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Colorectal Polyps (colorectal + polyp)
Selected AbstractsNARROW BAND IMAGING IN THE DETECTION OF COLORECTAL POLYP: KOREAN EXPERIENCEDIGESTIVE ENDOSCOPY, Issue 2 2008Jeong-Sik Byeon Background:, Although white light (WL) colonoscopy is a gold standard to detect colorectal polyps, substantial polyps are missed. Narrow band imaging (NBI) is a new technology that enables a more detailed visualization of the mucosal surface. The aim of the present study was to determine whether NBI can improve the detection of colorectal polyps. Methods:, We prospectively enrolled 188 (M : F = 99:89, 21,80 years) subjects undergoing colonoscopy as a screening procedure in nine referral centers. After a careful WL examination of the whole colorectum, rectosigmoid colon (0,30 cm from the anal verge) was reobserved by NBI. Size, macroscopic morphology, and the histology of all the polyps detected during WL and NBI examination were analyzed. Results:, WL examination detected 162 polyps in 188 subjects, of which 106 lesions were neoplastic, while NBI of rectosigmoid colon detected an additional 61 polyps of which eight lesions were neoplastic. Only 10 (6.2%) of 162 polyps discovered during WL examination were flat polyps compared to 10 (16.4%) of 61 newly detected polyps during NBI being flat type (P = 0.002). The mean polyp size detected by NBI was smaller than that found by WL colonoscopy (2.8 ± 1.0 mm vs 6.5 ± 4.5 mm, P < 0.001). Conclusion:, Many additional colorectal polyps, especially flat type, could be detected by NBI examination for normal-looking rectosigmoid mucosa. The role of NBI in colorectal neoplasm screening needs to be further investigated in future studies. [source] Advanced colorectal polyps with the molecular and morphological features of serrated polyps and adenomas: concept of a ,fusion' pathway to colorectal cancerHISTOPATHOLOGY, Issue 2 2006J R Jass Aim :,To establish and explain the pattern of molecular signatures across colorectal polyps. Methods and results :,Thirty-two sessile serrated adenomas (SSA), 10 mixed polyps (MP), 15 traditional serrated adenomas (SA), 49 hyperplastic polyps (HP) and 84 adenomas were assessed for mutation of KRAS and BRAF and aberrant expression of p53. The findings were correlated with loss of expression of O-6-methylguanine DNA methyltransferase (MGMT). KRAS mutation occurred more frequently (26.5%) than BRAF mutation (4.8%) in adenomas (P < 0.001) and particularly in adenomas with villous architecture (50%). Loss of expression of MGMT correlated with KRAS mutation in small tubular adenomas (P < 0.04). BRAF mutation was frequent in HPs (67%) and SSAs (81%), while KRAS mutation was infrequent (4% and 3%, respectively). Of MPs and SAs, 72% had either BRAF or KRAS mutation. Aberrant expression of p53 was uncommon overall, but occurred more frequently in MPs and SAs (12%) than adenomas (1%) (P < 0.04) and there was concordant loss of expression of MGMT. Conclusions :,Molecular alterations that are characteristic of the serrated pathway and adenoma,carcinoma sequence can co-occur in a minority of advanced colorectal polyps that then show morphological features of both pathways. These lesions account for only 2% of colorectal polyps, but may be relatively aggressive. [source] Distinct CpG island methylation profiles and BRAF mutation status in serrated and adenomatous colorectal polypsINTERNATIONAL JOURNAL OF CANCER, Issue 11 2008Yong Ho Kim Abstract A subset of colorectal cancers with CpG island methylator phenotype-high (CIMP-H) is frequently associated with MSI and BRAF V600E mutation. Since limited data are available on different histological types of colorectal polyps, we compared the pattern and the frequency of promoter methylation, CIMP-H, MSI, KRAS and BRAF V600E mutations and the relationship among these molecular parameters and the clinicopathologic characteristics in 110 serrated polyps (48 hyperplastic polyps, 32 sessile serrated adenomas and 30 serrated adenomas) and 32 tubular adenomas using 7 commonly used tumor-associated gene loci. No significant difference in the frequency of overall methylation frequency (86% vs. 100%) and CIMP-H (39% vs. 28%) between serrated polyps and tubular adenomas was observed, but proximally located serrated polyps showed more frequent methylation at 5 of 7 loci examined, and were more likely to be CIMP-H (62% vs. 22%). MGMT methylation was more common in tubular adenomas while MLH1 and HIC1 were more frequently methylated in serrated polyps. BRAF mutation was frequently present in all types of serrated polyps (80%), but was absent in tubular adenomas and was not associated with CIMP or MSI status. These results show comparable frequencies of promoter methylation of tumor-associated genes and CIMP-H, but distinct differences in gene-specific or colonic site-specific methylation profiles occur in serrated polyps and tubular adenomas. BRAF mutation occurs independently of CIMP and MSI in all types of serrated polyps and may serve as a marker of serrated pathway of colorectal carcinogenesis. © 2008 Wiley-Liss, Inc. [source] Association between entero-hepatic Helicobacter species and Crohn's disease: a prospective cross-sectional studyALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2009D. LAHARIE Summary Background, The pathogenesis of Crohn's disease (CD) involved microbial factors. Some Helicobacter species, the so-called entero-hepatic Helicobacters (EHH), can naturally colonize the intestinal surface and have been detected in humans. Aim, To look for an association between CD and the presence of EHH DNA in intestinal biopsies. Methods, Two groups of patients were included prospectively in a multicentre cross-sectional study: CD patients with an endoscopic post-operative recurrence within 2 years following a surgical resection and controls screened for colorectal polyps or cancer. Intestinal biopsies were taken for Helicobacter culture and Helicobacter 16S DNA detection. If positive, the EHH species were identified with specific PCRs, sequencing and denaturing gradient gel electrophoresis. Results, In the 165 included patients (73 CD and 92 controls), Helicobacter cultures were negative. PCR was positive in 44% of CD and 47% of controls. After age-adjustment, CD was significantly associated with EHH in intestinal biopsies (OR = 2.58; 95%CI: 1.04,6.67). All EHH species detected were identified as Helicobacter pullorum and the closely related species Helicobacter canadensis. Conclusion, Crohn's disease is associated with the presence of EHH species DNA in intestinal biopsies after adjustment for age. Whether these species play a role in the pathophysiology of CD remains to be determined. [source] Chemoprevention of colorectal cancerALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 1 2004E. D. J. Courtney Summary Colorectal cancer is a disease with a high mortality at present, due to the late stage at which many cases present. Attention is therefore focusing on preventative strategies for colorectal cancer given that polyps appear to be identifiable and treatable precursor lesions of this disease. Endoscopic polypectomy has been shown to reduce the incidence of colorectal cancer and there is a good case for endoscopic screening of the general population. However, this will require a large amount of manpower and resources and its success will also depend on the overall compliance of the population. Epidemiological studies have shown that individuals reporting a regular intake of aspirin and other non-steroidal anti-inflammatory drugs have a reduced risk of developing colorectal polyps and cancer. Similarly, a number of natural substances, such as calcium and folate, when supplemented regularly in the diet, have also been linked to a possible decreased incidence of colorectal cancer. This has led to the concept of using such agents to reduce the number of cases of colorectal cancer. In this article, we review the current evidence for the use of these and other agents for the chemoprevention of colorectal cancer, together with theories as to their possible mechanisms of action. [source] Endoscopists' estimation of size should not determine surveillance of colonic polypsCOLORECTAL DISEASE, Issue 7 2010S. J. Moug Abstract Objective, Current British Society of Gastroenterology guidelines use adenomatous polyp size as one of the key factors in determining polyp follow-up. This study aimed to compare polyp size assessment by colonoscopists and pathologists before and after fixation to determine the optimal method for measurement. Method, Thirty-five colorectal polyps were found during pre-arranged colonoscopies in one centre. Polyp size was measured to the nearest 1 mm by three different methods: 1by the endoscopist at colonoscopy; 2by the pathologist fresh, following removal; 3by the pathologist fixed, following fixation. The endoscopist and the pathologist were blinded to each other's measurements. Results, Seventeen men, eighteen women with mean age of 66.2 years (SD: 9.4, range: 38.7,85.5) underwent polypectomy/s with all polyps removed intact. Polypectomies were performed by consultants (43%), nurse specialists (34%) and specialist registrars (23%). The median size (mm) of polyps measured were endoscopically, 6.5 (2,25 mm); fresh specimen 7.0 (4,28 mm) and fixed 7.0 (4,28 mm). Endoscopic measurements were significantly lower than that of fresh and fixed sizes (P < 0.001 and P = 0.003 respectively), with poor correlation [correlation of variance (CV): 21.0% and intraclass correlation coefficient (ICCC): 0.841 for endoscopic and fresh measurements; CV: 21.1% and ICCC: 0.838 for endoscopic and fixed measurements]. There was no statistical difference between fresh and fixed specimen measurements (P > 0.05; CV: 4.2%, ICCC: 0.974). In three patients, the endoscopic measurement was < 1 cm in polyps that were found to be , 1 cm on pathological measurement. Conclusions, Endoscopists consistently underestimated polyp size. Fixation had no effect on polyp size. Pathologists' measurement of polyp size on fixed specimens should determine the need for further colonoscopic follow-up. [source] | ||||||||||