Significant Polyps Research Articles

The Fast Track FIT study: diagnostic accuracy of faecal immunochemical test for haemoglobin in patients with suspected colorectal cancer.

BackgroundThe faecal immunochemical test (FIT) is now available to support clinicians in the assessment of patients at low risk of colorectal cancer (CRC) and within the bowel cancer screening programme.AimTo determine the diagnostic accuracy of FIT for CRC and clinically significant disease in patients referred as they were judged by their GP to fulfil National Institute for Health and Care Excellence guideline 12 (NG12) criteria for suspected CRC.Design and settingPatients referred from primary care with suspected CRC, meeting NG12 criteria, to 12 secondary care providers in Yorkshire and Humber were asked to complete a FIT before investigation.MethodThe diagnostic accuracy of FIT based on final diagnosis was evaluated using receiver operating characteristics analysis. This permitted a statistically optimal cut-off value for FIT to be determined based on the maximisation of sensitivity and specificity. Clinicians and patients were blinded to the FIT results.ResultsIn total, 5040 patients were fully evaluated and CRC was detected in 151 (3.0%). An optimal cut-off value of 19 µg Hb/g faeces for CRC was determined, giving a sensitivity of 85.4% (95% confidence interval [CI] = 78.8% to 90.6%) and specificity of 85.2% (95% CI = 84.1% to 86.2%). The negative predictive value at this cut-off value was 99.5% (95% CI = 99.2% to 99.7%) and the positive predictive value 15.1% (95% CI = 12.8% to 17.7%). Sensitivity and specificity of FIT for CRC and significant premalignant polyps at this cut-off value were 62.9% (95% CI = 57.5% to 68.0%) and 86.4% (95% CI = 85.4% to 87.4%), respectively; and when including all organic enteric disease were 35.7% (95% CI = 32.9% to 38.5%) and 88.6% (95% CI = 87.5% to 89.6%), respectively.ConclusionFIT used in patients fulfilling NG12 criteria should allow for a more personalised CRC risk assessment. FIT should permit effective, patient-centred decision-making to inform the need for, type, and timing of further investigation.

Is there need for routine CT colonography after CT-verified uncomplicated diverticulitis of the sigmoid colon?

BackgroundFollowing an episode of acute diverticulitis, surgical guidelines commonly advise routine colonic follow-up to rule out underlying malignancy. However, as a CT of the abdomen is frequently performed during clinical work-up, the routine need for colonic follow-up has become debated. PurposeTo evaluate the need for routine CT colonography after an episode of CT-verified uncomplicated sigmoid diverticulitis to rule out underlying colorectal malignancy. Material and methodsThis study retrospectively evaluated 312 patients routinely referred to colonic evaluation by CT colonography following an episode of acute diverticulitis. Patients were excluded if lacking diagnostic CT of the abdomen at time of diagnosis, if presenting with atypical colonic involvement, or if CT findings were suggestive of complicated disease (e.g., abscess or perforation). CT colonography exams were routinely reviewed by experienced abdominal radiology consultants on the day of the procedure. If significant polyps were detected, or if colorectal malignancy could not be excluded, patients were referred to same-day optical colonoscopy. For these patients, medical records were reviewed for optical colonoscopy results and histology reports if applicable. ResultsAmong 223 patients with CT-verified uncomplicated sigmoid diverticulitis, no patients were found to have underlying colorectal malignancy. 27 patients were referred to optical colonoscopy based on CT colonography findings. 18 patients consequently underwent polypectomy, all with either hyperplastic or adenomatous histology. ConclusionsThis study indicates that routine colonic evaluation by CT colonography following an episode of CT-verified uncomplicated sigmoid diverticulitis may be unwarranted, and should arguably be reserved for patients with protracted or atypical clinical course.

Features associated with high-risk sessile serrated polyps at index and follow-up colonoscopy.

Clinically significant serrated polyps are precursors of colorectal cancers, with features considered high risk including size ≥10mm, dysplasia, and presence of synchronous conventional adenoma. While these features have been described in cohorts undergoing screening colonoscopy, there is little information regarding the prevalence and patient characteristics associated with high-risk sessile serrated polyps (SSPs) in those undergoing surveillance colonoscopy. Polyp pathology at the index and first follow-up colonoscopy performed between 2004 and 2019 were examined in patients enrolled in a surveillance program because of an index finding of adenoma and/or SSP. Demographics and pathology features for SSP were compared between the colonoscopies. Of 6297 patients undergoing index colonoscopy, 2035 underwent follow-up colonoscopy after 3.3years (interquartile range 2.1-4.8years). The proportion with SSP decreased from 7.6% at index to 5.0% at follow-up (P<0.001); however, the proportion of SSPs that were considered high risk was not different between the colonoscopies (62.8% vs 62.4%). Female gender was associated with the presence of high-risk SSP at index colonoscopy (odds ratio [OR] 1.62, 95% confidence interval [CI] 1.28-2.06), while age ≥75years (OR 3.38, 95% CI 1.67-6.81) and previous high-risk SSP (OR 9.40, 95% CI 4.23-20.88) were independently associated with high-risk SSP at follow-up. The prevalence of SSP falls by one-third at first follow-up colonoscopy although the proportion of SSP with high-risk features remains the same. While females were more likely to have a high-risk SSP at the index colonoscopy, those at greatest risk for high-risk SSP at follow-up colonoscopy were age >75years and an index high-risk SSP.

S3111 Metachronous Advanced Serrated Polyps in Post-Polypectomy Patients

INTRODUCTION: Clinically significant serrated polyps (SPs) including sessile serrated adenomas (SSAs), traditional serrated adenomas (TSAs) and hyperplastic polyps ≥ 10 mm have been shown to rapidly progress to colorectal cancer. Advanced serrated polyps (ASPs) include SSAs ≥ 10 mm, SSAs with cytological dysplasia, hyperplastic polyps ≥ 10 mm and TSAs of any size. The incidence and risk factors of metachronous ASPs are not well described and may affect surveillance guidelines. METHODS: We performed retrospective analysis of post-polypectomy patients ≥ 50 years old who received index and follow-up colonoscopy between January 2014 and December 2018 at a single tertiary centre. Exclusion criteria were applied, and the following data was collected: demographics, conventional adenoma characteristics, SP characteristics and adenoma multiplicity (≥3 adenomas). RESULTS: A total of 969 patients had at least one adenoma removed at index colonoscopy. Patients had a mean age of 65.4 years and a mean time of 23.9 months between colonoscopies. At index colonoscopy, SPs, TSAs and cytological dysplasia was seen in 37.3%, 1.8% and 0.7% of patients respectively. The incidence of metachronous SP and ASP was 20.3% and 4.0% respectively. On multivariate analysis, significant predictors of metachronous ASP included age 70–74 years, presence of a SP and SPs ≥ 10 mm (Table 1). CONCLUSION: The incidence of metachronous SP and ASP over a 23.9-month follow-up period was 20.3% and 4.0% respectively. Patients are at increased risk for metachronous ASP if they are aged 70-74yrs, have a SP or have a SP ≥ 10 mm.Table 1Keywords: metachronous advanced serrated polyps, incidence, risk

S0308 Prep-Free Screening Capsule to Redefine Colorectal Cancer Screening and Prevention

INTRODUCTION: Colorectal cancer (CRC) can be prevented by removal of polyps during colonoscopy. Colonoscopy barriers include invasiveness and need of bowel cleansing preparation. Non-invasive CRC stool based tests may increase CRC screening adherence, but are not designed as a tool to identify pre-cancerous polyps. We present data from a novel prep-free colon cancer screening technology for the detection of pre-cancerous polyps. METHODS: An ingestible capsule descends through the gastrointestinal tract via natural motility and scans the colon for structural abnormalities using an ultra-low-dose X-ray source. The data is transmitted to a recorder unit attached to the patient. The test requires no preparation or sedation, allowing patients to continue their daily routine. A 187 patients were performed in the U.S. and Israel designed to assess the safety and effectiveness of the technology in detecting polyps. All sites received EC/IRB approvals. Patients ingested the capsule with a contrast agent and underwent a colonoscopy performed by independent gastroenterologists, who were blinded to the test's results. RESULTS: Sensitivity of the capsule in detecting clinically significant polyps (≥10 mm) was 76% and specificity was 82% with no severe or serious adverse events reported. Some patients reported mild abdominal pain and nausea. Patient characteristics are shown in Table 1. A survey questionnaire resulted with a score of 4.18 compared to a 2.91 for colonoscopy (P = 0.0011) using a scoring system of 1 (strongly disagree) to 5 (strongly agree) in response to the phrase: “I would recommend the test for colonic screening”. CONCLUSION: The reported patient satisfaction, sensitivity, specificity and safety highlights the potential of the capsule technology as a tool for CRC prevention. Further studies are needed to make this technology part of our routine colon cancer prevention armamentarium.Figure 1.: Polyp as detected by the capsule system compared to colonoscopy (endoscopic image).Table 1.: Patients Characteristic dataTable 2.: Capsule sensitivity and specificity

Correlation between proximal serrated polyp detection and clinically significant serrated polyps: inter-endoscopist variability.

The adenoma detection rate (ADR) is the most important quality indicator for the prevention of colorectal cancer but serrated polyps are also precursor lesions of the disease. The aim of our study was to compare the detection rate of proximal serrated polyps (PSPs) and that of clinically significant serrated polyps (CSSPs) between endoscopists and analyze the relation of those parameters to the ADR. An observational, prospective, cross-sectional study was conducted on all patients that underwent colonoscopy at the Policlínico Peruano Japonés within the time frame of July 2015 and August 2016. The ADR and PSP and CSSP detection rates between endoscopists were compared through multivariate logistic regression and the association between those parameters was calculated through the Pearson correlation coefficient. The study included 15 endoscopists and 1,378 colonoscopies. The PSP detection rate ranged from 1.8-17% between endoscopists and had an almost perfect correlation with the CSSP detection rate (p = 0.922), as well as strongly correlating with the ADR (p = 0.769). There was great variability in the PSP detection rate between endoscopists. It also had an almost perfect correlation with the CSSP detection rate and strongly correlated with the ADR. Those results suggest a high CSSP miss rate at endoscopy and a low PSP detection rate.

Colonoscopy Outcomes in Average-Risk Screening Equivalent Young Adults: Data From the New Hampshire Colonoscopy Registry.

Data are needed to further inform the American Cancer Society recommendation to begin colorectal cancer (CRC) screening at age 45. We used the New Hampshire Colonoscopy Registry to compare the prevalence of advanced neoplasia (AN) in an "average-risk screening equivalent" group aged 45-49 years with patients aged 50-54 years and older receiving screening colonoscopy. Colonoscopies in adults older than 50 years of age usually have diagnostic indications of varying clinical significance. We combined patients older than 50 years with diagnostic indications (abdominal pain and constipation) expected to yield AN prevalence similar to screening low AN risk and those with a screening indication to form an "average-risk screening equivalent" group. We excluded high-risk indications (e.g., bleeding and anemia), surveillance examinations, and patients with a first-degree family history of CRC, incomplete examinations, and poor bowel preparation. We calculated prevalence/adjusted risks for AN (≥1 cm, villous, high-grade dysplasia, and CRC) and clinically significant serrated polyps (large [≥1 cm] hyperplastic polyps, sessile serrated polyp, traditional serrated adenomas, and proximal hyperplastic polyp ≥ 5 mm). In our sample (n = 40,812), AN prevalence was as follows: <40 years (1.1%), 40-44 years (3.0%), 45-49 years (3.7%), 50-54 years (3.6%), 55-59 years (5.1%), and 60+ years (6.7%) (P < 0.0001 across all groups). The prevalence of both AN and clinically significant serrated polyp was similar in the 45-49 and 50-54 years' age groups. Furthermore, the prevalence of AN increased significantly in the 40-44 group as compared to that in the <40 years group. Adjusted analyses confirmed these results. The diagnostic indications considered to have low risk were not predictive of AN. New Hampshire Colonoscopy Registry data, demonstrating an increase in AN risk starting at age 40 and a similar prevalence for individuals aged 45-49 and those ages 50-54, provide clinically useful evidence for optimization of prevention and the age to start screening. However, this is a complex issue involving additional considerations that will need to be addressed.

Visceral Fat Quantitated From CT Colonography Is Associated With the Presence of Colorectal Polyps

Background: An adenomatous polyp is known as a precancerous lesion of colorectal cancer. Detection and removal of adenomatous polyps are essential for colon cancer prevention. Previous studies have found the association between obesity and adenomatous polyp using many parameters.&#x0D; Objective: To determine the association between visceral fat visualized on computed tomography (CT) colonography (CTC) and colorectal polyps.&#x0D; Methods: This retrospective case-control study consisted of 280 adult subjects who underwent colon cancer screening by CTC at Ramathibodi Hospital; 129 cases with CT detected colorectal polyps who underwent polypectomy within 6 months, and 151 control subjects who were negative for significant polyps on CTC. Visceral fat areas of all subjects were measured on CT at the umbilical level by a semiautomatic method. Statistical analysis was performed to ascertain associations with the presence of colorectal polyps.&#x0D; Results: Of 280 adult subjects, there were classified into 4 groups; no polyps (n = 151), hyperplastic polyp (n = 23), low-risk adenomatous polyp (n = 75), and high-risk adenomatous polyp (n = 31). The mean visceral fat areas in 4 groups were 125.1 ± 55.7 cm2, 140.2 ± 63.8 cm2, 147.9 ± 74.2 cm2, and 156.6 ± 63.7 cm2, respectively. There were statistically significant differences in these means visceral fat between the no polyp group and both the low-risk and high-risk adenomatous polyp groups. In multivariate analyses, subjects who had visceral fat areas more than 168.60 cm2 were more likely to have polyps than subjects whose visceral fat areas were less than 93.65 cm2 (P &lt; .05).&#x0D; Conclusions: Visceral fat was positively associated with the presence of adenomatous colorectal polyps.

Simple proxies for detection of clinically significant serrated polyps and data for their benchmarks.

Serrated polyp detection rate (SDR) is a potential quality indicator for preventing colorectal cancer associated with the serrated pathway. Using clinically significant SDR (CSSDR) has been suggested based on clinically significant serrated polyp's ability to be colorectal cancer precursors. Correlations between CSSDR and simpler SDRs, other than proximal SDR, have not yet been studied. We aimed to investigate which simpler SDR indicator is most relevant to CSSDR or adenoma detection rate (ADR) and provide benchmark data. We analyzed 26627 colonoscopies performed by 30 endoscopists. Clinically significant serrated polyps were defined as any sessile serrated adenoma/polyp or traditional serrated adenoma, hyperplastic polyps≥5mm in the proximal colon, or hyperplastic polyps≥10mm anywhere in the colon. Correlation of CSSDR and ADR with other simple SDRs, SDR-pathology (sessile serrated adenoma/polyp or traditional serrated adenoma), SDR-size (≥10mm), and SDR-location (proximal location) was analyzed using Pearson's correlation test and Steiger's z-test. The CSSDR was 1.7% to 13.2% (mean=6.1%). The correlation coefficient of CSSDR/SDR-size was 0.91 (P<0.01), which was higher than that of CSSDR/SDR-location (0.64, P<0.01) (0.91 vs 0.61, P<0.01). The correlation coefficient of ADR/CSSDR and ADR/SDR-location was 0.41 (P<0.01) and 0.81 (P<0.01), respectively. For ADR≥25%, endoscopists' median screening CSSDR was 5.4%, while SDR-location and SDR-size were 10.9% and 2.2%, respectively. Large SDR could be a simple proxy for CSSDR, in addition to proximal SDR. Large SDR and proximal SDR benchmarks of 2.2% and 10.9% may guide adequate serrated polyp detection with uniform definitions and simpler calculations.

Audit of the impact of the York faecal calprotectin care pathway on colonoscopy activity

BackgroundThe York faecal calprotectin care pathway (YFCCP) was developed to optimise effective primary care differentiation between irritable bowel syndrome (IBS) and inflammatory bowel disease (IBD). We undertook an audit of...

Mass spectrometry transanal minimally invasive surgery (MS-TAMIS) to promote organ preservation in rectal cancer

BackgroundTransanal minimally invasive surgery (TAMIS) is deployed for organ preservation in early rectal cancer and significant rectal polyps. Rapid evaporative ionisation mass spectrometry (REIMS) provides biochemical tissue analysis, which could be applied intraoperatively to give real-time tissue feedback to the surgeon and decrease the risk of an involved margin. However, the accuracy and feasibility of this approach have not been established.MethodsIn this prospective observational study, patients undergoing resection of rectal adenomas or carcinomas were recruited. An electrosurgical handpiece analysed tissues ex vivo using diathermy, with the aerosol aspirated into a Xevo G2-S ToF mass spectrometer. The relative abundance of lipids underwent predictive statistical modelling and leave-one-patient-out cross-validation. The outcomes of interest were the ability of REIMS to differentiate normal, adenomatous and cancerous tissue, or any disease subtype from normal. REIMS was coupled with TAMIS for in vivo sampling, assessing the accuracy of tissue recognition and distinguishing bowel wall layers.ResultsForty-seven patients were included, yielding 266 spectra (121 normal, 109 tumour and 36 adenoma). REIMS differentiates normal, adenomatous and cancerous rectal tissues with 86.8% accuracy, and normal and adenomatous tissue with 92.4% accuracy and 91.4% accuracy when differentiating disease from normal. We have performed the first five in-man mass spectrometry augmented TAMIS (MS-TAMIS). In real time, MS-TAMIS can differentiate rectal mucosa and submucosa based on their relative abundance of triglycerides and glycerophospholipids. The ex vivo accuracy distinguishing diseased and normal tissues is maintained in vivo at 90%, with negative predictive value of 95%. The system identified a deep and lateral involved tumour margin during TAMIS.ConclusionsREIMS distinguishes rectal tissue types based on underlying lipid biology, and this can be translated in vivo by coupling it to TAMIS. There is a role for this technology in improving the efficacy of resection of early rectal cancers.

234 Higher Serrated Detection Rate Is Associated With Lower Risk for Post-Colonoscopy Colorectal Cancer

INTRODUCTION: The serrated pathway may account for a significant proportion of colorectal cancer (CRC). Achieving adequate serrated polyp detection rates (SDR) may reduce the incidence of post colonoscopy CRC (PCCRC). We used data from the New Hampshire Colonoscopy Registry (NHCR) to determine if exams performed by endoscopists who have a clinically significant serrated polyp detection rate (CSSDR) of 7% or greater, proposed by Anderson/Butterly (GIE 2017), had a reduced incidence of PCCRC. In addition, we compared CSSDR to the adenoma detection rate (ADR), the currently used benchmark. METHODS: We defined PCCRC as any CRC diagnosed between 6 and 36 months after an exam with an adenoma on index and between 6 and 60 months following a normal exam. Exclusion criteria were any CRC diagnosed at index or within 3 months, incomplete exams, IBD, and genetic syndromes. Clinically significant serrated polyps (CSSP) were defined as any sessile serrated polyp, traditional serrated adenoma, serrated polyp &gt;1 cm anywhere in the colon and any serrated polyp &gt;5 mm proximal to the sigmoid. CSSDR was defined as number of screening exams with at least one CSSP divided by all screening exams. The exposure variable was a CSSDR of 7% and adenoma detection rate of 25%. Cox regression was used to model the risk of PCCRC in terms of the covariates at index exam. Covariates were age, BMI, smoking, index findings (large serrated polyp, advanced adenoma or any adenoma), followup time (months), bowel prep quality, having more than 1 surveillance exam and family history of CRC. We also compared receiver operating characteristics (ROC) for CSSDR 7% to an ADR 25% using probabilities derived from a logistic regression analysis. RESULTS: In our sample (142,950 index exams) 75 CRCs were diagnosed during the 6–60 month period (45 CRCs diagnosed between 6–36 months) after the index exam. The hazard ratio (HR) for CSSDR of 7% (HR = 0.37 95% CI 0.17–0.83) was similar to that for an ADR of 25% (HR = 0.45 95% 0.23–0.89) (Table 1). The ROCs were similar for CSSDR and ADR and the combination of the 2 rates did not alter the ROC (Table 2). CONCLUSION: Having an exam performed by an endoscopist with a CSSDR of 7% or greater was associated with a decrease incidence of PCCRC (HR = 0.37). The performance of CSSDR and ADR for PCCRC incidence were similar. These data suggest that a CSSDR of 7% or greater may be associated with lower PCCRC rates. However, it may not add an information to that provided by the current primary colonoscopy benchmark, ADR.

238 Prevalence of Advanced Polyps at Age 45–49 Is Similar to 50–54 Years

INTRODUCTION: The American Cancer Society recommends that colorectal cancer (CRC) screening begin at 45 years. To further inform this issue, data on advanced adenoma (AA) and serrated polyp (SP) prevalence in this population are vital. We used the New Hampshire Colonoscopy Registry (NHCR) to examine age related prevalence of advanced findings in an average risk “screening” cohort &lt;50. METHODS: Indications for colonoscopies in adults &lt;50 are often diagnostic. We made the assumption that some indications (e.g., abdominal pain or constipation) might not be associated with increased risk of adenomas. To ensure an appropriate “average risk” population &lt;50, we included only those indications expected to yield AA prevalence rates similar to screening exams, and also tested this assumption. We excluded higher-risk indications, such as GI bleeding, occult blood, Fe deficiency anemia and abnormal imaging. We also excluded surveillance exams, family history of CRC, incomplete exams and poor bowel preparation. AAs were adenomas &gt;1 cm or with villous elements or high-grade dysplasia, or CRC. Clinically significant serrated polyps (CSSP) included large (&gt;1 cm) SPs, any sessile SP or traditional serrated adenoma, and any proximal SP &gt;5 mm. We present prevalence/adjusted risks for AA, adenomas and CSSP. Age was stratified into &lt;40 (reference), 40–44, 45–49, 50–54, 55–59 and 60+ years. Covariates were sex, smoking and BMI. To test our hypothesis regarding indications, we examined the prevalence in screening versus the prevalence in included and excluded indications. We also added the presence of low-yield symptoms as a covariate. RESULTS: In our sample (n = 42,600), AA prevalence increased significantly at 40 yrs. The prevalence of AA and CSSP was similar for ages 45–49 and 50–54. In the model, older age was associated with significantly increased risk for AA and adenomas (Table 2). Older age effect was less pronounced in CSSPs. The prevalence of AA was 4.4% for screening, 3.2% for the included diagnoses and 5.8% for the excluded diagnoses (P &lt; 0.001), supporting our assumption regarding indication. Low-risk symptoms were not associated with an increased risk (OR = 1.03: 0.84–1.13), further confirming our assumption. CONCLUSION: The prevalence of AA increased significantly in the 40–44 group as compared to those &lt;40. The increased prevalence for both AA and CSSP at age 45–49 was similar to that for those 50–54 years. These data support the suggestion that to optimize prevention, screening should begin at 45 years.

Referral for Colonoscopy in Patients with Streptococcus bovis Bacteremia and the Association with Colorectal Cancer and Adenomatous Polyps: A Quality Assurance Study

The association between Streptococcus bovis (S. bovis) bacteremia and colorectal cancer is well established. We aimed to review patients with S. bovis bacteremia at our local hospital system and determine the percentage of patients referred for colonoscopy. Methods: We searched the regional database to identify S. bovis-positive blood cultures from 2002 to 2016 and the clinical characteristics and outcomes of those patients. Results: A total of 86 patients with S. bovis bacteremia were identified. From the 86 patients, 14 were excluded. The mean age of the 72 remaining patients was 74.5 (SD 13), 42/72 (58%) were male, 12/72 (17%) had infective endocarditis, and 19 (26%) died during admission. Of the 53 patients who survived, 37 (70%) were referred for colonoscopy or CT colonography, of which 30 had a colonoscopy. Thus, 3/30 (10%) cases showed adenocarcinoma and 11/30 (37%) cases showed adenomatous polyps. Age, gender, or the presence of infective endocarditis were not associated with adenocarcinoma or adenomatous polyps. Discussion: In our local centers, a significant proportion of patients with S. bovis were found to have colon cancer or significant polyps, and thus the importance of referral to colonoscopy remains paramount.

Pre-therapeutic MRI Assessment of Early Stage Rectal Cancer and Significant Rectal Polyps to Avoid Major Resectional Surgery: A New Approach to the Management of Early Stage Rectal Cancer.

Pre-therapeutic MRI Assessment of Early Stage Rectal Cancer and Significant Rectal Polyps to Avoid Major Resectional Surgery: A New Approach to the Management of Early Stage Rectal Cancer.

Feasibility and economic assessment of chromocolonoscopy for detection of proximal serrated neoplasia within a population-based colorectal cancer screening programme (CONSCOP): an open-label, randomised controlled non-inferiority trial

Most post-colonoscopy interval colorectal cancers are proximal; serrated polyps are often precursors to these cancers and are considered difficult to detect. We assessed the safety, feasibility, and economic effect of chromocolonoscopy on detection of proximal serrated neoplasia. We did an open-label, multicentre, randomised, controlled non-inferiority trial including patients from Bowel Screening Wales centres. Participants who tested positive for faecal occult blood and who were eligible for and considered fit to have colonoscopy (patients with known cases of polyposis syndromes, Lynch syndrome, and chronic inflammatory disease were excluded) were randomly assigned (1:1; with the use of minimisation, stratified by centre with an 80:20 random element) to either standard white light colonoscopy (standard group) or chromocolonoscopy (indigo carmine dye [0·2%]; chromocolonoscopy group) using a secure, internet-based, computerised, randomisation system that used centralised, dynamic allocation. Participants were followed up for 1 year and data from index colonoscopies and associated clearance procedures were analysed. All proximal polyps were reviewed by an expert pathologist panel. The main outcome on which power was based was time taken to perform the colonoscopy procedure, defined as from the time when the scope was inserted to withdrawal from the anus, assessed in the per-protocol population. The non-inferiority margin was 15 min. This trial is complete and is registered with ClinicalTrials.gov, number NCT01972451. Between Nov 20, 2014, and June 16, 2016, 741 (72%) of 1031 patients screened were eligible and consented: 360 were randomly assigned to white light colonoscopy and 381 to chromocolonoscopy. In the chromocolonoscopy group, the procedure took a mean of 36·8 min (SD 15·0), compared with a mean of 30·6 min (13·7) in the standard group (mean difference 6·3 min [95% CI 4·2-8·4] longer with chromocolonoscopy than in the standard group). The mean difference was within the prespecified non-inferiority margin. Detection rates for proximal serrated lesions were significantly higher in the chromocolonoscopy group than in the control group (45 [12%] of 381 patients vs 23 [6%] of 360 patients; odds ratio 1·96 [95% CI 1·16-3·32]; p=0·012). Serious adverse events (four cases of postpolypectomy bleeding [two in each group], and one case of anxiety and hyperventilation [in the chromocolonoscopy group]), colonoscopy quality measures, comfort scores, and sedation were similar between groups. Chromocolonoscopy is feasible within a population-based colorectal cancer screening programme, is safe, and has significantly increased detection of proximal serrated neoplasia and other polyp types compared with standard colonoscopy. Larger randomised trials of chromocolonoscopy, powered for improved detection of significant serrated polyps and for longer-term follow-up to investigate the effect on reduction of interval cancers within screening populations, are warranted. Health and Care Research Wales (RfPPB-1021).

The MRI assessment of SPECC (significant polyps and early colorectal cancer) lesions.

The development of high-resolution magnetic resonance imaging (MRI) has resulted in the ability to clearly depict the finer details of rectal wall anatomy. Careful specialist assessment of images obtained in patients with significant polyps and early rectal cancer lesions enables the identification of lesions that are confined to the bowel wall and amenable to organ preserving local excision. Currently, one-third of screen detected rectal cancers are limited to the bowel wall without nodal spread yet more than 90% undergo major excision surgery resulting in significant loss of bowel function, quality of life and at high economic cost. The SPECC initiative has highlighted the need for specialist training and accreditation of radiology specialists in precision assessment of significant polyps and early rectal cancer. The detailed assessment will enable provision of detailed roadmaps for surgeons and gastroenterologists to facilitate definitive excision of more lesions using minimally invasive endoscopic technique. Finally, the use of high resolution MRI in surveillance will enable the close monitoring of such patients where the preservation of the rectum has been achieved.

Significant polyps and early colorectal cancer: the importance of high-quality standardized histopathology.

Significant polyps and early colorectal cancer: the importance of high-quality standardized histopathology.

Computed tomographic colonography for diagnosis of early cancer and polyps?

Computed tomographic (CT) colonography comprises thin-section CT scanning of the prepared, gas-distended colon, acquired in more than one patient position. The test is widely available internationally and is highly sensitive for colorectal cancer, including significant polyps and early colorectal cancers (SPECC). In this article, we will discuss the basic technique of CT colonography, its diagnostic performance, the challenge of detecting serrated polyps and handling of diminutive polyps. Since CT colonography permits a detailed assessment of polyp morphology, radiologists must communicate their descriptions of the CT appearances of larger polyps accurately and using widely-accepted terminology. This allows services to plan their resection strategy for these larger lesions in timely fashion and ensure availability of appropriate staff and equipment for that patient. Close collaboration between all members of the multi-disciplinary team will ensure that all patients have access to high-quality colonic imaging services.

Understanding variations in the treatment of significant polyps and early colorectal cancer

Understanding variations in the treatment of significant polyps and early colorectal cancer