BackgroundSpecific genes, such as BCAT1 and IKZF1, are methylated with high frequency in colorectal cancer (CRC) tissue compared to normal colon tissue specimens. Such DNA may leak into blood and be present as cell-free circulating DNA. We have evaluated the accuracy of a novel blood test for these two markers across the spectrum of benign and neoplastic conditions encountered in the colon and rectum.MethodsCirculating DNA was extracted from plasma obtained from volunteers scheduled for colonoscopy for any reason, or for colonic surgery, at Australian and Dutch hospitals. The extracted DNA was bisulphite converted and analysed by methylation specific real-time quantitative PCR (qPCR). A specimen was deemed positive if one or more qPCR replicates were positive for either methylated BCAT1 or IKZF1 DNA. Sensitivity and specificity for CRC were estimated as the primary outcome measures.ResultsPlasma samples were collected from 2105 enrolled volunteers (mean age 62 years, 54 % male), including 26 additional samples taken after surgical removal of cancers. The two-marker blood test was run successfully on 2127 samples. The test identified 85 of 129 CRC cases (sensitivity of 66 %, 95 % CI: 57–74). For CRC stages I-IV, respective positivity rates were 38 % (95 % CI: 21–58), 69 % (95 % CI: 53–82), 73 % (95 % CI: 56–85) and 94 % (95 % CI: 70–100). A positive trend was observed between positivity rate and degree of invasiveness. The colonic location of cancer did not influence assay positivity rates. Gender, age, smoking and family history were not significant predictors of marker positivity. Twelve methylation-positive cancer cases with paired pre- and post-surgery plasma showed reduction in methylation signal after surgery, with complete disappearance of signal in 10 subjects. Sensitivity for advanced adenoma (n = 338) was 6 % (95 % CI: 4–9). Specificity was 94 % (95 % CI: 92–95) in all 838 non-neoplastic pathology cases and 95 % (95 % CI: 92–97) in those with no colonic pathology detected (n = 450).ConclusionsThe sensitivity for cancer of this two-marker blood test justifies prospective evaluation in a true screening population relative to a proven screening test. Given the high rate of marker disappearance after cancer resection, this blood test might also be useful to monitor tumour recurrence.Trial registrationACTRN12611000318987.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-015-1674-2) contains supplementary material, which is available to authorized users.

Objectives:To compare the performance of a new blood test for colorectal cancer (CRC) to an established fecal immunochemical test (FIT) in a study population with the full range of neoplastic and non-neoplastic pathologies encountered in the colon and rectum.Methods:Volunteers were asked to complete a FIT prior to colonoscopy. Blood was collected after bowel preparation but prior to colonoscopy, and plasma was assayed for the presence of methylated BCAT1 and IKZF1 DNA using a multiplex real-time PCR assay. Sensitivity and specificity estimates for the blood test were calculated from true- and false-positive rates for neoplasia and compared with FIT at a range of fecal hemoglobin (Hb) concentration positivity thresholds.Results:In total, 1,381 volunteers (median age 64 years; 49% male) completed both tests prior to colonoscopy. Estimated sensitivity of the BCAT1/IKZF1 blood test for CRC was 62% (41/66; 95% confidence interval 49–74%) with a specificity of 92% (1207/1315; 90–93%). FIT returned the same specificity at a cutoff of 60 μg Hb/g, at which its corresponding sensitivity for cancer was 64% (42/66; 51–75%). In the range of commonly used FIT cutoffs, respective cancer sensitivity and specificity estimates with FIT were: 59% (46–71%) and 93% (92–95%) at 80 μg Hb/g, and 79% (67–88%) and 81% (78–83%) at 10 μg Hb/g. Although estimated sensitivities were not significantly different between the two tests for any stage of cancer, FIT showed a significantly higher sensitivity for advanced adenoma at the lower cutoffs. Specificity of FIT, but not of the BCAT1/IKZF1 blood test, deteriorated substantially in people with overt blood in the feces. When combining FIT (cutoff 10 μg Hb/g) with the BCAT1/IKZF1 blood test, sensitivity for cancer was 89% (79–96%) at 74% (72–77%) specificity.Conclusions:A test based on detection of methylated BCAT1/IKZF1 DNA in blood has comparable sensitivity but better specificity for CRC than FIT at the commonly used positivity threshold of 10 μg Hb/g. Further evaluation of the new test relative to FIT in the population screening context is now required to fully understand the potential advantages and disadvantages of these biomarkers in screening.

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Background and Aim Cold snare polypectomy is safe and efficacious for removing polyps <10 mm with reduced rates of delayed postpolypectomy bleeding and postpolypectomy syndrome. This technique can also be used for sessile polyps ≥10 mm; however, further evidence is required to establish its safety. The aim of this study was to compare intraprocedure and postprocedure adverse events in patients who underwent cold (CSP) versus hot snare polypectomy (HSP) of 10–20 mm sessile colonic polyps. Methods Electronic medical records and endoscopy reports of all patients who underwent polypectomy for Paris 0‐IIa, Is, or 0‐IIa + Is 10–20 mm colonic polyps between January 2015 and June 2017 at three tertiary academic hospitals and one private hospital were retrospectively reviewed. Data on patient demographics, polyp characteristics, method of polypectomy, and intraprocedural and postpolypectomy adverse events were collected. Results A total of 408 patients (median age 67, 50% male) had 604 polyps, 10–20 mm in size, removed. Of these, 258 polyps were removed by HSP, with a median size of 15 mm (interquartile range [IQR] 12–20), compared to 346 polyps that were removed by CSP, with median size of 12 mm (IQR 10–15), P < 0.001. In the HSP group, 15 patients presented with postprocedure complications, including 11 with clinically significant bleeding, 2 with postpolypectomy syndrome, and 2 with abdominal pain. This compares with no postpolypectomy complications in the CSP group, P < 0.001. Conclusion In this study, CSP was not associated with any postpolypectomy adverse events. CSP appears to be safer than HSP for removing 10–20 mm‐sized sessile polyps. A prospective multicenter study has been commenced to verify these findings and to assess the efficacy of CSP for the complete resection of polyps of this size.

BenedictDevereaux is a consultant and member on advisory board for Boston Scientific. Milan Bassan is a consultant for Boston Scientific. Payal Saxena is a consultant for Boston Scientific. Thawee Ratanachu-EK is a proctor for Boston Scientific. All other authors have no relevant conflicts of interest to disclose. Financial support: There were no sources of financial grants or other funding for this study.

Delayed postpolypectomy bleeding (DPPB) is the most common complication of colonoscopic polypectomy. Prophylactic clipping after an uncomplicated polypectomy is increasingly used, but it is unclear if this results in the prevention of DPPB. This study aimed to review prophylactic clip use and its effect on the rates of DPPB. MEDLINE, Embase, and the Cochran Library were systematically searched for studies (1995–March 2017) that used prophylactic hemoclips and assessed DPPB as an outcome. Of 1402 articles identified, nine papers were eligible for inclusion, evaluating 4311 patients and 7783 polyps; 118 patients experienced a DPPB, and 49 of these patients received prophylactic clips. There was no significant difference in DPPB rates in patients who received prophylactic clipping compared to those who did not (odd ratio: 0.8; 95% confidence interval: 0.36–1.77; P = 0.56). There was also no significant difference in the DPPB of polyps <20 mm compared with polyps ≥20 mm. Clip application for prophylactic management of an uncomplicated polypectomy has not been demonstrated to reduce the risk of DPPB, casting doubt on the use of this costly practice.

Background and AimBowel preparations with polyethylene glycol (PEG) and clear fluids are often poorly tolerated. We compared an innovative low‐residue White Diet and low‐volume, split‐dose Picosalax with the standard preparation at our institution of day‐before clear fluids and combination PEG plus sodium picosulfate/magnesium citrate (SPMC).MethodsAdults undergoing morning colonoscopy were randomized to either the White Diet and split‐dose, two sachets of Picosalax (WD/PICO) or day‐before clear fluids and 1‐L PEG plus two sachets of SPMC (CF/PEG + SPMC). The primary endpoint was successful bowel preparation defined by an Ottawa bowel preparation score ≤ 6. An intention‐to‐treat analysis with a predefined non‐inferiority margin of 15% was used to compare efficacy.ResultsA total of 250 patients were randomized (125 WD/PICO and 125 CF/PEG + SPMC). WD/PICO was non‐inferior to CF/PEG + SPMC for successful bowel preparation by intention‐to‐treat analysis (58% WD/PICO vs 62% CF/PEG + SPMC, 95%CI: −14.2 to 6.2%) and per‐protocol analysis (64% WD/PICO vs 65% CF/PEG + SPMC, 95%CI: −11.3 to 9.4%). Patients in the WD/PICO group reported greater satisfaction with the diet (P < 0.001), greater ease of following the diet (P < 0.001), and improved experience compared with prior colonoscopy (P < 0.0001), less bloating (P = 0.02), less weakness (P = 0.046), less hunger (P < 0.0001), and less interference with daily activities (P = 0.001). Procedure/withdrawal times and adenoma detection rates were similar between groups.ConclusionBowel preparation with the White Diet and low‐volume, split‐dose Picosalax was preferred and better tolerated without detriment to bowel preparation success compared with clear fluids and combination PEG plus SPMC for morning colonoscopy.

AIMTo compare high definition white light endoscopy and bright narrow band imaging for colon polyps’ detection rates.METHODSPatients were randomised to high definition white light endoscopy (HD-WLE) or the bright narrow band imaging (bNBI) during withdrawal of the colonoscope. Polyps identified in either mode were characterised using bNBI with dual focus (bNBI-DF) according to the Sano’s classification. The primary outcome was to compare adenoma detection rates (ADRs) between the two arms. The secondary outcome was to assess the negative predictive value (NPV) in differentiating adenomas from hyperplastic polyps for diminutive rectosigmoid lesions.RESULTSA total of 1006 patients were randomised to HD-WLE (n = 511) or bNBI (n = 495). The mean of adenoma per patient was 1.62 and 1.84, respectively. The ADRs in bNBI and HD-WLE group were 37.4% and 39.3%, respectively. When adjusted for withdrawal time (OR = 1.19, 95%CI: 1.15-1.24, P < 0.001), the use of bNBI was associated with a reduced ADR (OR = 0.69, 95%CI: 0.52-0.92). Nine hundred and thirty three polyps (86%) in both arms were predicted with high confidence. The sensitivity (Sn), specificity (Sp), positive predictive value and NPV in differentiating adenomatous from non-adenomatous polyps of all sizes were 95.9%, 87.2%, 94.0% and 91.1% respectively. The NPV in differentiating an adenoma from hyperplastic polyp using bNBI-DF for diminutive rectal polyps was 91.0%.CONCLUSIONADRs did not differ between bNBI and HD-WLE, however HD-WLE had higher ADR after adjustment of withdrawal time. bNBI surpassed the PIVI threshold for diminutive polyps.