Reduced incidence and mortality from colorectal cancer with flexible-sigmoidoscopy screening: A meta-analysis

AIM:To conduct a systematic review and meta-analysis of published population-based randomized controlled trials(RCTs).METHODS:RCTs evaluating the difference in mortality and incidence of colorectal cancer(CRC)between a screening flexible sigmoidoscopy(FS)group and control group(not assigned to screening FS)with a minimum 5 years median follow-up were identified by a search of MEDLINE and EMBASE databases and the Cochrane Central Register for Controlled Trials through August 2013.Random effects model was used for meta-analysis.RESULTS:Four RCTs with a total of 165659 patientsin the FS group and 249707 patients in the control group were included in meta-analysis.Intention-totreat analysis showed that there was a 22%risk reduction in total incidence of CRC(RR=0.78,95%CI:0.74-0.83),31%in distal CRC incidence(RR=0.69,95%CI:0.63-0.75),and 9%in proximal CRC incidence(RR=0.91,95%CI:0.83-0.99).Those who underwent screening FS were 18%less likely to be diagnosed with advanced CRC(OR=0.82,95%CI:0.71-0.94).There was a 28%risk reduction in overall CRC mortality(RR=0.72,95%CI:0.65-0.80)and 43%in distal CRC mortality(RR=0.57,95%CI:0.45-0.72).CONCLUSION:This meta-analysis suggests that screening FS can reduce the incidence of proximal and distal CRC and mortality from distal CRC along with reduction in diagnosis of advanced CRC.

Diagnostic yield of third eye retroscope on adenoma detection during colonoscopy:A systematic review and meta-analysis

AIM: To determine the diagnostic yield of the "third eye retroscope",on adenoma detection rate during screening colonoscopy.METHODS: The "third eye retroscope" when used with standard colonoscopy provides an additional retrograde view to visualize lesions on the proximal aspects of folds and flexures.We searched MEDLINE(Pub Med and Ovid),SCOPUS(including MEDLINE and EMBASE databases),Cochrane Database of Systemic Reviews,Google Scholar,and CINAHL Plus databases to identify studies that evaluated diagnostic yield of "third eye retroscope" during screening colonoscopy.Der Simonian Laird random effects model was used to generate the overall effect for each outcome.We evaluated statistical heterogeneity among the studies by using the Cochran Q statistic and quantified by I2 statistics.RESULTS: Four distinct studies with a total of 920 patients,mean age 59.83(95%CI: 56.77-62.83) years,were included in the review.The additional adenoma detection rate(AADR) defined as the number of additional adenomas identified due to "third eye retroscope" device in comparison to standard colonoscopy alone was 19.9%(95%CI: 7.3-43.9).AADR for right and left colon were 13.9%(95%CI: 9.4-20) and 10.7(95%CI: 1.9-42),respectively.AADR for polyps ≥ 6 mm and ≥ 10 mm were 24.6%(95%CI: 16.6-34.9) and 24.2%(95%CI: 12.9-40.8),respectively.The additional polyp detection rate defined as the number of additional polyps identified due to "third eye retroscope" device in comparison to standard colonoscopy alone was 19.8%(95%CI: 7.9-41.8).There were no complications reported with use of "third eye retroscope" device.CONCLUSION: The "third eye retroscope" device when used with standard colonoscopy is safe and detects 19.9% additional adenomas,compared to standard colonoscopy alone.

Role of self-expanding metal stents in patients with malignant colorectal obstruction: A systematic review and meta-analysis

AIM: To assess the safety and efficacy of self-expandable metal stents(SEMSs) for malignant colorectal obstruction. METHODS: Data regarding technical success, clinical success, and procedure related complications were collected from included studies. Der Simonian-Laird random effects model was used to generate the overall outcome. Thirty international studies with a total of 2058 patients with malignant colorectal obstruction were included. RESULTS: The technical and clinical success rates for SEMS placement were 94%(95%CI: 92-96) and 91%(95%CI: 88-93), respectively. Overall complication rate for SEMS was 23%(95%CI: 18-29). Stent migration8%(95%CI: 6-10) and stent obstruction 8%(95%CI: 6-11) were the most common complications, followed by perforation 5%(95%CI: 4%-7%). Surgical or endoscopic re-interventions were needed in 14%(95%CI: 10-18) of patients. Endoscopic repeat stent placement was required in 8%(95%CI: 6-10), while surgical intervention was needed in 6%(95%CI: 4-8).CONCLUSION: SEMS are effective when used as palliation or bridge to surgery for malignant colorectal obstruction with high technical and clinical success. About 14% of patients require repeat endoscopic or surgical intervention for stent failure or to manage stent related complications.