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To systematically determine the miss rate and risk factors for polyps, adenomas and advanced adenomas in the same population, and to further analyze the impact of colonoscopy with anesthesia on miss rate.We retrospectively analyzed the information of the patients undergoing the second colonoscopy within 1 year after their first. The patient and lesion miss rate were calculated. The patient and lesion features of missed lesion were compared with non-missed lesion. Finally, the patients were divided into anesthesia group and without anesthesia group, and the impact of colonoscopy with anesthesia on missed lesions was further analyzed.The patient miss rate of polyps, adenomas and advanced adenomas was 32.8, 25.6 and 10.4%, and the lesions miss rate was 19.6, 15.8 and 7.2%. In multivariable logistic regression analysis, lesion-related factors (large number of lesions, small lesion size, flat shape and location at the right colon) and patient-related factors (male, elder, abdominal symptoms, surgical history, diverticulum, colonoscopy without anesthesia and suboptimal bowel preparation) were found to be independently associated with missed polyps and adenomas (Many factors of patients and lesions can affect the lesions miss rate. Colonoscopy with anesthesia can reduce the PMR and male and elderly patients are more likely to be missed during colonoscopy without anesthesia.

Background and study aims On February 25, 2020, the first patient was diagnosed with COVID-19 in Austria. On March 16, 2020, the Austrian government imposed restrictions and subsequently the Austrian Medical Association recommended minimizing screening examinations in compliance with government restrictions. The aims of this study were to evaluate the impact of this recommendation on the number of colonoscopies performed weekly and detection of non-advanced adenomas, advanced adenomas (AA) and colorectal cancer (CRC) and to calculate how many undetected adenomas could have developed into CRC. Methods We analyzed the number of colonoscopies and pathological findings within a quality assured national colorectal cancer screening program before the COVID-19 pandemic (March 1,t 2019 to September 1, 2019, Period 1) and compared those rates to months during which access to colonoscopy was limited (March 1, 2020 and September 1, 2020, Period 2) with a Wilcoxon-rank-test and a chi-square test. Results A total of 29,199 screening colonoscopies were performed during Period 1 and 24,010 during Period 2. The mean rate of colonoscopies per week during Period 1 was significantly higher than during Period 2 (808,35 [SD = 163,75] versus 594,50 [SD = 282,24], P = 0.005). A total of 4,498 non-advanced adenomas were detected during Period 1 versus 3,562 during Period 2 (P Conclusions During the COVID-19 crisis, the number of colonoscopies performed per week was significantly lower compared to the year before, but there was no difference in the detection of CRCs and AAs.

Participants with a positive faecal immunochemical test (FIT) in screening programs for colorectal cancer (CRC) have a high risk for colorectal cancer and advanced adenomas. They are therefore recommended follow-up by colonoscopy. However, more than ten percent of positively screened persons do not adhere to this advice. To investigate FIT-positive individuals’ motives for non-adherence to colonoscopy advice in the Dutch CRC screening program. Non-adherent FIT-positive participants of the Dutch CRC screening program. We conducted semi structured in-depth interviews with 17 persons who did not undergo colonoscopy within 6 months after a positive FIT. Interviews were undertaken face-to-face and data were analysed thematically with open coding and constant comparison. All participants had multifactorial motives for non-adherence. A preference for more personalised care was described with the following themes: aversion against the design of the screening program, expectations of personalised care, emotions associated with experiences of impersonal care and a desire for counselling where options other than colonoscopy could be discussed. Furthermore, intrinsic motives were: having a perception of low risk for CRC (described by all participants), aversion and fear of colonoscopy, distrust, reluctant attitude to the treatment of cancer and cancer fatalism. Extrinsic motives were: having other health issues or priorities, practical barriers, advice from a general practitioner (GP) and financial reasons. Personalised screening counselling might have helped to improve the interviewees’ experiences with the screening program as well as their knowledge on CRC and CRC screening. Future studies should explore whether personalised screening counselling also has potential to increase adherence rates.Key pointsParticipants with a positive FIT in two-step colorectal cancer (CRC) screening programs are at high risk for colorectal cancer and advanced adenomas. Non-adherence after an unfavourable screening result happens in all CRC programs worldwide with the consequence that many of the participants do not undergo colonoscopy for the definitive assessment of the presence of colorectal cancer. Little qualitative research has been done to study the reasons why individuals participate in the first step of the screening but not in the second step. We found a preference for more personalised care, which was not reported in previous literature on this subject. Furthermore, intrinsic factors, such as a low risk perception and distrust, and extrinsic factors, such as the presence of other health issues and GP advice, may also play a role in non-adherence. A person-centred approach in the form of a screening counselling session may be beneficial for this group of CRC screening participants. Participants with a positive FIT in two-step colorectal cancer (CRC) screening programs are at high risk for colorectal cancer and advanced adenomas. Non-adherence after an unfavourable screening result happens in all CRC programs worldwide with the consequence that many of the participants do not undergo colonoscopy for the definitive assessment of the presence of colorectal cancer. Little qualitative research has been done to study the reasons why individuals participate in the first step of the screening but not in the second step. We found a preference for more personalised care, which was not reported in previous literature on this subject. Furthermore, intrinsic factors, such as a low risk perception and distrust, and extrinsic factors, such as the presence of other health issues and GP advice, may also play a role in non-adherence. A person-centred approach in the form of a screening counselling session may be beneficial for this group of CRC screening participants.

BACKGROUND AND AIM With the increasing necessity of colorectal cancer screening, observational screening colonoscopy during which only endoscopic observation and diagnosis is performed is worth consideration. However, whether detected lesions can be correctly identified at secondary colonoscopy performed for polypectomy is unclear. Further, whether new neoplastic lesions can be detected at secondary colonoscopy has not been fully examined. This study was performed to investigate the detectability of adenomatous polyps and advanced colorectal neoplasia (ACN) at secondary colonoscopy. METHODS Data were analyzed from individuals who underwent initial observational screening colonoscopy followed by secondary colonoscopy for polypectomy. The proportion of correct detection at secondary colonoscopy of the lesions detected at initial colonoscopy was assessed. The number and characteristics of lesions that were newly detected at secondary colonoscopy were also evaluated. RESULTS Data of 587 individuals were assessed. Among the 1 331 lesions detected at the initial colonoscopy, 1 151 (86.5%) were properly detected at the secondary colonoscopy. The proportions of correct detection at the secondary colonoscopy for ACN, non-advanced adenomas sized 5 to 9 mm, and non-advanced adenomas sized 1 to 4 mm were 100%, 95.4%, and 70.3%, respectively. In total, 175 adenomatous polyps and ACNs were newly detected at secondary colonoscopy in 112 individuals (19.1% of all individuals). Most of the lesions (165 lesions, 94.3%) were non-advanced adenomas, while advanced adenomas (5.7%) were also found. CONCLUSION Screening by observational colonoscopy followed by deferred polypectomy is a feasible option in terms of lesion detectability, particularly when lesions sized ≥ 5 mm are the treatment target.

Methylated SEPT9 showed relatively low sensitivity in detecting early stage colorectal cancer (CRC) and advanced adenomas (AA) in plasma. Combination of multiple biomarkers was an effective strategy to improve sensitivity in early stage cancer diagnosis and screening. A new qPCR‐based assay combining the detection of methylated SEPT9 and SDC2 (ColoDefense test) was used. Methylation statuses of SEPT9 and SDC2 were examined in 40 sets of cancer tissues and paired adjacent tissues, 10 adenomatous polyps and 3 hyperplastic polyps (HP). Then evaluated with 384 plasma samples, including 117 CRC patients, 23 AA patients, 78 small polyps patients, and 166 normal individuals. The limit of detection of ColoDefense was about 25 pg per reaction. Both SEPT9 and SDC2 were shown by ColoDefense to be heavily methylated in CRC tissues when compared to paired paracancerous tissues and HP (P, Colorectal cancer (CRC) is the most common malignancy of gastrointestinal tract and methylated SEPT9 showed relatively low sensitivity in detecting early stage CRC and advanced adenomas (AA) in plasma. We evaluated the performance of the new qPCR‐based assay (ColoDefense test) combining the detection of multiple methylated circulating tumor DNA biomarkers. The ColoDefense test showed high sensitivity and specificity in detecting early stage CRC (stage I) and AA in plasma when compared with methylated SEPT9 alone.

Objective To analyze the detection rates of colorectal cancer (CRC) and polyps by population‐based screening in Guangzhou. Methods From January 2011 to December 2015, the residents aged 30‐79 were selected for CRC screening. The residents were conducted Questionnaires and/or FOBT to assess high‐risk groups, the free colonoscopy examination was recommended, and the results were evaluated in detail. Results There were 98 927 residents involving screening, 5306 high‐risk residents identified (males 1859 and females 3447), and 4713 subjects underwent colonoscopy (males 1690 and females 3023). CRC was seen in 55 individuals (males 28 and females 27), and the detection rates in male were higher than in female (P = 0.019). And the detection rates increasing with age, for people over 60 years old, were obviously higher than those younger (x 2 = 18.64, P = 0.000924). The polyps were seen in 1458 (30.94%) cases， and 1420 subjects received pathological examination (adenomas 971 and non‐adenomatous polyps 449). Advanced adenomas were seen in 462 cases (males 240 and females 222) and 509 cases of non‐advanced adenomas (males 255 and females 254). For advanced adenomas, the detection rates in male were higher than female (14.20% vs 7.34%, P = 2.64 × 10−14). For the detection rates of adenomas or advanced adenomas by age, the people over 40 years were higher than younger (20.91% vs 3.61% P = 7.87 × 10−6; 9.94% vs 2.41%, P = 0.009). Conclusions For Guangzhou residents, the detection rates of CRC and adenoma were 1.17% and 20.60%. The detection rates of CRC increasing with age, for people over 60 years old, were obviously higher than those younger. But for people over 40 years, the detection rate of adenoma and advanced adenoma was higher than younger. So for people over 40 years, the CRC screening is recommended.

Background and Aims: Fecal immunochemical tests (FITs) and flexible sigmoidoscopies are commonly used modalities for colorectal cancer (CRC) screening. We performed a systematic review and meta-analysis to compare the effectiveness of FIT and sigmoidoscopy in CRC screening. Methods: PRISMA statement and Cochrane guidelines were followed for this review. Digital dissertation databases were searched from inception till December 1st 2020 and randomized clinical trials comparing the detection rates of CRC for FIT and sigmoidoscopy were included. Outcomes for analysis included participation rates and detection rates of CRC, advanced adenomas and advanced colorectal neoplasia for both screening modalities. Results: Five randomized clinical trials with a total of 261,755 patients were included for the analysis. The participation rate for FIT was significantly higher compared to flexible sigmoidoscopy (OR 2.11, 95% CI 1.29-3.44, p=0.003). In intention-to-screen analysis, the detection rate for advanced colorectal neoplasia was significantly lower with FIT (OR 0.62, 95% CI 0.45-0.84, p=0.002) as compared to flexible sigmoidoscopy but not statistically different for CRC (OR 1.15, 95% CI 0.65-2.02, p=0.63). Conclusion: Despite lower participation amongst patients, CRC screening with flexible sigmoidoscopy leads to higher detection of advanced colorectal neoplasia, when compared to a single round of fecal immunochemical testing.

Simple Summary Colorectal cancer is still one of the deadliest cancers, even though its detection at early stages has been shown to be a key factor for reducing mortality. Screening methods are available, but their efficacy for detecting early-stage lesions is limited. In the present discovery stage study, we used a targeted mRNA assay in the stools to optimize the identification of patients bearing precancerous lesions as well as colorectal cancers at curable stages with only five targets, thus compatible with standard multiplex PCR. Although further validation is required, this assay has high potential for improving colorectal cancer screening efficacy. Abstract Current approved non-invasive screening methods for colorectal cancer (CRC) include FIT and DNA-FIT testing, but their efficacy for detecting precancerous lesions that are susceptible to progressing to CRC such as advanced adenomas (AA) remains limited, thus requiring further options to improve the detection of CRC lesions at earlier stages. One of these is host mRNA stool testing. The aims of the present study were to identify specific stool mRNA targets that can predict AA and to investigate their stability under a clinical-like setting. A panel of mRNA targets was tested on stool samples obtained from 102 patients including 78 CRC stage I-III and 24 AA as well as 32 healthy controls. Area under the receiver operating characteristic (ROC) curves were calculated to establish sensitivities and specificities for individual and combined targets. Stability experiments were performed on freshly obtained specimens. Six of the tested targets were found to be specifically increased in the stools of patients with CRC and three in the stools of both AA and CRC patients. After optimization for the choice of the 5 best markers for AA and CRC, ROC curve analysis revealed overall sensitivities of 75% and 89% for AA and CRC, respectively, for a ≥95% specificity, and up to 75% and 95% for AA and CRC, respectively, when combined with the FIT score. Targets were found to be stable in the stools up to 3 days at room temperature. In conclusion, these studies show that the detection of host mRNA in the stools is a valid approach for the screening of colorectal cancerous lesions at all stages and is applicable to a clinical-like setup.

Aims We evaluated the initial impact of COVID-19 outbreak on endoscopic procedures from a Gastroenterology departmentin a Portuguese hospital. Methods All esophagogastroduodenoscopies (EGD), colonoscopies, endoscopic retrograde cholangio-pancreatographies(ERCP) and endoscopic ultrasounds (EUS) performed between April and June 2020 were compared with all theseprocedures performed between April and June 2019. In EGD and colonoscopies, whether they were elective or urgent wasregistered. The reasons of procedures leading to new cancer diagnosis and the presence of advanced polyps incolonoscopies were recorded. Results Between April and June 2020, 513 EGD and colonoscopies were performed, 42 % of those performed during thesame trimester in 2019. Although this difference occurred mainly due to a reduction to 34.5 % in the number of electiveprocedures, urgent EGD and colonoscopies were also reduced to 73.2 %. The detection rate of advanced adenomas wassimilar in 2019 and 2020 (16.8 % in 2019 and 17.8 % in 2020), meaning that only one third were detected in 2020. In2020, 87.2 % of ERCP and 46.3 % of EUS from 2019 were done. 4 EGD in COVID-19 positive patients were performed inthis trimester. In 2020, only 46 % of new cancer diagnosis were made, when compared to the same period of 2019. This reduction wassignificant in colorectal and esophageal cancers, but not in gastric cancer. The proportions of new oncological diagnosisduring urgent procedures in 2019 and 2020 were 20.5 % and 38.9 % respectively. Conclusions Although repercussions from this pandemic on digestive Oncology are already evident, its real impact is farfrom being known. The delay of colorectal cancer diagnosis, the second most common cause of cancer death in Europe, willlead to a significant increase in overall morbimortality. National and international programs to recover this fall in endoscopicprocedures will be of the most importance to reduce this outcome of COVID-19.

Aims On February 25 , the first patient was diagnosed with COVID-19 in Austria. On March 16 (week 12) Austriangovernment imposed restrictions and subsequently the Austrian Medical Association has recommended to minimizescreening examinations in compliance with government restrictions. Aim Aim was to evaluate the impact of this recommendation on the number of weekly performed colonoscopies, detection of non-advanced adenomas, advanced adenomas (AA) and colorectal cancer (CRC) and to calculate how many undetectedadenomas could develop into CRC. Methods We analyzed number of colonoscopies and pathological findings within a quality assured national colorectal cancerscreening program before the COVID-19 pandemic (January 1 2019 - July 5 2019, Period 1) and compared those ratesto months with limited access to colonoscopy (January 1 2020 and July 5 2020, Period 2) with a two-tailed T-test, aWilcoxon-rank-test and a chi-square test. Results 23.700 colonoscopies were performed in Period 1, and 15.569 in Period 2. The mean rate of colonoscopies perweek in Period 1 was significantly higher than in Period 2 (877,78 [SD=190,44] versus 576,63 [SD=350,58], p = 0,003).4.655 non-advanced adenomas were detected in Period 1 versus 3.221 in Period 2 (p = 0,012). In total 1.863 AAs and 170CRCs were detected in Period 1 versus 1.166 AAs and 91 CRCs in Period 2. These rates did not differ significantly (p = 0,177, and p = 0,131). Conclusions During the COVID-10 the number of performed colonoscopies per endoscopist was significantly lowercompared to the years before but there was no difference in the detection of CRCs and AAs.

Background: Fecal immunochemical tests (FITs) are widely used for colorectal cancer (CRC) screening. The detection of early-stage cancer and advanced adenoma (AA), the most important premalignant lesion, is highly relevant to reducing CRC-related deaths. We aimed to assess sensitivity for the detection of CRC and AA stratified by tumor stage, number, size, histology of AA, and by location, age, sex, and body mass index (BMI). Methods: Participants of screening colonoscopy (n = 2043) and newly diagnosed CRC patients (n = 184) provided a stool sample before bowel preparation or CRC surgery. Fecal hemoglobin concentration was determined in parallel by nine different quantitative FITs among 94 CRC patients, 200 AA cases, and 300 participants free of advanced neoplasm. Sensitivities were calculated at original cutoffs and at adjusted cutoffs, yielding 93% specificity among all FITs. Results: At adjusted cutoffs, UICC stage I cancers yielded consistently lower sensitivities (range: 62–68%) compared to stage II–IV cancers (range: 73–89%). An even stronger gradient was observed according to T status, with substantially lower sensitivities for T1 (range: 39–57%) than for T2–T4 cancers (range: 71–100%). Sensitivities for the detection of participants with multiple AAs ranged from 55% to 64% and were by up to 25% points higher than sensitivities for T1 cancers. Conclusions: FITs detect stage I cancers and especially T1 cancers at substantially lower sensitivities than more advanced cancer stages. Participants with multiple AAs were detected with slightly lower sensitivities than stage I cancers and with even higher sensitivities than T1 cancers. Further research should focus on improving the detection of early-stage cancers.

Objectives Interval colorectal advanced adenoma (I-CRAA) carries insidious risk of interval colorectal cancer (I-CRC). The study aims to determine the frequency of I-CRAA after negative colonoscopy and discover the characteristics and the risk factors.Methods We retrospectively analyzed the information of the patients undergoing colonoscopy in the endoscopic center (2015-2019). Frequency of I-CRAA was calculated. The clinical features of I-CRAA were compared with sporadic colorectal advanced adenoma (Sp-CRAA). Results The frequency of I-CRAA was 0.71% (112/15759) per colonoscopy. I-CRAA was more likely to be located in the proximal colon (65.2% vs 34.8%, ppppp = 0.012) are helpful for the detection of I-CRAA. I-CRAA found within 1 year other than 2 or 3 years after the initial colonoscopy were usually found by an endoscopist with higher ADR.Conclusions I-CRAA is usually located in the proximal colon and has high pathological grade. Diabetes, diverticulosis, smoking history, alcohol intake, and family history of CRC are the risk factors. Its occurrence is more related to low-quality colonoscopy, especially within one year.

ObjectiveWhen screening for colorectal cancer (CRC) using quantitative faecal immunochemical tests (FIT), test parameters requiring consideration are the faecal haemoglobin concentration (f-Hb) positivity cut-off and the number of stools sampled. This observational study explored variation in f-Hb between samples and the relationship between sensitivity for advanced neoplasia (AN, cancer or advanced adenoma) and colonoscopy workload across a range of independently-adjusted parameter combinations.DesignQuantitative FIT data (OC-Sensor) were accessed from individuals undergoing personalised colonoscopic screening with an offer of 2-sample FIT in the intervening years. We estimated variation in f-Hb between samples in 12 710 completing 2-sample FIT, plus test positivity rates (colonoscopy workload) and sensitivity for AN according to parameter combinations in 4037 instances where FIT was done in the year preceding colonoscopy.ResultsThere was large within-subject variability between samples, with the ratio for the second to the first sample f-Hb ranging up to 18-fold for all cases, and up to 56-fold for AN cases. Sensitivity for AN was greatest at lower f-Hb cut-offs and/or using 2-sample FIT. Colonoscopy workload varied according to how parameters were combined. Using different cut-offs for 1-sample FIT and 2-sample FIT to return similar sensitivity, workload was less with 2-sample FIT when the sensitivity goal exceeded 35%.ConclusionVariation in f-Hb between samples is such that both parameters are crucial determinants of sensitivity and workload; independent adjustment of each should be considered. The 2-sample FIT approach is best for detecting advanced adenomas as well as CRC provided that the colonoscopy workload is feasible.

Colorectal cancer (CRC) is the second most common cancer in Germany. Screening colonoscopies are considered an effective tool for early detection and prevention of CRC and are recommended in Germany for citizens over the age of 55. To increase the participation rate for screening colonoscopies, an invitation procedure was initiated in parts of Germany for patients between the ages of 55 and 75 who had never undergone a screening colonoscopy before.We examined the number of participating patients before, during, and after the invitation procedure and compared the number of the participating patients who received a cover letter with the participating patients from the control group. Additionally, we classified the findings of the colonoscopies including CRC, advanced adenomas, and polyps.During the invitation period, the participation rate of the invitation group increased from 220 patients to 531 patients compared to 1256 to 1693 in the control group. The increase was significantly greater in patients with cover letters (+141% vs.+35%,Our study clearly indicates that personal invitation letters are an effective measure to increase overall participation rates in screening colonoscopies.

Background The overall aim of this study was to describe trends in participation rates and detection of lesions in a colorectal cancer (CRC) screening programme, during three rounds, using faecal immunochemical test (FIT). Methods National registers were used to collect data on invitations for CRC screening in the Basque Country (Spain) from 2009 to 2014. Information about participation, age, gender and lesions in each round were collected. Results A total of 961.533 individuals were included in the analysis; respectively, 584.950, 298.143 and 78.440 in the first, second and third rounds. The average participation rate was 68.4% (66.8, 70.4 and 72.3%, respectively by round; P < 0.001) and the positivity rate was 6.3% (7, 5.5 and 5.4%, respectively by round; P < 0.001). The participation rate increased significantly with age and was found to be higher in women versus men. A total of 15.144 advanced adenomas and 2.131 CRCs were diagnosed, leading to a detection rate of 23.9 and 3.4‰, respectively. Regarding gender, men had the highest rates in all periods and rounds. The detection rate of advanced neoplasia was lower in the regular when compared with irregular paricipants. Conclusions In a CRC screening, this organization obtained high FIT participation rates. Older participants and women were associated with a higher participation. The detection rate of lesions was higher in men, independent on age and round.

Background Colorectal cancer (CRC) is a leading cause of death worldwide. Polyp detection rate (PDR) and adenoma detection rate (ADR) are key focus in endoscopic research for CRC screening and prevention. Use of anti-spasmodic agents during colonoscopy to help identify adenomas and polyps has remained a controversial topic. Hyoscine butyl bromide (HBB) is the most commonly used anti-spasmodic agent in patients undergoing colonoscopy. Some randomized controlled trials (RCTs) have questioned the clinical efficacy and safety of routine use of HBB for polyp and adenoma detection rates. Methods We conducted a systematic search in PubMed and MEDLINE from inception until February 10, 2018, for studies which compared HBB with placebo. We used RevMan version 5.3 for analysis. Procedural end-points were polyps, adenomas, and advanced adenoma detection rates, mean number of polyps detected and cecal intubation time. Results We included seven RCTs with 2,588 patients in our analysis. A total of 1,301 patients were randomized to HBB arm and 1,287 to the placebo arm. There was no significant difference in the primary outcome of polyp detection rate, 654 in HBB group vs. 616 in the placebo group, (odds ratio (OR) = 1.11, confidence interval (CI) = 0.93 - 1.34, P = 0.25). There was no difference in secondary outcomes of adenoma detection rate, 430 in HBB group vs. 396 in the placebo group, (OR = 1.06, CI = 0.89 - 1.26, P = 0.51), advanced adenoma detection rate, 92 in HBB vs. 95 in placebo group (OR = 0.95, CI = 0.70 - 1.30, P = 0.76), mean number of polyps detected (point estimate = 0.12, CI = 0.00 - 0.23, P = 0.05), adenomatous polyps (OR = 0.84, CI = 0.39 - 1.81, P = 0.65) and cecal intubation time (point estimate = 0.73, CI = -1.98 - 0.52, P = 0.25) between the two groups. Conclusions The use of HBB in patients undergoing colonoscopy does not appear to improve polyp or adenoma detection rates. It showed a non-significant trend of increased mean number of polyps detected with HBB.

Fecal immunochemical tests (FITs) for hemoglobin are increasingly recommended and used in colorectal cancer (CRC) screening. We aimed to provide a detailed assessment of the sensitivity of FIT according to type and subsite of neoplasms in a true screening setting. A quantitative FIT (FOB Gold, Sentinel Diagnostics, Milano, Italy) was applied prior to colonoscopy by 3,466 participants of the German screening colonoscopy program. Subsite specific sensitivity for various types of colorectal neoplasms was derived by comparing FIT results with findings at screening colonoscopy. The most advanced finding at colonoscopy was CRC, advanced adenoma, and nonadvanced adenoma in 29, 354 and 686 cases, respectively. Per-adenoma sensitivity for large advanced adenomas (>1 cm) strongly varied by location (p 50% for those located in the descending or sigmoid colon. By contrast, FIT sensitivity was uniformly excellent for CRC and uniformly poor for nonadvanced adenomas, regardless of their location.

Aberrant DNA methylation detected in liquid biopsies is a promising approach for colorectal cancer (CRC) detection, including premalignant advanced adenomas (AA). We evaluated the diagnostic capability of serum NEUROG1 methylation for the detection of AA and CRC. A CpG island in NEUROG1 promoter was assessed by bisulfite pyrosequencing in a case-control cohort to select optimal CpGs. Selected sites were evaluated through a nested methylation-specific qPCR custom assay in a screening cohort of 504 asymptomatic family-risk individuals. Individuals with no colorectal findings and benign pathologies showed low serum NEUROG1 methylation, similar to non-advanced adenomas. Contrarily, individuals bearing AA or CRC (advanced neoplasia&mdash, AN), exhibited increased NEUROG1 methylation. Using &gt, 1.3518% as NEUROG1 cut-off (90.60% specificity), 33.33% of AN and 32.08% of AA were identified, detecting 50% CRC cases. Nonetheless, the combination of NEUROG1 with fecal immunochemical test (FIT), together with age and gender through a multivariate logistic regression resulted in an AUC = 0.810 for AN, and 0.796 for AA, detecting all cancer cases and 35&ndash, 47% AA (specificity 98&ndash, 95%). The combination of NEUROG1 methylation with FIT, age and gender demonstrated a convenient performance for the detection of CRC and AA, providing a valuable tool for CRC screening programs in asymptomatic individuals.

Although colorectal cancer (CRC) is the second leading cause of death in developed countries, current diagnostic tests for early disease stages are suboptimal. We have performed a combination of UHPLC-MS metabolomics and 16S microbiome analyses on 224 feces samples in order to identify early biomarkers for both advanced adenomas (AD) and CRC. We report differences in fecal levels of cholesteryl esters and sphingolipids in CRC. We identified Fusobacterium, Parvimonas and Staphylococcus to be increased in CRC patients and Lachnospiraceae family to be reduced. We finally described Adlercreutzia to be more abundant in AD patients&rsquo, feces. Integration of metabolomics and microbiome data revealed tight interactions between bacteria and host and performed better than FOB test for CRC diagnosis. This study identifies potential early biomarkers that outperform current diagnostic tools and frame them into the stablished gut microbiota role in CRC pathogenesis.

Background Methylated SFRP2 was previously reported as a non-invasive biomarker for colorectal cancer (CRC) detection with a relatively low sensitivity for early stage CRC. The purpose of this study was to evaluate the performance of a new plasma based CRC screening assay, SpecColon test, which tested methylated SFRP2 and SDC2 simultaneously in a single qPCR reaction, in detecting CRC and advanced adenomas (AA). Method One milliliter plasma of 122 CRC patients, 12 AA patients, 93 patients with benign polyps, and 91 normal individuals were collected from the Affiliated Hospital of Xuzhou Medical University, and all samples were examined by SpecColon test. Results The sensitivities for detecting AA and CRC by methylated SFRP2 alone were 50.0% (95% CI: 22.2–77.7%) and 63.1% (95% CI: 53.9–71.5%) with a specificity of 90.1% (95% CI: 81.6–95.1%). The sensitivities by methylated SDC2 alone were 33.3% (95% CI: 11.3–64.6%) and 56.6% (95% CI: 47.3–65.4%) with a specificity of 95.6% (95% CI: 88.5–98.6%). However, when methylated SFRP2 and methylated SDC2 were combined, the sensitivities for AA and CRC detection improved to 58.3% (95% CI: 28.6–83.5%) and 76.2% (95% CI: 67.5–83.3%) with a specificity of 87.9% (95% CI: 79.0–93.5%). The positive detection rates of benign polyp group and normal control group showed no significant difference (p > 0.01), whereas AA and CRC groups had significantly higher positive detection rates than normal individual group (p Conclusion The sensitivities for AA and early stage CRC by combined test of methylated SFRP2 and methylated SDC2, the so called SpecColon test, improved upon those by either biomarker alone without significant impact on the specificity. It has the potential to become a powerful, convenient and highly effective screening tool for early CRC screening.

Many methylation markers associated with colorectal cancer have been reported, but few of them are actually used in clinical practice. This study was designed to identify promising methylation markers for stool-based detection of colorectal cancer. We first tested 324 reported methylated genes in colorectal cancer cell lines. A total of 111 heavily methylated genes were selected for further evaluation with a pilot set of colorectal cancer and adjacent normal tissues. Ten high-yield methylated markers were further studied in 319 tissue samples. Eventually, the four best markers, namely methylated COL4A1, COL4A2, TLX2, and ITGA4, were validated in 240 stool samples. Methylation-specific PCR (MSP) and real-time MSP (qMSP) were employed for methylation detection. After hierarchical selection, ten differentially methylated genes demonstrated high sensitivity and specificity for the detection of colorectal cancer in tissue. When validated in stool samples, the four with the best performance—COL4A1, COL4A2, TLX2, and ITGA4—were able to detect 82.5–92.5% of colorectal cancers and 41.6–58.4% of adenomas (≥ 1 cm) with specificity of 88.0–96.4%. The best combination, COL4A2 and TLX2, detected 91.3% of CRCs and 51.9% of advanced adenomas in stool with 97.6% specificity. Methylated COL4A1, COL4A2, TLX2, and ITGA4 demonstrated high accuracy for the detection of colorectal neoplasms in stool. They are potentially valuable markers for the detection of colorectal cancer.

Colorectal cancer (CRC) is the second‐leading cause of cancer‐related mortality worldwide, which may be effectively reduced by early screening. Colon cancer secreted protein‐2 (CCSP‐2) is a promising blood marker for CRC. An electric‐field effect colorectal sensor (E‐FECS), an ion‐sensitive field‐effect transistor under dual gate operation with nanostructure is developed, to quantify CCSP‐2 directly from patient blood samples. The sensing performance of the E‐FECS is verified in 7 controls and 7 CRC samples, and it is clinically validated on 30 controls, 30 advanced adenomas, and 81 CRC cases. The concentration of CCSP‐2 is significantly higher in plasma samples from CRC and advanced adenoma compared with controls (both P < 0.001). Sensitivity and specificity for CRC versus controls are 44.4% and 86.7%, respectively (AUC of 0.67), and 43.3% and 86.7%, respectively, for advanced adenomas (AUC of 0.67). CCSP‐2 detects a greater number of CRC cases than carcinoembryonic antigen does (45.6% vs 24.1%), and the combination of the two markers detects an even greater number of cases (53.2%). The E‐FECS system successfully detects CCSP‐2 in a wide range of samples including early stage cancers and advanced adenoma. CCSP‐2 has potential for use as a blood‐based biomarker for CRC.

Adenoma detection rate (ADR) is the best established quality parameter for screening colonoscopy. Guidelines recommend a target ADR25% because previous studies have shown that patients of endoscopists with higher ADRs have a lower risk of postcolonoscopy interval cancers. However, studies have shown that improvement in ADR mainly results in increased detection of clinically irrelevant nonadvanced adenomas (NAAs). The impact of ADR on the detection of advanced adenomas (AAs) as well as adverse event rates has yet to be determined.A total of 218,193 screening colonoscopies performed between 2007 and 2010 by 262 endoscopists within the Austrian quality assurance program were analyzed. We divided endoscopists into quintiles based on ADRs and calculated mean advanced ADRs (AADRs), NAA detection rates (NAADRs), and adverse event rates for each quintile. Spearman rank-order was used to calculate overall correlations between ADRs and AADRs as well as adverse event rates. Endoscopists with an ADR 25% were compared with those with an ADR25%.Fifty-one percent of patients were women. Mean ADR was 23.03% (95% confidence interval [CI], 21.93-24.13), AADRs 7.72% (95% CI, 7.19-8.25), and NAADRs 15.31% (95% CI, 14.36-16.27). Overall, there was a significant correlation between ADR and AADR (rho = .51; P .001). When ADR was divided into quintiles, mean AADR increased with increasing ADR. Even in the highest ADR group (ADR, 31.36%-52.27%) there was a further increase in AADR with a mean of 10.75% (95% CI, 9.31-12.19). Importantly, NAADRs increased continuously with improvement in ADRs but never dissociated from a simultaneous improvement in AADRs. However, there was also a significant correlation of ADRs and endoscopic adverse events (rho = .26, P .001), even if the perforation rate of .028% (95% CI, .004-.052) in the highest ADR group still remained within the accepted limits based on guidelines.Increasing ADR is associated with improved detection of AAs and therefore is likely to prevent more cases of colorectal cancer. However, higher ADR was also associated with a higher rate of adverse events, although the adverse event rate was low.

Colorectal cancer (CRC) is largely preventable with colonoscopy and other screening modalities. However, the effectiveness of screening and surveillance depends on the quality of the colonoscopy exam. Adenoma detection rate (ADR) is the best-validated metric by which we measure individual physicians’ performance. Recent evidence suggests that ADR benchmarks may be inappropriately low. There is proof that improving ADR leads to significant reductions in post-colonoscopy CRC (PCCRC). Two studies have demonstrated that when a colonoscopy is performed by physicians with higher ADRs, patients are less likely to have advanced adenomas on surveillance and less likely to develop or die from PCCRC. Finally, there is at least some evidence that higher ADRs do not lead to more cumulative surveillance exams. The ADR is a useful outcome measure that can provide individual endoscopists and their patients with information about the likelihood of developing PCCRC. To achieve the lowest possible PCCRC rate, we should be striving for higher ADRs. While strategies and innovations may help a bit in improving ADRs, our efforts should focus on ensuring a complete mucosal exam for each patient. Behavioral psychology theories may provide useful frameworks for studying motivating factors that drive a careful exam.

Objective Colorectal cancer (CRC) screening programmes based on faecal immunochemical testing for haemoglobin (FIT) typically use a screening interval of 2 years. We aimed to estimate how alternative FIT strategies that use a lower than usual positivity threshold followed by a longer screening interval compare with conventional strategies. Methods We analysed longitudinal data of 4523 Dutch individuals (50–74 years at baseline) participating in round I of a one-sample FIT screening programme, of which 3427 individuals also participated in round II after 1–3 years. The cohort was followed until 2 years after round II. In both rounds, a cut-off level of ≥50 ng haemoglobin (Hb)/mL buffer (corresponding to 10 µg Hb/g faeces) was used, representing the standard scenario. We determined the cumulative positivity rate (PR) and the numbers of subjects diagnosed with advanced adenomas (N_AdvAd) and early stage CRC (N_earlyCRC) in the cohort over two rounds of screening (standard scenario) and compared it with hypothetical single-round screening with use of a lower cut-off and omission of the second round (alternative scenario). Results In the standard scenario, the cumulative (ie, round I and II combined) PR, N_AdvAd and N_earlyCRC were 13%, 180% and 26%, respectively. In alternative scenarios using a cut-off level of respectively ≥11 and ≥22 ng Hb/mL buffer (corresponding to 2 and 4 µg Hb/g faeces), the PRs were 18% and 13%, the N_AdvAd were 180 and 162 and the N_earlyCRC ranged between 22–27 and 22–26. Conclusions The diagnostic yield of FIT screening using a lowered positivity threshold in combination with an extended screening interval (up to 5 years) may be similar to conventional FIT strategies. This justifies and motivates further research steps in this direction.

Background: Prevalence of (pre)cancerous colorectal lesions are higher in men than in women, although transition rates from advanced lesions to cancer is similar in both sexes. Our aim was to investigate whether the sex-specific difference in incidence of premalignant colorectal lesions might be explained by the impact of risk factors. Methods: A cross-sectional study analysing health check-up examinations and screening colonoscopies performed within a national quality assurance program. Results: A total of 25 409 patients were included in this study, 50.8% were women. Median age for both sexes was 60 years (interquartile range (IQR) 54–67). A multivariable model showed that risk factors mediated only 0.6 of the 10.4% gender gap in adenoma and 0.47 of the 3.2% gender gap in advanced adenoma detection rate. Smoking was the only independent risk factor with a varying sex-specific effect (men OR 1.46, CI 1.29, 1.64, women OR 1.76, CI 1.53, 2.06) and advanced adenomas (men OR 1.06, CI 0.80–1.42; women OR 2.08, CI 1.52–2.83). Independent risk factors for adenomas were BMI (OR 1.35 per IQR, CI 1.25–1.47) and triglyceride level (OR 1.03 per IQR, CI 1.00–1.06); for advanced adenomas physical activity (none vs regular: OR 1.54, CI 1.18–2.00, occasional vs regular: OR 1.17, CI 1.00–1.38), cholesterol level (OR 1.13 per IQR, CI 1.02–1.25), blood glucose level (OR 1.05 per IQR, CI 1.01–1.09) and alcohol score (OR 1.09 per IQR, CI 1.01–1.18). Conclusions: Risk factors cannot explain higher prevalence rates in men. Results of this study strongly underline the need for sex-specific screening recommendations.

43 Background: Blood-based screening tests for colorectal cancer (CRC) with high sensitivity and specificity are needed to improve adherence, facilitate early detection, and ultimately reduce mortality from CRC. Current stool-based tests have a sensitivity of 24-42% for colorectal advanced adenomas (AAs), while blood tests that rely on tumor-derived cell-free DNA (cfDNA) methylation signatures have shown limited sensitivity for AAs. Here we demonstrate the ability to detect AAs from blood using a multiomics test that incorporates both tumor- and immune-derived signatures, and compare it to the performance of a cfDNA methylation-only test. Methods: Participants enrolled in a prospective study (NCT03688906) were included in this analysis. The multiomics test includes signatures for cell-free nucleic acids based on next-generation sequencing, and for plasma proteins based on high-throughput multiplexed assays. Signatures are integrated computationally with a combination of convolutional neural networks and regularized logistic regression. We compared the multiomics test with one based on cfDNA methylation only. Results: This sub-study included 542 participants (AA: n = 122; colonoscopy-confirmed negative controls: n = 420). Participants with AA were 56% male with a mean age of 63 years, and colonoscopy-confirmed negative controls were 54% male with a mean age of 61 years. The multiomics test achieved a sensitivity of 41% (n = 50/122, 95% CI 34-48%) at 90% specificity (377/420). By contrast, the cfDNA methylation-only test achieved a sensitivity of 20% (24/122, 95% CI 15-25%) at 91% specificity (383/420). Performance was also analyzed by histological subtype and location, and superiority of the multiomics test to the cfDNA-methylation-only test was consistently observed. Conclusions: A novel multiomics blood test can detect colorectal AAs at a sensitivity and specificity comparable to existing stool-based tests. Combining signatures from both tumor- and immune-derived sources resulted in AA sensitivity greater than that of cfDNA-methylation alone.

25 Background: Effective colorectal cancer (CRC) prevention and screening requires sensitive detection of all advanced neoplasias (colorectal cancer and advanced adenomas). Existing noninvasive screening approaches cannot accurately detect precancerous adenomas with high sensitivity. Here we describe a multi-factor assay (RNA-FIT test) that combines 8 stool-derived eukaryotic RNA (seRNA) biomarkers, patient demographic information (smoking status), and a fecal immunochemical test (FIT) to sensitively detect advanced colorectal neoplasias and other precancerous adenomas in a 1,305 average risk (45-75 age) prospective cohort. Methods: Average-risk patients undergoing colorectal cancer screening were prospectively evaluated with the RNA-FIT assay prior to an optical colonoscopy. RNA-FIT test results were generated using an ordinal regression model and results were compared to the colonoscopy findings. The model was initially assessed via 5-fold internal cross-validation of the training set and the ultimate model performance was assessed on a hold out testing set. Results: Of the 1,305 eligible patients recruited, 939 were included in the training set and 366 samples were reserved for the hold out testing set. When evaluating all 5 folds of the training set, internal cross validation attained a 61% sensitivity for advanced neoplasias (n = 69), 22% sensitivity for other adenomas (n = 279), 80% specificity for hyperplastic polyps (n = 155) and 86% specificity for no findings on a colonoscopy (n = 436). When employed on the testing set, the RNA-FIT test attained a 62% sensitivity for advanced neoplasias (n = 52), 27% sensitivity for other adenomas (n = 139), 78% specificity for hyperplastic polyps (n = 74) and 84% specificity for no findings on a colonoscopy (n = 101). Sensitivity for colorectal cancer and advanced adenomas with high-grade dysplasia / carcinoma in-situ was 100% in both the training set (n = 6) and hold out testing set (n = 5). Sensitivity for villous / tubulovillous adenomas was 65% in the training set (n = 23) and 60% in the hold out testing set (n = 15). Additional retrospective sample collection from patients with CRC is ongoing to further validate assay sensitivity for CRC. Conclusions: The RNA-FIT assay demonstrated clinically relevant detection of all advanced neoplasia, including early carcinomas, advanced adenomas, and other precancerous lesions. This assay could represent a noninvasive option to prevent colorectal cancer development through precancerous adenoma detection.

The area of indications for advanced colonoscopic techniques like endoscopic mucosa resection, submucosal dissection and transanal endoscopic microsurgery is increasing. The demand for expertise ha...

Introduction: The fecal volatolome, which is composed of fecal volatile organic compounds (VOCs), seems to hold potential as non-invasive biomarker for the detection of colorectal cancer (CRC) and its precursor lesions advanced adenomas (AA). The potential of the fecal volatolome has been subject of various studies using either chemical analytical or pattern-recognition techniques. The available literature on the potential of the fecal volatolome as CRC and AA biomarker was reviewed. Methods: A systematic literature search was conducted in PubMed, Embase, the Cochrane Library, Google Scholar and ResearchGate using the following keywords: Colorectal Cancer, Advanced Adenoma, Volatile Organic Compound, Metabolome, Gas Chromatrography–Mass Spectrometry, Selected-Ion Flow-Tube Mass Spectrometry, eNose, and Fecal Biomarkers. Results: Eighty-eight titles or abstracts were identified from the search, of which 11 papers describing the potential of the fecal volatolome for CRC detection were selected. In these studies, different techniques were used for the headspace analyses of fecal VOCs, limiting the possibility to compare outcomes. Increased levels of amino acids and short chain fatty acids, and decreased levels of bile acids and polyol alcohols in the gas phase of feces were observed repeatedly. All selected papers reported high diagnostic value for the detection of both CRC and AA based on fecal VOCs. Conclusion: Based on the included studies, fecal VOC analyses seem promising for future screening of CRC and AA, with potentially improved test performances allowing for earlier detection of AA and CRC and consequently earlier initiation of treatment, possibly reducing morbidity and mortality rates next to lower rates of (unnecessary) colonoscopies.

Background Short telomeres have been associated with increased risk of many cancers, particularly cancers of the gastrointestinal tract including esophagus and stomach. However, the association between telomere length (TL) and colorectal cancer and its precursors, colorectal polyps, is not clear. Methods We investigated the relationship between TL and risk of colorectal polyp subtypes in a colonoscopy-based study in western Washington. Participants were 35–79 year-old enrollees at an integrated health care system, who underwent a colonoscopy between 1998 and 2007 (n = 190), completed a self-administered questionnaire, provided blood samples, and were distinguished as having adenomas, serrated polyps, or as polyp-free controls through a standardized pathology review. Telomere length (T) relative to a single copy gene (S) was measured in circulating leukocytes from stored buffy coat samples using quantitative polymerase chain reaction. Multivariable polytomous logistic regression was used to compare case groups with polyp-free controls and other case groups; adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated. Results TL in the shortest tertile (T/S ratio

Background: The expression of doublecortin-like kinase 1 (DCLK1) has been investigated in cancer; however not in precancerous adenomatous polyps. Materials and Methods: Immunohistological expression of DCLK1 was evaluated in various grades of adenomas, cancerous polyps, and hyperplastic polyps in resected human tissue specimens. Results: Ninety-two specimens were positive for DCLK1 and 134 were negative. Cancerous polyps showed a high DCLK1 positivity rate compared to adenomas (68.4% vs. 36.8%; p

Objective The English Bowel Cancer Screening Programme (BCSP) recommends 3 yearly colonoscopy surveillance for patients at intermediate risk of colorectal cancer (CRC) postpolypectomy (those with three to four small adenomas or one ≥10 mm). We investigated whether faecal immunochemical tests (FITs) could reduce surveillance burden on patients and endoscopy services. Design Intermediate-risk patients (60–72 years) recommended 3 yearly surveillance were recruited within the BCSP (January 2012–December 2013). FITs were offered at 1, 2 and 3 years postpolypectomy. Invitees consenting and returning a year 1 FIT were included. Participants testing positive (haemoglobin ≥40 µg/g) at years one or two were offered colonoscopy early; all others were offered colonoscopy at 3 years. Diagnostic accuracy for CRC and advanced adenomas (AAs) was estimated considering multiple tests and thresholds. We calculated incremental costs per additional AA and CRC detected by colonoscopy versus FIT surveillance. Results 74% (5938/8009) of invitees were included in our study having participated at year 1. Of these, 97% returned FITs at years 2 and 3. Three-year cumulative positivity was 13% at the 40 µg/g haemoglobin threshold and 29% at 10 µg/g. 29 participants were diagnosed with CRC and 446 with AAs. Three-year programme sensitivities for CRC and AAs were, respectively, 59% and 33% at 40 µg/g, and 72% and 57% at 10 µg/g. Incremental costs per additional AA and CRC detected by colonoscopy versus FIT (40 µg/g) surveillance were £7354 and £180 778, respectively. Conclusions Replacing 3 yearly colonoscopy surveillance in intermediate-risk patients with annual FIT could reduce colonoscopies by 71%, significantly cut costs but could miss 30%–40% of CRCs and 40%–70% of AAs. Trial registration number ISRCTN18040196; Results.

Colorectal cancer screening programmes in Italy invite 50-69-year-old residents for a faecal immunochemical test every two years, regardless of their citizenship.The 2013 National Survey on Italian colorectal cancer screening programmes compared immigrants born in low- or middle-income countries with subjects who were born in Italy, by collecting aggregated data on compliance, faecal immunochemical test results, compliance with colonoscopy, detected lesions and stage at diagnosis separately for Italians and immigrants.Overall, 85 screening programmes invited 3,292,451 subjects, of whom 192,629 had been born abroad (5.9%). Compliance with invitation was lower in immigrants (34.3% vs. 51.3% in Italians), with p0.001. Compliance was higher in females, regardless of the country of birth, in the youngest age group of immigrants but in the oldest of Italians. Immigrants showed a borderline excess of standardised faecal immunochemical test positivity rate at first screening (5.4% vs. 5.1% in Italians, p=0.05) and a significant excess at repeat screenings (4.8% vs. 4.4%, p=0.002). The detection rates for carcinoma and advanced adenomas were lower in immigrants than in Italians at first screening (respectively 1.34‰ vs. 1.62‰ and 8.41‰ vs. 9.25‰) - although the differences were not statistically significant - but not at repeat screening (respectively 1.06‰ vs. 0.98‰ and 6.90‰ vs. 6.79‰).Migrants showed a lower compliance with screening than Italians. The prevalence of neoplasia was lower at first screening and similar to the Italians' at repeat screenings.

Background: Colorectal cancer is the fourth cause of cancer-related deaths worldwide, though detection at early stages associates with good prognosis. Thus, there is a clear demand for novel non-invasive tests for the early detection of colorectal cancer and premalignant advanced adenomas, to be used in population-wide screening programs. Aberrant DNA methylation detected in liquid biopsies, such as serum circulating cell-free DNA (cfDNA), is a promising source of non-invasive biomarkers. This study aimed to assess the feasibility of using cfDNA pooled samples to identify potential serum methylation biomarkers for the detection of advanced colorectal neoplasia (colorectal cancer or advanced adenomas) using microarray-based technology. Results: cfDNA was extracted from serum samples from 20 individuals with no colorectal findings, 20 patients with advanced adenomas, and 20 patients with colorectal cancer (stages I and II). Two pooled samples were prepared for each pathological group using equal amounts of cfDNA from 10 individuals, sex-, age-, and recruitment hospital-matched. We measured the methylation levels of 866,836 CpG positions across the genome using the MethylationEPIC array. Pooled serum cfDNA methylation data meets the quality requirements. The proportion of detected CpG in all pools (> 99% with detection p value < 0.01) exceeded Illumina Infinium methylation data quality metrics of the number of sites detected. The differential methylation analysis revealed 1384 CpG sites (5% false discovery rate) with at least 10% difference in the methylation level between no colorectal findings controls and advanced neoplasia, the majority of which were hypomethylated. Unsupervised clustering showed that cfDNA methylation patterns can distinguish advanced neoplasia from healthy controls, as well as separate tumor tissue from healthy mucosa in an independent dataset We also observed that advanced adenomas and stage I/II colorectal cancer methylation profiles, grouped as advanced neoplasia, are largely homogenous and clustered close together. Conclusions: This preliminary study shows the viability of microarray-based methylation biomarker discovery using pooled serum cfDNA samples as an alternative approach to tissue specimens. Our strategy sets an open door for deciphering new non-invasive biomarkers not only for colorectal cancer detection, but also for other types of cancers. This work received funding from Plan Nacional I + D + I 2015-2018 (Accion Estrategica en Salud) Instituto de Salud Carlos III (Spain)-FEDER (PI15/02007), "Fundacion Cientifica de la Asociacion Espanola contra el Cancer" (GCB13131592CAST), and support from Centro Singular de Investigacion de Galicia (Conselleria de Cultura, Educacion e Ordenacion Universitaria) (ED431G/02, Xunta de Galicia and FEDER- European Union). Maria Gallardo-Gomez is supported by a predoctoral fellowship from Ministerio de Educacion, Cultura y Deporte (Spanish Government) (FPU15/02350).

Guidelines recommend surveillance colonoscopies based exclusively on findings at baseline colonoscopy. This recommendation leads to the paradox that the higher the baseline colonoscopy quality, the more surveillance colonoscopies will be indicated according to current guidelines.The aim of this study was to evaluate the effect on follow-up findings of different quality metrics of the endoscopist performing the baseline colonoscopy.This retrospective cohort study included individuals with advanced adenomas at baseline colonoscopy. Adenoma detection rate (ADR) and adenomas per colonoscopy rate (APCR) were determined for 44 endoscopists. Surveillance colonoscopies were checked after systematic tracking.A total of 574 individuals were diagnosed with advanced adenomas, of whom 270 received a surveillance colonoscopy. Patients whose baseline colonoscopy endoscopist had an ADR lower than the median of 33.8% had significantly higher rates of advanced neoplasia at follow-up (13.1% vs 4.0%;Our results suggest that the risk of identifying advanced adenomas at follow-up is closely related to the quality metrics of the endoscopist who performs the baseline colonoscopy.

Despite being readily preventable, colorectal cancer ranks second behind only lung cancer in overall mortality. However, this situation could be reversed if screening tests that effectively detect advanced adenomas and early cancers were broadly applied. Computed tomographic colonography (CTC) reflects an ideal balance of minimal invasiveness with high-level performance, assuming all facets of the examination are appropriately addressed. Unfortunately, this promising screening test remains grossly underused. This article details the technical and interpretive approaches used by one successful CTC screening program.

In this manuscript, we review current surveillance guidelines for serrated polyps (SPs) and discuss how recent studies inform the selection of appropriate surveillance intervals for patients with SPs. Large and/or proximal SPs, particularly sessile serrated polyps (SSPs), are associated with increased risk of both synchronous and metachronous neoplasia, including advanced adenomas and colorectal cancer (CRC). Persons harboring multiple SSPs or dysplastic SSPs are at the highest risk. Moreover, a high percentage of large and/or proximal SPs are reclassified as SSPs when read by trained gastrointestinal pathologists, even if they were originally reported as hyperplastic polyps. These findings support the adoption of surveillance guidelines that prescribe closer surveillance of large and/or proximal SPs, regardless of subtype. SSPs remain a challenge to reliably identify, resect, and diagnose via histology. The increased risk of future neoplasia in patients with SSPs is likely driven by a combination of underdetection, inadequate removal, misclassification, and biology. Until further evidence emerges, we support guidelines that recommend close surveillance of patients with a history of large and/or proximal SPs and SSPs specifically in order to mitigate the threat of interval CRC.