Effect of a high-fat diet in development of colonic adenoma in an animal model

AIM: To investigate the effect of a high-fat diet in the formation of the precursors of colorectal cancer using an animal model.

Colon adenoma features and their impact on risk of future advanced adenomas and colorectal cancer

AIMTo review the evidence on the association between specific colon adenoma features and the risk of future colonic neoplasia [adenomas and colorectal cancer (CRC)]. METHODSWe performed a literature search using the National Library of Medicine through PubMed from 1/1/2003 to 5/30/2015. Specific Medical Subject Headings terms (colon, colon polyps, adenomatous polyps, epidemiology, natural history, growth, cancer screening, colonoscopy, CRC) were used in conjunction with subject headings/key words (surveillance, adenoma surveillance, polypectomy surveillance, and serrated adenoma). We defined non-advanced adenomas as 1-2 adenomas each 25% villous histology or high-grade dysplasia. A combined endpoint of advanced neoplasia included advanced adenomas and invasive CRC. RESULTSOur search strategy identified 592 candidate articles of which 8 met inclusion criteria and were relevant for assessment of histology (low grade vs high grade dysplasia, villous features) and adenoma size. Six of these studies met the accepted quality indicator threshold for overall adenoma detection rate > 25% among study patients. We found 254 articles of which 7 met inclusion criteria for the evaluation of multiple adenomas. Lastly, our search revealed 222 candidate articles of which 6 met inclusion criteria for evaluation of serrated polyps. Our review found that villous features, high grade dysplasia, larger adenoma size, and having ≥ 3 adenomas at baseline are associated with an increased risk of future colonic neoplasia in some but not all studies. Serrated polyps in the proximal colon are associated with an increased risk of future colonic neoplasia, comparable to having a baseline advanced adenoma. CONCLUSIONData on adenoma features and risk of future adenomas and CRC are compelling yet modest in absolute effect size. Future research should refine this risk stratification.

Metabolic syndrome, lifestyle risk factors, and distal colon adenoma: A retrospective cohort study

AIM: To investigate relationships between colorectal adenoma incidence, metabolic syndrome (MS) components and lifestyle factors. METHODS: We conducted a retrospective cohort study using data from individuals who had multiple sigmoidoscopies for colon cancer at the Health Promotion Center of Ulsan University Hospital in Korea from 1998 to 2007. RESULTS: By multivariate analysis, the incidence of distal colon adenoma was increased by more than 1.76 times in individuals with at least one component of MS compared to those without a component of MS. After adjustment for age, gender, smoking, drinking, and physical exercise, only high body mass index (BMI) was significantly associated with the incidence of distal colon adenoma (Hazard ratio 1.66, 95% confidence interval 1.05-2.62). CONCLUSION: Our results suggest that high BMI may increase the risk of colorectal adenoma in Korean adults.

Pyogenic liver abscess associated with large colonic tubulovillous adenoma

Pyogenic liver abscesses usually occur in association with a variety of diseases. Rarely, liver abscess has been reported as the presenting manifestation of colonic tubulovillous adenoma. We report two cases of pyogenic liver abscess without hepatobiliary disease or other obvious etiologies except that one had a history of diabetes mellitus （DM）. The pathogen in the patient with DM was Klebsiella pneumonia （KP）. In both of the patients, Ueus developed about two to three weeks after the diagnosis of liver abscess. Colonoscopy revealed large polypoid tumors with pathological findings of tubulovillous adenoma in both cases. Two lessons were learned from these two cases： （1） an underlying cause should be aggressively investigated in patients with cryptogenic liver abscess; （2） DM could be one of the etiologies but not necessarily the only cause of KP liver abscess.

Significance of EZH2 and BMI-1 Protein Expression in Carcinogenesis of Colon Serrated Adenoma

Objective:To observe the significance of EZH2 and BMI-1 protein expression in the carcinogenesis process of colon serrated adenoma(SSA/P).Methods:Hematoxylin-eosin(HE)staining was used to observe the morphological characteristics of normal tissues,hyperplastic polyp(HP),SSA/P and colon cancer.Immunohistochemical staining was used to detect the expression of EZH2 and BMI-1 protein.The relative expression of EZH2 and BMI-1 was detected by qRT-PCR.Results:Compared with normal tissues,HP and colon cancer tissues,SSA/P showed serrated glandular hyperplasia,glandular dilatation,and deep nuclear staining,which had certain atypia.The positive expression rates of EZH2 and BMI-1 protein were 53.3%and 56%,which were close to those of colon cancer(66.7% and 76.6%)and higher than those of normal group and HP(16% and 8%,P<0.05).The relative expression of EZH2 and BMI-1 in SSA/P tissue was significantly higher than that in normal group and HP,but lower than that in carcinogenesis group(P<0.05).Conclusion:EZH2 and BMI-1 play an important role in the carcinogenesis of colon serrated adenoma,and can be used as the primary screening index before carcinogenesis.

Expression And Clinical Significance of Glucose Regulated Proteins GRP78 And GRP94 in Human Colon Cancer

Objective： To investigate the expression of glucose regulated proteins GRP78 and GRP94 in human colon cancer. Methods： Tissues of resected primary colon cancer, colon adenoma and normal tissue were investigated. Protein expression was detected with immunohistochemical staining, mRNA expression levels of GRP78 and GRP94 were determined by semiquantitative reverse transcriptase polymerase chain reaction （RT-PCR） after mRNA extraction. Results： The expression of GRP94 and GRP78 was significantly higher in colon cancer when compared to those in colon adenoma and normal tissue （P〈0.01）. GRP94 mRNA and protein expression was found to be in close relationship with the grade of differentiation, Dukes stages, lymph node involvement and remote metastasis in colon cancer （P〈0.01）, but no relationship with gender and age （P〉0.05）. GRP78 mRNA and protein expression increased with cancer progression along the normal tissue-adenoma-cancer sequence, but showed no association with grade of differentiation, Dukes stages, lymph node involvement, remote metastasis, gender and age （P〉0.05）. The mRNA expression of GRP78 and GRP94 was consistent with the proteins （P〈0.01）, but there is no correlation between overexpression of GRP78 and GRP94 （P〉0.05）, and the patients with both strong GRP78 and GRP94 protein expression did not show advanced tumor stages （P〉0.05）. Conclusion： Overexpression of GRP78 and GRP94 was found in colon cancer. Overexpression of GRP94 was closely related to cellular differentiation, Dukes stages, invasion and metastasis.

Clear cell adenocarcinoma of the colon:A case report and review of literature

A primary clear cell adenocarcinoma of the colon is a rare oncologic entity. We herein report a case of such a tumor of the sigmoid colon in a 71-year-old woman who was successfully treated by an endoscopic polypectomy in our hospital. We also reviewed the published reports regarding cases of primary clear cell tumors in the colon.

DNA end binding activity and Ku70/80 heterodimer expression in human colorectal tumor

AIM： TO determine the DNA binding activity and protein levels of the Ku70/80 heterodimer, the functional mediator of the NHEJ activity, in human colorectal carcinogenesis. METHODS： The Ku70/80 DNA-binding activity was determined by electrophoretic mobility shift assays in 20 colon adenoma and 15 colorectal cancer samples as well as matched normal colonic tissues. Nuclear and cytoplasmic protein expression was determined by immunohistochemistry and Western blot analysis. RESULTS： A statistical found in both adenomas y significant difference was and carcinomas as compared to matched normal colonic mucosa （P〈0.00）. However, changes in binding activity were not homogenous with approximately 50% of the tumors showing a clear increase in the binding activity, 30% displaying a modest increase and 15% showing a decrease of the activity.Tumors, with increased DNA-binding activity, also showed a statistically significant increase in Ku70 and Ku86 nuclear expression, as determined by Western blot and immunohistochemical analyses （P〈0.001）. Cytoplasmic protein expression was found in pathological samples, but not in normal tissues either from tumor patients or from healthy subjects. CONCLUSION： Overall, our DNA-binding activity and protein level are consistent with a substantial activation of the NHEJ pathway in colorectal tumors. Since the NHEJ is an error prone mechanism, its abnormal activation can result in chromosomal instability and ultimately lead to tumorigenesis.

Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis

AIM: To compare previously reported randomized controlled studies (RCTs) of cold and hot polypectomy, we systematically reviewed and clarify the utility of cold polypectomy over hot with respect to efficacy and adverse events.METHODS: A meta-analysis was conducted to evaluate the predominance of cold and hot polypectomy for removing colon polyps. Published articles and abstracts from worldwide conferences were searched using the keywords &#x0201c;cold polypectomy&#x0201d;. RCTs that compared either or both the effects or adverse events of cold polypectomy with those of hot polypectomy were collected. The patients&#x02019; demographics, endoscopic procedures, No. of examined lesions, lesion size, macroscopic and histologic findings, rates of incomplete resection, bleeding amount, perforation, and length of procedure were extracted from each study. A forest plot analysis was used to verify the relative strength of the effects and adverse events of each procedure. A funnel plot was generated to assess the possibility of publication bias.RESULTS: Ultimately, six RCTs were selected. No significant differences were noted in the average lesion size (less than 10 mm) between the cold and hot polypectomy groups in each study. Further, the rates of complete resection and adverse events, including delayed bleeding, did not differ markedly between cold and hot polypectomy. The average procedural time in the cold polypectomy group was significantly shorter than in the hot polypectomy group.CONCLUSION: Cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy.

Efficacy and tolerability of high and low-volume bowel preparation compared:A real-life single-blinded large-population study

BACKGROUND Low-volume preparations for colonoscopy have shown similar efficacy compared to high-volume ones in randomized controlled trials(RCT).However,most RCTs do not provide data about clinical outcomes including lesions detection rate.Moreover,real-life comparisons are lacking.AIM To compare efficacy(both in terms of adequate bowel preparation and detection of colorectal lesions)and tolerability of a high-volume(HV:4 L polyethylene glycol,PEG)and a low-volume(LV:2 L PEG plus bisacodyl)bowel preparation in a real-life setting.METHODS Consecutive outpatients referred for colonoscopy were prospectively enrolled between 1 December 2014 and 31 December 2016.Patients could choose either LV or HV preparation,with a day-before schedule for morning colonoscopies and a split-dose for afternoon procedures.Adequate bowel preparation according to Boston Bowel Preparation Scale(BBPS),clinical outcomes including polyp detection rate(PDR),adenoma detection rate(ADR),advanced adenoma detection rate(AADR),sessile/serrated lesion detection rate(SDR)and cancer detection rate and self-reported tolerability of HV and LV were blindly assessed.RESULTS Total 2040 patients were enrolled and 1815(mean age 60.6 years,50.2%men)finally included.LV was chosen by 52%of patients(50.8%of men,54.9%of women).Split-dose schedule was more common with HV(44.7%vs 38.2%,P=0.005).High-definition scopes were used in 33.4%of patients,without difference in the two groups(P=0.605).HV and LV preparations showed similar adequate bowel preparation rates(89.2%vs 86.6%,P=0.098),also considering the two different schedules(HV split-dose 93.8%vs LV split-dose 93.6%,P=1;HV daybefore 85.5%vs LV day-before 82.3%,P=0.182).Mean global BBPS score was higher for HV preparations(7.1±1.7 vs 6.8±1.6,P<0.001).After adjustment for sex,age and indications for colonoscopy,HV preparation resulted higher in PDR[Odds ratio(OR)1.32,95%CI:1.07-1.63,P=0.011]and ADR(OR 1.29,95%CI 1.02–1.63,P=0.038)and comparable to LV in AADR(OR 1.51,95%CI 0.97-2.35,P=0.069),SDR and cancer detection rate.The use of standard-definition colonoscopes was associated to lower PDR(adjusted OR 1.59,95%CI:1.22-2.08,P<0.001),ADR(adjusted OR 1.71,95%CI:1.26–2.30,P<0.001)and AADR(adjusted OR 1.97,95%CI:1.09-3.56,P=0.025)in patients receiving LV preparation.Mean Visual Analogue Scale tolerability scored equally(7,P=0.627)but a≥75%dose intake was more frequent with LV(94.6%vs 92.1%,P=0.003).CONCLUSION In a real-life setting,PEG-based low-volume preparation with bisacodyl showed similar efficacy and tolerability compared to standard HV preparation.However,with higher PDR and ADR,HV should still be considered as the reference standard for clinical trials and the preferred option in screening colonoscopy,especially when colonoscopy is performed with standard resolution imaging.

Comment on 'Efficacy and adverse events of cold vs hot polypectomy: A meta-analysis'

This is a comment on a meta-analysis of published studies comparing cold vs hot polypectomy. We believe that the conclusion of this meta-analysis that "cold polypectomy is a time-saving procedure for removing small polyps with markedly similar curability and safety to hot polypectomy" needs more rigorous evidence.