

PURPOSE

Flat colorectal adenomas may not be recognized or they may be seen and dismissed as normal mucosa. As a result, the "true" incidence of flat lesions is unknown. The aim of this study was to report the incidence and character of flat adenomas in a large series of patients in the United States.

METHODS

Details of colorectal polyps seen during colonoscopy are entered into a prospective database that was queried for flat adenomas. No magnification or dye spray was used. The colonoscopy completion rate was 96.8 percent. The flat adenoma detection rate of the senior author is in line with that of Japanese colonoscopists.

RESULTS

During 2,659 colonoscopies, 5,749 colorectal lesions were seen in 2,003 patients. Of these patients, 1,125 were men and 878 were women, with a mean age of 65 years (+/- 12 years). There were 3,115 adenomas (54 percent of lesions); 315 were flat (10.1 percent), 23 (0.8 percent) were depressed, 2,575 were sessile (82.7 percent), and 200 were pedunculated (6.4 percent). Two hundred twelve patients had flat adenomas (10.6 percent of patients); 172 patients had one and 40 had multiple (2 to 8) flat adenomas. Eight patients with flat adenomas had more flat adenomas on follow-up.

CONCLUSIONS

Colonoscopists in the United States must be aware of the existence of flat adenomas and sensitive to their appearance.

Increased expression of beta-catenin, phosphorylated glycogen synthase kinase 3beta, cyclin D1, and c-myc in laterally spreading colorectal tumors

Laterally spreading tumors (LSTs) are considered a special subtype of superficial colorectal tumor. This study was performed to characterize the clinicopathological features and examine activation of the Wnt/beta-catenin pathway in LSTs and protruded-type colorectal adenomas (PAs). Fifty LSTs and 54 PAs were collected, and their clinicopathological characteristics were compared. The expression of E-cadherin, beta-catenin, glycogen synthase kinase-3beta (GSK-3beta), phosphorylated GSK-3beta, (phospho-GSK-3beta), cyclin D1, and c-myc was investigated by immunohistochemical staining on serial sections. Patients with LSTs were significantly older than those bearing PAs (63.4 vs 47.4 years old; p<0.001). The mean size of LSTs was significantly larger than that of PAs (27.0 mm vs 14.6 mm; p<0.01). Forty-eight percent of LSTs were located in the proximal colon, which was significantly higher than that of PAs (18.5%; p<0.05). Expression of beta-catenin, phospho-GSK-3beta, cyclin D1, and c-myc was significantly increased in LSTs compared with PAs (p<0.05). However, E-cadherin and total GSK-3beta expression was not significantly different between the two groups. The level of beta-catenin expression correlated strongly with phospho-GSK-3beta, cyclin D1, and c-myc expression in LSTs but not in PAs. Our findings suggest that activation of the Wnt/beta-catenin pathway is more prevalent in LSTs than in PAs, suggesting that phosphorylation-dependent inactivation of GSK-3beta may be involved in LST carcinogenesis.

Comparison of the clinicopathologic features between flat and polypoid adenoma

OBJECTIVE

Several reports have suggested that flat colorectal adenomas might exhibit a higher potential for malignancy compared to polypoid adenomas. Although the clinical importance of the shape of polyps is stressed, the controversy surrounding the malignant potential of flat adenomas continues. The aim of this study was to compare the clinicopathologic characteristics, including degree of dysplasia and malignancy, between flat and polypoid adenomas 5 mm in size or larger.

MATERIAL AND METHODS

A total of 3263 polyps (254 flat adenomas and 3009 polypoid adenomas), >/=5 mm in size, diagnosed in 1883 patients by colonoscopy were analyzed.

RESULTS

Flat adenomas were found in 10% of patients, which represented 7.8% of all adenomas removed. The flat adenomas were larger in diameter than the polypoid adenomas (14.8+/-12.6 mm versus 8.6+/-5.0 mm, p <0.01), had a higher rate of villous components (18.5% versus 11.4%, p <0.01), a higher rate of high-grade dysplasia (9.4% versus 4.2%, p <0.01), and a higher rate of malignancy (10.2% versus 3.6%, p <0.01) than polypoid adenomas. However, there was no difference in the rate of high-grade dysplasia or carcinoma between flat and polypoid adenomas of equal size. It was shown by multivariate analysis that rectosigmoid location, larger size, and presence of a villous component were associated with a higher rate of malignancy, but not with flat morphology.

CONCLUSIONS

Flat adenomas, which were of a relatively large size in this study, were not associated with a higher risk for high-grade dysplasia and carcinoma compared with polypoid adenomas.

Flat and depressed neoplasms of the colon in Western populations

Flat and depressed neoplasms of the colon are defined endoscopically as visible non-exophytic, flat and/or depressed mucosal lesions with a height less than half the diameter of the lesion. These neoplasms are typically smaller than their polypoid counterparts, and might be associated with a more aggressive biological behavior. While these lesions have been described in cohorts of Japanese patients for over two decades, their existence in Western populations has been less well described. This review focuses on the epidemiology and biological behavior of flat and depressed neoplasms in Western populations as well as the strategies for their identification, endoscopic staging, and therapy.