Multicentre randomised controlled trial on virtual chromoendoscopy in the detection of neoplasia during colitis surveillance high-definition colonoscopy (the VIRTUOSO trial)

BACKGROUND

Longstanding colonic IBD increases the risk of developing colorectal cancer. The utility of chromoendoscopy with standard-definition white light technology has been established. However, the use of high-definition virtual chromoendoscopy (HDV) in colitis surveillance remains undefined.

OBJECTIVE

To compare the performance of HDV (i-scan OE mode 2) with high-definition white light (HDWL) for detection of neoplasia in patients with IBD undergoing surveillance colonoscopy. Additionally, we assessed the utility of protocol-guided quadrantic non-targeted biopsies.

DESIGN

A multioperator randomised controlled trial was carried out in two centres in the UK. Total of 188 patients (101 men, mean age 54) with longstanding ulcerative or Crohn's colitis were randomised, prior to starting the surveillance colonoscopy, to using either HDV (n=94) or HDWL (n=94) on withdrawal. Targeted and quadrantic non-targeted biopsies were taken in both arms per-randomisation protocol. The primary outcome was the difference in neoplasia detection rate (NDR) between HDV and HDWL.

RESULTS

There was no significant difference between HDWL and HDV for neoplasia detection. The NDR was not significantly different for HDWL (24.2%) and HDV (14.9%) (p=0.14). All intraepithelial neoplasia (IEN) detected contained low-grade dysplasia only. A total of 6751 non-targeted biopsies detected one IEN only. The withdrawal time was similar in both arms of the study; median of 24 min (HDWL) versus 25.5 min (HDV).

CONCLUSION

HDV and HDWL did not differ significantly in the detection of neoplasia. Almost all neoplasia were detected on targeted biopsy or resection. Quadrantic non-targeted biopsies have negligible additional gain.

TRIAL REGISTRATION NUMBER

Clinical Trial.gov ID NCT02822352.

To what extent is male excess risk of advanced colorectal neoplasms explained by known risk factors? Results from a large German screening population

Colorectal cancer (CRC) incidence and prevalence of its precursors are substantially higher among males than among females in most countries but the reasons for the male excess risk are incompletely understood. We aimed to assess to what extent it is explained by known risk factors. Prevalence of advanced neoplasia (AN, ie, CRC or advanced adenoma) and CRC risk and preventive factors were ascertained among 15 985 participants of screening colonoscopy aged 55-79 years in Germany. Logistic regression was used to calculate odds ratios (ORs) for the association between male sex and AN with and without adjustment for known risk and preventive factors. In age-adjusted comparisons, men had 2-fold increased risk for AN compared to women (OR = 1.98, 95% confidence interval [CI] 1.79-2.19). After comprehensive adjustment for medical, lifestyle and dietary factors, the OR was reduced to 1.52 (95% CI 1.30-1.77), suggesting that these factors accounted for 47% of male excess risk. Male excess risk increased from proximal colon to distal colon and rectum, with age-adjusted ORs (95% CI) of 1.63 (1.38-1.91), 2.13 (1.85-2.45) and 2.36 (1.95-2.85), respectively, and with the proportion of excess risk explained by covariates being lower for AN in the rectum (26%) than for AN in the proximal (52%) or distal colon (46%). Male excess risk was somewhat lower (age-adjusted OR 1.87) and explained excess risk was smaller (36%) when men were compared to women who never used hormone replacement therapy. In conclusion, most of the male excess risk and the potential to overcome it remain to be explored by further research.

Evaluation of a 92 multiplex protein panel in detection of colorectal cancer and high-risk adenoma in 784 symptomatic individuals

BACKGROUND

Blood-based protein biomarkers for detection of colorectal cancer (CRC) have been submitted to intense research to improve the full potential in screening for CRC.

OBJECTIVE

The aim was to explore the diagnostic performance of 92 proteins related to inflammation and carcinogenesis in detection of CRC or precancerous lesions.

METHODS

Blood-samples were collected from 4,698 individuals undergoing colonoscopy. An explorative unmatched case-control study was designed with 294 cases (individuals with CRC or high-risk colorectal adenoma) and 490 controls (individuals with low-risk colorectal adenoma, non-malignant findings or clean colorectum at colonoscopy). Protein profiling was performed by multiplex proximity extension assay. Statistical analyses were performed as univariate and multivariate logistic regression analyses.

RESULTS

Univariably, CSF-1, MMP12 and IL8 demonstrated superior performance in discrimination of individuals with CRC. Recurrently, IL8 was included as contributor in majority of multivariate models discriminating individuals with CRC. The multivariate evaluation in discrimination of individuals with CRC demonstrated AUC=ROC 0.82, sensitivity = 0.39 at specificity = 0.80. Discrimination of individuals with late stage CRC from individuals with clean colorectum demonstrated AUC=ROC 0.90, sensitivity = 0.58 at specificity = 0.80.

CONCLUSIONS

A subset of biomarker candidates, specifically IL8, investigated in the present study suggest a potential as blood-based biomarkers in screening of CRC.

Prevalence and risk factors for sessile serrated lesions in an average risk colorectal cancer screening population

BACKGROUND AND AIM

The reported prevalence and risk factors for sessile serrated lesions (SSLs) show significant variation. We aimed to specifically study the prevalence and potential risk factors of SSLs in an average risk colorectal cancer (CRC) screening population of Chinese subjects.

METHODS

This is a case-control study of prospectively collected data from a territory-wide colorectal screening program in Hong Kong. Information on risk factors was obtained from questionnaires completed prior to screening colonoscopy. We compared subjects with SSLs against controls without these lesions to identify potential risk factors using multivariable logistic regression.

RESULTS

Of 12 039 asymptomatic screening subjects, 6011 subjects received a screening colonoscopy with 2214 subjects (36.8%) having conventional adenomas, 486 subjects (8.1%) having hyperplastic polyps, and 85 subjects (1.4%) having SSLs only. Of these subjects, three had synchronous advanced adenomas and were excluded from the analysis. More than 60% of these lesions were in the proximal colon. We compared these 82 subjects with SSLs only and 3226 controls without any polyps. After multivariable logistic regression, age ≥ 66 years, smoking, and diabetes mellitus (DM) were significant independent risk factors for SSLs.

CONCLUSION

In this study, we report the prevalence of SSLs to be 1.4%. Age ≥ 66 years, smoking, and DM were independent risk factors for these lesions. Our findings provide relevant new data that should be taken into consideration when designing region-specific surveillance programs for SSLs with the ultimate goal of reducing the risk of CRC.

WASh multicentre randomised controlled trial: water-assisted sigmoidoscopy in English NHS bowel scope screening

OBJECTIVES

The English Bowel Cancer Screening Programme invites 55 year olds for a sigmoidoscopy (Bowel Scope Screening (BSS)), aiming to resect premalignant polyps, thus reducing cancer incidence. A national patient survey indicated higher procedural pain than anticipated, potentially impacting on screening compliance and effectiveness. We aimed to assess whether water-assisted sigmoidoscopy (WAS), as opposed to standard CO₂ technique, improved procedural pain and detection of adenomatous polyps.

DESIGN

The WASh (Water-Assisted Sigmoidoscopy) trial was a multicentre, single-blind, randomised control trial for people undergoing BSS. Participants were randomised to either receive WAS or CO₂ from five sites across England. The primary outcome measure was patient-reported moderate/severe pain, as assessed by patients on a standard Likert scale post procedure prior to discharge. The key secondary outcome was adenoma detection rate (ADR). The costs of each technique were also measured.

RESULTS

1123 participants (50% women, mean age 55) were randomised (561 WAS, 562 CO₂). We found no difference in patient-reported moderate/severe pain between WAS and CO₂ (14% in WAS, 15% in CO2; p=0.47). ADR was 15% in the CO₂ arm and 11% in the WAS arm (p=0.03); however, it remained above the minimum national performance standard in both arms. There was no statistical difference in mean number of adenomas nor overall polyp detection rate. There was negligible cost difference between the two techniques.

CONCLUSION

In the context of enema-prepared unsedated screening sigmoidoscopies performed by screening-accredited endoscopists, no difference in patient-reported pain was seen when using either a CO₂ or WAS intubation technique.

TRIAL REGISTRATION NUMBER

ISRCTN81466870.

Tissue mRNA for S100A4, S100A6, S100A8, S100A9, S100A11 and S100P Proteins in Colorectal Neoplasia: A Pilot Study

S100 proteins are involved in the pathogenesis of sporadic colorectal carcinoma through different mechanisms. The aim of our study was to assess tissue mRNA encoding S100 proteins in patients with non-advanced and advanced colorectal adenoma. Mucosal biopsies were taken from the caecum, transverse colon and rectum during diagnostic and/or therapeutic colonoscopy. Another biopsy was obtained from adenomatous tissue in the advanced adenoma group. The tissue mRNA for each S100 protein (S100A4, S100A6, S100A8, S100A9, S100A11 and S100P) was investigated. Eighteen biopsies were obtained from the healthy mucosa in controls and the non-advanced adenoma group (six individuals in each group) and thirty biopsies in the advanced adenoma group (ten patients). Nine biopsies were obtained from advanced adenoma tissue (9/10 patients). Significant differences in mRNA investigated in the healthy mucosa were identified between (1) controls and the advanced adenoma group for S100A6 (p = 0.012), (2) controls and the non-advanced adenoma group for S100A8 (p = 0.033) and (3) controls and the advanced adenoma group for S100A11 (p = 0.005). In the advanced adenoma group, differences between the healthy mucosa and adenomatous tissue were found in S100A6 (p = 0.002), S100A8 (p = 0.002), S100A9 (p = 0.021) and S100A11 (p = 0.029). Abnormal mRNA expression for different S100 proteins was identified in the pathological adenomatous tissue as well as in the morphologically normal large intestinal mucosa.

Primary Squamous Cell Carcinoma of the Cecum Presenting as Spontaneous Perforation

Squamous cell carcinoma (SCC) of the colon is an extremely rare condition, and its pathogenesis is not fully understood. Bowel perforation is a very infrequent manifestation of colonic SCC, and only a few cases have been reported in the literature involving sigmoid and splenic flexure perforation. To the best of our knowledge, no cases of ileocecal perforation have been documented in the literature. Here we present a case of cecal SCC that presented with bowel perforation, necessitating emergent surgical intervention. Histopathological examination showed SCC with lymph node metastasis. This case reviews current knowledge and highlights the rare manifestation that these rare tumors can present.

Solute carrier family 12 member 2 as a proteomic and histological biomarker of dysplasia and neoplasia in ulcerative colitis

BACKGROUND AND AIMS

Ulcerative colitis (UC) patients have a greater risk of developing colorectal cancer through inflammation-dysplasia-carcinoma sequence of transformation. The histopathological diagnosis of dysplasia is therefore of critical clinical relevance, but dysplasia may be difficult to distinguish from inflammatory changes.

METHODS

A proteomic pilot study on 5 UC colorectal dysplastic patients highlighted proteins differentially distributed between paired dysplastic, inflammatory and normal tissues. The best candidate marker was selected and immunohistochemistry confirmation was performed on AOM/DSS mouse model lesions, 37 UC dysplasia, 14 UC cancers, 23 longstanding UC, 35 sporadic conventional adenomas, 57 sporadic serrated lesions and 82 sporadic colorectal cancers.

RESULTS

Differential proteomics found 11 proteins significantly more abundant in dysplasia compared to inflammation, including Solute carrier family 12 member 2 (SLC12A2) which was confidently identified with 8 specific peptides and was below the limit of quantitation in both inflammatory and normal colon. SLC12A2 immunohistochemical analysis confirmed the discrimination of preneoplastic and neoplastic lesions from inflammatory lesions in mice, UC and in sporadic contexts. A specific SLC12A2 staining pattern termed "loss of gradient" reached 89% sensitivity, 95% specificity and 92% accuracy for UC-dysplasia diagnosis together with an inter-observer agreement of 95.24% (multirater κfree of 0.90; IC95%: 0.78 - 1.00). Such discrimination could not be obtained by Ki67 staining. This specific pattern was also associated with sporadic colorectal adenomas and cancers.

CONCLUSIONS

We found a specific SLC12A2 immunohistochemical staining pattern in precancerous and cancerous colonic UC-lesions which could be helpful for diagnosing dysplasia and cancer in UC and non-UC patients.

Association of Cardiovascular Risk Assessment with Early Colorectal Neoplasia Detection in Asymptomatic Population: A Systematic Review and Meta-Analysis

Previous studies have shown a strong coexistence of colorectal neoplasia (CRN) and cardiovascular diseases (CVD). This study was aimed to summarize the available evidence on association of CVD risk with early CRN detection in asymptomatic populations. PubMed, Web of Science, and Embase were systematically searched for eligible studies published until Dec 20, 2019. Studies exploring the associations of recommended CVD risk assessment methods (e.g., risk scores, carotid artery plaque, and coronary artery calcium score [CACS]) with risk of CRN were included. Meta-analyses were conducted to determine the overall association of CVD risk with the CRN. A total of 12 studies were finally included. The association of carotid artery plaque with the risk of colorectal adenoma (AD) was weakest (pooled odds ratio [OR)] 1.27, 95% confidence interval [CI), 1.12, 1.45]. Participants with CACS>100 had about 2-fold increased risk of AD than those with CACS=0. The pooled ORs were 3.36 (95% CI, 2.15, 5.27) and 2.30 (95% CI, 1.69, 3.13) for the risk of advanced colorectal neoplasia (AN) and AD, respectively, in participants with Framingham risk score (FRS)>20%, when compared to participants at low risk (FRS<10%). FRS might help identify subgroups at increased risk for AN, but further studies are needed.

Colorectal Neoplasia among Patients with and without Human Immunodeficiency Virus

BACKGROUND

Increasing availability of highly active antiretroviral therapy (HAART) for human immunodeficiency virus (HIV) has led to prolonged survival and rising incidence of non-HIV-defining cancers among patients with HIV. Compared with the general population, risk of colorectal cancer may differ among those with HIV due to immunosuppression, oncogenic viral coinfections, and higher prevalence of risk factors.

METHODS

We identified patients (age ≥50 years) diagnosed with HIV, prescribed HAART for ≥6 months, and receiving care in two large health care systems in Dallas, TX. Patients received a first colonoscopy between January 2009 and December 2017. We calculated a standardized prevalence ratio as the ratio of observed to expected number of advanced neoplasia (high-risk adenoma or colorectal cancer) using an age- and sex-matched cohort of patients without HIV (n = 10,250).

RESULTS

Among patients with HIV (n = 839), about two thirds (60.1%) had normal findings at colonoscopy; 6.8% had hyperplastic polyps only, 20.4% had low-risk adenomas, 11.7% had high-risk adenomas, and 1.1% had colorectal cancer. Prevalence of advanced neoplasia was similar between patients with and without HIV, with a standardized prevalence ratio of 0.99 (95% confidence interval, 0.81-1.19).

CONCLUSIONS

There was no difference in the prevalence of colorectal neoplasia between patients with and without HIV.

IMPACT

Patients with HIV appear to have similar risk of colorectal neoplasia compared to those without HIV and can therefore follow average-risk colorectal cancer screening guidelines.

Endoscopic Management of a Tubulovillous Adenoma Within a Diverticulum: Report of a Case and Review of Literature

Adenomas or adenocarcinomas located within a colonic diverticulum are considered a rare phenomenon that has been described in the literature. These lesions are technically difficult to manage endoscopically and usually require surgical intervention for removal. There is also an increased risk of perforation upon endoscopic resection owing to the lack of a muscular layer within the diverticulum. We report a case and include a literature review to evaluate different endoscopic techniques and propose the most effective for management of adenomas within a diverticulum. This technique is potentially comprised of employing a combined approach using a suction banding device, an over-the-scope clip (OTSC; Ovesco Endoscopy AG, Tübingen, Germany) , and hyperthemic snare to successfully remove the polyp, ensure tissue retrieval, and reduce risk of iatrogenic colonic perforation.

The second round of the Dutch colorectal cancer screening program: Impact of an increased fecal immunochemical test cut-off level on yield of screening

The Dutch colorectal cancer (CRC) screening program started in 2014, inviting the target population biennially to perform a fecal immunochemical test (FIT). We obtained prospectively collected data from the national screening information‐system to present the results of the second round (2016) and evaluate the impact of increasing the FIT cut‐off halfway through the first round from 15 to 47 μg Hb/g feces on outcomes in the second round. Second round screening was done with a 47 μg Hb/g feces FIT cut‐off. Participants were classified based on first round participation status as either FIT (15,47) or FIT (47,47) participants, and previous nonparticipants. In total, 348,891 (75.9%) out of 459,740 invitees participated in the second round. Participation rates were 93.4% among previous participants and 21.0% among previous non‐participants. FIT(47,47) participants had a significantly higher detection rate of AN (15.3 vs. 10.4 per 1,000 participants) compared to FIT(15,47) participants in the second round, while their cumulative detection rate of AN over two rounds was significantly lower (45.6 vs. 52.6 per 1,000 participants). Our results showed that participation in the Dutch CRC screening program was consistently high and that second round detection rates depended on the first round FIT cut‐off. The cumulative detection over two rounds was higher among FIT(15,47) participants. These findings suggest that a substantial part of, but not all the missed findings in the first round due to the increased FIT cut‐off were detected in the subsequent round.

What's new?

In 2014, the Netherlands implemented colorectal cancer (CRC) screening based on non‐invasive fecal immunochemical testing (FIT), which offers a practical approach for population‐based CRC detection. In the Dutch program's first round, to match local resources, FIT cut‐off was increased, resulting in reduced positivity rates and reduced colonoscopy referrals, at the cost of missing advanced neoplasias. The current study shows that many of these missed advanced neoplasias were detected in subsequent screening, suggesting that increased FIT cut‐off had marginal impact on screening outcome. The findings could benefit other CRC screening programs in establishing effective FIT cut‐offs.

Hotspots of Sequence Variability in Gut Microbial Genes Encoding Pro-Inflammatory Factors Revealed by Oligotyping

The gut microbiota has been implicated in a number of normal and disease biological processes. Recent studies have identified a subset of gut bacterial genes as potentially involved in inflammatory processes. In this work, we explore the sequence variability for some of these bacterial genes using a combination of deep sequencing and oligotyping, a data analysis application that identifies mutational hotspots in short stretches of DNA. The genes for pks island, tcpC and usp, all harbored by certain strains of E. coli and all implicated in inflammation, were amplified by PCR directly from stool samples and subjected to deep amplicon sequencing. For comparison, the same genes were amplified from individual bacterial clones. The amplicons for pks island and tcpC from stool samples showed minimal levels of heterogeneity comparable with the individual clones. The amplicons for usp from stool samples, by contrast, revealed the presence of five distinct oligotypes in two different regions. Of these, the oligotype GT was found to be present in the control uropathogenic clinical isolate and also detected in stool samples from individuals with colorectal cancer (CRC). Mutational hotspots were mapped onto the USP protein, revealing possible substitutions around Leu110, Glu114, and Arg115 in the middle of the pyocin domain (Gln110, Gln114, and Thr115 in most healthy samples), and also Arg218 in the middle of the nuclease domain (His218 in the uropathogenic strain). All of these results suggest that a level of variability within bacterial pro-inflammatory genes could explain differences in bacterial virulence and phenotype.

Helicobacter pylori infection coexisting with intestinal metaplasia is not associated with colorectal neoplasms

Introduction

Colorectal cancer is one of the most common cancers and is a major cause of morbidity and mortality in the world and our country. Studies have indicated that there might be a relationship between Helicobacter pylori (Hp) and colorectal neoplasia (CN), although others have not found any relationship.

Aim

To determine whether there is a potential relationship between Hp and CN in our patients.

Material and methods

A total of 314 patients, aged 16–86 years, who underwent gastroscopy and colonoscopy at our department between 2015 and 2017 were evaluated retrospectively. The age, gender, endoscopy results, presence of Hp, complete blood count (CBC), vitamin B₁₂, folic acid, C-reactive protein (CRP), and sedimentation levels of the patients were examined.

Results

CBC, ferritin, vitamin B₁₂, and CRP measurements did not show statistical significance in terms of the presence of Hp (p > 0.05). Folate values of Hp-positive patients were significantly lower than Hp-negative patients (p = 0.007; p < 0.01). No significant relationship was detected between Hp and colon cancer (p > 0.05). Adenomatous polyps were not related to Hp (p > 0.05). Correlation between intestinal metaplasia (IM) and adenomatous polyps was insignificant. There was no statistically significant difference between colon and gastric pathology results.

Conclusions

In our study, no significant relationship was noted between Hp and CN. A few studies have been conducted in our country, and our results are consistent with some of these studies while it is contradictory to others. Large populational multicentre studies are needed in order to identify the relationship between Hp and CN.

Patients with breast cancer may be at higher risk of colorectal neoplasia

Background

The risk of colorectal neoplasia in breast cancer survivors is unclear. This study aimed to determine the colonic adenoma detection rate (ADR) in patients with breast cancer.

Methods

We conducted a retrospective study of patients with breast cancer who underwent a colonoscopy between 2000 and 2017. A control group (n=3295), comprising cancer-free patients undergoing their first screening colonoscopy, was used for comparison.

Results

Of 62,820 breast cancer patients, 3304 met the inclusion criteria. The mean age at the time of first colonoscopy was 59 years. ADR was 55%; 1803 patients had adenomas. High-grade dysplasia was evident in 28% of polyps and invasive adenocarcinoma was detected in 172 patients (5%). The median time from breast cancer diagnosis to adenoma detection was 3 years. The ADR was 21% in patients aged <40 years (n=63) and 39% in patients aged 40-50 years (n=314). The ADR was 26% in patients <50 years with a body mass index (BMI) lower than 30 kg/m² or no family history of colorectal cancer. Multivariate logistic regression analysis revealed that the following independent factors were associated with a greater risk of colon adenoma: older age, higher BMI, family history of colorectal cancer, and personal history of breast cancer.

Conclusions

In patients with breast cancer, the ADR was higher than the reported rates for the general population. Screening colonoscopy should be considered soon after breast cancer diagnosis in patients <50 years of age. Further prospective studies investigating our findings are warranted.

Endoscopic surveillance strategies for dysplasia in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory bowel disorder with an increased risk of colorectal cancer (CRC). This has led to the implementation of surveillance programmes to minimise this risk. Overall, these proactive programmes in association with better medical therapies have reduced the incidence of CRC in this population. Specific populations remain at increased risk, such as younger age at diagnosis, primary sclerosing cholangitis, colonic strictures and pseudopolyps. The majority of gastrointestinal international societies favour chromoendoscopy with targeted biopsies or random biopsies. The aim of this review is to present the current literature on dysplasia surveillance, the methodology and endoscopic technology available to assess dysplasia in UC.

Impact of family history of colorectal cancer on age-specific prevalence of colorectal neoplasia

BACKGROUND AND AIM

There are no established guidelines on screening strategies for persons with a family history of colorectal cancer (CRC) in Korea. We aimed to evaluate the age-specific risk of colorectal neoplasia according to family history of CRC.

METHODS

Participants who underwent screening colonoscopy were included. Age-specific prevalence of non-advanced adenoma (NAA) and advanced colorectal neoplasia (ACRN) was calculated according to family history of CRC.

RESULTS

Among 35 997 participants, 1339 (3.7%) had a family history of CRC in first-degree relatives. A family history of CRC was an independent risk factor for NAA (adjusted odds ratio [AOR] 1.33, 95% confidence interval [CI] 1.16-1.52). In the subgroup analysis by age, family history of CRC was a risk factor for NAA in the 50-59 and ≥ 60 years groups (AOR [95% CI]: 1.42 [1.04-1.91] and 2.33 [1.34-4.09], respectively), but not in the 30-39 and 40-49 years groups. In the curve of age-specific prevalence of NAA, the gap of the prevalence between the family history and non-family history groups began to widen after the mid-50s. In cases of ACRN, a family history of CRC was not a risk factor in the entire age group (AOR 1.16, 95% CI 0.75-1.70). In the curve of age-specific prevalence of ACRN, however, the gap of the prevalence between the family history and non-family history groups began to widen after the early 60s.

CONCLUSION

Although a family history of CRC is a risk factor for NAA, it may affect NAA development from the mid-50s and ACRN development from the early 60s.

Cumulative burden of inflammation predicts colorectal neoplasia risk in ulcerative colitis: a large single-centre study

OBJECTIVE

Ulcerative colitis (UC) is a dynamic disease with its severity continuously changing over time. We hypothesised that the risk of colorectal neoplasia (CRN) in UC closely follows an actuarial accumulative inflammatory burden, which is inadequately represented by current risk stratification strategies.

DESIGN

This was a retrospective single-centre study. Patients with extensive UC who were under colonoscopic surveillance between 2003 and 2012 were studied. Each surveillance episode was scored for a severity of microscopic inflammation (0=no activity; 1=mild; 2=moderate; 3=severe activity). The cumulative inflammatory burden (CIB) was defined as sum of: average score between each pair of surveillance episodes multiplied by the surveillance interval in years. Potential predictors were correlated with CRN outcome using time-dependent Cox regression.

RESULTS

A total of 987 patients were followed for a median of 13 years (IQR, 9-18), 97 (9.8%) of whom developed CRN. Multivariate analysis showed that the CIB was significantly associated with CRN development (HR, 2.1 per 10-unit increase in CIB (equivalent of 10, 5 or 3.3 years of continuous mild, moderate or severe active microscopic inflammation); 95% CI 1.4 to 3.0; P<0.001). Reflecting this, while inflammation severity based on the most recent colonoscopy alone was not significant (HR, 0.9 per-1-unit increase in severity; 95% CI 0.7 to 1.2; P=0.5), a mean severity score calculated from all colonoscopies performed in preceding 5 years was significantly associated with CRN risk (HR, 2.2 per-1-unit increase; 95% CI 1.6 to 3.1; P<0.001).

CONCLUSION

The risk of CRN in UC is significantly associated with accumulative inflammatory burden. An accurate CRN risk stratification should involve assessment of multiple surveillance episodes to take this into account.

The Presence of Gut Microbial Genes Encoding Bacterial Genotoxins or Pro-Inflammatory Factors in Stool Samples from Individuals with Colorectal Neoplasia

Gut bacterial toxins are thought to contribute to the development of colorectal cancer (CRC). This study examines the presence of specific gut bacterial toxin genes in stool samples from individuals with colorectal neoplasia (adenomas and/or CRC). The presence of bacterial genes encoding genotoxic or pro-inflammatory factors (pks, tcpC, gelE, cnf-1, AMmurB, and usp) was established by PCR of stool samples from individuals from mainland US (n = 30; controls = 10, adenoma = 10, CRC = 10) and from Puerto Rico (PR) (n = 33; controls = 13; adenomas = 8; CRC = 12). Logistic regression models and multinomial logistic regression models were used to estimate the magnitude of association. Distinct bacterial gene profiles were observed in each sample cohort. In individuals with CRC, AMmurB was detected more frequently in samples from the US and gelE in samples from PR. In samples from PR, individuals with ≥2 gut bacterial toxin genes in stool had higher odds of having colorectal neoplasia (OR = 11.0, 95%: CI 1.0–637.1): however, no significant association between bacterial genes and colorectal neoplasia was observed in the US cohort. Further analyses are warranted in a larger cohort to validate these preliminary findings, but these encouraging results highlight the importance of developing bacterial markers as tools for CRC diagnosis or risk stratification.

A snare combined with endoclips to assist in endoscopic submucosal dissection for intraepithelial neoplasia in the entire colon and rectum

OBJECTIVE

The use of mucosal traction to assist in colonic and rectal endoscopic submucosal dissection (ESD), especially for deep colonic ESD, is challenging. We developed a method of inverse insertion of a snare into the endoscopic working channel to deliver it into the colon together with the endoscope. With this method, two types of mucosal traction, per-anal external traction (PET) and per-anal internal traction (PIT), could be achieved using a snare with endoclips to assist in ESD (ESD-SE). Here, we aimed to examine its safety and feasibility.

METHODS

From January 2017 to September 2018, 50 colonic and rectal intraepithelial neoplasias in 50 patients were treated with ESD-SE. Data on lesion location and size, operation time, en bloc resection and R0 resection rates, and operative complications were collected.

RESULTS

Among 50 lesions, 15 lesions were located in the deep colon/proximal colon, and 35 lesions were in the distal colon. The median (interquartile range) size of lesions, submucosal dissection time, and total operation time were 4.5 (3.0-5.0) cm, 32 (18-81) min, and 50 (33-108) min, respectively. All lesions were completely resected, with R0 resection rates of 100%. No intraoperative and postoperative complications occurred. Postoperative pathology revealed 40 and 10 cases of high-grade and low-grade intraepithelial neoplasia, respectively.

CONCLUSIONS

The approach using insertion of a selective snare into the colon together with the endoscope, especially into the deep colon, was safe and simple. Use of the snare combined with endoclips could effectively assist in total colonic ESD. Further research is warranted.

Genetic susceptibility in the development of colorectal adenomas according to family history of colorectal cancer

Our study aimed to evaluate the relevance of genetic susceptibility in the development of colorectal adenomas (CRA) and its relationship with the presence of family history of colorectal cancer (CRC). Genomic DNA from 750 cases (first degree relatives of patients with CRC) and 750 controls (subjects with no family history of CRC) was genotyped for 99 single nucleotide polymorphisms (SNPs) previously associated with CRC/CRA risk by GWAS and candidate gene studies by using the MassArray™ (Sequenom) platform. Cases and controls were matched by gender, age and histological lesion. Eight hundred and fifty‐eight patients showed no neoplastic lesions, whereas 288 patients showed low‐risk adenomas, and 354 patients presented high‐risk adenomas. Two SNPs (rs10505477, rs6983267) in the CASC8 gene were associated with a reduced risk of CRA in controls (log‐additive models, OR: 0.67, 95%CI:0.54–0.83, and OR:0.66, 95%CI:0.54–0.84, respectively). Stratified analysis by histological lesion revealed the association of rs10505477 and rs6983267 variants with reduced risk of low‐ and high‐risk adenomas in controls, being this effect stronger in low‐risk adenomas (log‐additive models, OR:0.63, 95%CI:0.47–0.84 and OR:0.64, 95%CI:0.47–0.86, respectively). Moreover, 2 SNPs (rs10795668, rs11255841) in the noncoding LINC00709 gene were significantly associated with a reduced risk of low‐risk adenomas in cases (recessive models, OR:0.22, 95%CI:0.06–0.72, and OR:0.08, 95%CI:0.03–0.61) and controls (dominant models, OR:0.50, 95%CI:0.34–0.75, and OR:0.52, 95%CI:0.35–0.78, respectively). In conclusion, some variants associated with CRC risk (rs10505477, rs6983267, rs10795668 and rs11255841) are also involved in the susceptibility to CRA and specific subtypes. These associations are influenced by the presence of family history of CRC.

What's new?

While numerous candidate gene variants have been associated with colorectal cancer, little is known about the relevance of genetic susceptibility or influence of family history in the development of precancerous colorectal adenomas. In the present study, certain genetic variants previously associated with colorectal cancer risk, including two variants in the CASC8 gene and two in the lnc‐RNA LINC00709 gene, were found to be also involved in susceptibility to colorectal adenomas. The associations were modified by family history of colorectal cancer. The results could have implications for colorectal cancer screening and the identification of individuals at increased risk of colorectal adenoma.

Introduction of a colorectal cancer screening programme: results from a single-centre study

AIM

In 2014, a national colorectal cancer (CRC) screening programme was launched in the Netherlands. It is difficult to assess for the individual patients with CRC whether the oncological benefits of surgery will outweigh the morbidity of the procedure, especially in early lesions. This study compares patient and tumour characteristics between screen-detected and nonscreen-detected patients. Also, we present an overview of treatment options and clinical dilemmas when treating patients with early-stage colorectal disease.

METHOD

Between January 2014 and December 2016, all patients with nonmalignant polyps or CRC who were referred to the Department of Surgery of the Leiden University Medical Centre in the Netherlands were included. Baseline characteristics, type of treatment and short-term outcomes of patients with screen-detected and nonscreen-detected colorectal tumours were compared.

RESULTS

A total of 426 patients were included, of whom 240 (56.3%) were identified by screening. Nonscreen-detected patients more often had comorbidity (P = 0.03), the primary tumour was more often located in the rectum (P = 0.001) and there was a higher rate of metastatic disease (P < 0.001). Of 354 surgically treated patients, postoperative adverse events did not significantly differ between the two groups (P = 0.38). Of 46 patients with T1 CRC in the endoscopic resection specimen, 23 underwent surgical resection of whom only 30.4% had residual invasive disease at colectomy.

CONCLUSION

Despite differences in comorbidity, stage and surgical outcome of patients with screen-detected tumours compared to nonscreen-detected tumours were not significantly different. Considering its limited oncological benefits as well as the rate of adverse events, surgery for nonmalignant polyps and T1 CRC should be considered carefully.