Longitudinal molecular characterization of endoscopic specimens from colorectal lesions

AIM: To compare molecular profiles of proximal colon, distal colon and rectum in large adenomas, early and late carcinomas. To assess feasibility of testing directed at molecular markers from this study in routine clinical practice. METHODS: A prospective 3-year study has resulted in the acquisition of samples from 159 large adenomas and 138 carcinomas along with associated clinical parameters including localization, grade and histological type for adenomas and localization and stage for carcinomas. A complex molecular phenotyping has been performed using multiplex ligation-dependent probe amplification technique for the evaluation of Cp G-islandmethylator phenotype(CIMP), PCR fragment analysis for detection of microsatellite instability and denaturing capillary electrophoresis for sensitive detection of somatic mutations in KRAS, BRAF, TP53 and APC genes.RESULTS: Molecular types according to previously introduced Jass classification have been evaluated for large adenomas and early and late carcinomas. An increase in CIMP+ type, eventually accompanied with KRAS mutations, was notable between large adenomas and early carcinomas. As expected, the longitudinal observations revealed a correlation of the CIMP+/BRAF + type with proximal location. CONCLUSION: Prospective molecular classification of tissue specimens is feasible in routine endoscopy practice. Increased frequency of some molecular types corresponds to the developmental stages of colorectal tumors. As expected, a clear distinction is notable for tumors located in proximal colon supposedly arising from the serrated(methylation) pathway.

Improved specimen adequacy using jumbo biopsy forceps in patients with Barrett's esophagus

AIM:To assess the sampling quality of four different forceps(three large capacity and one jumbo) in patients with Barrett's esophagus.METHODS:This was a prospective,single-blind study.A total of 37 patients with Barrett's esophagus were enrolled.Targeted or random biopsies with all four forceps were obtained from each patient using a diagnostic endoscope during a single endoscopy.The following forceps were tested:A:FB-220 K disposable large capacity;B:BI01-D3-23 reusable large capacity;C:GBF-02-23-180 disposable large capacity;and jumbo:disposable Radial Jaw 4 jumbo.The primary outcome measurement was specimen adequacy,defined as a well-oriented biopsy sample 2 mm or greater with the presence of muscularis mucosa.RESULTS:A total of 436 biopsy samples were analyzed.We found a significantly higher proportion of adequate biopsy samples with jumbo forceps(71%)(P < 0.001 vs forceps A:26%,forceps B:17%,and forceps C:18%).Biopsies with jumbo forceps had the largest diameter(median 2.4 mm)(P < 0.001 vs forceps A:2 mm,forceps B:1.6 mm,and forceps C:2mm).There was a trend for higher diagnostic yield per biopsy with jumbo forceps(forceps A:0.20,forceps B:0.22,forceps C:0.27,and jumbo:0.28).No complications related to specimen sampling were observed with any of the four tested forceps.CONCLUSION:Jumbo biopsy forceps,when used with a diagnostic endoscope,provide more adequate specimens as compared to large-capacity forceps in patients with Barrett's esophagus.