Risk of advanced proximal neoplasms in asymptomatic adults according to the distal colorectal findings

Critical Analysis of Markov Models Used for the Economic Evaluation of Colorectal Cancer Screening: A Systematic Review

BACKGROUND

The economic evaluation of colorectal cancer screening is challenging because of the need to model the underlying unobservable natural history of the disease.

OBJECTIVES

To describe the available Markov models and to critically analyze their main structural assumptions.

METHODS

A systematic search was performed in eight relevant databases (MEDLINE, Embase, Econlit, National Health Service Economic Evaluation Database, Health Economic Evaluations Database, Health Technology Assessment database, Cost-Effective Analysis Registry, and European Network of Health Economics Evaluation Databases), identifying 34 models that met the inclusion criteria. A comparative analysis of model structure and parameterization was conducted using two checklists and guidelines for cost-effectiveness screening models.

RESULTS

Two modeling techniques were identified. One strategy used a Markov model to reproduce the natural history of the disease and an overlaying model that reproduced the screening process, whereas the other used a single model to represent a screening program. Most of the studies included only adenoma-carcinoma sequences, a few included de novo cancer, and none included the serrated pathway. Parameterization of adenoma dwell time, sojourn time, and surveillance differed between studies, and there was a lack of validation and statistical calibration against local epidemiological data. Most of the studies analyzed failed to perform an adequate literature review and synthesis of diagnostic accuracy properties of the screening tests modeled.

CONCLUSIONS

Several strategies to model colorectal cancer screening have been developed, but many challenges remain to adequately represent the natural history of the disease and the screening process. Structural uncertainty analysis could be a useful strategy for understanding the impact of the assumptions of different models on cost-effectiveness results.

Adenoma Detection Rate in Colonoscopy: Does the Participation of a Resident Matter?

Presently, endoscopic procedures are a requirement for training competency for completion of a general surgery residency. There are no studies to date that have assessed whether having a resident perform a colonoscopy impacts quality indicators such as adenoma detection rate (ADR). To retrospectively review ADR in adult patients, who undergo screening colonoscopy at a single institution with (ColFacR) and without (ColFac) the participation of a general surgery resident. A total of 792 patients were identified in the database screening colonoscopies between the ages of 45 and 80 from July 2013 to June 2015. Of those, 501 were reviewed after exclusion criteria. When comparing the ColFac group (n = 316) to the ColFacR group (n = 185), there were no differences between age, gender, body mass index, American Society of Anesthesiologists score, or quality of bowel preparation. The mean number of total polyps, hyperplastic polyps, and adenomatous polyps retrieved were similar between the two groups. There was no difference in the ADR for the ColFac cases and ColFacR cases (25.95% vs 27.03%, respectively, P = 0.834). ADR is similar in elective colonoscopies that were performed with or without a general surgery resident. The participation of a general surgery resident in routine colonoscopies should not impact reported quality indicators.

I-scan optical enhancement for the in vivo prediction of diminutive colorectal polyp histology: Results from a prospective three-phased multicentre trial

BACKGROUND AND AIMS

Dye-less chromoendoscopy is an emerging technology for colorectal polyp characterization. Herein, we investigated whether the newly introduced I-scan optical enhancement (OE) can accurately predict polyp histology in vivo in real-time.

METHODS

In this prospective three-phased study, 84 patients with 230 diminutive colorectal polyps were included. During the first two study phases, five endoscopists assessed whether analysis of polyp colour, surface and vascular pattern under i-scan OE can differentiate in vivo between adenomatous and hyperplastic polyps. Finally, junior and experienced endoscopists (JE, EE, each n = 4) not involved in the prior study phases made a post hoc diagnosis of polyp histology using a static i-scan OE image database. Histopathology was used as a gold-standard in all study phases.

RESULTS

The overall accuracy of i-scan OE for histology prediction was 90% with a sensitivity, specificity, positive (PPV) and negative prediction value (NPV) of 91%, 90%, 86% and 94%, respectively. In high confidence predictions, the diagnostic accuracy increased to 93% with sensitivity, specificity, PPV and NPV of 94%, 91%, 89% and 96%. Colonoscopy surveillance intervals were predicted correctly in ≥ 90% of patients. In the post hoc analysis EE predicted polyp histology under i-scan OE with an overall accuracy of 91%. After a single training session, JE achieved a comparable diagnostic performance for predicting polyp histology with i-scan OE.

CONCLUSION

The histology of diminutive colorectal polyps can be accurately predicted with i-scan OE in vivo in real-time. Furthermore, polyp differentiation with i-scan OE appears to require only a short learning curve.

Flexible sigmoidoscopy in colorectal cancer screening: implications of different colonoscopy referral strategies

Flexible sigmoidoscopy (FS) screening reduces colorectal cancer incidence and mortality. Its potential to detect proximal neoplasms depends on colonoscopy referral. We estimated diagnostic performance of sigmoidoscopy using 12 different referral criteria in detecting colorectal cancer and advanced adenomas. Colonoscopy results from 14,947 participants of screening colonoscopy in Germany were used to derive sensitivity of sigmoidoscopy for colorectal cancer, advanced adenomas (AAs), and any advanced neoplasms in the proximal colon. It was assumed that FS detects the same neoplasms as colonoscopy within its reach and that distal neoplasms would be followed by colonoscopy. In addition, numbers of colonoscopies needed (NCN) to detect one proximal advanced neoplasm were calculated. The most advanced findings during colonoscopy were colorectal cancer in 213 subjects (1.4%), AA in 1539 subjects (10.2%) and non-advanced adenomas in 2988 subjects (19.8%). Without colonoscopy referral, overall sensitivities for any colorectal cancer, advanced adenoma and any advanced neoplasm (proximal or distal) would be 79, 65 and 66%, respectively. These sensitivities could be increased to up to 86, 83 and 84% by the referral strategies investigated. Compared to referral due to advanced adenomas, referral due to non-advanced adenomas would substantially increase the NCN at a modest gain in sensitivity. Sensitivities were higher and NCNs were lower in men than in women for every strategy. In conclusion, colonoscopy referral can substantially increase sensitivity of sigmoidoscopy-based screening, but the gain by referral due to non-advanced adenomas substantially increases NCN compared to referral due to advanced neoplasms only. Major sex differences may call for sex-specific referral strategies.

Helicobacter pylori is associated with increased risk of serrated colonic polyps: Analysis of serrated polyp risk factors

BACKGROUND

Sessile serrated adenomas (SSA) and traditional serrated adenomas (TSA) are recognized precursors of colorectal cancer, but their risk factors are not well established. We investigated the association between Helicobacter pylori infection (HPI) and the development of SSA and TSA.

METHODS

Retrospective data were collected on patients aged ≥ 18 years that underwent colonoscopy with biopsy between 2006 and 2016. Based on histology, patients were classified into three groups: those with SSA and/or TSA, (serrated neoplasia group, SN); conventional adenomas only (CA); and with no polyps (NP). Gastric HPI status, demographic, and clinical risk factors were compared between groups using bivariate and multivariable analysis.

RESULTS

HPI was significantly associated with increased risk of SN (SN vs. NP: OR 1.71 [95% CI 1.29-2.27]; SN vs. CA: 1.49 [1.14-1.96]). Additional factors associated with increased risk of SN included the following: age 50-75 years, compared to younger age (SN vs. NP: 2.83 [1.69-4.74]), female gender (SN vs. CA: 1.28 [0.99-1.64]), White race, compared to Blacks (SN vs. CA: 1.52 [1.07-2.15)], overweight and obese body mass index [SN vs. NP: p < 0.001) and current smoking status (SN vs. CA: 2.09 [1.55-2.82)]. Among SN, higher HPI prevalence was associated with dysplasia (p = 0.05) and proximal location (p = 0.01).

CONCLUSIONS

Our data suggest that gastric HPI is associated with increased risk of SN and CA, with a stronger association with SN as compared to CA. Age 50-75 years, female gender, White race, obesity, and smoking were also predictors of SN. A positive correlation of HPI with proximal and dysplastic SN suggests a possible role in serrated pathway carcinogenesis. Prospective studies with large patient population are needed to further investigate this association.

Individual invitation letters lead to significant increase in attendance for screening colonoscopies: Results of a pilot study in Northern Hesse, Germany

Background

Colorectal cancer (CRC) is the second most common cancer in Germany. Screening colonoscopies are considered an effective tool for early detection and prevention of CRC and are recommended in Germany for citizens over the age of 55. To increase the participation rate for screening colonoscopies, an invitation procedure was initiated in parts of Germany for patients between the ages of 55 and 75 who had never undergone a screening colonoscopy before.

Methods

We examined the number of participating patients before, during, and after the invitation procedure and compared the number of the participating patients who received a cover letter with the participating patients from the control group. Additionally, we classified the findings of the colonoscopies including CRC, advanced adenomas, and polyps.

Results

During the invitation period, the participation rate of the invitation group increased from 220 patients to 531 patients compared to 1256 to 1693 in the control group. The increase was significantly greater in patients with cover letters (+141% vs.+35%, p < 0.0001). Also, significantly more polyps and adenomas were found in patients from the invitation letter group (254 (+102%) vs. 679 (-9%), p < 0.0001).

Conclusions

Our study clearly indicates that personal invitation letters are an effective measure to increase overall participation rates in screening colonoscopies.

Evaluation of the benefits, harms and cost-effectiveness of potential alternatives to iFOBT testing for colorectal cancer screening in Australia

The Australian National Bowel Cancer Screening Program (NBCSP) will fully roll-out 2-yearly screening using the immunochemical Faecal Occult Blood Testing (iFOBT) in people aged 50 to 74 years by 2020. In this study, we aimed to estimate the comparative health benefits, harms, and cost-effectiveness of screening with iFOBT, versus other potential alternative or adjunctive technologies. A comprehensive validated microsimulation model, Policy1-Bowel, was used to simulate a total of 13 screening approaches involving use of iFOBT, colonoscopy, sigmoidoscopy, computed tomographic colonography (CTC), faecal DNA (fDNA) and plasma DNA (pDNA), in people aged 50 to 74 years. All strategies were evaluated in three scenarios: (i) perfect adherence, (ii) high (but imperfect) adherence, and (iii) low adherence. When assuming perfect adherence, the most effective strategies involved using iFOBT (annually, or biennially with/without adjunct sigmoidoscopy either at 50, or at 54, 64 and 74 years for individuals with negative iFOBT), or colonoscopy (10-yearly, or once-off at 50 years combined with biennial iFOBT). Colorectal cancer incidence (mortality) reductions for these strategies were 51-67(74-80)% in comparison with no screening; 2-yearly iFOBT screening (i.e. the NBCSP) would be associated with reductions of 51(74)%. Only 2-yearly iFOBT screening was found to be cost-effective in all scenarios in context of an indicative willingness-to-pay threshold of A$50,000/life-year saved (LYS); this strategy was associated with an incremental cost-effectiveness ratio of A$2,984/LYS-A$5,981/LYS (depending on adherence). The fully rolled-out NBCSP is highly cost-effective, and is also one of the most effective approaches for bowel cancer screening in Australia.

Management of Serrated Polyps of the Colon

PURPOSE OF REVIEW

The purpose of this review is to summarize the management of serrated colorectal polyps (SPs), with a particular focus on the most common premalignant SP, sessile serrated adenoma or polyp (SSA/P). These lesions present a challenge for endoscopists with respect to detection and resection, and are also susceptible to pathologic misdiagnosis.

RECENT FINDINGS

Patients with SSA/Ps are at an increased risk of future colorectal neoplasia, including advanced polyps and cancer. Reasonable benchmarks for SP detection rates are 5-7% for SSA/Ps and 10-12% for proximal SPs. Certain endoscopic techniques such as chromoendoscopy, narrow band imaging, water immersion, and wide-angle viewing may improve SSA/P detection. Emerging endoscopic techniques such as underwater polypectomy, suction pseudopolyp technique, and piecemeal cold snare polypectomy are helpful tools for the endoscopist's armamentarium for removing SSA/Ps. Proper orientation of SSA/P specimens can improve the accuracy of pathology readings. Patients with confirmed SSA/Ps and proximal HPs should undergo surveillance at intervals similar to what is recommended for patients with conventional adenomas. Patients with SSA/Ps may also be able to lower their risk of future polyps by targeting modifiable risk factors including tobacco and alcohol use and high-fat diets. NSAIDs and aspirin appear to be protective agents. SPs and SSA/Ps in particular are important colorectal cancer precursors that merit special attention to ensure adequate detection, resection, and surveillance.

Effectiveness of Screening Modalities in Colorectal Cancer: A Network Meta-Analysis

The aim of the study was to evaluate on the effectiveness of screening modalities in the prevention of colorectal cancer (CRC) occurrence and deaths. General meta-analysis was performed to produce pooled estimates of the effect of CRC incidence and mortality using a search of PubMed, Web of Science, and the Cochrane Library for eligible studies from January 1992 to March 2016. A network meta-analysis was performed to synthetically compare the effectiveness of 5 frequently used screening modalities. A total of 44 studies with a focus on mortality from CRC using different screening methods were included. General meta-analysis showed that fecal immunohistochemical testing (FIT), flexible sigmoidoscopy (FS), colonoscopy, combination of fecal occult blood testing and FS screening respectively reduced CRC mortality by 59% (relative risk [RR], 0.41; 95% confidence interval [CI], 0.29-0.59), 33% (RR, 0.67; 95% CI, 0.58-0.78), 61% (RR, 0.39; 95% CI, 0.31-0.50), 38% (RR, 0.62; 95% CI, 0.42-0.91) compared with no screening, whereas guaiac fecal occult blood testing (gFOBT) reduced CRC-related mortality by 14% (RR, 0.86; 95% CI, 0.82-0.90). Subgroup analysis showed that summary estimates of reduction in distal CRC mortality and proximal CRC mortality were 26% (95% CI, 62%-89%) and 10% (95% CI, 83%-98%). A network meta-analysis revealed rank probability analysis in which the colonoscopy had a 94.6% probability of being the most effective examination to reduce CRC mortality. In addition, the network meta-analysis estimated odds ratio, which was a 79% reduction (95% CI, 0.09-0.60) in CRC mortality when screening with FIT was compared with annual or biennial gFOBT and colonoscopy was approximately 80% more effective than gFOBT for reducing CRC mortality (RR, 0.25; 95% CI, 0.13-0.54). Analysis of the effects of different screening methods showed that there was a significant reduction in the incidence of colon cancer, excluding gFOBT. This meta-analysis confirmed that gFOBT, FIT, FS, and colonoscopy were all effective in preventing CRC deaths and a major reduction in distal but not proximal CRC mortality was found. In addition, they were more effective in preventing CRC incidence in addition to gFOBT. The network meta-analysis suggests that colonoscopy is the most effective screening for preventing CRC deaths.

Factors Associated with Surveillance Adenoma and Sessile Serrated Polyp Detection Rates

BACKGROUND

Adenoma detection rate (ADR) and sessile serrated polyp detection rate (SSPDR) data in surveillance colonoscopy are limited.

AIMS

Our aim was to determine surveillance ADR and SSPDR and identify associated predictors.

METHODS

A retrospective review of subjects who underwent surveillance colonoscopy for adenoma and/or SSP at an academic center was performed. The following exclusion criteria were applied: prior colonoscopy ≤ 3 years, incomplete examination, or another indication for colonoscopy. Patient, endoscopist, and procedure characteristics were collected. Predictors were identified using multivariable logistic regression.

RESULTS

Of 3807 colonoscopies, 2416 met inclusion criteria. Surveillance ADR was 49% and, SSPDR was 8%. Higher ADR was associated with: age per year (OR 1.03; 95% CI 1.02-1.04), male gender (OR 1.55; 95% CI 1.29-1.88), BMI per kg/m² (OR 1.02; 95% CI 1.01-1.04), withdrawal time per minute (OR 1.09; 95% CI 1.07-1.10), and endoscopists' screening ADR (OR 1.01; 95% CI 1.00-1.03). Years since training (OR 0.99; 95% CI 0.98-0.99) was associated with lower ADR. Family history of CRC (OR 1.58; 95% CI 1.02-2.27) and endoscopists' screening ADR (OR 1.40; 95% CI 1.15-1.74) were associated with higher SSPDR. African-American race (OR 0.36; 95% CI 0.10-0.75) and diabetes (OR 0.41; 95% CI 0.21-0.76) were associated with lower SSPDR.

CONCLUSIONS

For surveillance colonoscopy, nearly half of patients had an adenoma and one in twelve had an SSP. In addition to established factors, BMI, endoscopists' screening ADR, and years since training were associated with ADR, whereas African-American race and diabetes were inversely associated with SSPDR. Further studies are needed prior to integrating surveillance ADR and SSPDR into quality metrics.

Colorectal Cancer Incidence Trend and Projections in Tunisia (1994 - 2024)

Objectives: The aim of this study was to describe trends of colorectal cancer incidence during the period 1994-2009 and to generate projections until 2024. Methods: The North-Tunisia Cancer Registry (NTCR) was the source of data for patients with CRC. This registry lists, since 1994, cases of malignant tumors in people living in North Tunisia, including the District of Tunis, the north east and the north west. Cases were classified using the International Classification of Diseases for Oncology. Data were analyzed using R software and Joinpoint one was employed to analyse trends. Projections were performed using the Age Period Cohort based on poisson regression. Results: During the period 1994 to 2009, 6,909 new cases of CRC were registered in Northern Tunisia. The age standardized incidence rate (ASR) increased significantly from 6.4/100,000 in 1994 to 12.4/100,000 in 2009. Trends in CRC incidence was significantly rising with an annual percentage change (APC) of + 3,9% [2.8% -5.1%]. Without effective interventions, the predicted CRC ASR would be 39.3/100,000 [CI 95%: 32,9/100,000 - 48,8/100,000] in 2024. Conclusion: The incidence of colorectal cancer is clearly increasing in Tunisia. Strengthening of screening and primary prevention measures is to be recommended.

Editorial: The Name Game: Circumventing Quality Metrics by Categorizing Incomplete Colonoscopy as Sigmoidoscopy

Cecal intubation rate (CIR) is an important metric for colonoscopy quality. Guidelines propose a minimum CIR of 90% for all indications, and 95% in screening procedures. In this issue, a study of three UK teaching hospitals demonstrated one-third of endoscopists inappropriately converted colonoscopies to flexible sigmoidoscopies, and several endoscopists only reached the 90% CIR benchmark because of these inappropriate conversions. Our professional societies and healthcare organizations must continue to work to improve the accurate assessment of colonoscopy quality in order to identify underperforming clinicians who should be provided with additional training for the benefit of their patients.

Clinical Significance of Preoperative Virtual Colonoscopy for Evaluation of the Proximal Colon in Patient With Obstructive Colorectal Cancer

Purpose

Virtual colonoscopy is the most recently developed tool for detecting colorectal cancers and polyps, but its effectiveness is limited. In our study, we compared the result of preoperative virtual colonoscopy to result of preoperative and postoperative colonoscopy. We evaluated also the accuracy of preoperative virtual colonoscopy in patients who had obstructive colorectal cancer that did not allow passage of a colonoscope.

Methods

A total of 164 patients who had undergone preoperative virtual colonoscopy and curative surgery after the diagnosis of a colorectal adenocarcinoma between November 2008 and August 2013 were pooled. We compared the result of conventional colonoscopy with that of virtual colonoscopy in the nonobstructive group and the results of preoperative virtual colonoscopy with that of postoperative colonoscopy performed at 6 months after surgery in the obstructive group.

Results

Of the 164 patients, 108 were male and 56 were female patients. The mean age was 62.7 years. The average sensitivity, specificity, and accuracy of virtual colonoscopy for all patients were 31.0%, 67.2%, and 43.8%, respectively. In the nonobstructive group, the average sensitivity, specificity, and accuracy were 36.6%, 66.2%, and 48.0%, respectively, whereas in the obstructive group, they were 2%, 72.4%, and 25.4%. Synchronous cancer was detected via virtual colonoscopy in 4 of the 164 patients.

Conclusion

Virtual colonoscopy may not be an effective method for the detection of proximal colon polyps, but it can be helpful in determining the therapeutic plan when its results are correlated with the results of other studies.

New device to implement the adenoma detection rate

It is well-known that colonoscopy is considered the gold standard for colon cancer prevention. Although performed by experienced endoscopists, the matter remains of polyps missed during this examination. The reasons may include the size, shape and location of the lesions. Many colorectal cancer screening programs have been proposed to increase the adenoma detection rate. The substantial difference between these methods is whether the improvement in vision, particularly the detection of irregularities of the mucosa, is inside the endoscope electronic components (magnification, wide-angle vision, narrow band imaging, flexible spectral imaging colour enhancement, i-Scan) or outside the same, by the use of specific caps (EndoCuff, EndoVision, EndoRings). Endocuff is a plastic device mounted at the end of the scope with a constant vision field of the entire colon. The aim of this study is to explore the potential clinical and technical benefits of Endocuff.

Frequency and risk factors of colorectal adenoma in patients with early gastric cancer

BACKGROUND/AIM

The authors aimed to determine the clinical value of colonoscopy by evaluating the frequency of colorectal neoplasm (CRN) detection in patients with early gastric cancer (EGC) as compared with healthy controls and analysed the risk factors of advanced CRN in patients with EGC.

METHODS

The medical records of 201 patients diagnosed as EGC and age- and gender-matched healthy controls were retrospectively reviewed. Frequencies and clinical features of colorectal polyps of patients and controls were compared. Risk factors of advanced CRN in patients with EGC were also analysed.

RESULTS

Frequencies of CRN in patients and controls were 49.8 and 49.3% respectively (P = 0.90). They were more common in the right colon in patients (P < 0.05). Advanced CRN were found in 10.3% of patients and in 3% of controls (P < 0.05). Multivariate analysis revealed that old age and smoking history were risk factors of an advanced CRN in patients with EGC.

CONCLUSION

The prevalence of a coexisting advanced CRN was higher in EGC patients. The study shows colonoscopy plays an important role with respect to the detection of synchronous advanced CRN in patients with EGC.

Detection rate and predictive factors of sessile serrated polyps in an organised colorectal cancer screening programme with immunochemical faecal occult blood test: the EQuIPE study (Evaluating Quality Indicators of the Performance of Endoscopy)

OBJECTIVES

To assess detection rate and predictive factors of sessile serrated polyps (SSPs) in organised colorectal cancer (CRC) screening programmes based on the faecal immunochemical test (FIT).

DESIGN

Data from a case series of colonoscopies of FIT-positive subjects were provided by 44 Italian CRC screening programmes. Data on screening history, endoscopic procedure and histology results, and additional information on the endoscopy centre and the endoscopists were collected, including the age-standardised and sex-standardised adenoma detection rate (ADR) of the individual endoscopists. The SSP detection rate (SSP-DR) was assessed for the study population. To identify SSP-predictive factors, multilevel analyses were performed according to patient/centre/endoscopist characteristics.

RESULTS

We analysed 72 021 colonoscopies, of which 1295 presented with at least one SSP (SSP-DR 1.8%; 95% CI 1.7% to 1.9%). At the per-patient level, SSP-DR was associated with males (OR 1.35; 95% CI 1.17 to 1.54) and caecal intubation (OR 3.75; 95% CI 2.22 to 6.34), but not with the FIT round. The presence of at least one advanced adenoma was more frequent among subjects with SSPs than those without (OR 2.08; 95% CI 1.86 to 2.33). At the per-endoscopist level, SSP-DR was associated with ADR (third vs first ADR quartile: OR 1.55; 95% CI 1.03 to 2.35; fourth vs first quartile: OR 1.89; 95% CI 1.24 to 2.90).

CONCLUSION

The low prevalence of SSPs and the lack of association with the FIT round argue against SSP as a suitable target for FIT-based organised programmes. Strict association of SSP-DR with the key colonoscopy quality indicators, namely caecal intubation rate and high ADR further marginalises the need for SSP-specific quality indicators in FIT-based programmes.

Clinical importance of colonoscopy in patients with gastric neoplasm undergoing endoscopic submucosal dissection

AIM

To evaluate the usefulness of total colonoscopy (TCS) for patients undergoing gastric endoscopic submucosal dissection (ESD) and to assess risk factors for colorectal neoplasms.

METHODS

Of the 263 patients who underwent ESD at our department between May 2010 and December 2013, 172 patients undergoing TCS during a one-year period before and after ESD were targeted. After excluding patients with a history of surgery or endoscopic therapy for colorectal neoplasms, 158 patients were analyzed. Of the 868 asymptomatic patients who underwent TCS during the same period because of positive fecal immunochemical test (FIT) results, 158 patients with no history of either surgery or endoscopic therapy for colorectal neoplasms who were matched for age and sex served as the control group for comparison.

RESULTS

TCS revealed adenoma less than 10 mm in 53 patients (33.6%), advanced adenoma in 17 (10.8%), early colorectal cancer in 5 (3.2%), and advanced colorectal cancer in 4 (2.5%). When the presence or absence of adenoma less than 10 mm, advanced adenoma, and colorectal cancer and the number of adenomas were compared between patients undergoing ESD and FIT-positive patients, there were no statistically significant differences in any of the parameters assessed. The patients undergoing ESD appeared to have the same risk of colorectal neoplasms as the FIT-positive patients. Colorectal neoplasms were clearly more common in men than in women (P = 0.031). Advanced adenoma and cancer were significantly more frequent in patients with at least two of the following conditions: hypertension, dyslipidemia, and diabetes mellitus (P = 0.019).

CONCLUSION

In patients undergoing gastric ESD, TCS appears to be important for detecting synchronous double neoplasms. Advanced adenoma and cancer were more common in patients with at least two of the following conditions: hypertension, dyslipidemia, and diabetes mellitus. Caution is therefore especially warranted in patients with these risk factors.

Adenoma Prevalence and Distribution Among US Latino Subgroups Undergoing Screening Colonoscopy

BACKGROUND

Colorectal cancer (CRC) is the second leading malignancy diagnosed among US Latinos. Latinos in the USA represent a heterogeneous amalgam of subgroups varying in genetic background, culture, and socioeconomic status. Little is known about the frequency of CRC precursor lesions found at screening colonoscopy among Latino subgroups.

AIM

The aim was to determine the prevalence and distribution of histologically confirmed adenomas found at screening colonoscopy among average-risk, asymptomatic US Latinos according to their subgroup and socio-demographic background.

METHODS

Cross-sectional analysis of pathological findings resulting from screening colonoscopy among average-risk, asymptomatic US Latinos aged ≥50 in two prospective randomized controlled trials at an academic medical center.

RESULTS

Among the 561 Latinos who completed screening colonoscopy, the two largest subgroups were Puerto Ricans and Dominicans. The findings among both subgroups were: adenomas 30.6%, proximal adenomas 23.5%, advanced adenomas 12.0%, and proximal advanced adenomas 8.9%. These rates are at least as high as those found at screening colonoscopy among US whites. While Puerto Ricans were more likely than Dominicans to be born in the USA, speak English, be acculturated, have a smoking history, and be obese, there were no significant differences in adenoma rates between these subgroups.

CONCLUSIONS

The prevalence of adenomas, advanced adenomas, and proximal neoplasia was high among both subgroups. These findings have implications for CRC screening and surveillance among the increasingly growing Latino population in the USA.

Early detection: the impact of genomics

The field of genomics has shifted our view on disease development by providing insights in the molecular and functional processes encoded in the genome. In the case of cancer, many alterations in the DNA accumulate that enable tumor growth or even metastatic dissemination. Identification of molecular signatures that define different stages of progression towards cancer can enable early tumor detection. In this review, the impact of genomics will be addressed using early detection of colorectal cancer (CRC) as an example. Increased understanding of the adenoma-to-carcinoma progression has led to the discovery of several diagnostic biomarkers. This combined with technical advancements, has facilitated the development of molecular tests for non-invasive early CRC detection in stool and blood samples. Even though several tests have already made it to clinical practice, sensitivity and specificity for the detection of precancerous lesions still need improvement. Besides the diagnostic qualities, also the accuracy of the intermediate endpoint is an important issue on how the effectiveness of a novel test is perceived. Here, progression biomarkers may provide a more precise measure than the currently used morphologically based features. Similar developments in biomarker use for early detection have taken place in other cancer types.

Complication Rates in Colonoscopy Screening for Cancer

BACKGROUND

Screening colonoscopy has been offered in Germany since 2002. Complications during colonoscopy were reported to be rare, but data on potential complications after colonoscopy are sparse. We aimed to comprehensively assess the frequency of complications arising during or within four weeks of screening colonoscopy.

METHODS

Residents of the German federal state of Saarland without a history of colorectal cancer and without previous polypectomy who underwent a screening colonoscopy between 2010 and 2013 were included. A follow-up was conducted three months after the screening colonoscopy, including participant questionnaires and subsequent validation of self-reported complications arising during or within four weeks of screening colonoscopy, by reviewing colonoscopy records and contacting the treating physicians. A comprehensive mortality follow-up was conducted for non-responders.

RESULTS

We recruited a total of 5527 participants from 26 practices (median age 61 years, 52% women). 5252 (95%) fully completed the questionnaire on complications and met the inclusion criteria for analysis. Among these participants, 16 cases of physician-confirmed bleeding (0.30%) and four cases of physician-confirmed perforation (0.08%) occurred during or within four weeks of colonoscopy. According to consistent reports from patients and physicians, bleeding and perforation led to hospitalization in 5 (0.095%) and 2 (0.04%) cases, respectively. Three participants died within three months of colo - noscopy. In none of these cases was the cause of death related to colonoscopy.

CONCLUSION

We found the risk of complications of screening colonoscopy to be low, even when taking into account a potential delay of up to four weeks.

Predictors for difficult cecal insertion in colonoscopy: The impact of obesity indices

AIM

To identify the factors influencing cecal insertion time (CIT) and to evaluate the effect of obesity indices on CIT.

METHODS

We retrospectively reviewed the data for participants who received both colonoscopy and abdominal computed tomography (CT) from February 2008 to May 2008 as part of a comprehensive health screening program. Age, gender, obesity indices [body mass index (BMI), waist-to-hip circumference ratio (WHR), waist circumference (WC), visceral adipose tissue (VAT) volume and subcutaneous adipose tissue (SAT) volume on abdominal CT], history of prior abdominal surgery, constipation, experience of the colonoscopist, quality of bowel preparation, diverticulosis and time required to reach the cecum were analyzed. CIT was categorized as longer than 10 min (prolonged CIT) and shorter than or equal to 10 min, and then the factors that required a CIT longer than 10 min were examined.

RESULTS

A total of 1678 participants were enrolled. The mean age was 50.42 ± 9.931 years and 60.3% were men. The mean BMI, WHR, WC, VAT volume and SAT volume were 23.92 ± 2.964 kg/m², 0.90 ± 0.076, 86.95 ± 8.030 cm, 905.29 ± 475.220 cm³ and 1707.72 ± 576.550 cm³, respectively. The number of patients who underwent abdominal surgery was 268 (16.0%). Colonoscopy was performed by an attending physician alone in 61.9% of cases and with the involvement of a fellow in 38.1% of cases. The median CIT was 7 min (range 2-56 min, IQR 5-10 min), and mean CIT was 8.58 ± 5.291 min. Being female, BMI, VAT volume and involvement of fellow were significantly associated with a prolonged CIT in univariable analysis. In multivariable analysis, being female (OR = 1.29, P = 0.047), lower BMI (< 23 kg/m²) (OR = 1.62, P = 0.004) or higher BMI (≥ 25 kg/m²) (OR = 1.80, P < 0.001), low VAT volume (< 500 cm³) (OR = 1.50, P = 0.013) and fellow involvement (OR = 1.73, P < 0.001) were significant predictors of prolonged CIT. In subgroup analyses for gender, lower BMI or higher BMI and fellow involvement were predictors for prolonged CIT in both genders. However, low VAT volume was associated with prolonged CIT in only women (OR = 1.54, P = 0.034).

CONCLUSION

Being female, having a lower or higher BMI than the normal range, a low VAT volume, and fellow involvement were predictors of a longer CIT.

Recent Advances in Diagnostic Colonoscopy for Colorectal Cancer Screening: An Update for Radiologists

OBJECTIVE

Colonoscopy accuracy in detecting colorectal neoplasia is critical for colorectal cancer prevention but has been shown to be operator- and technology-dependent. This article will discuss several recent improvements in the technique and technology of colonoscopy.

CONCLUSION

More rigorous training and retraining programs, active monitoring of endoscopist technique and outcomes, and exclusion of poorly performing endoscopists are urgently needed to improve the ultimate efficacy of colorectal cancer screening programs.

Recommendations on Fecal Immunochemical Testing to Screen for Colorectal Neoplasia: A Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer

The use of the fecal occult blood test (FOBT) for colorectal cancer (CRC) screening is supported by randomized trials demonstrating effectiveness in cancer prevention and widely recommended by guidelines for this purpose. The fecal immunochemical test (FIT), as a direct measure of human hemoglobin in stool has a number of advantages relative to conventional FOBT and is increasingly used relative to that test. This review summarizes current evidence for FIT in colorectal neoplasia detection and the comparative effectiveness of FIT relative to other commonly used CRC screening modalities. Based on evidence, guidance statements on FIT application were developed and quality metrics for program implementation proposed.

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.

Association between Nutrient Intake and Metabolic Syndrome in Patients with Colorectal Cancer

The purpose of this study was to investigate the difference of nutritional status according to metabolic syndrome in colorectal cancer patients. The subjects were divided into 2 groups (metabolic syndrome group and normal group) according to the presence or absence of metabolic syndrome in 143 patients diagnosed with colorectal cancer, and their lifestyle and nutritional status were analyzed. Recall method was used for the dietary survey, and metabolic syndrome was defined as the presence of 3 or more of waist circumference, fasting blood glucose, triglyceride, high-density lipoprotein (HDL)-cholesterol, and blood pressure. This study showed that the metabolic syndrome group had a low age, a high body mass index (BMI), and a high drinking rate. The intake of energy, protein, fat, calcium, and phosphorus was significantly higher in the metabolic syndrome group than in the normal group, and the intake of β-carotene, vitamin C, and folic acid was significantly low. The intake of cholesterol, fatty acid, saturated fatty acid, and polyunsaturated fatty acid was also higher in the metabolic syndrome group. Higher BMI, alcohol consumption, intake of fat, total fatty acid or saturated fatty acid increased the risk of metabolic syndrome, but fiber, vitamin C, or folic acid intake lowered the risk.Weight management and balanced nutritional intake should be emphasized to prevent metabolic syndrome and to improve the condition in patients with colorectal cancer.

Yield of a second screening colonoscopy 10 years after an initial negative examination in average-risk individuals

BACKGROUND AND AIMS

Current guidelines recommend screening colonoscopy at 10-year intervals in average-risk individuals who had baseline screening colonoscopy (no polyps or only hyperplastic polyps ≤5 mm in the recto-sigmoid colon), but the yield of repeat screening at 10 years is unknown. Our aim was to describe the yield of second screening colonoscopy in average-risk individuals performed at least 8 years after a first screening colonoscopy had shown no polyps or only distal hyperplastic polyps ≤5 mm in size.

METHODS

This was a review of a database for colonoscopies performed at Indiana University Hospital between January 1999 and November 2015.

RESULTS

A total of 4463 individuals underwent screening colonoscopy between January 1999 and July 2007, of which 1566 individuals had no polyps, and 334 individuals had only distal hyperplastic polyps ≤5 mm; 378 individuals (58.4% female) had follow-up screening at least 8 years after the baseline screening examination, with a mean (± standard deviation [SD]) interval of 9.74 years (± 1.2 years; range 8-15 years). Mean (± SD) age at baseline screening examination was 56.7 years (± 5.5 years) and at follow-up screening examination was 66.4 years (± 5.6 years). At the second screening, there were 224 patients (59.3%) with at least 1 polyp, including 144 (38.1%) with at least 1 conventional adenoma. The adenoma detection rate at the second screening examination was 36.1% and 56.8% in the groups with no polyp at baseline and with only distal hyperplastic polyps, respectively. There were 15 advanced neoplasms in 13 individuals (3.4%), of which 12 lesions were proximal to the sigmoid colon. There were no cancers at follow-up.

CONCLUSIONS

Among individuals aged ≥50 years, with normal baseline screening colonoscopy results, the incidence of advanced lesions at a second screening colonoscopy at least 8 years later was comparable to that in baseline screening studies. Our findings support current recommendations for screening at 10-year intervals in average-risk individuals.

Prevalence, distribution, and risk factor for colonic neoplasia in 1133 subjects aged 40-49 undergoing screening colonoscopy

BACKGROUND AND AIM

Colorectal cancer (CRC) incidence is rising among <50-year olds. The objective of this study was to determine screening colonoscopy outcomes among 40- to 49-year olds, which are currently limited.

METHODS

Asymptomatic 40- to 49-year olds underwent one time CRC screening colonoscopy at The Chinese University of Hong Kong between 2007 and 2011. Screening outcomes, including prevalence, distribution, and predictive factors for overall and specifically proximal colorectal neoplasia were determined.

RESULTS

Among 1133 ethnic Chinese, colorectal neoplasia prevalence was 20.5%. In men, distal adenomas were associated with proximal colorectal neoplasia. Men, advancing age, a first degree relative (FDR) with CRC, and diabetes mellitus were independently associated with colorectal neoplasia. A colorectal neoplasia was three times more likely to be found in a 45- to 49-year-old man with FDR of CRC compared with a 40- to 44-year-old woman without a FDR of CRC. The numbers needed to screen one colorectal neoplasia, and one advanced neoplasm in the highest risk group of 45- to 49-year-old men with FDR with CRC were 2.8 (95% CI: 2.2-4.4) and 18.5 (95% CI: 8.9-39.2), respectively.

CONCLUSIONS

Colorectal neoplasia prevalence in this 40- to 49-year-old Chinese cohort was higher than previous studies. Men, advancing age, FDR with CRC, and diabetes mellitus, can be used to risk stratify for neoplasia development. Men 45-49 years old with FDR with CRC represented the highest risk subgroup, with the lowest number needed to screen.

Recommendations on Fecal Immunochemical Testing to Screen for Colorectal Neoplasia: A Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer

The use of the fecal occult blood test (FOBT) for colorectal cancer (CRC) screening is supported by randomized trials demonstrating effectiveness in cancer prevention and widely recommended by guidelines for this purpose. The fecal immunochemical test (FIT), as a direct measure of human hemoglobin in stool has a number of advantages relative to conventional FOBT and is increasingly used relative to that test. This review summarizes current evidence for FIT in colorectal neoplasia detection and the comparative effectiveness of FIT relative to other commonly used CRC screening modalities. Based on evidence, guidance statements on FIT application were developed and quality metrics for program implementation proposed.

Appropriateness of endoscopic surveillance recommendations in organised colorectal cancer screening programmes based on the faecal immunochemical test

OBJECTIVES

To assess the appropriateness of recommendations for endoscopic surveillance in organised colorectal cancer (CRC) screening programmes based on the faecal immunochemical test (FIT).

DESIGN

74 Italian CRC screening programmes provided aggregated data on the recommendations given after FIT-positive colonoscopies in 2011 and 2013. Index colonoscopies were divided into negative/no adenoma and low- risk, intermediate-risk and high-risk adenomas. Postcolonoscopy recommendations included a return to screening (FIT after 2 years or 5 years), an endoscopic surveillance after 6 months or after 1 year, 3 years or 5 years, surgery or other. We assessed the deviation from the postcolonoscopy recommendations of the European Guidelines in 2011 and 2013 and the correlation between overuse of endoscopic surveillance in 2011 and the process indicators associated with the endoscopic workload in 2013.

RESULTS

49 704 postcolonoscopy recommendations were analysed. High-risk, intermediate-risk and low-risk adenomas, and no adenomas were reported in 5.9%, 19.3%, 15.3% and 51.5% of the cases, respectively. Endoscopic surveillance was inappropriately recommended in 67.4% and 7%, respectively, of cases with low-risk and no adenoma. Overall, 37% of all endoscopic surveillance recommendations were inappropriate (6696/17 860). Overuse of endoscopic surveillance was positively correlated with the extension of invitations (correlation coefficient (cc) 0.29; p value 0.03) and with compliance with post-FIT+ colonoscopy (cc 0.25; p value 0.05), while it was negatively correlated with total colonoscopy waiting times longer than 60 days (cc -0.26; p value 0.05).

CONCLUSIONS

In organised screening programmes, a high rate of inappropriate recommendations for patients with low risk or no adenomas occurs, affecting the demand for endoscopic surveillance by a third.

Consequences of Increasing Time to Colonoscopy Examination After Positive Result From Fecal Colorectal Cancer Screening Test

BACKGROUND & AIMS

Delays in diagnostic testing after a positive result from a screening test can undermine the benefits of colorectal cancer (CRC) screening, but there are few empirical data on the effects of such delays. We used microsimulation modeling to estimate the consequences of time to colonoscopy after a positive result from a fecal immunochemical test (FIT).

METHODS

We used an established microsimulation model to simulate an average-risk United States population cohort that underwent annual FIT screening (from ages 50 to 75 years), with follow-up colonoscopy examinations for individuals with positive results (cutoff, 20 μg/g) at different time points in the following 12 months. Main evaluated outcomes were CRC incidence and mortality; additional outcomes were total life-years lost and net costs of screening.

RESULTS

For individuals who underwent diagnostic colonoscopy within 2 weeks of a positive result from an FIT, the estimated lifetime risk of CRC incidence was 35.5/1000 persons, and mortality was 7.8/1000 persons. Every month added until colonoscopy was associated with a 0.1/1000 person increase in cancer incidence risk (an increase of 0.3%/month, compared with individuals who received colonoscopies within 2 weeks) and mortality risk (increase of 1.4%/month). Among individuals who received colonoscopy examinations 12 months after a positive result from an FIT, the incidence of CRC was 37.0/1000 persons (increase of 4%, compared with 2 weeks), and mortality was 9.1/1000 persons (increase of 16%). Total years of life gained for the entire screening cohort decreased from an estimated 93.7/1000 persons with an almost immediate follow-up colonoscopy (cost savings of $208 per patient, compared with no colonoscopy) to 84.8/1000 persons with follow-up colonoscopies at 12 months (decrease of 9%; cost savings of $100/patient, compared with no colonoscopy).

CONCLUSIONS

By using a microsimulation model of an average-risk United States screening cohort, we estimated that delays of up to 12 months after a positive result from an FIT can produce proportional losses of up to nearly 10% in overall screening benefits. These findings indicate the importance of timely follow-up colonoscopy examinations of patients with positive results from FITs.

Complications of diagnostic colonoscopy, upper endoscopy, and enteroscopy

Endoscopy is an inherent and an invaluable tool in every gastroenterologist's armamentarium. The prerequisite for quality and safety remains foremost. Adverse events should be minimized and proactive steps should taken before, during and after the endoscopic procedure. Upper endoscopy and colonoscopy are part of basic endoscopy and their major complications will be reviewed here, together with those of enteroscopy. The most common of all endoscopy related complications are cardiopulmonary and thus they will be addressed in detail first. Colonoscopy's major complications are bleeding and perforation. Their epidemiology, mechanisms/risk factors, diagnosis, treatment and prevention will be addressed. The incidence of both of these complications increases significantly with polypectomy. Thus clinical judgment and experience in both polypectomy techniques and the ways to treat these complications, especially with the advanced endoscopic options advanced in the last decade, are of paramount importance. Post-polypectomy syndrome, infection and gas explosion are less frequent and will be reviewed briefly. Bleeding and perforation are upper endoscopy's major complications as well. Advances in endoscopic techniques in recent years offer endoscopic treatment instead of directly resorting to surgery, as was used to be the case and still is if the first fails. Enteroscopy is generally a more advanced procedure and overall complication rate is often quoted as 1%, most of them have been attributed to the passage of the overtube. Perforation and bleeding are the major complications, and a unique upper enteroscopy-associated complication is pancreatitis.

Review: capsule colonoscopy-a concise clinical overview of current status

The colon capsule endoscopy (CCE) was first introduced in 2007. Currently, the main clinical indications for CCE are completion of incomplete colonoscopy, polyp detection and investigation of inflammatory bowel disease (IBD). Although conventional colonoscopy is the gold standard in bowel cancer screening, incomplete colonoscopy remains a problem as lesions are missed. CCE compares favourably to computer tomography colonography (CTC) in adenoma detection and has therefore been proposed as a method for completing colonoscopy. However the data on CCE remains sparse and current evidence does not show its superiority over CTC or conventional colonoscopy in bowel cancer screening. CCE also seems to show good correlation with conventional colonoscopy when used to evaluate IBD, but there are not many published studies at present. Other significant limitations include the need for aggressive bowel preparation and the labour-intensiveness of CCE reading. Therefore, much further software and hardware development is required to enable CCE to fulfill its potential as a minimally-invasive and reliable method of colonoscopy.

Diagnostic accuracy of 18F-FDG PET/CT for detecting synchronous advanced colorectal neoplasia in patients with gastric cancer

Preoperative screening for synchronous colorectal neoplasia (CRN) has been recommended in patients with gastric cancer because patients with gastric cancer are at increased risk for synchronous CRN. The aim of this study was to investigate the diagnostic accuracy of F-fluorodeoxyglucose (F-FDG) positron emission tomography/computed tomography (PET/CT) for detecting synchronous advanced CRN in patients with gastric cancer.A total of 256 patients who underwent colonoscopy and F-FDG PET/CT for preoperative staging were enrolled in this study. The diagnosis of focal colonic F-FDG uptake on F-FDG PET/CT image was made based on histopathologic results from the colonoscopic biopsy. The F-FDG PET/CT result was considered as true positive for advanced CRN when focal F-FDG uptake matched colorectal carcinoma or adenoma with high-grade dysplasia in the same location on colonoscopy.Synchronous advanced CRN was detected in 21 of the 256 patients (4.7%). Sensitivity, specificity, and accuracy of F-FDG PET/CT were 76.2%, 96.2%, and 94.5%. The size of CRN with a true positive result was significantly larger than that with a false negative result.F-FDG PET/CT demonstrated high diagnostic accuracy for detecting synchronous advanced CRN in patients with gastric cancer. Colonoscopy is recommended as the next diagnostic step for further evaluation of a positive F-FDG PET/CT result in patients with gastric cancer.

Population-based screening for cancer: hope and hype

Several important lessons have been learnt from our experiences in screening for various cancers. Screening programmes for cervical and colorectal cancers have had the greatest success, probably because these cancers are relatively homogenous, slow-growing, and have identifiable precursors that can be detected and removed; however, identifying the true obligate precursors of invasive disease remains a challenge. With regard to screening for breast cancer and for prostate cancer, which focus on early detection of invasive cancer, preferential detection of slower-growing, localized cancers has occurred, which has led to concerns about overdiagnosis and overtreatment; programmes for early detection of invasive lung cancers are emerging, and have faced similar challenges. A crucial consideration in screening for breast, prostate, and lung cancers is their remarkable phenotypic heterogeneity, ranging from indolent to highly aggressive. Efforts have been made to address the limitations of cancer-screening programmes, providing an opportunity for cross-disciplinary learning and further advancement of the science. Current innovations are aimed at identifying the individuals who are most likely to benefit from screening, increasing the yield of consequential cancers on screening and biopsy, and using molecular tests to improve our understanding of disease biology and to tailor treatment. We discuss each of these concepts and outline a dynamic framework for continuous improvements in the field of cancer screening.

Colorectal Cancer: Genetics is Changing Everything

Cancer is fundamentally a genetic disease caused by mutational or epigenetic alterations in DNA. There has been a remarkable expansion of the molecular understanding of colonic carcinogenesis in the last 30 years and that understanding is changing many aspects of colorectal cancer care. It is becoming increasingly clear that there are genetic subsets of colorectal cancer that have different risk factors, prognosis, and response to treatment. This article provides a general update on colorectal cancer and highlights the ways that genetics is changing clinical care.

Risk of Advanced Neoplasia Using the National Cancer Institute's Colorectal Cancer Risk Assessment Tool

Background

There is no validated, discriminating, and easy-to-apply tool for estimating risk of colorectal neoplasia. We studied whether the National Cancer Institute's (NCI's) Colorectal Cancer (CRC) Risk Assessment Tool, which estimates future CRC risk, could estimate current risk for advanced colorectal neoplasia among average-risk persons.

Methods

This cross-sectional study involved individuals age 50 to 80 years undergoing first-time screening colonoscopy. We measured medical and family history, lifestyle information, and physical measures and calculated each person's future CRC risk using the NCI tool's logistic regression equation. We related quintiles of future CRC risk to the current risk of advanced neoplasia (sessile serrated polyp or tubular adenoma ≥ 1 cm, a polyp with villous histology or high-grade dysplasia, or CRC). All statistical tests were two-sided.

Results

For 4457 (98.5%) with complete data (mean age = 57.2 years, SD = 6.6 years, 51.7% women), advanced neoplasia prevalence was 8.26%. Based on quintiles of five-year estimated absolute CRC risk, current risks of advanced neoplasia were 2.1% (95% confidence interval [CI] = 1.3% to 3.3%), 4.8% (95% CI = 3.5% to 6.4%), 6.4% (95% CI = 4.9% to 8.2%), 10.0% (95% CI = 8.1% to 12.1%), and 17.6% (95% CI = 15.5% to 20.6%; P < .001). For quintiles of estimated 10-year CRC risk, corresponding current risks for advanced neoplasia were 2.2% (95% CI = 1.4% to 3.5%), 4.8% (95% CI = 3.5% to 6.4%), 6.5% (95% CI = 5.0% to 8.3%), 9.3% (95% CI = 7.5% to 11.4%), and 18.4% (95% CI = 15.9% to 21.1%; P < .001). Among persons with an estimated five-year CRC risk above the median, current risk for advanced neoplasia was 12.8%, compared with 3.7% among those below the median (relative risk = 3.4, 95 CI = 2.7 to 4.4).

Conclusions

The NCI's Risk Assessment Tool, which estimates future CRC risk, may be used to estimate current risk for advanced neoplasia, making it potentially useful for tailoring and improving CRC screening efficiency among average-risk persons.

Colorectal Cancer Screening in Average Risk Populations: Evidence Summary

Introduction. The objectives of this systematic review were to evaluate the evidence for different CRC screening tests and to determine the most appropriate ages of initiation and cessation for CRC screening and the most appropriate screening intervals for selected CRC screening tests in people at average risk for CRC. Methods. Electronic databases were searched for studies that addressed the research objectives. Meta-analyses were conducted with clinically homogenous trials. A working group reviewed the evidence to develop conclusions. Results. Thirty RCTs and 29 observational studies were included. Flexible sigmoidoscopy (FS) prevented CRC and led to the largest reduction in CRC mortality with a smaller but significant reduction in CRC mortality with the use of guaiac fecal occult blood tests (gFOBTs). There was insufficient or low quality evidence to support the use of other screening tests, including colonoscopy, as well as changing the ages of initiation and cessation for CRC screening with gFOBTs in Ontario. Either annual or biennial screening using gFOBT reduces CRC-related mortality. Conclusion. The evidentiary base supports the use of FS or FOBT (either annual or biennial) to screen patients at average risk for CRC. This work will guide the development of the provincial CRC screening program.

Advanced colonic neoplasia in the first degree relatives of colon cancer patients: A colonoscopy-based study

We aimed to determine the risk of advanced neoplasms among a cohort of asymptomatic first degree relatives (FDRs) of patients with sporadic colorectal cancer (CRC) compared with matched controls. Data for patients with a diagnosis of CRC made between September 2013 and August 2014 were obtained from a population-based cancer registry system in Tehran. Screening colonoscopies were done for 342 FDRs and the findings were compared to those from 342 age- and gender-matched healthy controls without a family history of CRC. We reported the association as conditional Odds Ratio (OR) using Mantel Hazel and Logistic regression. The prevalence of advanced neoplasia was 13.2% among FDRs and 3.8% in controls (matched OR [mOR], 4.0, 95% confidence interval [CI], 2.1 - 7.6; p < 0.001). In FDRs aged 40-49 years, the prevalence of advanced neoplasia was significantly higher than in their matched controls (mOR, 6.8, 95% CI, 1.5-31.4; p = 0.01). Family history of CRC in at least one FDR was the strongest predictor of advanced neoplasia (adjusted OR, 4.0, 95% CI: 2.1-7.6; p < 0.001). The age of the index case at diagnosis did not predict the presence of advanced colonic neoplasms in their FDRs. Our study indicates a high risk of advanced neoplasia in FDRs of CRC cases, where only eight colonoscopies are needed to detect one advanced neoplasia. Our data suggest that all FDRs, regardless of the age of CRC diagnosis in their index case, should be considered for a targeted early screening.

Incidental Rectal Mucosa Obtained via Transrectal Ultrasound-Guided Prostatic Core Biopsies

A retrospective review was conducted of material from 782 transrectal ultrasound-guided prostatic core biopsies to determine whether incidental pieces of rectal mucosa obtained in this manner could harbor clinically significant rectal pathology or incur artifacts that cause diagnostic difficulty. Material from 114 biopsies (14.6%) showed rectal mucosa, and material from 19 (16.7%) showed rectal pathology, including a hyper-plastic polyp in 1, changes consistent with ulcerative proctitis in 8, focal active proctitis in 7, and granulomas in 3. The original pathologist overlooked the hyperplastic polyp. In 1 specimen, rectal lymphocytes and plasma cells that were displaced over prostatic tissue closely mimicked prostatic adenocarcinoma (Gleason score 5). Conversely, in another specimen, prostatic adenocarcinoma (Gleason score 5) that was displaced near rectal mucosa closely mimicked a rectal lymphoid aggregate. Incidental rectal mucosa obtained via transrectal ultrasound-guided prostatic core biopsies occasionally harbors clinically significant rectal pathology and rarely incurs artifacts that cause diagnostic difficulty.

Colorectal cancer development and advances in screening

Most colon tumors develop via a multistep process involving a series of histological, morphological, and genetic changes that accumulate over time. This has allowed for screening and detection of early-stage precancerous polyps before they become cancerous in individuals at average risk for colorectal cancer (CRC), which may lead to substantial decreases in the incidence of CRC. Despite the known benefits of early screening, CRC remains the second leading cause of cancer-related deaths in the United States. Hence, it is important for health care providers to have an understanding of the risk factors for CRC and various stages of disease development in order to recommend appropriate screening strategies. This article provides an overview of the histological/molecular changes that characterize the development of CRC. It describes the available CRC screening methods and their advantages and limitations and highlights the stages of CRC development in which each screening method is most effective.

Alternatives to Incomplete Colonoscopy

A thorough and complete colonoscopy is critically important in preventing colorectal cancer. Factors associated with difficult and incomplete colonoscopy include a poor bowel preparation, severe diverticulosis, redundant colon, looping, adhesions, young and female patients, patient discomfort, and the expertise of the endoscopist. For difficult colonoscopy, focusing on bowel preparation techniques, appropriate sedation and adjunct techniques such as water immersion, abdominal pressure techniques, and patient positioning can overcome many of these challenges. Occasionally, these fail and other alternatives to incomplete colonoscopy have to be considered. If patients have low risk of polyps, then noninvasive imaging options such as computed tomography (CT) or magnetic resonance (MR) colonography can be considered. Novel applications such as Colon Capsule™ and Check-Cap are also emerging. In patients in whom a clinically significant lesion is noted on a noninvasive imaging test or if they are at a higher risk of having polyps, balloon-assisted colonoscopy can be performed with either a single- or double-balloon enteroscope or colonoscope. The application of these techniques enables complete colonoscopic examination in the vast majority of patients.