Colorectal cancer risk in adenoma patients: a nation-wide study

Yield of Surveillance Colonoscopy in Older Adults with a History of Polyps: A Systematic Review and Meta-Analysis

BACKGROUND

The benefit of surveillance colonoscopy in older adults is not well described.

AIMS

To quantify the detection of colorectal cancer (CRC) and advanced polyps during surveillance colonoscopy in older adults with a history of colon polyps.

METHODS

We conducted a systematic review (MEDLINE, Cochrane Library, Web of Science, and Embase) for all published studies through May 2020 in adults age > 70 undergoing surveillance colonoscopy. The main outcome was CRC and advanced polyps detection. We performed meta-analysis to pool results by age (>70 vs. 50-70).

RESULTS

The search identified 6239 studies, of which 569 underwent full-text review and 64 data abstraction, of which 19 were included. The risk of detecting CRC (N = 11) was higher in those >70 compared to 50-70 (risk ratio 1.5 (95% CI 1.1-2.2); risk difference 0.8% (95% CI -0.2%-1.8%)). Similarly, the risk of detecting advanced polyps (N = 8) was higher in those >70 compared to 50-70 (risk ratio 1.3 (95% CI 1.2-1.3), risk difference 2.7% (95% CI 1.3%-4.0%)). Most studies did not stratify results by baseline polyp risk.

CONCLUSIONS

The detection of CRC and advanced polyps during surveillance colonoscopy in older individuals was higher than in younger controls; however, the absolute risk increase for both was small. These differences must be weighed against competing medical problems and limited life expectancy in older adults when making decisions about surveillance colonoscopy. More primary data on the risks of CRC and advanced polyps accounting for number of past colonoscopies, prior polyp risk, and duration of time since last polyp are needed.

Long-term colorectal cancer incidence and mortality after adenoma removal in women and men

BACKGROUND

Women and men with colorectal adenomas are at increased risk of colorectal cancer and colonoscopic surveillance is recommended. However, the long-term cancer risk remains unknown.

AIMS

To investigate colorectal cancer incidence and mortality after adenoma removal in women and men METHODS: We identified all individuals who had adenomas removed in Norway from 1993 to 2007, with follow-up through 2018. We calculated standardized incidence ratios (SIR) and incidence-based mortality ratios (SMR) with 95% confidence intervals (CI) for colorectal cancer in women and men using the female and male population for comparison. We defined high-risk adenomas as ≥2 adenomas, villous component, or high-grade dysplasia.

RESULTS

The cohort comprised 40 293 individuals. During median follow-up of 13.0 years, 1079 women (5.5%) and 866 men (4.2%) developed colorectal cancer; 328 women (1.7%) and 275 men (1.3%) died of colorectal cancer. Colorectal cancer incidence was more increased in women (SIR 1.64, 95% CI 1.54-1.74) than in men (SIR 1.12, 95% CI 1.05-1.19). Colorectal cancer mortality was increased in women (SMR 1.13, 95% CI 1.02-1.26) and reduced in men (SMR 0.79, 95% CI 0.71-0.89). Women with high-risk adenomas had an increased risk of colorectal cancer death (SMR 1.37, 95% CI 1.19-1.57); women with low-risk adenomas (SMR 0.90, 95% CI 0.76-1.07) and men with high-risk adenomas had a similar risk (SMR 0.89, 95% CI 0.76-1.04), while men with low-risk adenomas had reduced risk (SMR 0.70, 95% CI 0.59-0.84).

CONCLUSIONS

After adenoma removal, women had an increased risk of colorectal cancer death, while men had reduced risk, compared to the general female and male populations. Sex-specific surveillance recommendations after adenoma removal should be considered.

Effect of Diminutive Adenoma with High-Grade Dysplasia on Surveillance Colonoscopy Interval

BACKGROUND

Colonoscopy surveillance guidelines set the surveillance schedule based on polyp characteristics. Polyps with high-grade dysplasia (HGD) require 3 years of follow-up regardless of size. However, it is unclear whether patients with diminutive polyps (≤5 mm) with HGD have a higher risk. We evaluated the effect of diminutive adenoma with HGD on adenoma occurrence.

METHODS

From January 2015 to December 2017, patients who underwent index and surveillance colonoscopy were retrospectively screened. The patients were grouped into no adenoma group, low-risk (patients with ≤2 low-grade dysplasia [LGD]), diminutive HGD, and high-risk (HGD >5 mm, ≥3 adenomas) groups according to the index colonoscopy results. Each group was analyzed using logistic analysis.

RESULTS

The mean follow-up period was 22.47 months. Altogether, 610 (50.45%) patients had LGD and 152 (12.5%) had HGD. Among them, 61 (5.0%) patients had a diminutive polyp with HGD. Analysis of the risks of developing advanced adenoma in the surveillance colonoscopy showed that compared to the no adenoma group, the diminutive HGD group did not show a significant risk (odds ratio [OR] = 1.503 [0.449-5.027], p = 0.509), while the high-risk group showed a significant risk (OR = 2.044 [1.015-4.114], p = 0.045).

CONCLUSIONS

Diminutive adenoma with HGD increased the risk of adenoma on surveillance colonoscopy, and in the case of advanced adenoma, the risk was increased, but it was not statistically significant.

Evaluation of recurrence and surgical complementation rates after endoscopic resection of large colorectal non-pedunculated lesions

BACKGROUND AND AIM

the process that leads to the development of colorectal cancer takes many years and most tumors originate from polyps and non-polypoid lesions. Techniques of endoscopic resection are surgical treatment options, even in case of large lesions or with initial invasion. This study aimed to evaluate the recurrence and surgical complementation rates after endoscopic resection of large colorectal non-pedunculated lesions.

METHODS

a retrospective, longitudinal and descriptive trial was performed via an analysis of colonoscopies with the resection of non-pedunculated lesions larger than 3 cm, performed between 2014 and 2017.

RESULTS

sixty-two lesions were included from 61 patients and 32 (52.5 %) were female. The age ranged from 36 to 89 years, with a mean age of 60.5 years. Lesions had an average diameter of 40.08 mm, ranging from 30 to 80 mm. Regarding the location of the lesions, the most frequent colonic segments were the ascending and rectum, both accounting for 22.6 %. Considering the morphologic endoscopic classification, 67.7 % were granular laterally spreading tumors (LST), 38.8 % were homogeneous granular and 29 % were mixed granular. The most frequent histological types were tubulovillous adenoma (30.7 %) and intramucosal adenocarcinoma (29 %). The resection technique was piecemeal mucosectomy in 85.5 %. Five lesions were removed by en bloc mucosectomy, two (3.2 %) by endoscopic submucosal dissection (ESD) and two (3.2 %) by a hybrid technique. The recurrence rate was 25.8 %. Three patients needed complementary surgical treatment and the clinical success of endoscopic treatment was 95.1 %.

CONCLUSION

recurrence rate after endoscopic resection of large colorectal lesions was 25.8 % and surgical complementation rate due to failure in the endoscopic treatment of recurrence was 4.8 %.

Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population

BACKGROUND & AIMS

The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings.

METHODS

Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders.

RESULTS

Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18).

CONCLUSIONS

With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

Colorectal Cancer Incidence and Mortality After Removal of Adenomas During Screening Colonoscopies

BACKGROUND & AIMS

Recommendation of surveillance colonoscopy should be based on risk of colorectal cancer and death after adenoma removal. We aimed to develop a risk classification system based on colorectal cancer incidence and mortality following adenoma removal.

METHODS

We performed a multicenter population-based cohort study of 236,089 individuals (median patient age, 56 years; 37.8% male) undergoing screening colonoscopies with adequate bowel cleansing and cecum intubation at 132 centers in the Polish National Colorectal Cancer Screening Program, from 2000 through 2011. Subjects were followed for a median 7.1 years and information was collected on colorectal cancer development and death. We used recursive partitioning and multivariable Cox models to identify associations between colorectal cancer risk and patient and adenoma characteristics (diameter, growth pattern, grade of dysplasia, and number of adenomas). We developed a risk classification system based on standardized incidence ratios, using data from the Polish population for comparison. The primary endpoints were colorectal cancer incidence and colorectal cancer death.

RESULTS

We identified 130 colorectal cancers in individuals who had adenomas removed at screening (46.5 per 100,000 person-years) vs 309 in individuals without adenomas (22.2 per 100,000 person-years). Compared with individuals without adenomas, adenomas ≥20 mm in diameter and high-grade dysplasia were associated with increased risk of colorectal cancer (adjusted hazard ratios 9.25; 95% confidence interval [CI] 6.39-13.39, and 3.58; 95% CI 1.96-6.54, respectively). Compared with the general population, colorectal cancer risk was higher or comparable only for individuals with adenomas ≥20 mm in diameter (standardized incidence ratio [SIR] 2.07; 95% CI 1.40-2.93) or with high-grade dysplasia (SIR 0.79; 95% CI 0.39-1.41), whereas for individuals with other adenoma characteristics the risk was lower (SIR 0.35; 95% CI 0.28-0.44). We developed a high-risk classification based on adenoma size ≥20 mm or high-grade dysplasia (instead of the current high-risk classification cutoff of ≥3 adenomas or any adenoma with villous growth pattern, high-grade dysplasia, or ≥10 mm in diameter). Our classification system would reduce the number of individuals classified as high-risk and requiring intensive surveillance from 15,242 (36.5%) to 3980 (9.5%), without increasing risk of colorectal cancer in patients with adenomas (risk difference per 100,000 person-years, 5.6; 95% CI -10.7 to 22.0).

CONCLUSIONS

Using data from the Polish National Colorectal Cancer Screening Program, we developed a risk classification system that would reduce the number of individuals classified as high risk and require intensive surveillance more than 3-fold, without increasing risk of colorectal cancer in patients with adenomas. This system could optimize the use of surveillance colonoscopy.

Long-term outcomes of endoscopically resected laterally spreading tumors with a positive histological lateral margin

BACKGROUND

With advances in diagnostic endoscopy, the incidence of superficial colorectal tumors, including laterally spreading tumors (LSTs), has increased. However, little is known about the long-term results of LSTs with positive lateral margin after endoscopic treatment. This study aimed to evaluate the long-term clinical outcomes and risk factors for local recurrence of LSTs with positive lateral margin after initial endoscopic resection.

METHODS

We performed a retrospective analysis of the medical records of 324 patients who had 363 LSTs with positive lateral margin after endoscopic resection at a tertiary academic medical center. The medical records from 2011 to 2015 were analyzed. Local recurrence was confirmed through endoscopic finding and subsequent biopsy analysis. We assessed the local recurrence rate and performed multivariate analyses to identify the factors associated with local recurrence.

RESULTS

Follow-up colonoscopy was performed in 176 of 363 LSTs. The local recurrence rate was 6.3% (11/176), with a median (interquartile range [IQR]) follow-up period of 19.8 (12.4-46.5) months. In multivariate analysis, local recurrence was associated with piecemeal resection (odds ratio [OR] 6.62, 95% confidence interval [CI] 1.28-34.33; p = 0.024) and inversely associated with thermal ablation (OR 0.033, 95% CI 0.00-0.45; p = 0.011). At surveillance colonoscopy, histology of the recurrent tumor was adenoma in 10 (90.9%) of 11; these were treated endoscopically.

CONCLUSIONS

In this retrospective study, we found that endoscopically resected LSTs with positive lateral margin have a low recurrence rate. Piecemeal resection was associated with higher local recurrence, and thermal ablation was inversely associated with local recurrence. Endoscopic resection with positive lateral margin combined with thermal ablation leads to a low recurrence rate.

Long-term Risk of Colorectal Cancer and Related Deaths After a Colonoscopy With Normal Findings

Importance

Guidelines recommend a 10-year rescreening interval after a colonoscopy with normal findings (negative colonoscopy results), but evidence supporting this recommendation is limited.

Objective

To examine the long-term risks of colorectal cancer and colorectal cancer deaths after a negative colonoscopy result, in comparison with individuals unscreened, in a large, community-based setting.

Design, Setting, and Participants

A retrospective cohort study was conducted in an integrated health care delivery organization serving more than 4 million members across Northern California. A total of 1 251 318 average-risk screening-eligible patients (age 50-75 years) between January 1, 1998, and December 31, 2015, were included. The study was concluded on December 31, 2016.

Exposures

Screening was examined as a time-varying exposure; all participants contributed person-time unscreened until they were either screened or censored. If the screening received was a negative colonoscopy result, the participants contributed person-time in the negative colonoscopy results group until they were censored.

Main Outcomes and Measures

Using Cox proportional hazards regression models, the hazard ratios (HRs) for colorectal cancer and related deaths were calculated according to time since negative colonoscopy result (or since cohort entry for those unscreened). Hazard ratios were adjusted for age, sex, race/ethnicity, Charlson comorbidity score, and body mass index.

Results

Of the 1 251 318 patients, 613 692 were men (49.0%); mean age was 55.6 (7.0) years. Compared with the unscreened participants, those with a negative colonoscopy result had a reduced risk of colorectal cancer and related deaths throughout the more than 12-year follow-up period, and although reductions in risk were attenuated with increasing years of follow-up, there was a 46% lower risk of colorectal cancer (hazard ratio, 0.54; 95% CI, 0.31-0.94) and 88% lower risk of related deaths (hazard ratio, 0.12; 95% CI, 0.02-0.82) at the current guideline-recommended 10-year rescreening interval.

Conclusions and Relevance

A negative colonoscopy result in average-risk patients was associated with a lower risk of colorectal cancer and related deaths for more than 12 years after examination, compared with unscreened patients. Our study findings may be able to inform guidelines for rescreening after a negative colonoscopy result and future studies to evaluate the costs and benefits of earlier vs later rescreening intervals.

The effect of small or diminutive adenomas at baseline colonoscopy on the risk of developing metachronous advanced colorectal neoplasia: KASID multicenter study

BACKGROUND

The clinical significance of diminutive or small adenomas remains ill defined.

AIMS

We evaluated the clinical impact of diminutive or small adenomas at baseline on the risk of developing metachronous advanced colorectal neoplasia (CRN).

METHODS

This multicenter, retrospective cohort study included 2252 patients with 1 or more colorectal adenomas at baseline and subsequent follow-up colonoscopy. Baseline colonoscopy findings were classified into 5 groups: 1 or 2 tubular adenomas (TAs) (<10 mm); 3-10 diminutive TAs (≤5 mm); 3-10 TAs, including 1 or 2 small adenomas (6-10 mm); 3-10 TAs, including 3 or more small adenomas; and advanced adenoma.

RESULTS

In multivariate analysis, after adjusting for possible confounding variables (age at baseline, sex, body mass index, smoking habits, family history of colorectal cancer, regular use of aspirin or NSAIDs, and adenoma location), 3-10 TAs including 3 or more small adenomas (hazard ratio [HR] = 2.36, p = 0.034) and advanced adenoma (HR = 2.14, p < 0.001) were independent predictors for the risk of developing metachronous advanced CRN. However, 3-10 diminutive TAs or 3-10 TAs, including 1 or 2 small adenomas, were not associated with this outcome.

CONCLUSIONS

Multiplicity of diminutive TAs, without advanced lesions, showed no clinical significance for risk of developing metachronous advanced CRN.

Colorectal cancer death after adenoma removal in Scandinavia

OBJECTIVES

Improved understanding of the subsequent risk death from colorectal cancer (CRC) among individuals who had adenomas removed is needed. We aimed to quantify this risk using prospectively collected data from population-based cohorts.

MATERIALS AND METHODS

Using Norwegian and Swedish registries, a cohort of 90,864 individuals with colorectal adenomas removed between 1980 and 2013 was identified. Surveillance was only recommended for high-risk adenomas. The validity of the registry data did not allow classification into low- and high-risk adenomas. Virtually complete follow-up was achieved through linkage to nationwide registers. We calculated incidence-based standardised mortality ratios (SMRs) with 95% confidence intervals (CI).

RESULTS

The median follow-up was 7.2 years; 48,058 individuals were followed for more than 10 years. We observed 819 deaths (0.9%) from CRC and expected 731 CRC deaths (0.8%), corresponding to an absolute excess risk of 88 cases (0.1%) and a relative risk of 12% (SMR 1.12; 95%CI 1.05-1.20). The relative risk of CRC death following adenoma removal was slightly higher in Sweden (SMR 1.22; 95%CI 1.11-1.34) than in Norway (SMR 1.03; 95%CI 0.93-1.14), and higher in women (SMR 1.24; 95%CI 1.12-1.36) than in men (SMR 1.02; 95%CI 0.93-1.13). Among individuals with more than 10 years of follow-up, the estimates were similar to the overall cohort, absolute excess risk 0.1% (SMR 1.15; 95%CI 1.06-1.24).

CONCLUSION

The excess risk of CRC death following adenoma removal is small. Optimal surveillance recommendations should be tested in randomised trials.

Elevated Neutrophil-to-Lymphocyte Ratio in Metabolic Syndrome Is Associated with Increased Risk of Colorectal Adenoma

BACKGROUND

Metabolic syndrome (MetS) is an important cardiovascular risk factor for insulin resistance and has been linked to colorectal adenoma via inflammation. The neutrophil-to-lymphocyte ratio (NLR) has been suggested as an important inflammatory marker. We initiated this investigation to determine the relationship between colorectal adenoma and NLR in patients with MetS.

METHODS

We examined participants who visited the Health Promotion Center at Kosin University Gospel Hospital, Busan, Korea. Subjects who underwent both colonoscopy and liver ultrasonography were included. Colorectal adenoma was defined as the presence of a colon polyp with a histologically adenomatous component. MetS was defined according to the modified National Cholesterol Education Program Adult Treatment Panel III definition for South Asians. Anthropometric measurements and biochemical tests of liver and metabolic function were assessed.

RESULTS

A total of 1007 subjects were included in the study sample. Their mean age was 48.3 ± 9.7 years and 262 (26.0%) subjects had MetS, while 439 (43.6%) subjects had pathologically proven colorectal adenoma. Subjects with MetS were older, more likely to be male, and had significantly higher prevalences of colorectal adenoma (49.2% vs. 41.6%, P = 0.032), nonalcoholic fatty liver disease (62.8% vs. 19.5%, P < 0.001), and higher NLR (2.0 ± 0.9 vs. 1.7 ± 0.7, P < 0.001) compared to those without MetS. High NLR (≥2.0) was an independent factor affecting the prevalence of colorectal adenoma [odds ratio (OR) 1.38, confidence interval (95% CI) 1.02-1.88, P = 0.040], especially in subjects with MetS (OR 1.91, 95% CI 1.12-3.28, P = 0.018).

CONCLUSION

High NLR was associated with increased colorectal adenomatous polyps, particularly in subjects with MetS. Screening colonoscopies for the prevention of colorectal adenoma may be warranted for patients with high NLR and MetS.

Assessment of colon polyp morphology: Is education effective?

AIM

To determine the inter-observer variability for colon polyp morphology and to identify whether education can improve agreement among observers.

METHODS

For purposes of the tests, we recorded colonoscopy video clips that included scenes visualizing the polyps. A total of 15 endoscopists and 15 nurses participated in the study. Participants watched 60 video clips of the polyp morphology scenes and then estimated polyp morphology (pre-test). After education for 20 min, participants performed a second test in which the order of 60 video clips was changed (post-test). To determine if the effectiveness of education was sustained, four months later, a third, follow-up test was performed with the same participants.

RESULTS

The overall Fleiss’ kappa value of the inter-observer agreement was 0.510 in the pre-test, 0.618 in the post-test, and 0.580 in the follow-up test. The overall diagnostic accuracy of the estimation for polyp morphology in the pre-, post-, and follow-up tests was 0.662, 0.797, and 0.761, respectively. After education, the inter-observer agreement and diagnostic accuracy of all participants improved. However, after four months, the inter-observer agreement and diagnostic accuracy of expert groups were markedly decreased, and those of beginner and nurse groups remained similar to pre-test levels.

CONCLUSION

The education program used in this study can improve inter-observer agreement and diagnostic accuracy in assessing the morphology of colon polyps; it is especially effective when first learning endoscopy.

Acetylcholine-related proteins in non-neoplastic appearing colonic mucosa from patients with colorectal neoplasia

The pathogenesis of colorectal neoplasia (CRN) has been associated with altered non-neuronal acetylcholine (ACh) metabolism. The aim of this study was to characterize expression, function, and cellular location of ACh-related proteins in biopsies obtained from endoscopic normal-appearing sigmoid colon in patients with and without CRN. Messenger-RNA (mRNA) levels of 17 ACh-related proteins were quantified by rt-qPCR. Functional responses to ACh, measured as electrogenic transepithelial short circuit current (SCC), were recorded using the Ussing chamber technique. Finally, cellular localization of choline transporter-like proteins (CTLs) and butyryl-cholinesterase enzyme (BChE) was determined by immunohistochemistry. mRNA expression of CTL1 and CTL4 was increased in patients with CRN (P = 0.002 and P = 0.04, respectively). In functional experiments, baseline SCC was increased in CRN patients. ACh induced rapid biphasic changes in SCC. An initial decreasing phase was observed in the minority of CRN patients versus the majority of controls (25% vs 69%, respectively, P = 0.031). For the second increasing phase of SCC, data indicated ACh-activation of two receptors. For both parts of the biphasic response, the half maximal effective concentration and maximal responses showed no difference between patient groups. Immunohistochemistry demonstrated CTL1, 3 and 4 and BChE to be localized to colonic crypt cells. We conclude that CRN is associated with increased expression of CTL1 and CTL4, augmented basal prostaglandin-dependent secretion, and altered functional channel response to ACh in human endoscopic normal-appearing colonic mucosa. The immunohistochemical findings support CTL1, CTL3, CTL4, and BChE to be involved in non-neuronal mucosal ACh metabolism.

Molecular stool testing as an alternative for surveillance colonoscopy: a cross-sectional cohort study

BACKGROUND

As in many other European countries, a nationwide screening program for colorectal cancer (CRC) has recently been introduced in the Netherlands. As a side effect, such a screening program will inherently yield an increase in the demand for surveillance after removal of polyps/adenomas or CRC. Although these patients are at increased risk of metachronous colorectal neoplasia, solid evidence on CRC-related mortality reduction as a result of colonoscopy-based surveillance programs is lacking. Furthermore, colonoscopy-based surveillance leads to high patient burden, high logistic demands and high costs. Therefore, new surveillance strategies are needed. The aim of the present study, named Molecular stool testing for Colorectal CAncer Surveillance (MOCCAS), is to determine the performance characteristics of two established non-invasive tests, i.e., the multitarget stool DNA test Cologuard® and the faecal immunochemical test (FIT) in the detection of CRC and advanced adenomas as an alternative for colonoscopy surveillance.

METHODS

In this observational cross-sectional cohort study, subjects aged 50 to 75 years will be approached to collect (whole-) stool samples for molecular testing and a FIT prior to their scheduled surveillance colonoscopy. The results of the tests will allow calculation of test sensitivities and specificities in the context of surveillance. This will provide the required input for the Dutch ASCCA model (Adenoma and Serrated pathway to Colorectal CAncer) to simulate surveillance strategies differing in frequency and duration. The model will allow predictions of lifetime health effects and costs. Multiple centres in the Netherlands will participate in the study that aims to include 4,000 individuals.

DISCUSSION

The outcome of this study will inform on the (cost-) effectiveness of stool based molecular testing as an alternative for colonoscopy in the rapidly expanding surveillance population.

TRIAL REGISTRATION

ClinicalTrials.gov ( https://clinicaltrials.gov/ ): NCT02715141 . Retrospectively registered 17 February 2016.

Risk factors for metachronous colorectal cancer or polyp: A systematic review and meta-analysis

BACKGROUND AND AIM

We conducted a systematic review and meta-analysis to identify personal, lifestyle, and tumor-related risk factors for metachronous colorectal cancer (CRC) and polyp.

METHODS

Relevant studies were identified by searching MEDLINE, Web of Science and Cochrane Central Register through 15 May 2016. Estimates for associations were summarized using random effects models.

RESULTS

Fifty-five studies were included in the review. For individuals who had a CRC resection, having a synchronous polyp was a risk factor for metachronous CRC or polyp (relative risk [RR], 2.04; 95% confidence interval [CI], 1.48-2.82) and having a synchronous CRC (RR, 1.90; 95% CI, 1.25-2.91) and proximally located CRC (RR, 2.12; 95% CI, 1.24-3.64) were risk factors for metachronous CRC. For individuals who had a polypectomy, larger size (RR, 4.26; 95% CI, 2.11-8.57) or severe dysplasia of the initial polyp (RR, 5.15; 95% CI, 2.02-13.14), and having a synchronous polyp (RR, 2.52; 95% CI, 1.35-4.73) were risk factors for metachronous CRC; and a family history of CRC (RR, 1.90; 95% CI, 1.26-2.87), having a synchronous polyp (RR, 2.47; 95% CI, 1.74-3.50) and a larger size (RR, 1.49; 95% CI, 1.03-2.15) and proximal location of the initial polyp (RR, 1.20; 95% CI, 1.02-1.40) were risk factors for metachronous polyp. Meta-regression showed duration of follow-up was not a source of heterogeneity for most associations. There was no evidence that lifestyle factors were associated with metachronous CRC or polyp risk.

CONCLUSION

A comprehensive list of risk factors identified for metachronous CRC or polyp may have important clinical implications.

The association between location, age and advanced colorectal adenoma characteristics: a propensity-matched analysis

PURPOSE

Evidence supports an association between certain colorectal adenoma characteristics and predisposition to cancer. The association between anatomical location of colorectal adenoma, age and advanced adenomas needs attention. The objective of this study was to evaluate the possible association between occurrence of sporadic advanced adenomas with location and age.

MATERIALS AND METHODS

A cross-sectional study using baseline data from index colonoscopy from a randomized controlled trial evaluating chemopreventive treatment against recurrence of colorectal adenomas was performed. Inclusion criteria for patients were one adenoma of >1 cm in diameter or multiple adenomas of any size, or an adenoma of any size and familial disposition for colorectal cancer. Multivariate regression and propensity score-matched analyses were used to correlate location of adenomas and age with advanced adenoma features.

RESULTS

In this study, 2149 adenomas were removed in 1215 patients. Advanced colorectal adenomas primarily occurred in the anal part of the colon. Older age was associated with more adenomas and more oral occurrence of adenomas, as well as a higher risk of advanced adenomas. Surprisingly, specifically for the oral adenomas the risk of advanced adenoma seems to be lower for older patients compared with younger.

CONCLUSIONS

This study presents new results with regard to association between age, location of adenomas and risk of advanced adenomas. The results indicate that sigmoidoscopy for screening purposes may be obsolete, and add to the existing literature on which future guidelines for screening may be based.

Phosphodiesterases in non-neoplastic appearing colonic mucosa from patients with colorectal neoplasia

Background

Intracellular signaling through cyclic nucleotides, both cyclic AMP and cyclic GMP, is altered in colorectal cancer. Accordingly, it is hypothesized that an underlying mechanism for colorectal neoplasia involves altered function of phosphodiesterases (PDEs), which affects cyclic nucleotide degradation. Here we present an approach to evaluate the function of selected cyclic nucleotide-PDEs in colonic endoscopic biopsies from non-neoplastic appearing mucosa.

Methods

Biopsies were obtained from patients with and without colorectal neoplasia. Activities of PDEs were characterized functionally by measurements of transepithelial ion transport and their expression and localization by employing real-time qPCR and immunohistochemistry.

Results

In functional studies PDE subtype-4 displayed lower activity in colorectal neoplasia patients (p = 0.006). Furthermore, real-time qPCR analysis showed overexpression of subtype PDE4B (p = 0.002) and subtype PDE5A (p = 0.02) in colorectal neoplasia patients. Finally, immunohistochemistry for 7 PDE isozymes demonstrated the presence of all 7 isozymes, albeit with weak reactions, and with no differences in localization between colorectal neoplasia and control patients. Of note, quantification of PDE subtype immunostaining revealed a lower amount of PDE3A (p = 0.04) and a higher amount of PDE4B (p = 0.02) in samples from colorectal neoplasia patients.

Conclusion

In conclusion, functional data indicated lower activity of PDE4 subtypes while expressional and abundance data indicated a higher expression of PDE4B in patients with colorectal neoplasia. We suggest that cyclic nucleotide-PDE4B is overexpressed as a malfunctioning protein in non-neoplastic appearing colonic mucosa from patients with colorectal neoplasia. If a predisposition of reduced PDE4B activity in colonic mucosa from colorectal neoplasia patients is substantiated further, this subtype could be a potential novel early diagnostic risk marker and may even be a target for future medical preventive treatment of colorectal cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2980-z) contains supplementary material, which is available to authorized users.

Organization of surveillance in GI practice

BACKGROUND

Several reports documented an inefficient utilisation of available resources, as well as a suboptimal compliance with surveillance recommendations. Although, evidence suggests that organisational issues can influence the quality of care delivered, surveillance protocols are usually based on non-organized approaches.

METHODS

We conducted a literature search (publication date: 01/2000-06/2016) on PubMed and Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects and Cochrane Central Register of Controlled Trials for guidelines, or consensus statements, for surveys of practice, reporting information about patients, or providers attitudes and behaviours, for intervention studies to enhance compliance with guidelines. Related articles were also scrutinised. Based on the clinical relevance and burden on endoscopy services this review was focused on surveillance for Barrett's oesophagus, IBD and post-polypectomy surveillance of colonic adenomas.

RESULTS

Existing guidelines are generally recognising structure and process requirements influencing delivery of surveillance interventions, while less attention had been devoted to transitions and interfaces in the care process. Available evidence from practice surveys is suggesting the need to design organizational strategies aimed to enable patients to attend and providers to deliver timely and appropriate care. Well designed studies assessing the effectiveness of specific interventions in this setting are however lacking. Indirect evidence from screening settings would suggest that the implementation of automated standardized recall systems, utilisation of clinical registries, removing financial barriers, could improve appropriateness of use and compliance with recommendations.

CONCLUSIONS

Lack of sound evidence regarding utility and methodology of surveillance can contribute to explain the observed variability in providers and patients attitudes and in compliance with the recommended surveillance.

Optimizing post-polypectomy surveillance: A practical guide for the endoscopist

Several gastrointestinal societies strongly recommend colonoscopy surveillance after endoscopic and surgical resection of colorectal neoplasms. Common denominators to these recommendations include: high-quality baseline colonoscopy before inclusion in a surveillance program; risk stratification based on clinicopathological profiles to guide surveillance intervals; and endoscopist responsibility for providing surveillance advice. Considerable variability also exists between guidelines (i.e. regarding risk classification and surveillance intervals). In this review, we examine key factors for quality of post-polypectomy surveillance practice, in particular bowel preparation, endoscopic findings at baseline examination and adherence to surveillance recommendations. Frequently asked questions by the practising endoscopist are addressed.

Colorectal cancer screening by colonoscopy: putting it into perspective

Implementation of nationwide screening programs aims to decrease the disease burden of colorectal cancer (CRC) in the general population. Globally, most population screening programs for CRC are carried out by either fecal occult blood test, flexible sigmoidoscopy or colonoscopy. For screening programs with colonoscopy as the primary method, only circumstantial evidence from observational studies is available to prove its effectiveness, suggesting that colonoscopy effectively reduces CRC incidence and mortality. Currently, large randomized trials are being conducted to corroborate these findings. Besides the direct effect of a screening program for CRC, its protective effect is further enhanced by enrolment of patients that underwent polypectomy in surveillance programs. However, despite CRC screening and surveillance colonoscopies, interval CRC still occur. Those are predominantly located in the right-sided colon and potential explanations, besides unfavorable tumor characteristics, are preventable operator-dependent factors relating to the quality of the colonoscopy procedure. In an effort to reduce differences in endoscopists' performance and thereby the occurrence of interval CRC, quality indicators of colonoscopy have been introduced. In addition, emerging advanced colonoscopy techniques might contribute to improvement in polyp detection and removal. Meticulous inspection of the colonic mucosa not only results in the detection of advanced and relevant lesions, but also in the removal of many diminutive and small lesions leading to an increasing number of surveillance colonoscopies, known as the 'high-detection paradox'. More data on the cost-effectiveness of high-quality colonoscopy as a primary screening method and surveillance programs with intervals based on optimal risk stratification are eagerly awaited.

Is forceps more useful than visualization for measurement of colon polyp size?

AIM: To identify whether the forceps estimation is more useful than visual estimation in the measurement of colon polyp size.

METHODS: We recorded colonoscopy video clips that included scenes visualizing the polyp and scenes using open biopsy forceps in association with the polyp, which were used for an exam. A total of 40 endoscopists from the Busan Ulsan Gyeongnam Intestinal Study Group Society (BIGS) participated in this study. Participants watched 40 pairs of video clips of the scenes for visual estimation and forceps estimation, and wrote down the estimated polyp size on the exam paper. When analyzing the results of the exam, we assessed inter-observer differences, diagnostic accuracy, and error range in the measurement of the polyp size.

RESULTS: The overall intra-class correlation coefficients (ICC) of inter-observer agreement for forceps estimation and visual estimation were 0.804 (95%CI: 0.731-0.873, P < 0.001) and 0.743 (95%CI: 0.656-0.828, P < 0.001), respectively. The ICCs of each group for forceps estimation were higher than those for visual estimation (Beginner group, 0.761 vs 0.693; Expert group, 0.887 vs 0.840, respectively). The overall diagnostic accuracy for visual estimation was 0.639 and for forceps estimation was 0.754 (P < 0.001). In the beginner group and the expert group, the diagnostic accuracy for the forceps estimation was significantly higher than that of the visual estimation (Beginner group, 0.734 vs 0.613, P < 0.001; Expert group, 0.784 vs 0.680, P < 0.001, respectively). The overall error range for visual estimation and forceps estimation were 1.48 ± 1.18 and 1.20 ± 1.10, respectively (P < 0.001). The error ranges of each group for forceps estimation were significantly smaller than those for visual estimation (Beginner group, 1.38 ± 1.08 vs 1.68 ± 1.30, P < 0.001; Expert group, 1.12 ± 1.11 vs 1.42 ± 1.11, P < 0.001, respectively).

CONCLUSION: Application of the open biopsy forceps method when measuring colon polyp size could help reduce inter-observer differences and error rates.

Colorectal Cancer Risk Following Adenoma Removal: A Large Prospective Population-Based Cohort Study

BACKGROUND

Randomized controlled trials have demonstrated significant reductions in colorectal cancer incidence and mortality associated with polypectomy. However, little is known about whether polypectomy is effective at reducing colorectal cancer risk in routine clinical practice. The aim of this investigation was to quantify colorectal cancer risk following polypectomy in a large prospective population-based cohort study.

METHODS

Patients with incident colorectal polyps between 2000 and 2005 in Northern Ireland were identified via electronic pathology reports received to the Northern Ireland Cancer Registry. Patients were matched to the Northern Ireland Cancer Registry to detect colorectal cancer and deaths up to December 31, 2010. Colorectal cancer standardized incidence ratios (SIR) were calculated and Cox proportional hazards modeling applied to determine colorectal cancer risk.

RESULTS

During 44,724 person-years of follow-up, 193 colorectal cancer cases were diagnosed among 6,972 adenoma patients, representing an annual progression rate of 0.43%. Colorectal cancer risk was significantly elevated in patients who had an adenoma removed (SIR, 2.85; 95% CI, 2.61-3.25) compared with the general population. Male sex, older age, rectal site, and villous architecture were associated with an increased colorectal cancer risk in adenoma patients. Further analysis suggested that not having a full colonoscopy performed at, or following, incident polypectomy contributed to the excess colorectal cancer risk.

CONCLUSIONS

Colorectal cancer risk was elevated in individuals following polypectomy for adenoma, outside of screening programs.

IMPACT

This finding emphasizes the need for full colonoscopy and adenoma clearance, and appropriate surveillance, after endoscopic diagnosis of adenoma.

Simple colonoscopy reporting system checking the detection rate of colon polyps

AIM: To present a simple colonoscopy reporting system that can be checked easily the detection rate of colon polyps.

METHODS: A simple colonoscopy reporting system Kosin Gastroenterology (KG quality reporting system) was developed. The polyp detection rate (PDR), adenoma detection rate (ADR), serrated polyp detection rate (SDR), and advanced adenoma detection rate (AADR) are easily calculated to use this system.

RESULTS: In our gastroenterology center, the PDR, ADR, SDR, and AADR test results from each gastroenterologist were updated, every month. Between June 2014, when the program was started, and December 2014, the overall PDR and ADR in our center were 62.5% and 41.4%, respectively. And the overall SDR and AADR were 7.5% and 12.1%, respectively.

CONCLUSION: We envision that KG quality reporting system can be applied to develop a comprehensive system to check colon polyp detection rates in other gastroenterology centers.

Surveillance colonoscopy in low-risk postpolypectomy patients: Is it necessary?

AIM

Patients who have had colorectal adenomas removed are at increased risk of developing colorectal cancer in the future. We sought to determine whether surveillance colonoscopy at 5 years in low-risk postpolypectomy patients is necessary and effective.

METHOD

UK multicentre retrospective study. Patients diagnosed with 'low-risk' colorectal adenomas between April 2004 and April 2007 were identified and results of all subsequent lower gastrointestinal (GI) endoscopies were noted. Where no colonoscopy had been done at or after 5 years from the index investigation, patient details were cross-checked against hospital colorectal multidisciplinary team databases to ensure no colorectal cancer had been detected in the meantime.

RESULTS

641 patients were included. 131 patients (20.4%) had a 'per protocol' surveillance colonoscopy at 5 years. Of these, no patients were found to have colorectal cancer, 10 patients (7.6%) had advanced adenomas, 26 patients (19.8%) had non-advanced adenomas and 95 patients (72.5%) had no further adenomas. 510 patients (79.6%) did not have a surveillance colonoscopy at 5 years. Of these, 110 patients (17.2%) developed lower GI symptoms within 5 years of their index endoscopy and underwent a further lower GI endoscopy to investigate these symptoms. 3 colorectal cancers in 3 patients were found during these endoscopies and two further colorectal cancers were found at symptomatic colonoscopies at or after 5 years from index.

CONCLUSIONS

Patients with low-risk adenomas should be risk profiled. Those with risk factors, such as two adenomas, male sex and advanced adenomas at index procedure should be offered 5-year surveillance colonoscopy.

The impact of screening on colorectal cancer mortality and incidence: has it really made a difference?

About sixty percent of the US population of those age fifty and older are currently up to date with colorectal cancer screening recommendations. Has this level of screening made a difference for reducing colorectal cancer (CRC) incidence and/or mortality? Randomized controlled trials of guaiac-based fecal occult blood tests, which have relatively low sensitivity but high specificity for CRC, have shown a modest effect but with a long-term reduction in CRC mortality. Newer fecal immunochemical tests are expected to have a greater effect. Randomized controlled trials of flexible sigmoidoscopy have also demonstrated a reduction in CRC mortality. Observational studies of screening colonoscopy suggest an effect of greater than fifty percent reduction in CRC mortality. We have assessed past trends of colorectal cancer screening in the US population which suggest that more than fifty percent of the decline in colorectal cancer mortality can be attributed to the increased acceptance and uptake in colorectal cancer screening. Current and future levels of increased screening could provide for even larger reductions for the USA. Colorectal cancer screening has and will continue to make a significant impact on reducing colorectal cancer mortality.

Association between Diverticular Disease and Pre-Neoplastic Colorectal Lesions in an Urban African-American Population

BACKGROUND

It is unclear whether there is a shared pathway in the development of diverticular disease (DD) and potentially neoplastic colorectal lesions since both diseases are found in similar age groups and populations.

AIM

To determine the association between DD and colorectal pre-neoplastic lesions in an African-American urban population.

METHODS

Data from 1986 patients who underwent colonoscopy at the Howard University Hospital from January 2012 through December 2012 were analyzed for this study. The presence of diverticula and polyps was recorded using colonoscopy reports. Polyps were further classified into adenoma or hyperplastic polyp based on histopathology reports. Multiple logistic regression was done to analyze the association between DD and colonic lesions.

RESULTS

Of the 1986 study subjects, 1,119 (56%) were females, 35% had DD and 56% had at least one polyp. There was a higher prevalence of polyps (70 vs. 49%; OR = 2.3; 95% CI: 1.9-2.8) and adenoma (43 vs. 25%; OR = 2.0; 95% CI: 1.7-2.5) in the diverticular vs. non-diverticula patients. Among patients who underwent screening colonoscopy, the presence of diverticulosis was associated with increased odds of associated polyps (OR = 9.9; 95% CI: 5.4-16.8) and adenoma (OR = 5.1; 95% CI: 3.4-7.8).

CONCLUSION

Patients with DD are more likely to harbor colorectal lesions. These findings call for more vigilance on the part of endoscopists during colonoscopy in patients known to harbor colonic diverticula.

Interobserver variability in assessing dysplasia and architecture in colorectal adenomas: a multicentre Canadian study

AIMS

Following the introduction of colorectal cancer screening programmes throughout Canada, it became necessary to standardise the diagnosis of colorectal adenomas. Canadian guidelines for standardised reporting of adenomas were developed in 2011. The aims of the present study were (a) to assess interobserver variability in the classification of dysplasia and architecture in adenomas and (b) to determine if interobserver variability could be improved by the adoption of criteria specified in the national guidelines.

METHODS

An a priori power analysis was used to determine an adequate number of cases and participants. Twelve pathologists independently classified 40 whole-slide images of adenomas according to architecture and dysplasia grade. Following a wash-out period, participants were provided with the national guidelines and asked to reclassify the study set.

RESULTS

At baseline, there was moderate interobserver agreement for architecture (K=0.4700; 95% CI 0.4427 to 0.4972) and dysplasia grade (K=0.5680; 95% CI 0.5299 to 0.6062). Following distribution of the guidelines, there was improved interobserver agreement in assessing architecture (K=0.5403; 95% CI 0.5133 to 0.5674)). For dysplasia grade, overall interobserver agreement remained moderate but decreased significantly (K=0.4833; 95% CI 0.4452 to 0.5215). Half of the cases contained high-grade dysplasia (HGD). Two pathologists diagnosed HGD in ≥75% of cases.

CONCLUSIONS

The improvement in interobserver agreement in classifying adenoma architecture suggests that national guidelines can be useful in disseminating knowledge, however, the variability in the diagnosis of HGD, even following guideline review suggests the need for ongoing knowledge-transfer exercises.

Long-term colorectal-cancer mortality after adenoma removal

BACKGROUND

Although colonoscopic surveillance of patients after removal of adenomas is widely promoted, little is known about colorectal-cancer mortality among these patients.

METHODS

Using the linkage of the Cancer Registry and the Cause of Death Registry of Norway, we estimated colorectal-cancer mortality among patients who had undergone removal of colorectal adenomas during the period from 1993 through 2007. Patients were followed through 2011. We calculated standardized incidence-based mortality ratios (SMRs) using rates for the Norwegian population at large for comparison. Norwegian guidelines recommended colonoscopy after 10 years for patients with high-risk adenomas (adenomas with high-grade dysplasia, a villous component, or a size ≥10 mm) and after 5 years for patients with three or more adenomas; no surveillance was recommended for patients with low-risk adenomas. Polyp size and exact number were not available in the registry. We defined high-risk adenomas as multiple adenomas and adenomas with a villous component or high-grade dysplasia.

RESULTS

We identified 40,826 patients who had had colorectal adenomas removed. During a median follow-up of 7.7 years (maximum, 19.0), 1273 patients were given a diagnosis of colorectal cancer. A total of 398 deaths from colorectal cancer were expected and 383 were observed, for an SMR of 0.96 (95% confidence interval [CI], 0.87 to 1.06) among patients who had had adenomas removed. Colorectal-cancer mortality was increased among patients with high-risk adenomas (expected deaths, 209; observed deaths, 242; SMR, 1.16; 95% CI, 1.02 to 1.31), but it was reduced among patients with low-risk adenomas (expected deaths, 189; observed deaths, 141; SMR, 0.75; 95% CI, 0.63 to 0.88).

CONCLUSIONS

After a median of 7.7 years of follow-up, colorectal-cancer mortality was lower among patients who had had low-risk adenomas removed and moderately higher among those who had had high-risk adenomas removed, as compared with the general population. (Funded by the Norwegian Cancer Society and others.).

Rural-urban differences in the long-term risk of colorectal cancer after adenoma removal: a population-based study

BACKGROUND

We investigated the impact of municipality of residence on colonoscopic surveillance and colorectal cancer risk after adenoma resection in a French well-defined administrative area.

METHODS

This registry-based study included all patients residing in Côte d'Or (n=5769) first diagnosed with colorectal adenomas between January 1, 1990, and December 31, 1999. Information about colonoscopic surveillance and colorectal cancer incidence was collected until December 31, 2003.

RESULTS

A rural place of residence reduced the probability of colonoscopic surveillance in men [HR=0.89 (95%CI: 0.79-0.99), p=0.041] and in patients without family history of colorectal cancer [HR=0.91(0.82-0.99), p=0.044]. After a median follow-up of 7.7 years, 87 patients developed invasive colorectal cancer. After advanced adenoma removal, the standardized incidence ratio for colorectal cancer was 3.03 (95%CI: 1.92-4.54) for rural patients and 1.87 (95%CI: 1.26-2.66) for urban patients compared with the general population. The risk of colorectal cancer was higher in rural patients than in urban ones only after removal of the initial advanced adenoma [HR=1.73 (95%CI: 1.01-3.00, p=0.048)]. Further adjustment for surveillance colonoscopy, physician location, and other confounders had little impact on these results.

CONCLUSION

The increased risk of subsequent colorectal cancer after advanced adenoma removal in French rural patients was not explained by a lower rate of colonoscopic surveillance. The role of socio-economic and environmental factors requires further exploration.

A direct comparison of the prevalence of advanced adenoma and cancer between surveillance and screening colonoscopies

BACKGROUND/AIMS

Surveillance colonoscopy is recommended after polypectomy of adenoma and surgery for colorectal cancer. The purpose of this study was to assess the frequency of advanced adenoma and cancer in colonoscopies performed for surveillance compared to screening colonoscopies.

METHODS

Analysis of relative frequencies of findings in colonoscopies performed for post-adenoma surveillance (post-ad), post-cancer surveillance (post-crc), screening, and follow-up of a positive fecal occult blood test (FOBT). Logistic regression was used to identify the risk for advanced adenoma (adenoma ≥10 mm, containing high-grade dysplasia, or villous histology) and cancer.

RESULTS

324,912 colonoscopies were included in the analysis: 81,877 post-ad, 26,896 post-crc, 178,305 screening, 37,834 positive FOBT. Advanced adenoma (cancer) was diagnosed in 8.0% (0.4%) of post-ad, 5.0% (1.0%) of post-crc, 7.4% (1.1%) of screening, and 11.7% (3.6%) of positive FOBT colonoscopies. Compared to screening, the odds ratios for finding advanced adenoma were 0.93 (95% CI 0.88-0.98) for post-ad, 0.96 (0.86-1.08) for post-crc, and 1.18 (1.09-1.28) for positive FOBT colonoscopies. The odds ratios for the diagnosis of cancer were 0.29 (0.24-0.36) for post-ad, 0.81 (0.61-1.07) for post-crc, and 2.77 (2.43-3.17) for positive FOBT.

CONCLUSION

Colonoscopy for post-ad surveillance but not colonoscopy for post-crc surveillance is associated with a lower risk of diagnosis of advanced adenoma and cancer.

The appropriateness of surveillance colonoscopy intervals after polypectomy

BACKGROUND

Adherence to surveillance colonoscopy guidelines is important to prevent colorectal cancer (CRC) and unnecessary workload.

OBJECTIVE

To evaluate how well Canadian gastroenterologists adhere to colonoscopy surveillance guidelines after adenoma removal or treatment for CRC.

METHODS

Patients with a history of adenomas or CRC who had surveillance performed between October 2008 and October 2010 were retrospectively included. Time intervals between index colonoscopy and surveillance were compared with the 2008 guideline recommendations of the American Gastroenterological Association and regarded as appropriate when the surveillance interval was within six months of the recommended time interval.

RESULTS

A total of 265 patients were included (52% men; mean age 58 years). Among patients with a normal index colonoscopy (n=110), 42% received surveillance on time, 38% too early (median difference = 1.2 years too early) and 20% too late (median difference = 1.0 year too late). Among patients with nonadvanced adenomas at index (n=96), 25% underwent surveillance on time, 61% too early (median difference = 1.85) and 14% too late (median difference = 1.1). Among patients with advanced neoplasia at index (n=59), 29% underwent surveillance on time, 34% too early (median difference = 1.86) and 37% later than recommended (median difference = 1.61). No significant difference in adenoma detection rates was observed when too early surveillance versus appropriate surveillance (34% versus 33%; P=0.92) and too late surveillance versus appropriate surveillance (21% versus 33%; P=0.11) were compared.

CONCLUSION

Only a minority of surveillance colonoscopies were performed according to guideline recommendations. Deviation from the guidelines did not improve the adenoma detection rate. Interventions aimed at improving adherence to surveillance guidelines are needed.

Prevention of interval colorectal cancers: what every clinician needs to know

Colonoscopic screening and surveillance have been very effective tools in the fight against colorectal cancer (CRC). Colonoscopy is more than a cancer screening test; it also can prevent CRC by detecting and removing precancerous lesions. Despite this potential, there has been increasing concern about CRCs that occur after a previous colonoscopy and before the next screening/surveillance examination (interval CRCs). The etiology of interval CRC is thought to be caused mostly by missed or incompletely resected lesions on index colonoscopy with some contribution of rapidly progressive new lesions. If this is true, many interval cancers should be preventable by improving colonoscopy technique. There are a variety of strategies to decrease interval CRC rates including use of a split-dosed bowel preparation, optimizing withdrawal technique, ensuring complete polypectomy, and careful pathologic examination of the tissue removed. Furthermore, there should be an increased emphasis on how endoscopists are trained to cultivate high-quality technique throughout their careers. It is important to inform patients that even high-quality colonoscopy is not perfectly sensitive for the detection of advanced neoplasia. Improving colonoscopy quality can decrease interval CRC rates and further decrease CRC incidence and mortality.

Repeat colonoscopy’s value in gastrointestinal bleeding

AIM: To assess the diagnostic yield and clinical value of early repeat colonoscopies for indications other than colorectal cancer (CRC) screening/surveillance.

METHODS: A retrospective review of patients who had more than one colonoscopy performed for the same indication within a three year time frame at our tertiary care referral hospital between January 1, 2000 and January 1, 2010 was conducted. Exclusion criteria included repeat colonoscopies performed for CRC screening/surveillance, poor bowel preparation, suspected complications from the index procedure, and incomplete initial procedure. Primary outcome was new endoscopic finding that led to an endoscopic therapeutic intervention or any change in clinical management. Clinical parameters including age, sex, race, interval between procedures, indication of the procedure, presenting symptoms, severity of symptoms, hemodynamic instability, duration between onset of symptoms and when the procedure was performed, change in endoscopist, withdrawal time, location of colonic lesions and improvement of quality of bowel preparation were analyzed using bivariate analysis and logistic regression analysis to examine correlation with this primary outcome.

RESULTS: Among 19  772 colonoscopies performed during the above mentioned period, 947 colonoscopies (4.79%) were repeat colonoscopies performed within 3 years from the index procedure. Out of these repeat colonoscopies, 139 patient pairs met the inclusion criteria. The majority of repeat colonoscopies were for lower gastrointestinal bleeding (88.4%), change in bowel habits (6.4%) and abdominal pain (5%). Among 139 eligible patient pairs of colonoscopies, only repeat colonoscopies that were done for lower gastrointestinal bleeding and abdominal pain produced endoscopic findings that led to a change in management [25 out of 123 (20.33%) and 2 out of 7 (28.57%), respectively]. When looking at only recurrent lower gastrointestinal bleeding cases, new endoscopic findings included 8 previously undetected hemorrhoid lesions (6.5%), 7 actively bleeding lesions requiring endoscopic intervention, which included 3 bleeding arterio-venous malformations (2.43%), 2 bleeding radiation colitis (1.6%), and 2 bleeding internal hemorrhoids (1.6%), 5 previously undetected tubular adenomas [4 were smaller than 1 cm (4.9%) and 1 was larger than 1 cm (0.8%)], 3 radiation colitis (2.43%), 1 rectal ulcer (0.8%), and 1 previously undetected right sided colon cancer (0.8%). Of the 25 new endoscopic findings, 18 (72%) were found when repeat colonoscopy was done within the first year after the index procedure. These findings were 1 rectal ulcer, 3 radiation colitis, 4 new hemorrhoid lesions, 3 previously undetected tubular adenomas, and 7 actively bleeding lesions requiring endoscopic intervention. Of all parameters analyzed, only the interval between procedures less than one year was associated with higher likelihood of finding a clinically significant change in repeat colonoscopy (odds ratios of interval between procedures of 1-2 year and 2-3 year compared to 0-1 year were 0.09; 95%CI 0.01-0.74, P = 0.025 and 0.26; 95%CI 0.09-0.72, P = 0.010 respectively). No complications were observed among all 139 colonoscopy pairs.

CONCLUSION: There is clinical value of repeating a colonoscopy for recurrent lower gastrointestinal bleeding, especially within the first year after the index procedure.

Colorectal cancer screening--optimizing current strategies and new directions

The first evidence that screening for colorectal cancer (CRC) could effectively reduce mortality dates back 20 years. However, actual population screening has, in many countries, halted at the level of individual testing and discussions on differences between screening tests. With a wealth of new evidence from various community-based studies looking at test uptake, screening-programme organization and the importance of quality assurance, population screening for CRC is now moving into a new realm, promising better results in terms of reducing CRC-specific morbidity and mortality. Such a shift in the paradigm requires a change from opportunistic, individual testing towards organized population screening with comprehensive monitoring and full-programme quality assurance. To achieve this, a combination of factors--including test characteristics, uptake, screenee autonomy, costs and capacity--must be considered. Thus, evidence from randomized trials comparing different tests must be supplemented by studies of acceptance and uptake to obtain the full picture of the effectiveness (in terms of morbidity, mortality and cost) the different strategies have. In this Review, we discuss a range of screening modalities and describe the factors to be considered to achieve a truly effective population CRC screening programme.

Plasma B vitamins and LINE-1 DNA methylation in leukocytes of patients with a history of colorectal adenomas

SCOPE

Low concentrations of folate, other B vitamins, and methionine are associated with colorectal cancer risk, possibly by changing DNA methylation patterns. Here, we examine whether plasma concentrations of B vitamins and methionine are associated with methylation of long interspersed nuclear element-1 (LINE-1) among those at high risk of colorectal cancer, i.e. patients with at least one histologically confirmed colorectal adenoma (CRA) in their life.

METHODS AND RESULTS

We used LINE-1 bisulfite pyrosequencing to measure global DNA methylation levels in leukocytes of 281 CRA patients. Multivariable linear regression was used to assess associations between plasma B vitamin concentrations and LINE-1 methylation levels. Plasma folate was inversely associated with LINE-1 methylation in CRA patients, while plasma methionine was positively associated with LINE-1 methylation.

CONCLUSION

This study does not provide evidence that in CRA patients, plasma folate concentrations are positively related to LINE-1 methylation in leukocytes but does suggest a direct association between plasma methionine and LINE-1 methylation in leukocytes.

Rural-urban inequalities in detection rates of colorectal tumours in the population

BACKGROUND

Because few data are available on this topic, we investigated the influence of geographical determinants on colorectal adenoma detection and cancer incidence rates.

METHODS

Between 1990 and 1999, 6220 Côte d'Or inhabitants (France) were first-diagnosed with a colorectal adenoma, and 2389 with an invasive adenocarcinoma. The impact of the rural-urban place of residence and of a physician location in municipalities on adenoma and cancer detection rates was studied using Poisson regression.

RESULTS

World-standardized adenoma detection rate was significantly higher in urban areas (102 [95% CI: 97-107]) than in rural areas (78 [95% CI: 72-84]). The impact of the absence of physicians in municipalities was only found in rural areas. The detection rate ratio associated with the absence of a primary care physician was 0.70 [95% CI: 0.61-0.81], and the detection rate ratio associated with the absence of a gastroenterologist was 0.75 [95% CI: 0.64-0.89]. Colorectal cancer incidence rates were similar in urban and rural areas with only marginal variations related to physician location.

CONCLUSIONS

These results suggested a differential impact of geographical variables on the detection rates of colorectal adenomas and cancers in the population. Further studies are needed to examine socio-economic factors likely to be involved in these disparities.

Colorectal cancer incidence is low in patients following a colonoscopy

BACKGROUND/AIMS

Colonoscopy has been proven a valuable tool in preventing colorectal cancer in controlled studies; we conducted a longitudinal confirmation study in everyday clinical practice.

METHODS

In a retrospective study, we monitored the outcome of patients with a total colonoscopy at our hospital between 1994 and 2007. We analysed the data of in-house follow-up colonoscopies, a national person registry and the morphological tumour registry centralizing all histopathological data at a national level. Patients with a particular colorectal cancer risk were excluded.

RESULTS

8950 patients were included in our study. 2032 (22.7%) patients had at least one colorectal adenoma at index colonoscopy. Adenoma prevalence was significantly higher in men than in women (27.9% vs. 17.4%, p<0.001) and was increasing with age in both sexes. Patients were followed for a mean of 5.2 years and 19 had invasive colorectal cancer detected over 47,725 person years of follow-up. The incidence rate was 0.40 cases/1000 person years of follow-up (95% confidence interval, 0.25-0.62), and the standardized incidence ratio was 0.37 (95% confidence interval, 0.24-0.58).

CONCLUSION

Incidence rates of colorectal cancer are low in the follow-up of patients having undergone a total colonoscopy in everyday practice. After standard therapy of colorectal adenomas at colonoscopy, there is little evidence for excess colorectal cancer incidence in this subgroup.

Risk factors for advanced adenomas amongst small and diminutive colorectal polyps: a prospective monocenter study

BACKGROUND

The management of colorectal polyps <10mm in diameter is controversial. Our aim was to evaluate the rate and risk factors for advanced adenomas and high grade neoplasia amongst small (6-9 mm) and diminutive (1-5mm) colorectal polyps.

METHODS

Endoscopic and pathological reports of colonoscopies performed in our centre were collected prospectively. Advanced adenoma was defined by presence of a villous component and/or high grade dysplasia; high grade neoplasia by presence of high grade dysplasia and/or intramucosal carcinoma.

RESULTS

1468 patients were included (53.1% male, mean age 59.5±14 years); 414 polyps <10mm were detected, 9.9% advanced adenomas and 1.7% high grade neoplasia. Amongst small polyps, 25 (35.2%) were advanced adenomas, mainly due to villous features, and 3 (4.2%) were high grade neoplasia. Polyp size was associated with advanced adenomas (odds ratio=8.47).

CONCLUSION

The rate of advanced adenomas amongst small polyps was 35%, mainly due to the presence of villous features. Polyp size was identified as a risk factor of advanced adenoma amongst polyps <10mm. Given these results, we believe that polypectomy should be warranted for patients presenting with small polyps at computed tomography colonography.

Long-term outcomes following positive fecal occult blood test results in older adults: benefits and burdens

BACKGROUND

In the United States, older adults have low rates of follow-up colonoscopy after a positive fecal occult blood test (FOBT) result. The long-term outcomes of these real world practices and their associated benefits and burdens are unknown.

METHODS

Longitudinal cohort study of 212 patients 70 years or older with a positive FOBT result at 4 Veteran Affairs (VA) facilities in 2001 and followed up through 2008. We determined the frequency of downstream outcomes during the 7 years of follow-up, including procedures, colonoscopic findings, outcomes of treatment, complications, and mortality based on chart review and national VA and Medicare data. Net burden or benefit from screening and follow-up was determined according to each patient's life expectancy. Life expectancy was classified into 3 categories: best (age, 70-79 years and Charlson-Deyo comorbidity index [CCI], 0), average, and worst (age, 70-84 years and CCI, ≥4 or age, ≥85 years and CCI, ≥1).

RESULTS

Fifty-six percent of patients received follow-up colonoscopy (118 of 212), which found 34 significant adenomas and 6 cancers. Ten percent experienced complications from colonoscopy or cancer treatment (12 of 118). Forty-six percent of those without follow-up colonoscopy died of other causes within 5 years of FOBT (43 of 94), while 3 died of colorectal cancer within 5 years. Eighty-seven percent of patients with worst life expectancy experienced a net burden from screening (26 of 30) as did 70% with average life expectancy (92 of 131) and 65% with best life expectancy (35 of 51) (P = .048 for trend).

CONCLUSIONS

Over a 7-year period, older adults with best life expectancy were less likely to experience a net burden from current screening and follow-up practices than are those with worst life expectancy. The net burden could be decreased by better targeting FOBT screening and follow-up to healthy older adults.

Prognostic significance of high-grade dysplasia in colorectal adenomas

AIM

Colonoscopy to detect and remove polyps has contributed to a reduction in colorectal carcinoma. Three-year follow up is recommended for patients considered to be at high risk (at least three adenomas, adenoma ≥ 1 cm, villous or high-grade features). Our study focused on patients diagnosed with high-grade dysplasia with regard to initial management and follow up.

METHOD

A search of patients who had had endoscopic removal of a high-grade adenoma was carried out. Patients with the following were excluded: follow up of < 1 year, polyposis syndromes, prior colon cancer and a diagnosis of adenocarcinoma within 6 months following initial diagnosis.

RESULTS

Eighty-three patients treated between 1999 and 2007 for high-grade dysplasia (HGD) in a colorectal adenoma were identified. Over a median follow-up period of 4 years, 53 (64%) developed further adenomatous polyps. Among these, 7% had an adenoma with HGD or an adenocarcinoma. In all these patients, the initial high-grade adenoma was > 1 cm in diameter. Initial follow-up colonoscopy was performed on average 7 months following the initial diagnosis. Ten per cent of patients underwent prophylactic segmental resection, and 6% received argon laser therapy.

CONCLUSION

The study demonstrates that patients who have a colorectal adenoma > 1 cm with HGD may be at high risk of developing further adenomas with HGD or carcinoma. Close follow up is warranted.

Narrow band imaging to detect residual or recurrent neoplastic tissue during surveillance endoscopy

BACKGROUND

There is little data on the prevalence of residual neoplastic tissue or the rate of endoscopically detected recurrence in patients with prior surgical or endoscopic resection of advanced neoplasia.

AIMS

To compare standard white light with NBI for both the detection, as well as the differentiation, of residual or recurrent neoplastic tissue during real-time endoscopy.

METHODS

A prospective study of 46 consecutive patients undergoing surveillance colonoscopy or upper endoscopy was conducted. Prior resection sites were examined first with white light and then with NBI. Main outcome measurements included the number of distinct lesions identified with white light, the number of additional lesions identified with NBI, and the overall accuracy of endoscopic diagnosis using white light alone or with NBI.

RESULTS

Sixty discrete lesions were identified, 43 with white light alone, and an additional 17 with NBI. NBI identified more lesions per patient than white light alone (mean 1.33 vs. 0.96, p < 0.05) and there was a trend towards increased detection of neoplastic lesions. Recurrent/residual neoplasia was present in 14 patients (30%) and there was a trend towards increased detection with the addition of NBI. About 63% of lesions identified with white light appeared more extensive when examined with NBI. The diagnostic accuracy in predicting histology was equivalent for NBI and white light (87 vs. 88%), though there was a trend towards higher sensitivity for neoplastic lesions with NBI (88 vs. 69%, p = 0.16).

CONCLUSIONS

A substantial number of patients undergoing surveillance endoscopy had residual or recurrent neoplastic tissue identified at the prior resection site. As NBI detected additional neoplastic lesions as well as demonstrated that lesions detected with white light were more extensive, adjunctive use of NBI for examining post-endoscopy resection sites should be studied in future, larger studies.

Colorectal cancers detected after colonoscopy frequently result from missed lesions

BACKGROUND & AIMS

Colorectal cancers (CRCs) that are detected in patients who have received colonoscopies (interval cancers) arise from missed lesions, incomplete resections of adenomas, or de novo. We estimated rates of interval cancer from missed lesions.

METHODS

Adenoma miss rates, cancer prevalence among patients with adenoma (based on size), and rates of adenoma-to-cancer transitions were estimated from the literature. We used a model to apply these risk estimates to a hypothetical average-risk population that received screening colonoscopies. We calculated the proportion of individuals with tumors missed at the baseline colonoscopy and tumors that arose from missed adenomas during a 5-year follow-up period. Sensitivity analyses were performed to assess robustness.

RESULTS

We found that 0.7 per 1000 persons undergoing a screening colonoscopy had a cancer that was missed at the baseline colonoscopy and an additional 1.1 per 1000 subsequently developed cancer from a missed adenoma. Therefore, the expected rate of individuals with CRC, based on missed adenomas, was 1.8 per 1000 persons within 5 years. By using the most conservative assumptions-a low miss rate and low prevalence of cancer in adenomas-0.5 per 1000 persons would have a detectable CRC within 5 years after a screening colonoscopy. In contrast, using the highest reported miss rates and cancer prevalence, CRCs from missed lesions would occur in 3.5 per 1000 screened persons.

CONCLUSIONS

A significant number of patients undergoing a screening colonoscopy that did not detect cancer actually have a malignant lesion or adenoma that could progress in a short interval. Most interval cancers might reflect missed rather than new lesions. Improving adenoma detection could reduce the rate of interval cancers.

Application of ANAES guidelines for colonoscopy in France: a practical survey

OBJECTIVES

In 2004, the French health authorities published guidelines on the indications for colonoscopy. However, no study has evaluated the awareness of healthcare practitioners of these guidelines. The aim of this study was to determine the level of awareness of the ANAES guidelines among French gastroenterologists.

PATIENTS AND METHODS

A questionnaire comprising 20 multiple choice questions (MCQ) was presented to a group of 79 gastroenterologists between February and June in 2008. The questions covered screening tests for colon cancer (one question), endoscopic mucosal resection (two questions) and the ANAES guidelines (17 questions). According to the number of colonoscopies performed per year (less than 100, 100-500, more than 500), the answers to these questions were analyzed separately.

RESULTS

Among the practitioners carrying out less than 100, 100-500 and more than 500 colonoscopies per year, the guidelines for colon cancer screening were known by 33, 50 and 56%, respectively, the quality criteria for endoscopic mucosal resection by 0, 0 and 3.7%, respectively, and the ANAES guideline indications for colonoscopy by 34.3, 51.2 and 48.9%, respectively (P<0.001). The ANAES guidelines were significantly better known by practitioners who were performing more than 100 colonoscopies per year, while the indications for control colonoscopy were less often correctly anticipated. No differences were found concerning postponed indications.

CONCLUSION

The ANAES guidelines consists of the following elements: (1) awareness of the ANAES guidelines is poor, with control colonoscopy being correctly anticipated in just over a third of the gastroenterologists; (2) performing more than 100 colonoscopies per year improves knowledge of the ANAES guidelines; and (3) the ANAES guidelines need to be simplified and should be covered by continuing medical education.

Quality assurance of endoscopy in colorectal cancer screening

This chapter explores the concept of quality assurance of colorectal cancer screening. It argues that effective quality assurance is critical to ensure that the benefits of screening outweigh the harms. The three key steps of quality assurance, definition of standards, measurement of standards and enforcement of standards, are explained. Quality is viewed from the perspective of the patient and illustrated by following the path of patients accessing endoscopy within screening services. The chapter discusses the pros and cons of programmatic versus non-programmatic screening and argues that quality assurance of screening can and should benefit symptomatic services. Finally, the chapter emphasises the importance of a culture of excellence underpinned by continuous quality improvement and effective service leadership.

Recurrence and surveillance of colorectal adenoma after polypectomy in a southern Chinese population

BACKGROUND AND AIM

Repeat colonoscopy is often performed within a short time after polypectomy due to the fear that colorectal adenomas were missed during the initial colonoscopy or that new adenomas have developed. The aim of this study was to estimate the actual recurrence rate of adenoma and its association with the length of the surveillance interval after polypectomy in a southern Chinese population.

METHODS

A total of 1,356 patients undergoing endoscopic polypectomy and completing three or more surveillence colonoscopies between 1976 and 2007 were retrospectively analyzed. The recurrence rates of adenoma and advanced adenoma and surveillance intervals after polypectomy were identified based on the features of adenomas detected on initial colonoscopy.

RESULTS

The recurrence rates of advanced adenoma in patients with non-advanced adenoma on the initial colonoscopy were 0.9, 3.9, 5.8, and 29.2% during surveillance intervals of 1-3, 3-5, 5-10, and 10-20 years post-initial colonoscopy; for patients with advanced adenoma on the initial colonoscopy, the recurrence rates were 3.8, 13.1, 34.7, and 52.0% during the same surveillance intervals, respectively. Older age (p < 0.05 for trend) and male sex [hazard ratio (HR) 2.11, 95% confidence interval (CI) 1.27-3.53] were significantly associated with recurrence for advanced adenoma, as were the size and number of baseline adenoma (p < 0.05 for trend), tubulovillous, villous adenoma (HR 2.57, 95% CI 1.24-5.32), and high-grade dysplasia (HR 1.61, 95% CI 1.07-2.42). When 5% of patients had recurring advanced adenoma, the surveillance interval was estimated to be 6.9 (95% CI 6.3-12.2) years in the low-risk group and 3.0 (95% CI 2.7-3.2) years in the high-risk group.

CONCLUSIONS

Among our patient group, the recurrence of advanced adenoma after polypectomy increased with the length of the surveillance interval. Based on our results, a 3-year follow-up of patients after polypectomy could be effective in preventing the recurrence of advanced adenoma in high-risk patients.

Polyp surveillance

Surveillance after colonic polypectomy is important to detect and remove missed synchronous polyps and cancers and new metachronous polyps or cancers. The authors review methods of surveillance and the risk of recurrent adenomas and provide surveillance recommendations.

Circumstances in which colonoscopy misses cancer

Colonoscopy is associated with a varying risk of missing colorectal cancer (CRC). The objective of this paper was to review the existing evidence that indicates when colonoscopy may miss cancer in usual clinical practice and to provide information that would be helpful to endoscopists in their daily practice. CRC is diagnosed within 3 years in about 5% of persons with CRC who undergo colonoscopy in whom the cancer is not detected. Future research should be directed at disentangling the relative contributions of tumour biology and colonoscopy quality in explaining this result. When consent is obtained for colonoscopy, patients must be informed of the small risk that a cancer may not be detected. Steps that can be taken to address colonoscopy quality include formal training in colonoscopy and polypectomy technique, coupled with maintenance of skills by performing at least 300 colonoscopies per year. The use of split dose bowel preparation is advised. Colonoscopy should be completed to the caecum with documentation of landmarks (ileocaecal valve; appendiceal orifice). Careful colonoscopy technique includes examining the proximal sides of flexures and folds, washing and suctioning debris and ensuring adequate colonic distension. Caecal intubation and adenoma detection rates should be reported and reviewed. Lesions should be completely removed at polypectomy and attention given to appropriate surveillance.