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

Overuse of screening colonoscopy in the Medicare population

BACKGROUND

All relevant authorities recommend an interval of 10 years between normal screening colonoscopies. We assessed the timing of repeated colonoscopies after a negative screening colonoscopy finding in a population-based sample of Medicare patients.

METHODS

A 5% national sample of Medicare enrollees from 2000 through 2008 was used to identify average-risk patients undergoing screening colonoscopy between 2001 and 2003. Colonoscopy was classified as a negative screening examination finding if no indication other than screening were in the claims and if no biopsy, fulguration, or polypectomy was performed. Time to repeated colonoscopy was calculated.

RESULTS

Among 24,071 Medicare patients who had a negative screening colonoscopy finding in 2001 through 2003, 46.2% underwent a repeated examination in fewer than 7 years. In 42.5% of these patients (23.5% of the overall sample), there was no clear indication for the early repeated examination. In patients aged 75 to 79 years or 80 years or older at the time of the initial negative screening colonoscopy result, 45.6% and 32.9%, respectively, received a repeated examination within 7 years. In multivariable analyses, male sex, more comorbidities, and colonoscopy by a high-volume colonoscopist or in an office setting were associated with higher rates of early repeated colonoscopy without clear indication, while those 80 years or older had a reduced risk. There were also marked geographic variations, from less than 5% in some health referral regions to greater than 50% in others.

CONCLUSIONS

A large proportion of Medicare patients who undergo screening colonoscopy do so more frequently than recommended. Current Medicare regulations intending to limit reimbursement for screening colonoscopy to every 10 years would not appear to be effective.

Left-sided polyps detected at screening CT colonography: do we need complete optical colonoscopy for further evaluation?

PURPOSE

To estimate the relative yield of therapeutic flexible sigmoidoscopy compared with complete optical colonoscopy for isolated left-sided polyps (≥6 mm in diameter) identified at screening computed tomographic (CT) colonography.

MATERIALS AND METHODS

This retrospective institutional review board-approved and HIPAA-compliant study included a review of CT colonographic screening results in 6570 consecutive asymptomatic adults (3551 women, 3019 men; mean age, 56.8 years ± 7.3 [standard deviation]). Of 887 (13.5%) patients with cases positive for nondiminutive polyps (≥6 mm), a subset of 171 patients met the inclusion criteria (a) of having left-sided-only lesions of 6 mm or larger identified at CT colonography (rectum-to-splenic flexure) and (b) of undergoing subsequent evaluation with complete optical colonoscopy. CT colonography-optical colonoscopy concordance and proximal-versus-distal diagnostic yield at optical colonoscopy were assessed. The 95% confidence intervals (CIs) were calculated for relevant results.

RESULTS

From the study group of 171 patients, a total of 234 left-sided lesions of 6 mm or larger were prospectively reported at CT colonography, of which 222 (94.9%; 95% CI: 91.3%, 97.0%) were confirmed as true-positive findings at optical colonoscopy. With optical colonoscopy, an additional 17 benign left-sided polyps of 6 mm or larger (13 small, four large) were found in 11 patients, resulting in a total left-sided yield of 239 nondiminutive lesions, including 137 small polyps (6-9 mm) and 102 large lesions (≥10 mm), 160 neoplasms, 82 advanced adenomas, and seven cancers. Evaluation of the colon proximal to the splenic flexure in this cohort yielded eight small and two large benign polyps in nine patients but no proximal cancers or histologically advanced lesions.

CONCLUSION

For patients with left-sided-only polyps detected at CT colonography, the additional yield of complete optical colonoscopy beyond the expected reach of flexible sigmoidoscopy is very low and may not justify the added costs, potential risks, and procedural time.

Transparent Cap Colonoscopy versus Standard Colonoscopy for Investigation of Gastrointestinal Tract Conditions

BACKGROUND

Colonoscopy is considered the gold-standard investigation for screening and diagnosis of colorectal cancer. It is also becoming increasingly desirable for assessment, management, diagnosis and follow-up of other colorectal diseases, such as inflammatory bowel diseases and acute diverticulitis. Hence, due to the increasing demand for colonoscopy, devices to advance examination techniques are highly sought-after and the colonoscope with the transparent cap could be one of these.

OBJECTIVES

To identify and review all relevant data in order to determine whether colonoscopy with a transparent cap is a more effective diagnostic tool than colonoscopy.

SEARCH STRATEGY

We searched the MEDLINE, EMBASE and CINAHL databases, and the Cochrane Central Register of Controlled Trials for all randomised controlled trials (RCTs) comparing the use of colonoscopy with a transparent cap with standard colonoscopy.

SELECTION CRITERIA

Studies were included if they were randomised controlled trials which compared the use of colonoscopy with a transparent cap with standard colonoscopy.

DATA COLLECTION AND ANALYSIS

Data on study methods, participants, interventions used and outcomes measured was extracted from each study. Data was entered into the Cochrane Review Manager software (RevMan 5.0, 2008) and analysed using Cochrane MetaView.

MAIN RESULTS

In the present meta-analysis, we considered for the first time all five randomised controlled trials so far performed. The findings of our work indicate that colonoscopy with transparent cap has a faster caecal intubation time when compared with standard colonoscopy. Reviewing studies individually would also seem to favour colonoscopy with transparent cap for polyp detection rate and pain during procedure but due to lack of comparable data meta-analysis was not feasible.

AUTHORS' CONCLUSIONS

This review suggests that a transparent cap on the end of the colonoscope may give a marginally faster caecal intubation time compared with standard colonoscopy. It also suggests that there is a better polyp detection rate and less pain with the cap. However, the authors feel that further randomised controlled trials in this area would provide more clinically significant information on this adjunct to colonoscopy.

Risk of colorectal neoplasia in patients with solid organ transplantation

The incidence of colorectal adenomas and advanced neoplasia in the transplant population has not been well characterized. The aim of this study was to determine whether or not there was an increased incidence of colorectal adenomas and advanced neoplasia in solid organ transplantation (SOT) recipients compared with an average-risk population. We reviewed 360 patients with solid organ transplants who underwent colonoscopy between February 1995 and July 2008, and 360 age- and gender-matched patients in an average-risk population. The mean duration from transplantation to colonoscopy in the SOT group was 40.4 ± 34.0 months. Ninety-three (25.8%) adenomas were detected in the SOT group, while 98 (27.2%) adenomas were detected in the control group (p = 0.763). There was a statistically significant difference (p < 0.0001) in the number of patients with advanced neoplasia in the SOT group (24 patients [6.7%]) compared with the control group (3 patients [0.8%]). The independent risk factors of advanced neoplasia were old age (odds ratio [OR], 1.067; 95% CI, 1.019-1.118) and transplantation (OR, 6.069; 95% CI, 1.455-25.314). In summary, there was a significant increase in the incidence of advanced colorectal neoplasia in SOT recipients. The reason for this finding is unclear, and studies with a larger number of patients are needed to further evaluate this group.

The impact of a novel computer-based decision aid on shared decision making for colorectal cancer screening: a randomized trial

BACKGROUND

Eliciting patients' preferences within a framework of shared decision making (SDM) has been advocated as a strategy for increasing colorectal cancer (CRC) screening adherence. Our objective was to assess the effectiveness of a novel decision aid on SDM in the primary care setting.

METHODS

An interactive, computer-based decision aid for CRC screening was developed and evaluated within the context of a randomized controlled trial. A total of 665 average-risk patients (mean age, 57 years; 60% female; 63% black, 6% Hispanic) were allocated to 1 of 2 intervention arms (decision aid alone, decision aid plus personalized risk assessment) or a control arm. The interventions were delivered just prior to a scheduled primary care visit. Outcome measures (patient preferences, knowledge, satisfaction with the decision-making process [SDMP], concordance between patient preference and test ordered, and intentions) were evaluated using prestudy/poststudy visit questionnaires and electronic scheduling.

RESULTS

Overall, 95% of patients in the intervention arms identified a preferred screening option based on values placed on individual test features. Mean cumulative knowledge, SDMP, and intention scores were significantly higher for both intervention groups compared with the control group. Concordance between patient preference and test ordered was 59%. Patients who preferred colonoscopy were more likely to have a test ordered than those who preferred an alternative option (83% v. 70%; P < 0.01). Intention scores were significantly higher when the test ordered reflected patient preferences.

CONCLUSIONS

Our interactive computer-based decision aid facilitates SDM, but overall effectiveness is determined by the extent to which providers comply with patient preferences.

Endoscopic management of failed colonoscopy in clinical practice: to change endoscopist, instrument, or both?

BACKGROUND AND AIMS

Caecal intubation fails up to 20% of colonoscopy in clinical practice. We aimed to assess whether (1) in patients with a prior incomplete colonoscopy with a standard adult colonoscope, a subsequent caecal intubation may be achieved with the same instrument; (2) there are factors predicting a repeated unsuccessful colonoscopy; and (3) how frequently completion can be further achieved by shifting to a standard gastroscope.

MATERIALS AND METHODS

Data of patients with a previously failed bowel examination referred to our community hospital for a further colonoscopy were reviewed. When caecal intubation still failed with standard colonoscope, complete colonoscopy was usually attempted by shifting to a gastroscope.

RESULTS

Overall, 451 patients with a prior colonoscopy were considered. By using a standard colonoscope, caecal intubation rate was achieved in 285 out of 296 patients with prior complete examination and in 121 out of 155 patients with a prior failed colonoscopy (96.3% vs. 78.1%, p < .001). Caecum visualization was significantly lower when prior colonoscopy was stopped in the sigmoid tract as compared to any other proximal tract (65.1% vs. 86.9%, p < .001). After a second failed examination, colonoscopy was completed in 15 (51.7%) out of 29 cases by shifting to a standard gastroscope. No procedure-related complications were observed in the study.

CONCLUSIONS

After incomplete colonoscopy with a standard adult colonoscope, a further colonoscopy may be completed with same standard colonoscope or by using a gastroscope in the same session. A prior failed colonoscopy, particularly when stopped in the sigmoid tract, is significantly associated with a lower caecal intubation rate at second colonoscopy.

Utilization and predictors of early repeat colonoscopy in Medicare beneficiaries

OBJECTIVES

Early repeat colonoscopy after an index examination may be justifiable, but may also reflect quality issues during the first examination. The aims of this study were to examine the use of second colonoscopy within 1 year of an index colonoscopy, and to examine patient and provider factors associated with use of early repeat colonoscopy.

METHODS

We performed a retrospective cohort study using a 20% nationally representative sample of 2003 Medicare claims. Patients aged ≥ 66 years undergoing colonoscopy were included in this study. We identified the use of second colonoscopy and barium enema within 1 year of the index procedure. We used logistic regression analyses to examine the independent predictors of these procedures.

RESULTS

We included 328,167 outpatient colonoscopies. In all, 5% had second colonoscopy and 2.2% had barium enema within 1 year of the index examination. Early repeat colonoscopy was more common if the index examination was performed by a family physician (odds ratio 1.39, 95% confidence interval 1.23-1.56), general surgeon (odds ratio 1.18, 95% confidence interval 1.10-1.27) or internist (odds ratio 1.12, 95% confidence interval 1.02-1.23) compared with a gastroenterologist, or after colonoscopies by an endoscopist in the lower quartiles of colonoscopy volume compared with endoscopists in the highest quartile. Increasing patient age and comorbidity, polyp detection, biopsy, polyp removal, incomplete index examination, and site of service were also significantly associated with early repeat colonoscopy.

CONCLUSIONS

Early repeat colonoscopy is not unusual. The association of specialty and colonoscopy volume with early repeat colonoscopy suggests that there are modifiable processes of care or training that may prevent some of these repeat procedures.

A shift from distal to proximal neoplasia in the colon: a decade of polyps and CRC in Italy

Background

In the last years a trend towards proximalization of colorectal carcinomas (CRC) has been reported. This study aims to evaluate the distribution of CRC and adenomatous polyps (ADP) to establish the presence of proximalization and to assess the potential predictors.

Methods

We retrieved histology reports of colonic specimens excised during colonoscopy, considering the exams performed between 1997 and 2006 at Cuneo Hospital, Italy. We compared the proportion of proximal lesions in the period 1997-2001 and in the period 2002-2006.

Results

Neoplastic lesions were detected in 3087 people. Proximal CRC moved from 25.9% (1997-2001) to 30.0% (2002-2006). Adjusting for sex and age, the difference was not significant (OR 1.23; 95% CI: 0,95-1,58). The proximal ADP proportion increased from 19.2% (1997-2001) to 26.0% (2002-2006) (OR: 1.43; 95% CI: 1.17-1.89). The corresponding figures for advanced proximal ADP were 6.6% and 9.5% (OR: 1.48; 95% CI: 1.02-2.17). Adjusting for gender, age, diagnostic period, symptoms and number of polyps the prevalence of proximal advanced ADP was increased among people ≥ 70 years compared to those aged 55-69 years (OR 1.49; 95% CI: 1.032.16). The main predictor of proximal advanced neoplasia was the number of polyps detected per exam (> 1 polyp versus 1 polyp: considering all ADP: OR 2.16; 95% CI: 1.59-2.93; considering advanced ADP OR 1.63; 95% CI: 1.08-2.46). Adjusting for these factors, the difference between the two periods was no longer significant.

Conclusions

CRC do not proximalize while a trend towards a proximal shift in adenomas was observed among people ≥ 70 years.

Colorectal cancer screening for average-risk North Americans: an economic evaluation

BACKGROUND

Colorectal cancer (CRC) fulfills the World Health Organization criteria for mass screening, but screening uptake is low in most countries. CRC screening is resource intensive, and it is unclear if an optimal strategy exists. The objective of this study was to perform an economic evaluation of CRC screening in average risk North American individuals considering all relevant screening modalities and current CRC treatment costs.

METHODS AND FINDINGS

An incremental cost-utility analysis using a Markov model was performed comparing guaiac-based fecal occult blood test (FOBT) or fecal immunochemical test (FIT) annually, fecal DNA every 3 years, flexible sigmoidoscopy or computed tomographic colonography every 5 years, and colonoscopy every 10 years. All strategies were also compared to a no screening natural history arm. Given that different FIT assays and collection methods have been previously tested, three distinct FIT testing strategies were considered, on the basis of studies that have reported "low," "mid," and "high" test performance characteristics for detecting adenomas and CRC. Adenoma and CRC prevalence rates were based on a recent systematic review whereas screening adherence, test performance, and CRC treatment costs were based on publicly available data. The outcome measures included lifetime costs, number of cancers, cancer-related deaths, quality-adjusted life-years gained, and incremental cost-utility ratios. Sensitivity and scenario analyses were performed. Annual FIT, assuming mid-range testing characteristics, was more effective and less costly compared to all strategies (including no screening) except FIT-high. Among the lifetimes of 100,000 average-risk patients, the number of cancers could be reduced from 4,857 to 1,393 [corrected] and the number of CRC deaths from 1,782 [corrected] to 457, while saving CAN$68 per person. Although screening patients with FIT became more expensive than a strategy of no screening when the test performance of FIT was reduced, or the cost of managing CRC was lowered (e.g., for jurisdictions that do not fund expensive biologic chemotherapeutic regimens), CRC screening with FIT remained economically attractive.

CONCLUSIONS

CRC screening with FIT reduces the risk of CRC and CRC-related deaths, and lowers health care costs in comparison to no screening and to other existing screening strategies. Health policy decision makers should consider prioritizing funding for CRC screening using FIT.

Novel methylation panel for the early detection of colorectal tumors in stool DNA

BACKGROUND

Previous studies showed that the assessment of promoter hypermethylation of a limited number of genes in tumor biopsies may identify the majority of colorectal tumors. This study aimed to assess the clinical usefulness of a panel of methylation biomarkers in stool DNA in the identification of colorectal tumors, using methylation-specific melting curve analysis (MS-MCA), a technique that simultaneously analyzes all cytosine-phosphate-guanine (CpG) residues within a promoter.

MATERIALS AND METHODS

The promoter methylation status of 4 tumor-related genes (RARB2, p16INK4a, MGMT, and APC) was analyzed in DNA stool samples and corresponding tissues in an initial set of 12 patients with newly diagnosed primary colorectal carcinomas and 20 patients with newly diagnosed colorectal adenomas, using methylation-specific polymerase chain reaction. Results were replicated in a set of 82 patients (20 healthy subjects, 16 patients with inflammatory bowel disease (IBD), 20 patients with adenomas, and 26 patients with carcinomas), using MS-MCA analyses.

RESULTS

In the initial set, >or= 1 positive methylation marker was detected in the stools of 9 of 12 patients (75%) with carcinomas and 12 of 20 patients (60%) with adenomas, with no false-positive results. Stool analyses missed 7 methylated lesions (25%). In the replication set, stool DNA testing detected 16 of 26 carcinomas (62%) and 8 of 20 adenomas (40%). The MS-MCAs missed 14 methylated tumors (37%). No aberrant methylation was evident in healthy subjects, but the RARB2 marker was positive in 2 of 15 stool samples (13%) of patients with IBD.

CONCLUSION

Analysis via MS-MCA of a panel of methylation markers in stool DNA may offer a good alternative in the early, noninvasive detection of colorectal tumors.

Expanding colorectal cancer screening among minority women

BACKGROUND

Colorectal cancer screening (CRCS) in the United States is inadequate in minority communities and particularly among those who lack insurance. Finding ways to increase screenings in these minorities presents a healthcare challenge. The authors sought to determine whether offering CRCS at the time of mammography is an effective way to increase CRCS among minority women.

METHODS

This study was offered to women attending the Breast Examination Center of Harlem (BECH), a community outreach program of Memorial Sloan-Kettering serving the primarily black and Hispanic Harlem Community. Screening was explained, medical fitness was determined, and colonoscopies were performed. Barriers to screening and ways to overcome them were ascertained. Participants had to be at least 50 years of age without a history of colorectal cancer or screening within the last 10 years.

RESULTS

There were 2616 women eligible for CRCS, of these women 2005 (77%) refused to participate in the study, and 611 (23%) women were enrolled. There was a high interest in CRCS including among those who declined to participate in the study. The major barrier was lack of medical insurance, which was partially overcome by alternative funding. Of the 611 women enrolled, 337 (55%) went on to have screening colonoscopy. Forty-nine (15%) women had adenomatous polyps.

CONCLUSIONS

Offering CRCS to minority women at the time of mammography and without a physician's referral is an effective way to expand screening. Screening colonoscopy findings are similar to those in the general population. Alternatives to traditional medical insurance are needed for the uninsured.

Efficacy and effectiveness of colonoscopy: how do we bridge the gap?

Colonoscopy is sometimes considered the preferred colorectal cancer screening modality, yet this modality may be subject to variation in operator performance more than any other screening test. Failures of colonoscopy to consistently detect precancerous lesions threaten the effectiveness of this technique for the prevention of colorectal cancer. Studies on high-level adenoma detectors under optimal conditions have begun to establish the true efficacy of colonoscopy and further widen the gap between efficacy and effectiveness. Research is required to establish the component skills, attitudes, and behaviors for high-level mucosal inspection competence necessary for training and assessment. Interventions to bridge the gap between efficacy and effectiveness are lacking, yet they should emphasize quality measurement and operate at various levels within the health system to motivate change in endoscopist behavior.

Complications of colonoscopy: magnitude and management

Although complications of colonoscopy are rare, they are potentially serious and life threatening. In addition, less serious adverse events may occur frequently and may have an impact on a patient's willingness to undergo future procedures. This article reviews the magnitude of and risk factors for major and minor colonoscopy complications, discusses management of complications, and suggests ways to design quality improvement programs to reduce the risk of complications.

Prevalence and risk of colorectal neoplasms in asymptomatic, average-risk screenees 40 to 49 years of age

BACKGROUND

A paucity of information exists regarding colorectal neoplasm in asymptomatic, average-risk individuals 40 to 49 years of age.

OBJECTIVE

To evaluate the prevalence and risk factors of colorectal neoplasms in those in their 40s.

DESIGN

Cross-sectional study.

SETTING

Results offered to subjects of a health care provider that offers screening services as part of an employer-provided wellness program.

PATIENTS

A consecutive series of 1761 asymptomatic, average-risk screenees 40 to 59 years of age.

INTERVENTION

First screening colonoscopy.

RESULTS

The prevalence of overall colorectal neoplasm in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with increasing age (13.7%, 20.2%, 21.0%, and 23.8%, respectively; P < .001). The prevalence of advanced adenomas in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with age (1.9%, 3.0%, 3.2%, and 5.9%, respectively; P = .004). Multivariate analysis of data from the 40- to 49-year age group identified an increased risk of colorectal neoplasm associated with ages 45 years and older (odds ratio [OR], 1.68; 95% CI, 1.20-2.35), male sex (OR, 1.76; 95% CI, 1.15-2.69), presence of abdominal obesity (OR, 1.57; 95% CI, 1.12-2.21), and metabolic syndrome (OR, 1.56; 95% CI, 1.03-2.35), whereas for advanced adenomas, abdominal obesity (OR, 2.37; 95% CI, 1.06-5.27) and metabolic syndrome (OR, 2.83; 95% CI, 1.23-6.53) were the independent risk factors.

LIMITATIONS

Single-center study and the cohort composed of ethnic Korean subjects who lived in the same geographic region.

CONCLUSION

In average-risk individuals 40 to 49 years of age, men with abdominal obesity or metabolic syndrome might benefit from screening colonoscopy starting at 45 years of age to detect colorectal neoplasm.

Improving colonoscopy quality through health-care payment reform

Problems with the quality of colonoscopy are well recognized. Variation in colonoscopist performance is compounded by payment structures that reward volume rather than quality. Payment reform has emerged as one strategy to address these and more systemic problems in the quality of health care. Various forms of value-based purchasing might encourage a realignment of incentives, and allow reimbursement to be directly linked with clinically important goals of colonoscopy. This paper proposes criteria for the selection of quality measures, and three candidate indicators to define quality for the purpose of payment reform in colonoscopy: cecal intubation rate, adenoma detection rate, and recommended post-polypectomy surveillance interval. These measures represent valid, credible, and reliable indicators of the quality of colonoscopy for colorectal cancer screening and surveillance. Payment reform should explicitly link public reporting and performance on these quality measures to payment for colonoscopy.

Polymorphisms in the adenomatous polyposis coli (APC) gene and advanced colorectal adenoma risk

While germline mutations in the adenomatous polyposis coli (APC) gene cause the hereditary colon cancer syndrome (familial adenomatous polyposis (FAP)), the role of common germline APC variants in sporadic adenomatous polyposis remains unclear. We studied the association of eight APC single nucleotide polymorphisms (SNPs), possibly associated with functional consequences, and previously identified gene-environment (dietary fat intake and hormone replacement therapy (HRT) use) interactions, in relation to advanced colorectal adenoma in 758 cases and 767 sex- and race-matched controls, randomly selected from the screening arm of the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Cases had at least one verified advanced adenoma of the distal colon; controls, a negative sigmoidoscopy. We did not observe an association between genotypes for any of the eight APC SNPs and advanced distal adenoma risk (P(global gene-based)=0.92). Frequencies of identified common haplotypes did not differ between cases and controls (P(global haplotype test)=0.97). However, the risk for advanced distal adenoma was threefold higher for one rare haplotype (cases: 2.7%; controls: 1.6%) (odds ratio (OR)=3.27; 95% confidence interval (CI)=1.08-9.88). The genetic association between D1822V and advanced distal adenoma was confined to persons consuming a high-fat diet (P(interaction)=0.03). Similar interactions were not observed with HRT use. In our large, nested case-control study of advanced distal adenoma and clinically verified adenoma-free controls, we observed no association between specific APC SNPs and advanced adenoma. Fat intake modified the APC D1822V-adenoma association, but further studies are warranted.

Does level of sedation impact detection of advanced neoplasia?

BACKGROUND AND AIMS

Two of the foremost issues in screening colonoscopy involve delivering quality and maximizing adenoma detection rates (ADR). Little is known about the impact of deep sedation on ADR. This study aims to compare the detection of advanced lesions during screening colonoscopy performed with moderate conscious sedation (MCS) versus deep sedation (DS).

METHODS

A retrospective cohort study was performed using the Clinical Outcomes Research Initiative database. Average risk screening colonoscopies performed January 2000 to December 2005 were examined for practice setting, patient demographics, and findings, including detection of a polyp >9 mm and suspected malignant lesions.

RESULTS

A total of 104,868 colonoscopies were examined, 97% of which were performed with MCS. Univariate analysis demonstrated that more polyps of any size were detected with MCS (38 vs. 34%, p < 0.0001) and more advanced lesions were found with DS compared with MCS (7 vs. 6%, p = 0.01). When exclusively examining sites that performed DS > 10% for all procedures, a more significant increase in advanced lesion detection when using DS was observed (7.5 vs. 5.7%, p = 0.003). When adjusted for age, gender, race/ethnicity, site, prep quality, and ASA group, DS was 25% more likely to detect an advanced lesion.

CONCLUSIONS

Our data suggest that use of DS may be associated with a higher rate of advanced lesion detection. However, this retrospective design has limitations that necessitate follow-up with prospective studies. These follow-up studies would be essential to support any change in the standard practices of sedation.

Evidence for colorectal cancer screening

The incidence of colorectal cancer (CRC) has been increasing during the past decades, and the lifetime risk for CRC in industrialised countries is about 5%. CRC is a good candidate for screening, because it is a disease with high prevalence, has recognised precursors, and early treatment is beneficial. This paper outlines the evidence for efficacy from randomised trials for the most commonly used CRC screening tests to reduce CRC incidence and mortality in the average-risk population. Four randomised trials have investigated the effect of guaiac-based fecal occult blood screening on CRC mortality, with a combined CRC mortality risk reduction of 15-17% in an intention-to-screen analysis, and 25% for those people who attended screening. Flexible sigmoidoscopy screening has been evaluated in three randomised trials. The observed reduction in CRC incidence varied between 23 and 80%, and between 27 and 67% for CRC mortality, respectively (intention-to-screen analyses) in the trials with long follow-up time. No randomised trials exist in other CRC screening tools, included colonoscopy screening. FOBT and flexible sigmoidoscopy are the two CRC screening methods which have been tested in randomised trials and shown to reduce CRC mortality. These tests can be recommended for CRC screening.

An evidence-based microsimulation model for colorectal cancer: validation and application

BACKGROUND

The Colorectal Cancer Simulated Population model for Incidence and Natural history (CRC-SPIN) is a new microsimulation model for the natural history of colorectal cancer that can be used for comparative effectiveness studies of colorectal cancer screening modalities.

METHODS

CRC-SPIN simulates individual event histories associated with colorectal cancer, based on the adenoma-carcinoma sequence: adenoma initiation and growth, development of preclinical invasive colorectal cancer, development of clinically detectable colorectal cancer, death from colorectal cancer, and death from other causes. We present the CRC-SPIN structure and parameters, data used for model calibration, and model validation. We also provide basic model outputs to further describe CRC-SPIN, including annual transition probabilities between various disease states and dwell times. We conclude with a simple application that predicts the impact of a one-time colonoscopy at age 50 on the incidence of colorectal cancer assuming three different operating characteristics for colonoscopy.

RESULTS

CRC-SPIN provides good prediction of both the calibration and the validation data. Using CRC-SPIN, we predict that a one-time colonoscopy greatly reduces colorectal cancer incidence over the subsequent 35 years.

CONCLUSIONS

CRC-SPIN is a valuable new tool for combining expert opinion with observational and experimental results to predict the comparative effectiveness of alternative colorectal cancer screening modalities.

IMPACT

Microsimulation models such as CRC-SPIN can serve as a bridge between screening and treatment studies and health policy decisions by predicting the comparative effectiveness of different interventions. As such, it is critical to publish model descriptions that provide insight into underlying assumptions along with validation studies showing model performance.

Systems of support to increase colorectal cancer screening and follow-up rates (SOS): design, challenges, and baseline characteristics of trial participants

BACKGROUND

Screening decreases colorectal cancer (CRC) morbidity and mortality, yet remains underutilized. Screening breakdowns arise from lack of uptake and failure to follow-up after a positive screening test.

OBJECTIVES

Systems of support to increase colorectal cancer screening and follow-up (SOS) is a randomized trial designed to increase: (1) CRC screening and (2) follow-up of positive screening tests. The Chronic Care Model and the Preventive Health Model inform study design.

METHODS

The setting is a large nonprofit healthcare organization. In part-1 study, patients age 50-75 due for CRC screening are randomized to one of 4 study conditions. Arm 1 receives usual care. Arm 2 receives automated support (mailed information about screening choices and fecal occult blood tests (FOBT)). Arm 3 receives automated and assisted support (a medical assistant telephone call). Arm 4 receives automated, assisted, and care management support (a registered nurse provides behavioral activation and coordination of care). In part-2, study patients with a positive FOBT or adenomas on flexible sigmoidoscopy are randomized to receive either usual care or nurse care management. Primary outcomes are: 1) the proportion with CRC screening, 2) the proportion with a complete diagnostic evaluation after a positive screening test.

RESULTS

We sent recruitment letters to 15,414 patients and 4675 were randomized. Randomly assigned treatment groups were similar in age, sex, race, education, self-reported health, and CRC screening history.

CONCLUSIONS

We will determine the effectiveness and cost effectiveness of stepped increases in systems of support to increase CRC screening and follow-up after a positive screening test over 2years.

[Synchronous colorectal adenomas]

INTRODUCTION

Colorectal adenomas which are discovered simultaneously or 6 months after the diagnosis of primary adenoma or colorectal cancer (CRC) are called synchronous adenomas. The presence of synchronous adenomas increases the probability of adenomas with severe dysplasia as well as CRC.

OBJECTIVE

The aim of the study is to show the characteristics of synchronous colorectal adenomas and to present the relation between the index rectal adenoma and the proximal synchronous tumours.

METHODS

The research included 114 synchronous colorectal adenomas diagnosed in 58 patients. Total colonoscopy was performed on all patients.

RESULTS

The largest number of patients had two adenomas (p < 0.001). Synchronous adenomas were more often diagnosed in men older than 50 (p < 0.001). The largest number of adenomas was localized in the sigma (52 patients, 43.0%) (p < 0.001). The biggest number of tumours was localized in the combination of rectum-sigma segments (p < 0.001). There were 31 (25.6%) synchronous, that is index tumours of the rectum and 90 (74.4%) the so-called proximal synchronous tumours of the proximal part of the colon. In 33 (56.9%) patients, who did not have the index tumour, the prevalence of proximal synchronous tumours was the highest (57.0%) (p < 0.001).

CONCLUSION

The probability of adenoma multiplication is higher in men, and it increases with age. Beside the fact that synchronous adenomas are more often found distally, a great probability of finding proximal tumours shows that total colonoscopy is the method of choice for the discovery of colorectal tumours. Complete colonoscopic mapping of all colorectal adenomas and their removal prevents the development of metachronous, overlooked benign CRC already present at the moment of initial diagnostics that could be the cause of the development of metachronous CRC.

Adenomatous colorectal polyps in patients referred for colonoscopy in a regional hospital in Kuwait

BACKGROUND/AIM

Adenomatous colorectal polyps (ACPs) are known to be the precursor lesions for colorectal cancer. The aim of the study was to determine the prevalence, endoscopic and pathological features of ACPs in patients referred for colonoscopy.

PATIENTS AND METHODS

The endoscopic and histological reports of adult patients who underwent complete colonoscopy in the gastroenterology unit of a regional Kuwaiti hospital between January 2008 and December 2008 were retrospectively studied. The specimens of polyps were reviewed by an experienced pathologist who was blinded to the clinical or endoscopic information. Non-neoplastic polyps were not included in the analysis.

RESULTS

Of 530 eligible patients (mean age, 45 years; male-female ratio, 2:1), 54 (10%) had 103 ACPs. Of the patients with ACPs (mean age, 57 years), 43 (80%) were males and 36 (67%) were Kuwaitis. Histopathological examination of the most significant polyp in each patient revealed that 40 (74%) polyps were tubular adenomas (TAs); 11 (20%), tubulovillous (TV) adenomas; and 3 (6%), villous adenomas. High-grade dysplasia was noticed in 4 (10%) adenomas. Fifteen (2.8%) of the 530 patients had advanced ACPs. Logistic regression analysis of some variables and their association with ACPs found that age (P < 0.001; OR, 1.9; CI, 1.5-2.3), history of adenoma (P=0.001; OR, 6.4; CI, .2.1-19.4) and being Kuwaitis (P=0.029; OR, 2.1; CI, 1.1-4.1) to be independently associated with ACPs.

CONCLUSION

The most common histological type of ACPs was tubular adenoma. Advancing age, being Kuwaiti nationals and prior removal of ACPs were significantly associated with the occurrence of ACPs.

Comparison of discriminatory power and accuracy of three lung cancer risk models

Background:

Three lung cancer (LC) models have recently been constructed to predict an individual's absolute risk of LC within a defined period. Given their potential application in prevention strategies, a comparison of their accuracy in an independent population is important.

Methods:

We used data for 3197 patients with LC and 1703 cancer-free controls recruited to an ongoing case–control study at the Harvard School of Public Health and Massachusetts General Hospital. We estimated the 5-year LC risk for each risk model and compared the discriminatory power, accuracy, and clinical utility of these models.

Results:

Overall, the Liverpool Lung Project (LLP) and Spitz models had comparable discriminatory power (0.69), whereas the Bach model had significantly lower power (0.66; P=0.02). Positive predictive values were highest with the Spitz models, whereas negative predictive values were highest with the LLP model. The Spitz and Bach models had lower sensitivity but better specificity than did the LLP model.

Conclusion:

We observed modest differences in discriminatory power among the three LC risk models, but discriminatory powers were moderate at best, highlighting the difficulty in developing effective risk models.

Progress and challenges in colorectal cancer screening and surveillance

Colorectal cancer is a leading cause of cancer death throughout the world. There is evidence that screening of average-risk individuals can result in mortality reduction with early cancer detection and cancer prevention by detection and removal of cancer precursor lesions. The optimal form of screening is not clear. Fecal screening tests can be performed at home at low initial cost, but current versions lack high sensitivity for cancer precursor lesions, and tests need to be repeated at regular intervals. Adherence to repeat testing for negative tests and referral for colonoscopy for positive tests are important elements of program effectiveness. Structural examinations of the colon are more invasive and may result in detection of both early cancer and cancer precursor lesions. Every screening program has advantages and limitations, but each program ultimately depends on quality and patient adherence.

Principles of cancer screening: lessons from history and study design issues

Early detection of cancer has held great promise and intuitive appeal in the medical community for well over a century. Its history developed in tandem with that of the periodic health examination, in which any deviations--subtle or glaring--from a clearly demarcated "normal" were to be rooted out, given the underlying hypothesis that diseases develop along progressive linear paths of increasing abnormalities. This model of disease development drove the logical deduction that early detection, by "breaking the chain" of cancer development, must be of benefit to affected individuals. In the latter half of the 20th century, researchers and guidelines organizations began to explicitly challenge the core assumptions underpinning many clinical practices. A move away from intuitive thinking began with the development of evidence-based medicine. One key method developed to explicitly quantify the overall risk-benefit profile of a given procedure was the analytic framework. The shift away from pure deductive reasoning and reliance on personal observation was driven, in part, by a rising awareness of critical biases in cancer screening that can mislead clinicians, including healthy volunteer bias, length-biased sampling, lead-time bias, and overdiagnosis. A new focus on the net balance of both benefits and harms when determining the overall worth of an intervention also arose: it was recognized that the potential downsides of early detection were frequently overlooked or discounted because screening is performed on basically healthy persons and initially involves relatively noninvasive methods. Although still inconsistently applied to early detection programs, policies, and belief systems in the United States, an evidence-based approach is essential to counteract the misleading--even potentially harmful--allure of intuition and individual observation.

High-definition chromocolonoscopy vs. high-definition white light colonoscopy for average-risk colorectal cancer screening

OBJECTIVES

Flat and depressed colon neoplasms are an increasingly recognized precursor for colorectal cancer (CRC) in Western populations. High-definition chromoscopy is used to increase the yield of colonoscopy for flat and depressed neoplasms; however, its role in average-risk patients undergoing routine screening remains uncertain.

METHODS

Average-risk patients referred for screening colonoscopy at four U.S. medical centers were randomized to high-definition chromocolonoscopy or high-definition white light colonoscopy. The primary outcomes, patients with at least one adenoma and the number of adenomas per patient, were compared between the two groups. The secondary outcome was patients with flat or depressed neoplasms, as defined by the Paris classification.

RESULTS

A total of 660 patients were randomized (chromocolonoscopy: 321, white light: 339). Overall, the mean number of adenomas per patient was 1.2+/-2.1, the mean number of flat polyps per patient was 1.4+/-1.9, and the mean number of flat adenomas per patient was 0.5+/-1.0. The number of patients with at least one adenoma (55.5% vs. 48.4%, absolute difference 7.1%, 95% confidence interval (-0.5% to 14.7%), P=0.07), and the number of adenomas per patient (1.3+/-2.4 vs. 1.1+/-1.8, P=0.07) were marginally higher in the chromocolonoscopy group. There were no significant differences in the number of advanced adenomas per patient (0.06+/-0.37 vs. 0.04+/-0.25, P=0.3) and the number of advanced adenomas<10 mm per patient (0.02+/-0.26 vs. 0.01+/-0.14, P=0.4). Two invasive cancers were found, one in each group; neither was a flat neoplasm. Chromocolonoscopy detected significantly more flat adenomas per patient (0.6+/-1.2 vs. 0.4+/-0.9, P=0.01), adenomas<5 mm in diameter per patient (0.8+/-1.3 vs. 0.7+/-1.1, P=0.03), and non-neoplastic lesions per patient (1.8+/-2.3 vs. 1.0+/-1.3, P<0.0001).

CONCLUSIONS

High-definition chromocolonoscopy marginally increased overall adenoma detection, and yielded a modest increase in flat adenoma and small adenoma detection, compared with high-definition white light colonoscopy. The yield for advanced neoplasms was similar for the two methods. Our findings do not support the routine use of high-definition chromocolonoscopy for CRC screening in average-risk patients. The high adenoma detection rates observed in this study may be due to the high-definition technology used in both groups.

Cumulative evaluation of a quantitative immunochemical fecal occult blood test to determine its optimal clinical use

BACKGROUND

Quantified, human hemoglobin (Hb)-specific, immunochemical fecal occult blood test (IFOBT) measurements are now used for colorectal cancer (CRC) screening. The objective was to evaluate sensitivity and specificity for CRC and advanced adenomatous polyps (APs) by the fecal Hb threshold used to determine a positive test and the number of IFOBTs prepared per test, so as to determine the least number of colonoscopies required to detect a neoplasm.

METHODS

Cumulative data were analyzed from a prospective cross-sectional double-blind study of 1682 consecutive, ambulatory, nonbleeding colonoscopy patients who volunteered for IFOBTs, most of above average risk, from 3 ambulatory-endoscopy centers. Fecal Hb was measured in 3 samples and analyzed by an automated instrument, and the highest result >or=50 ng Hb/mL of buffer was related to findings.

RESULTS

Colonoscopy identified CRC in 20 patients and advanced APs in 129. Sensitivity for either was best when any of 3 tests had >or=50 ng Hb/mL of buffer; sensitivity was 61.1% (95% confidence interval [CI], 53.2-68.9), and specificity was 87.8% (95% CI, 86.2-89.4). Positive tests identified 100% of CRCs and 55% of advanced APs every 3.1 colonoscopies. Sensitivity of a single test at the commonly used 100-ng Hb/mL threshold was lower at 31.5% (95% CI, 24.1-39.0) (P<.001), but specificity was higher at 96.4% (95% CI, 95.5-97.3) (P<.001). Positive tests identified 65% of CRCs and 26.4% of advanced APs every 2.2 colonoscopies.

CONCLUSIONS

The fecal Hb cutoff chosen by the screener and the number of samples collected per patient determine sensitivity and specificity for CRC/advanced AP; these factors determine the number of colonoscopies needed for positive tests and neoplasia yield. This information provides guidelines for IFOBT screening. Limitations are 1-time screening and most examinees not being at average risk for CRC.

Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: a multicentre randomised controlled trial

BACKGROUND

Colorectal cancer is the third most common cancer worldwide and has a high mortality rate. We tested the hypothesis that only one flexible sigmoidoscopy screening between 55 and 64 years of age can substantially reduce colorectal cancer incidence and mortality.

METHODS

This randomised controlled trial was undertaken in 14 UK centres. 170 432 eligible men and women, who had indicated on a previous questionnaire that they would accept an invitation for screening, were randomly allocated to the intervention group (offered flexible sigmoidoscopy screening) or the control group (not contacted). Randomisation by sequential number generation was done centrally in blocks of 12, with stratification by trial centre, general practice, and household type. The primary outcomes were the incidence of colorectal cancer, including prevalent cases detected at screening, and mortality from colorectal cancer. Analyses were intention to treat and per protocol. The trial is registered, number ISRCTN28352761.

FINDINGS

113 195 people were assigned to the control group and 57 237 to the intervention group, of whom 112 939 and 57 099, respectively, were included in the final analyses. 40 674 (71%) people underwent flexible sigmoidoscopy. During screening and median follow-up of 11.2 years (IQR 10.7-11.9), 2524 participants were diagnosed with colorectal cancer (1818 in control group vs 706 in intervention group) and 20 543 died (13 768 vs 6775; 727 certified from colorectal cancer [538 vs 189]). In intention-to-treat analyses, colorectal cancer incidence in the intervention group was reduced by 23% (hazard ratio 0.77, 95% CI 0.70-0.84) and mortality by 31% (0.69, 0.59-0.82). In per-protocol analyses, adjusting for self-selection bias in the intervention group, incidence of colorectal cancer in people attending screening was reduced by 33% (0.67, 0.60-0.76) and mortality by 43% (0.57, 0.45-0.72). Incidence of distal colorectal cancer (rectum and sigmoid colon) was reduced by 50% (0.50, 0.42-0.59; secondary outcome). The numbers needed to be screened to prevent one colorectal cancer diagnosis or death, by the end of the study period, were 191 (95% CI 145-277) and 489 (343-852), respectively.

INTERPRETATION

Flexible sigmoidoscopy is a safe and practical test and, when offered only once between ages 55 and 64 years, confers a substantial and longlasting benefit.

FUNDING

Medical Research Council, National Health Service R&D, Cancer Research UK, KeyMed.

Clinicopathological features of colon polyps from African-Americans

BACKGROUND AND AIMS

Among the ethnic groups, the age-standardized incidence rate of colorectal cancer (CRC) is highest among African-Americans. The majority of CRC arise from preexisting adenoma. It is shown that 30% of the US adult population has adenomas. The potential risk of malignant transformation in adenomas differs by specific pathologic and clinical characteristics that we aimed to study in AAs.

MATERIALS AND METHODS

All pathologic reports (150,000) in Howard University Hospital from 1959 to 2006 were reviewed manually. Those pathology reports compatible with the colorectal polyps were carefully reviewed and selected by a GI pathologist. All cases with cancer were then excluded from the list. Data were then entered into Microsoft Excel and checked for missing data and duplications. Differences in right-side and left-side polyps for sex, histology, and clinical symptoms were assessed by Chi-2 test.

RESULTS

A total number of 5,013 colorectal polyps were diagnosed in this period that include 47% male, with mean age (SD) of 63 (12). Half of the cases were diagnosed in 2001-2006. Tubular adenoma was the most frequent pathology (73%). The highest frequency of right-sided polyps was observed in the 1990s (56%). Left-sided polyps were younger (p < 0.0001), more hyperplasic (23 vs. 5%; p < 0.0001), and more frequent in female (56 vs. 52%; p = 0.02) compared to right-sided polyps. The frequency of right-sided adenoma significantly increases from 18% in the 1960s to 51% in the period of 2001-2006 (p < 0.0001). The most frequent symptom in both sides was GI bleeding (21%).

CONCLUSION

There was a ratio of 8:1 for neoplastic to hyperplastic polyps in our study, which is more than what has been reported in Caucasians (7:1). Our data shows a shift in polyps from the left side to the right side of the colon in recent years. This data is consistent with the lack of a reduction in the incidence of colon cancer in African-Americans. Screening is thus very important in AA to reduce the incidence of colon cancer.

Participation in colorectal cancer screening with FOBT and colonoscopy: an Italian, multicentre, randomized population study

BACKGROUND

Data on the adherence rate to screening colonoscopy (OC) in the average-risk general population are limited and variable. Aim of this study was to compare the uptake of OC screening with that of fecal occult blood (FOBT).

METHODS

A nationwide, population-based, multicentre, randomized trial comparing attendance to OC with that to FOBT was performed. Sixty-four general practitioners (GPs), overall including in their lists 9889 average-risk subjects aged 55-64 years, were randomized between OC and FOBT screening programs. Eligible subjects were mailed a personal invitation letter co-signed by their GP and the coordinator of the area-reference GI centre. Attendance rate and detection rate for advanced neoplasia (colorectal cancer, adenoma >10mm or with villous histology or high-grade dysplasia) for each arm of the study were assessed.

RESULTS

The overall attendance rate was 18.7% (1563/8378 eligible subjects). It was markedly lower in the OC than in the FOBT strategy (10% vs. 27.1%; OR 0.28, 95% CI: 0.25-0.32; P<0.0001). In particular, participation in OC screening arm was extremely low in South Italy (2.8%), whilst it was higher in North-Central Italy (12.4%; P<0.0001). Compliance to colonoscopy in those with a positive FOBT was only 58%. Advanced neoplasia was detected in 28 (6.8%) patients in the OC arm and in 6 (18%) in those with a positive FOBT submitted to OC.

CONCLUSIONS

The results of our study underline the difficulties and barriers to implement a OC population screening in Italy, at least through primary care. Although attendance to FOBT was higher, it was disappointingly less than 30%. Significant actions to improve awareness amongst GPs and the population are a high priority.

Do indication and demographics for colonoscopy affect completion? A large national database evaluation

BACKGROUND AND AIM

Indication for colonoscopy has not been examined as a predictor of colonoscopy completion. We hypothesized that colonoscopy conducted for colorectal cancer screening might have higher in completion rates than colonoscopy conducted for other indications.

METHODS

The study design was a retrospective cohort. Colonoscopies recorded within the Clinical Outcomes Research Initiative database conducted between 1 January 2002 and 30 June 2003 were analyzed. Indication included: average-risk screening; surveillance; nonspecific abdominal symptoms; bleeding symptoms; or family history of colorectal carcinoma. Demographic factors and indication for colonoscopy were evaluated for the outcome of incomplete colonoscopy using logistic regression analysis.

RESULTS

129 549 Colonoscopy procedures were analyzed. Average risk screening seemed to be protective for completion (relative risk: 0.69; 95% confidence interval: 0.63-0.75). Bleeding and nonspecific symptoms had higher risk of incomplete procedure compared to other indications. Males had higher completion rates compared to females (relative risk: 0.62; 95% confidence interval: 0.58-0.66). Community setting had higher completion rates compared to academic or Veteran's administration sites. Increasing age was associated with higher rate of incomplete colonoscopy.

CONCLUSION

Colonoscopy conducted for screening indication has comparable completion rates when compared with other indications. An overall completion rate of around 95% was noted in this study. This is the largest study to date verifying that completion rates are meeting recommended multisociety guidelines in the USA. Nonspecific abdominal symptoms in Caucasian population, female sex, advanced age, clinical setting, and ethnic groups African-American and Hispanic were found to have increased risk of incomplete procedure.

Colonoscopy screening for individuals aged 40-49 years with a family history of stomach cancer in Korea

BACKGROUND

For asymptomatic individuals aged 40-49 years, screening for colorectal cancer is recommended only if individuals are at an increased risk. A family history of colon cancer (FHCRC) is considered to increase risk, however, whether family history of stomach cancer (FHSC) increases the risk of adenoma is not well known. We aimed to see whether FHSC increases the risk in asymptomatic individuals aged 40-49 years in Korea.

METHODS

Among asymptomatic individual aged 40-49 years who underwent colonoscopy screening, risk of adenoma was assessed according to FHCRC or FHSC.

RESULTS

Of 3,160 individuals, male comprised 1,602 individuals (50.7%). FHCRC and FHSC was noticed in 163 (5.2%) and 227 (7.0%) individuals, respectively. Prevalence of adenoma was 31.9 %, 28.8%, and 22.3% for individuals with FHCRC, individuals with FHSC, and individuals without family history of cancer, respectively. FHSC was an independent risk factor for adenoma (odds ratio, 1.38; 95% confidence interval, 1.02-1.87, P = 0.039) in asymptomatic individuals aged 40-49 years. Compared with individuals with FHCRC, individuals with FHSC showed no difference in risk for adenoma (P = 0.347).

CONCLUSIONS

As with individuals with FHCRC, individuals with FHSC might need to be considered as an individual with increased risk for adenoma. Therefore, earlier screening might be needed for asymptomatic individuals aged 40-49 years with FHSC in Korea.

The role of CT colonography in a colorectal cancer screening program

Computed tomography colonography (CTC) has the potential to become a major component of colorectal cancer (CRC) screening programs and to have a significant effect on CRC prevention. This article describes the potential role of CTC within the framework of colorectal cancer screening. Current screening recommendations and traditional screening tests are reviewed, followed by a summary of recent study results on the use of CTC as a screening tool. Several factors that are affecting the acceptance and adoption of CTC are outlined. Although CTC is valuable and holds considerable promise as a way to increase the use of CRC screening, these issues need to be addressed before CTC becomes more widely disseminated as a screening modality.

Exposure to colorectal examinations before a colorectal cancer diagnosis: a case-control study

OBJECTIVES

To assess the prior exposure to colorectal examinations between colorectal cancer (CRC) patients and matched control participants to estimate the effect of these examinations on the development of CRC and to obtain insight into the background incidence of colorectal examinations.

METHODS

A population-based case-control study was conducted within the Dutch Integrated Primary Care Information database over the period 1996-2005. All incident CRC cases were matched with up to 18 controls (n=7,790) for age, sex, index date (date of CRC diagnosis) and follow-up before diagnosis. All colorectal examinations performed in symptomatic participants in the period 0.5-5 years before index date were considered in the analyses.

RESULTS

Within the source population of 457 024 persons, we identified 594 incident cases of CRC. In the period 0.5-5 years before index date 2.9% (17 of 594) of the CRC cases had undergone colorectal examinations, compared with 4.4% (346 of 7790) in the control population [odds ratio (ORadj): 0.56, 95% confidence interval (CI): 0.33-0.94]. For left-sided CRC, significantly more controls than cases had undergone a colorectal examination (4.7 vs. 2.0%, respectively, ORadj: 0.36, 95% CI: 0.17-0.76), which was not seen for right-sided CRCs (3.3 vs. 3.9%, respectively, ORadj: 0.98, 95% CI: 0.42-2.25).

CONCLUSION

Patients diagnosed with CRC were less likely than controls to have had a colorectal examination in previous years, being more pronounced in patients diagnosed with left-sided CRCs. If diagnostic examinations have a similar protective effect as screening examinations, this finding supports the concept that colorectal examination can have a major impact on the reduction of CRC risk.

Race and colorectal cancer disparities: health-care utilization vs different cancer susceptibilities

BACKGROUND

It is unclear whether the disproportionately higher incidence and mortality from colorectal cancer among blacks compared with whites reflect differences in health-care utilization or colorectal cancer susceptibility.

METHODS

A total of 60, 572 non-Hispanic white and black participants in the ongoing Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial underwent trial-sponsored screening flexible sigmoidoscopy (FSG) without biopsy at baseline in 10 geographically dispersed centers from November 1993 to July 2001. Subjects with polyps or mass lesions detected by FSG were referred to their physicians for diagnostic workup, the cost of which was not covered by PLCO. The records of follow-up evaluations were collected and reviewed. We used log binomial modeling with adjustment for age, education, sex, body mass index, smoking, family history of colorectal cancer, colon examination within previous 3 years, personal history of polyps, and screening center to examine whether utilization of diagnostic colonoscopy and yield of neoplasia differed by race.

RESULTS

Among 57 561 whites and 3011 blacks who underwent FSG, 13,743 (23.9%) and 767 (25.5%) had abnormal examinations, respectively. A total of 9944 (72.4%) whites and 480 (62.6%) blacks had diagnostic colonoscopy within 1 year following the abnormal FSG screening. When compared with whites, blacks were less likely to undergo diagnostic evaluation (adjusted risk ratio = 0.88, 95% confidence interval = 0.83 to 0.93). Overall, among subjects with diagnostic colonoscopy (n = 10 424), there was no statistically significant difference by race in the prevalence of adenoma, advanced adenoma, advanced pathology in small adenomas (high-grade dysplasia or villous histology in adenomas <10 mm), or colorectal cancer.

CONCLUSIONS

We observed a lower follow-up for screen-detected abnormalities among blacks when compared with whites but little difference in the yield of colorectal neoplasia. Health-care utilization may be playing more of a role in colorectal cancer racial disparity than biology.

[Colonoscopic findings in asymptomatic people]

CONTEXT

Colorectal cancer is the second leading cause of cancer-related death. Prevention of colorectal cancer should be achievable by screening programs in asymptomatic patients.

OBJECTIVE

To assess the colonoscopic findings in asymptomatic people submitted to screening.

METHODS

A prospective study was undertaken on 153 consecutive asymptomatic people submitted to colonoscopy. Sex, age, previous diseases and familial cases of cancer, as well as tobacco and alcohol ingestion were assessed. Patients with rectal macro- or microscopic bleeding and colorectal diseases were excluded. Bowel preparation, polyps, angioectasias, diverticular disease, inflammation and neoplasm were also verified. Polyps were classified according to their size, number and location.

RESULTS

Mean age was 52.5 +/- 11.7 years. Family history for colorectal cancer occurred in 79.8% of individuals. Colonoscopic alterations were detected in 99 individuals: polyps in 64.3%, diverticular disease in 27.9%, inflammatory mucosal alterations in 9.7%, melanosi coli in 2.6% and angioectasias in 7.8%. There were an increasing incidence of polyps in patients older than 50 year. Multivariate logistic regression showed age and sex as predictive factors for polyps (OR = 1.43; 1.19 <OR <2.67).

CONCLUSION

There is a significant incidence of colonoscopic alterations in asymptomatic people submitted to colonoscopy for colorectal cancer screening.

Can patients at high risk for significant colorectal neoplasms and having normal quantitative faecal occult blood test postpone elective colonoscopy?

BACKGROUND

Common reasons for elective screening and surveillance colonoscopy, at predetermined intervals, are family or personal history of colorectal cancer (CRC) or advanced adenoma (AAP). Quantified, human haemoglobin (Hb)-specific, immunochemical faecal occult blood tests (I-FOBT) detect bleeding.

AIM

To determine I-FOBT sensitivity for CRC or AAP before elective colonoscopy in patients at high-risk of cancer or advanced adenoma.

METHODS

Prospective double-blind study of 1000 ambulatory asymptomatic high-risk patients (555 family history of CRC, 445 surveillance for past neoplasm), who prepared three I-FOBTs before elective colonoscopy. I-FOBTs quantified as ngHb/mL of buffer by OC-MICRO instrument and results >or=50 ngHb/mL considered positive.

RESULTS

At colonoscopy, eight patients had CRC, 64 others had AAP. Sensitivity for CRC and/or AAP was the highest, 65.3% (95% CI 54.3, 76.3), when any of the three I-FOBTs was >or=50 ngHb (15.4%), with specificity of 87.5% (95% CI 86.4, 90.5) identifying all CRCs and 62% of AAPs.

CONCLUSIONS

All cancers or an AAP were detected every third I-FOBT-positive colonoscopy (47/154), so colonoscopy was potentially not needed at this time in 84.6% (846 patients). I-FOBT screening might provide effective supervision of high-risk patients, delaying unnecessary elective colonoscopies. This favourable evaluation needs confirmation and cost-benefit study by risk-group.

Serious complications within 30 days of screening and surveillance colonoscopy are uncommon

BACKGROUND & AIMS

The risk of serious complications after colonoscopy has important implications for the overall benefits of colorectal cancer screening programs. We evaluated the incidence of serious complications within 30 days after screening or surveillance colonoscopies in diverse clinical settings and sought to identify potential risk factors for complications.

METHODS

Patients age 40 and over undergoing colonoscopy for screening, surveillance, or evaluation based an abnormal result from another screening test were enrolled through the National Endoscopic Database (CORI). Patients completed a standardized telephone interview approximately 7 and 30 days after their colonoscopy. We estimated the incidence of serious complications within 30 days of colonoscopy and identified risk factors associated with complications using logistic regression analyses.

RESULTS

We enrolled 21,375 patients. Gastrointestinal bleeding requiring hospitalization occurred in 34 patients (incidence 1.59/1000 exams; 95% confidence interval [CI], 1.10-2.22). Perforations occurred in 4 patients (0.19/1000 exams; 95% CI, 0.05-0.48), diverticulitis requiring hospitalization in 5 patients (0.23/1000 exams; 95% CI, 0.08-0.54), and postpolypectomy syndrome in 2 patients (0.09/1000 exams; 95% CI, 0.02-0.30). The overall incidence of complications directly related to colonoscopy was 2.01 per 1000 exams (95% CI, 1.46-2.71). Two of the 4 perforations occurred without biopsy or polypectomy. The risk of complications increased with preprocedure warfarin use and performance of polypectomy with cautery.

CONCLUSIONS

Complications after screening or surveillance colonoscopy are uncommon. Risk factors for complications include warfarin use and polypectomy with cautery.

Value-of-information analysis to guide future research in the management of the colorectal malignant polyp

PURPOSE

The efficacy of surgery in the postendoscopic management of low-risk malignant polyps is unclear. Although interobserver variability in the histological diagnosis was shown, its importance is unknown. The purpose of this study was to guide future research on the optimal strategy for low-risk polyps with the use of value-of-information analysis.

METHODS

A decision-analysis model was constructed comparing the strategies of referring or not referring (waiting) to surgery patients with low-risk polyps. Probabilistic sensitivity analysis was performed to explore the effect of uncertainty about the input parameters. Value-of-information analysis was used to estimate the expected benefit of future research that would eliminate the decision uncertainty.

RESULTS

The number of postendoscopic surgeries to prevent 1 cancer-related death was 208. The incremental cost-effectiveness ratio of surgery vs waiting strategy was $215,291/life-year gained, surgery being a suboptimal choice in the reference case analysis. Probabilistic sensitivity analysis demonstrated that surgery was the optimal choice in 61% of the simulated scenarios. Most of the decision uncertainty was related with the combination of histological inaccuracy, prevalence of residual disease, and surgical mortality. The expected societal monetary benefit of further research from the perspective of the United States was estimated to be $1 billion.

CONCLUSIONS

The small benefit and the relatively high costs associated with surgery argue against surgical referral for low-risk malignant polyps; however, when a suboptimal histopathological accuracy was simulated, surgery appeared to be the most cost-effective option, prompting the need for further research.

Performance value of high risk factors in colorectal cancer screening in China

AIM: To analyze the performance value of high risk factors in population-based colorectal cancer (CRC) screening in China.

METHODS: We compared the performance value of the immunochemical fecal occult blood test (iFOBT) and other high risk factors questionnaire in a population sample of 13 214 community residents who completed both the iFOBT and questionnaire investigation. Patients with either a positive iFOBT and/or questionnaire were regarded as a high risk population and those eligible were asked to undergo colonoscopy.

RESULTS: The iFOBT had the highest positive predictive value and negative predictive value in screening for advanced neoplasia. The iFOBT had the highest sensitivity, lowest number of extra false positive results associated with the detection of one extra abnormality for screening advanced neoplasias and adenomas. A history of chronic cholecystitis or cholecystectomy, chronic appendicitis or appendectomy, and chronic diarrhea also had a higher sensitivity than a history of adenomatous polyps in screening for advanced neoplasias and adenomas. The sensitivity of a history of chronic cholecystitis or cholecystectomy was highest among the 10 high risk factors in screening for non-adenomatous polyps. A history of chronic appendicitis or appendectomy, chronic constipation, chronic diarrhea, mucous and bloody stool, CRC in first degree relatives, malignant tumor and a positive iFOBT also had higher sensitivities than a history of adenomas polyps in screening for non-adenomatous polyps. Except for a history of malignant tumor in screening for non-adenomatous polyps, the gain in sensitivity was associated with an increase in extra false positive results associated with the detection of one extra abnormality.

CONCLUSION: The iFOBT may be the best marker for screening for advanced neoplasias and adenomas. Some unique high risk factors may play an important role in CRC screening in China.

A previous cholecystectomy increases the risk of developing advanced adenomas of the colon

BACKGROUND

There is limited data assessing the relationship between cholecystectomy and colorectal adenomatous polyps (AP). Our aim was to determine if cholecystectomy was associated with an increased prevalence of advanced AP in male veterans.

METHODS

The relationship of whether prior cholecystectomy modified the natural history of AP was investigated in a retrospective study. The patients were divided into two groups: 1) those with AP and a history of cholecystectomy, and 2) those with AP, but without a history of cholecystectomy. Factors in each group associated with advanced AP were examined by univariate analysis (UA) and stepwise logistic regression analysis to determine independent predictors of aggressive clinical characteristics of polyps. Statistical significance was determined at a P < or = 0.05.

RESULTS

We identified a total of 1234 patients with AP (cases = 127, controls = 1107). The mean age of patients was 64.1 +/- 1.9 (standard deviation) years. By UA, those with a prior cholecystectomy had a greater mean number of AP (4.2 vs. 3.5; P = 0.04) and more advanced polyps (P = 0.037) than those without a cholecystectomy. By logistic regression, prior cholecystectomy was associated with more advanced AP (OR = 1.5 [1.0-2.2]; P = 0.04). Patients who had a cholecystectomy were 51% more likely to have advanced AP. There appeared to be a trend towards increased time from cholecystectomy being associated with advanced polyps (9.69 years vs. 8.99 years, P = 0.056).

CONCLUSIONS

A prior cholecystectomy was independently associated with an increased risk of developing advanced AP. Also, there appeared to be a trend toward a greater prevalence of advanced lesions as postcholecystectomy time increased.