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

Identification of subjects at risk of proximal advanced neoplasia for colorectal cancer screening

Flexible sigmoidoscopy (FS) and colonoscopy are two commonly used screening tools for colorectal cancer (CRC), and FS mainly detects distal lesions. Colonoscopy resource is limited, yet there is no definite evidence on when flexible sigmoidoscopy is suitable as a screening alternative. This study evaluated the optimal cut-off score from a validated risk stratification system which best predicts proximal advanced neoplasia (PAN) by comparing the sensitivity, specificity and relative risk of PAN according to various cut-off scores. 5819 asymptomatic subjects aged between 50 and 70years (average age 57.7years, standard deviation (SD) 4.9) received colonoscopy between 2008 and 2014 in Hong Kong. Their prevalence of PAN was evaluated according to a prediction tool for colorectal neoplasia based on age, gender, smoking status, family history of CRC, body mass index (BMI) and diabetes (ranging from 0 to 6). One binary logistic regression model was performed with PAN as the outcome variable and the risk score as the variable tested for association. In multivariate regression analysis, risk score ⩾3 was associated with significantly higher risk of PAN (3.4-9.1%; AOR=3.18-8.09, p<0.001) when compared with those scoring 0. Risk scores 0-2 were associated with either insignificant or lower risks of PAN compared to the overall risk. Applying FS for screening those who scored 0-2 and colonoscopy for those who scored ⩾3 led to a very small proportion of PAN being missed (1.60%), whilst maintaining a high level of specificity (81.9%). Clinicians may use this scoring system to inform subjects and facilitate their choice between colonoscopy and FS.

Assessing bowel preparation quality using the mean number of adenomas per colonoscopy

INTRODUCTION

The quality of the bowel preparation directly influences colonoscopy effectiveness. Quality indicators are widely employed to monitor operator performance and to gauge colonoscopy effectiveness. Some have suggested that the enumeration of the mean number of adenomas per colonoscopy (MNA) may be a more useful measure of bowel preparation quality, but evidence of the utility of this metric is limited. The relationship between bowel preparation quality and MNA was assessed.

METHODS

Records of adult patients, aged 50-74 years, who had undergone a screening colonoscopy in a 6 month period at a hospital-based endoscopy suite in New York City were examined. Excluded were those who were symptomatic or having a colonoscopy for surveillance. Patient and procedural characteristics and clinical findings were abstracted from the endoscopy database. Bowel preparation quality was recorded as excellent, good, fair and poor. Histology and size of polyps removed were gathered from pathology reports. MNA was calculated and incident rate ratios assessing the relationship between bowel preparation quality, MNA, and covariates was calculated using Poisson regression.

RESULTS

A total of 2422 colonoscopies were identified; 815 (33.6%) were screening colonoscopies among average risk individuals, 50-74 years; 203 (24.9%) had ≥1 adenomas; and 666 (81.7%) had excellent/good preparation quality. Overall MNA was 0.34 [standard deviation (SD) 0.68] and MNA was greater among those >60 years [incident rate ratio (IRR) 1.89, 95% confidence interval (CI) 1.48-2.42), males (IRR 1.60, 95%CI 1.26-2.04) and those with good bowel preparation (IRR 2.54, 95%CI 1.04-6.16). Among those with ≥1 adenomas, MNA was 1.48 (SD 1.05) for excellent and 1.00 (SD 0.00) for poor quality preparation (p = 0.55).

CONCLUSIONS

We found that MNA is sensitive to changes in bowel preparation with higher MNA among those with good bowel preparation compared with those with poor preparation. Our evidence suggests MNA was particularly sensitive when restricted to only those in whom adenomas were seen.

Impact of sigmoidoscopy and colonoscopy on colorectal cancer incidence and mortality: an evidence-based review of published prospective and retrospective studies

Screening for colorectal cancer (CRC) using sigmoidoscopy or colonoscopy is now common in many developed countries. This concise, evidence-based review looks at the impact of sigmoidoscopy or colonoscopy screening on CRC incidence, CRC mortality and overall mortality. Data from controlled retrospective and prospective (observational or randomized) studies have generally shown that sigmoidoscopy and colonoscopy, whether for diagnostic, screening or surveillance purposes, are associated with a significant reduction in CRC incidence and CRC mortality. The data on their impact on overall mortality is much more limited, with most studies unable to report a reduction in overall mortality. The results of three meta-analyses have confirmed these conclusions. As expected, sigmoidoscopy has a predominant effect on left-sided CRC, although some studies have shown modest effects on right-sided colon cancer as well. Most studies on colonoscopy have demonstrated that the protective effect applies to both right and left-sided cancer, although the protection seemed better on the left side. Despite the introduction of other screening and diagnostic modalities for the colon, such as computed tomography colonography and colonic capsule endoscopy, lower endoscopy will continue to be an important mode of screening for CRC and evaluating the colon.

Rate of detection of advanced neoplasms in proximal colon by simulated sigmoidoscopy vs fecal immunochemical tests

BACKGROUND & AIMS

We compared the ability of biennial fecal immunochemical testing (FIT) and one-time sigmoidoscopy to detect colon side-specific advanced neoplasms in a population-based, multicenter, nationwide, randomized controlled trial.

METHODS

We identified asymptomatic men and women, 50-69 years old, through community health registries and randomly assigned them to groups that received a single colonoscopy examination or biennial FIT. Sigmoidoscopy yield was simulated from results obtained from the colonoscopy group, according to the criteria proposed in the UK Flexible Sigmoidoscopy Trial for colonoscopy referral. Patients who underwent FIT and were found to have ≥75 ng hemoglobin/mL were referred for colonoscopy. Data were analyzed from 5059 subjects in the colonoscopy group and 10,507 in the FIT group. The main outcome was rate of detection of any advanced neoplasm proximal to the splenic flexure.

RESULTS

Advanced neoplasms were detected in 317 subjects (6.3%) in the sigmoidoscopy simulation group compared with 288 (2.7%) in the FIT group (odds ratio for sigmoidoscopy, 2.29; 95% confidence interval, 1.93-2.70; P = .0001). Sigmoidoscopy also detected advanced distal neoplasia in a higher percentage of patients than FIT (odds ratio, 2.61; 95% confidence interval, 2.20-3.10; P = .0001). The methods did not differ significantly in identifying patients with advanced proximal neoplasms (odds ratio, 1.17; 95% confidence interval, 0.78-1.76; P = .44). This was probably due to the lower performance of both strategies in detecting patients with proximal lesions (sigmoidoscopy detected these in 19.1% of patients and FIT in 14.9% of patients) vs distal ones (sigmoidoscopy detected these in 86.8% of patients and FIT in 33.5% of patients). Sigmoidoscopy, but not FIT, detected proximal lesions in lower percentages of women (especially those 50-59 years old) than men.

CONCLUSIONS

Sigmoidoscopy and FIT have similar limitations in detecting advanced proximal neoplasms, which depend on patients' characteristics; sigmoidoscopy underperforms for women 50-59 years old. Screening strategies should be designed on the basis of target population to increase effectiveness and cost-effectiveness. ClinicalTrials.gov number: NCT00906997.

Advanced proximal neoplasia of the colon in average-risk adults

BACKGROUND

Estimating risk for advanced proximal neoplasia (APN) based on distal colon findings can help identify asymptomatic persons who should undergo examination of the proximal colon after flexible sigmoidoscopy (FS) screening.

OBJECTIVE

We aimed to determine the risk of APN by most advanced distal finding among an average-risk screening population.

DESIGN

Prospective, cross-sectional study.

SETTING

Teaching hospital and colorectal cancer screening center.

PATIENTS

A total of 4651 asymptomatic persons at average risk for colorectal cancer aged 50 to 74 years (54.4% women [n = 2529] with a mean [± standard deviation] age of 58.4 ± 6.2 years).

INTERVENTIONS

All participants underwent a complete colonoscopy, including endoscopic removal of all polyps.

MAIN OUTCOME MEASUREMENTS

We explored associations between several risk factors and APN. Logistic regression was used to identify independent predictors of APN.

RESULTS

A total of 142 persons (3.1%) had APN, of whom 85 (1.8%) had isolated APN (with no distal findings). APN was associated with older age, a BMI >27 kg/m(2), smoking, distal advanced adenoma and/or cancer, and distal non-advanced tubular adenoma. Those with a distal advanced neoplasm were more than twice as likely to have APN compared with those without distal lesions.

LIMITATIONS

Distal findings used to estimate risk of APN were derived from colonoscopy rather than FS itself.

CONCLUSION

In persons at average risk for colorectal cancer, the prevalence of isolated APN was low (1.8%). Use of distal findings to predict APN may not be the most effective strategy. However, incorporating factors such as age (>65 years), sex, BMI (>27 kg/m(2)), and smoking status, in addition to distal findings, should be considered for tailoring colonoscopy recommendations. Further evaluation of risk stratification approaches in other asymptomatic screening populations is warranted.

Narrow band imaging vs. high definition colonoscopy for detection of colorectal adenomas in patients with positive faecal occult blood test: a randomised trial

BACKGROUND

The impact of narrow band imaging in improving the adenoma detection rate in a screening scenario is still unclear.

AIM

To evaluate whether narrow band imaging compared with high definition white light colonoscopy can enhance the adenoma detection rate during screening colonoscopy.

METHODS

Consecutive patients presenting for screening colonoscopy were included into this study and were randomly assigned to the narrow band imaging group (Group 1) or standard colonoscopy group (Group 2). Primary end point was the adenoma detection rate and secondary aim was the detection rate of advanced adenomas.

RESULTS

Overall, 117 patients were allocated to Group 1 and 120 to Group 2. Both the adenoma detection rate and the detection rate of advanced adenomas were not significantly different between the two groups (respectively, 52.1% vs. 55%, RR=0.95, 95% CI 0.75-1.20; 32.5% vs. 44.2%, RR=0.74, 95% CI 0.53-1.02). No significant difference between the proportions of polypoid and flat adenomas was found. Male gender, no prior history of screening, and endoscopist's adenoma detection rate were independent predictive factors of higher advanced adenoma detection rate.

CONCLUSIONS

In a screening scenario, narrow band imaging did not improve the adenoma nor advanced adenoma detection rates compared to high definition white light colonoscopy.

Characteristics of adenomas detected by fecal immunochemical test in colorectal cancer screening

BACKGROUND

Fecal immunochemical test (FIT) diagnostic accuracy for colorectal adenoma detection in colorectal cancer screening is limited.

METHODS

We analyzed 474 asymptomatic subjects with adenomas detected on colonoscopy in two blinded diagnostic tests studies designed to assess FIT diagnostic accuracy. We determined the characteristics of adenomas (number, size, histology, morphology, and location) and the risk of metachronous lesions (according to European guidelines). Finally, we performed a logistic regression to identify those variables independently associated with a positive result.

RESULTS

Advanced adenomas were found in 145 patients (75.6% distal and 24.3% only proximal to splenic flexure). Patients were classified as low (59.5%), intermediate (30.2%), and high risk (10.3%) according to European guidelines. At a 100-ng/mL threshold, FIT was positive in 61 patients (12.8%). Patients with advanced adenomas [odds ratio (OR), 8.8; 95% confidence interval (CI), 4.76-16.25], distal advanced adenomas (OR, 6.7; 95% CI, 1.9-8.8), high risk (OR, 20.1; 95% CI, 8.8-45.8), or intermediate risk lesions (OR, 6; 95% CI, 2.9-12.4) had more probabilities to have a positive test. The characteristics of adenomas independently associated were number of adenomas (OR, 1.22; 95% CI, 1.04-1.42), distal flat adenomas (OR, 0.44; 95% CI, 0.21-0.96), pedunculated adenomas (OR, 2.28; 95% CI, 1.48-3.5), and maximum size of distal adenomas (mm; OR, 1.24; 95% CI, 1.16-1.32).

CONCLUSIONS

European guidelines classification and adenoma location correlates with the likelihood of a positive FIT result.

IMPACT

This information allows us to understand the FIT impact in colorectal cancer prevention. Likewise, it should be taken into account in the development of new colorectal adenomas biomarkers.

Whites and blacks have similar risk of metachronous advanced colorectal neoplasia

BACKGROUND

Current guidelines for surveillance of colonic neoplasia are based on data from predominantly white populations, yet whether these recommendations are applicable to blacks is unknown.

AIM

To define the prevalence of advanced colorectal neoplasia (ACN) among whites and blacks undergoing surveillance colonoscopy.

METHODS

This was a retrospective, cross-sectional analysis of asymptomatic, average-risk non-Hispanic white (N = 246) and non-Hispanic black (N = 203) patients with colorectal neoplasia who underwent baseline screening colonoscopy between January 1, 2000, and December 31, 2007, and a surveillance colonoscopy before December 31, 2010, at an academic safety-net hospital. The main outcome measure was the prevalence of ACN, defined as a tubular adenoma or sessile serrated adenoma (SSA) ≥ 10 mm, any adenoma with villous histology or high-grade dysplasia, any serrated lesion with dysplasia, or invasive cancer at surveillance.

RESULTS

During a median follow-up of 4.3 years, the overall prevalence of ACN at surveillance was similar among blacks and whites (11.3 vs. 9.8 %; P = 0.59) with an odds ratio of 1.18 (95 % CI 0.65-2.16) [corrected]. Blacks and whites with non-advanced neoplasia had similar rates of ACN at the 1-3, 4-5, and >5 year follow-up intervals. Blacks with ACN or multiplicity at baseline had higher rates of ACN at the 1- to 3-year interval compared with whites, but the difference was non-significant (26.7 vs. 12.5 %; P = 0.32). No interval cancers were observed for either group.

CONCLUSIONS

The overall prevalence of ACN was similar between non-Hispanic blacks and non-Hispanic whites undergoing surveillance in a safety-net healthcare setting suggesting that current surveillance guidelines are appropriate for both blacks and whites.

Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: a randomized clinical trial

IMPORTANCE

Colorectal cancer is a major health burden. Screening is recommended in many countries.

OBJECTIVE

To estimate the effectiveness of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality in a population-based trial.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of 100,210 individuals aged 50 to 64 years, identified from the population of Oslo city and Telemark County, Norway. Screening was performed in 1999-2000 (55-64-year age group) and in 2001 (50-54-year age group), with follow-up ending December 31, 2011. Of those selected, 1415 were excluded due to prior colorectal cancer, emigration, or death, and 3 could not be traced in the population registry.

INTERVENTIONS

Participants randomized to the screening group were invited to undergo screening. Within the screening group, participants were randomized 1:1 to receive once-only flexible sigmoidoscopy or combination of once-only flexible sigmoidoscopy and fecal occult blood testing (FOBT). Participants with positive screening test results (cancer, adenoma, polyp ≥10 mm, or positive FOBT) were offered colonoscopy. The control group received no intervention.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality.

RESULTS

A total of 98,792 participants were included in the intention-to-screen analyses, of whom 78,220 comprised the control group and 20,572 comprised the screening group (10,283 randomized to receive a flexible sigmoidoscopy and 10,289 to receive flexible sigmoidoscopy and FOBT). Adherence with screening was 63%. After a median of 10.9 years, 71 participants died of colorectal cancer in the screening group vs 330 in the control group (31.4 vs 43.1 deaths per 100,000 person-years; absolute rate difference, 11.7 [95% CI, 3.0-20.4]; hazard ratio [HR], 0.73 [95% CI, 0.56-0.94]). Colorectal cancer was diagnosed in 253 participants in the screening group vs 1086 in the control group (112.6 vs 141.0 cases per 100,000 person-years; absolute rate difference, 28.4 [95% CI, 12.1-44.7]; HR, 0.80 [95% CI, 0.70-0.92]). Colorectal cancer incidence was reduced in both the 50- to 54-year age group (HR, 0.68; 95% CI, 0.49-0.94) and the 55- to 64-year age group (HR, 0.83; 95% CI, 0.71-0.96). There was no difference between the flexible sigmoidoscopy only vs the flexible sigmoidoscopy and FOBT screening groups.

CONCLUSIONS AND RELEVANCE

In Norway, once-only flexible sigmoidoscopy screening or flexible sigmoidoscopy and FOBT reduced colorectal cancer incidence and mortality on a population level compared with no screening. Screening was effective both in the 50- to 54-year and the 55- to 64-year age groups.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00119912.

Race, ethnicity, and sex affect risk for polyps >9 mm in average-risk individuals

BACKGROUND & AIMS

Colorectal cancer risk differs based on patient demographics. We aimed to measure the prevalence of significant colorectal polyps in average-risk individuals and to determine differences based on age, sex, race, or ethnicity.

METHODS

In a prospective study, colonoscopy data were collected, using an endoscopic report generator, from 327,785 average-risk adults who underwent colorectal cancer screening at 84 gastrointestinal practice sites from 2000 to 2011. Demographic characteristics included age, sex, race, and ethnicity. The primary outcome was the presence of suspected malignancy or large polyp(s) >9 mm. The benchmark risk for age to initiate screening was based on white men, 50-54 years old.

RESULTS

Risk of large polyps and tumors increased progressively in men and women with age. Women had lower risks than men in every age group, regardless of race. Blacks had higher risk than whites from ages 50 through 65 years and Hispanics had lower risk than whites from ages 50 through 80 years. The prevalence of large polyps was 6.2% in white men 50-54 years old. The risk was similar among the groups of white women 65-69 years old, black women 55-59 years old, black men 50-54 years old, Hispanic women 70-74 years old, and Hispanic men 55-59 years old. The risk of proximal large polyps increased with age, female sex, and black race.

CONCLUSIONS

There are differences in the prevalence and location of large polyps and tumors in average-risk individuals based on age, sex, race, and ethnicity. These findings could be used to select ages at which specific groups should begin colorectal cancer screening.

Colonoscopy utilization and outcomes 2000 to 2011

BACKGROUND

Understanding colonoscopy utilization and outcomes can help determine when the procedure is most effective.

OBJECTIVE

To study trends in utilization and outcomes of colonoscopy in the United States from 2000 to 2011.

DESIGN

Prospective collection of colonoscopy data.

SETTING

A total of 84 adult diverse GI practices.

PATIENTS

All adult patients receiving colonoscopy for any reason.

INTERVENTION

Colonoscopy.

MAIN OUTCOME MEASUREMENTS

Polyps >9 mm or suspected malignant tumor.

RESULTS

We analyzed 1,372,838 reports. The most common reason for colonoscopy in patients aged <50 years is evaluation of symptoms such as irritable bowel syndrome (IBS) (28.7%) and bleeding or anemia (35.3%). In patients aged 50 to 74 years, colorectal cancer screening accounts for 42.9% of examinations. In patients aged >74 years, surveillance for cancer or polyps is the most common indication. The use of colonoscopy for average-risk screening increased nearly 3-fold during the study period. The prevalence of large polyps increases with age and is higher in men for every procedure indication. The prevalence of large polyps in patients with symptoms of IBS was lower than in those undergoing average-risk screening (odds ratio [OR] 0.85; 95% confidence interval [CI], 0.83-0.87). With increasing age, there was a shift from distal to proximal large polyps. The rate of proximal large polyps is higher in the black population compared with the white population (OR 1.19; 95% CI, 1.13-1.25).

LIMITATIONS

In the absence of pathology data, use of surrogate as the main outcome.

CONCLUSION

Colonoscopy utilization changed from 2000 to 2011, with an increase in primary screening. The proximal location of large polyps in the black population and with advancing age has implications for screening and surveillance.

A validated tool to predict colorectal neoplasia and inform screening choice for asymptomatic subjects

OBJECTIVE

We aim to develop and validate a clinical scoring system to predict the risks of colorectal neoplasia to better inform screening participants and facilitate their screening test choice.

DESIGN

We recruited 5220 Chinese asymptomatic screening participants who underwent colonoscopy in Hong Kong during 2008-2012. From random sampling of 2000 participants, independent risk factors were evaluated for colorectal neoplasia, defined as adenoma, advanced neoplasia, colorectal cancer or any combination thereof using binary regression analysis. The ORs for significant risk factors were used to develop a scoring system ranging from 0 to 6: 0-2 'average risk' (AR) and 3-6 'high risk' (HR). The other 3220 screening participants prospectively enrolled between 2008 and 2012 for screening colonoscopy formed an independent validation cohort. The performance of the scoring system for predicting colorectal neoplasia was evaluated.

RESULTS

The prevalence of colorectal neoplasia in the derivation and validation cohorts was 31.4% and 30.8%, respectively. Using the scoring system developed, 78.9% and 21.1% in the validation cohort were classified as AR and HR, respectively. The prevalence of colorectal neoplasia in the AR and HR groups was 27.1% and 44.6%, respectively. The subjects in the HR group had 1.65-fold (95% CI 1.49 to 1.83) increased prevalence of colorectal neoplasia than the AR group.

CONCLUSIONS

The scoring system based on age, gender, smoking, family history, Body Mass Index and self-reported diabetes is useful in predicting the risk of colorectal neoplasia.

Predictive factors of proximal advanced neoplasia in the large bowel

INTRODUCTION

The aim of the study was to evaluate the impact of sex, age, family history and distal findings on the risk of proximal advanced neoplasia (cancer or advanced adenoma) in the large bowel.

MATERIAL AND METHODS

Records for 10 111 asymptomatic participants of the Colonoscopy Screening Program (CSP), recruited from the Warsaw region between 2000 and 2004, were analyzed. A multivariate logistic regression model was used to estimate the impact of sex, age, family history and most advanced distal lesions on the occurrence of proximal advanced neoplasia. To enhance comparability of the study two definitions of the proximal colon were applied - either the splenic flexure (1(st)) or the bend between the descending and sigmoid colon (2(nd) definition) represented the boundary.

RESULTS

One hundred and thirty-three (1(st)) and 167 patients (2(nd) definition) were found to have at least one advanced neoplastic lesion in the proximal part, respectively. Eleven and 14 patients were found to have carcinoma, while in 130 and 163 patients at least one proximal advanced adenoma appeared. Men were at twice as high risk of having advanced neoplasia in the proximal colon than women (OR = 1.94, 95% CI: 1.31-2.87, p = 0.001 or OR = 1.69, 95% CI: 1.20-2.40, p = 0.003, respectively). The presence of distal advanced neoplastic lesions was associated with 3.5 times higher risk of proximal advanced neoplasia (OR = 3.58, 95% CI: 2.00-6.43, p < 0.0001 or OR = 3.41, 95% CI: 1.95-5.96, p < 0.0001), respectively.

CONCLUSIONS

The results may confirm some limitation of flexible sigmoidoscopy in the screening settings in comparison with colonoscopy, at least in men and people with distal advanced neoplasia.

Developing screening services for colorectal cancer on Android smartphones

INTRODUCTION

Colorectal cancer (CRC) is an important health problem in Western countries and also in Asia. It is the third leading cause of cancer deaths in both men and women in Taiwan. According to the well-known adenoma-to-carcinoma sequence, the majority of CRC develops from colorectal adenomatous polyps. This concept provides the rationale for screening and prevention of CRC. Removal of colorectal adenoma could reduce the mortality and incidence of CRC. Mobile phones are now playing an ever more crucial role in people's daily lives. The latest generation of smartphones is increasingly viewed as hand-held computers rather than as phones, because of their powerful on-board computing capability, capacious memories, large screens, and open operating systems that encourage development of applications (apps).

SUBJECTS AND METHODS

If we can detect the potential CRC patients early and offer them appropriate treatments and services, this would not only promote the quality of life, but also reduce the possible serious complications and medical costs. In this study, an intelligent CRC screening app on Android™ (Google™, Mountain View, CA) smartphones has been developed based on a data mining approach using decision tree algorithms. For comparison, the stepwise backward multivariate logistic regression model and the fecal occult blood test were also used.

RESULTS

Compared with the stepwise backward multivariate logistic regression model and the fecal occult blood test, the proposed app system not only provides an easy and efficient way to quickly detect high-risk groups of potential CRC patients, but also brings more information about CRC to customer-oriented services.

CONCLUSIONS

We developed and implemented an app system on Android platforms for ubiquitous healthcare services for CRC screening. It can assist people in achieving early screening, diagnosis, and treatment purposes, prevent the occurrence of complications, and thus reach the goal of preventive medicine.

Systematic review with meta-analysis: the incidence of advanced neoplasia after polypectomy in patients with and without low-risk adenomas

BACKGROUND

Patients with one to two tubular adenomas <1 cm in size without high-grade dysplasia (low-risk group) are considered at low risk for colorectal cancer. However, it is uncertain whether they have the same risk of subsequent advanced neoplasia as those with no neoplasia at baseline colonoscopy.

AIM

To compare incidence of metachronous advanced neoplasia between patients in the low-risk adenoma group and those without neoplasia at index colonoscopy.

METHODS

Relevant publications were identified by MEDLINE/EMBASE and other databases for the period 1992-2013. Studies comparing the incidence of post-polypectomy advanced neoplasia (adenomas ≥10 mm/high-grade dysplasia/villous or cancer) between the low-risk group and patients without colorectal neoplasia at the first colonoscopy were included. Detection rates for advanced neoplasia at endoscopic surveillance were extracted. Study quality was ascertained according to Newcastle-Ottawa Scale. Forest plot was produced based on random-effect models. Inter-study heterogeneity was assessed using the I(2) statistic.

RESULTS

Seven studies provided data on 11 387 patients. Mean surveillance periods ranged between 2 and 5 years. Altogether, 267 patients with post-polypectomy advanced neoplasia were detected in the two groups. The incidence of advanced neoplasia was 1.6% (119/7308) in those without neoplasia and 3.6% (148/4079) in those with low-risk adenoma, respectively, corresponding to a relative risk of 1.8 (95% CI: 1.3-2.6). Inter-study heterogeneity was only moderate (I(2) : 37%). No publication bias was present.

CONCLUSIONS

Patients with low-risk adenomas at baseline had a higher risk of metachronous advanced neoplasia than the group with no adenomas at baseline, though the absolute risk was low in both groups.

Colorectal neoplasia detection among black and Latino individuals undergoing screening colonoscopy: a prospective cohort study

BACKGROUND

Most prospective studies of screening colonoscopy (SC) in average-risk, asymptomatic individuals have included few minority individuals. Little is known about the prevalence and distribution of adenomas found at screening colonoscopy among black and Latino individuals.

OBJECTIVE

To determine the prevalence and distribution of histologically confirmed adenomas among black and Latino participants enrolled in a prospective SC study.

DESIGN

Cross-sectional analysis of consecutive patients undergoing SC between 2008 and 2011.

SETTING

Urban academic medical center.

PATIENTS

Average risk, asymptomatic black and Latino patients aged ≥50 years undergoing SC.

INTERVENTION SC MAIN OUTCOME MEASUREMENTS

Adenoma prevalence and distribution by ethnic group.

RESULTS

A total of 584 patients (270 black, 314 Latino) completed SC. Overall, 26.4% had adenomas, and 20% had proximal adenomas. Advanced adenomas occurred in 11.5% (12.2% black vs 10.8% Latino; P = .21) and proximal advanced adenomas in 7.5% (5.9% black vs 8.9% Latino; P = .17). These rates were at least as high as those of other studies that enrolled mainly white participants.

LIMITATIONS

Lack of comparison group of white patients.

CONCLUSION

The prevalence of adenomas, advanced adenomas, and proximal adenomas was high in both black and Latino participants. The high prevalence of clinically significant proximal lesions has implications for the choice of colon cancer screening test and colonoscopic surveillance intervals.

Standard forward-viewing colonoscopy versus full-spectrum endoscopy: an international, multicentre, randomised, tandem colonoscopy trial

BACKGROUND

Although colonoscopy is the accepted standard for detection of colorectal adenomas and cancers, many adenomas and some cancers are missed. To avoid interval colorectal cancer, the adenoma miss rate of colonoscopy needs to be reduced by improvement of colonoscopy technique and imaging capability. We aimed to compare the adenoma miss rates of full-spectrum endoscopy colonoscopy with those of standard forward-viewing colonoscopy.

METHODS

We did an international, multicentre, randomised trial at three sites in Israel, one site in the Netherlands, and two sites in the USA between Feb 1, 2012, and March 31, 2013. Patients aged 18-70 years referred for colorectal cancer screening, polyp surveillance, or diagnostic assessment underwent same-day, back-to-back tandem colonoscopy with standard forward-viewing colonoscope and the full-spectrum endoscopy colonoscope. The patients were randomly assigned (1:1), via computer-generated randomisation with block size of 20, to which procedure was done first. The endoscopist was masked to group allocation until immediately before the start of colonoscopy examinations; patients were not masked. The primary endpoint was adenoma miss rates. We did per-protocol analyses. This trial is registered with ClinicalTrials.gov, number NCT01549535.

FINDINGS

197 participants were enrolled. 185 participants were included in the per-protocol analyses: 88 (48%) were randomly assigned to receive standard forward-viewing colonoscopy first, and 97 (52%) to receive full-spectrum endoscopy colonoscopy first. By per-lesion analysis, the adenoma miss rate was significantly lower in patients in the full-spectrum endoscopy group than in those in the standard forward-viewing procedure group: five (7%) of 67 vs 20 (41%) of 49 adenomas were missed (p<0·0001). Standard forward-viewing colonoscopy missed 20 adenomas in 15 patients; of those, three (15%) were advanced adenomas. Full-spectrum endoscopy missed five adenomas in five patients in whom an adenoma had already been detected with first-pass standard forward-viewing colonoscopy; none of these missed adenomas were advanced. One patient was admitted to hospital for colitis detected at colonoscopy, whereas five minor adverse events were reported including vomiting, diarrhoea, cystitis, gastroenteritis, and bleeding.

INTERPRETATION

Full-spectrum endoscopy represents a technology advancement for colonoscopy and could improve the efficacy of colorectal cancer screening and surveillance.

FUNDING

EndoChoice.

Water injection versus air insufflation for colonoscopy in elderly patients

AIM: To compare the impact of water injection versus air insufflation for colonoscopy on cecal intubation rate, cecal intubation time and pain degree in elderly patients.

METHODS: Two hundred elderly patients (aged 65-82 years) who underwent non-narcotic colonoscopy were randomly divided into two groups: water injection and air insufflation. The cecal intubation rate, cecal intubation time and pain degree were compared between the two groups.

RESULTS: There were no significant differences in cecal intubation rate (98% vs 94%, P > 0.05) or cecal intubation time (7.83 min ± 1.58 min vs 8.01 min ± 1.26 min, P > 0.05) between the water injection and air insufflation groups. Abdominal pain score was significantly lower in the water injection than in the air insufflation group (3.23 ± 1.71 vs 4.87 ± 1.94, P < 0.05).

CONCLUSION: Compared with air insufflation colonoscopy, water injection colonoscopy has similar cecal intubation rate and cecal intubation time, but is associated with significantly lower pain in elderly patients.

Delivering colonoscopy screening for low-income populations in Suffolk County: strategies, outcomes, and benchmarks

BACKGROUND

Current and pending legislation provides colorectal cancer screening reimbursement for previously uninsured populations. Colonoscopy is currently the screening method most frequently recommended by physicians for insured patients. The experience of the SCOPE (Suffolk County Preventive Endoscopy) demonstration project (Project SCOPE) at Stony Brook University Medical Center provides a model for delivering colonoscopy screening to low-income populations to meet anticipated increasing demands.

METHODS

Project SCOPE, based in the Department of Preventive Medicine, featured internal collaboration with the academic medical center's large gastroenterology practice and external collaboration with the Suffolk County Department of Health Services' network of community health centers. Colonoscopies were performed by faculty gastroenterologists or supervised fellows. Measures of colonoscopy performance were compared with quality indicators and differences between faculty and supervised fellows were identified.

RESULTS

During a 40-month screening period, 800 initial colonoscopies were performed. Approximately 21% of women screened were found to have adenomatous polyps compared with 36% of men. Five cancers were detected. The majority of the population screened (70%) were members of minority populations. African American individuals had a higher percentage of proximally located adenomas (78%) compared with white individuals (65%) and Hispanics (49%), based on the location of the most advanced lesion. Hispanic individuals had a 36% lower risk of adenomas compared with white individuals. Performance measures including the percentage of procedures with adequate bowel preparation, cecum reached, scope withdrawal time, and adenoma detection rate met quality benchmarks when performed by either faculty or supervised fellows.

CONCLUSIONS

Project SCOPE's operational strategies demonstrated a feasible method for an academic medical center to provide high-quality screening colonoscopy for low-income populations.

Measuring endoscopic performance for colorectal cancer prevention quality improvement in a gastroenterology practice

A gastroenterology practice lacked quality measures to evaluate the practice's colorectal cancer prevention efforts. Colonoscopy performance data were gathered from a retrospective review of 90 charts using a modified Colorectal Cancer Prevention Data Collection Form. Practice stakeholders and project leader reviewed the data, identified practice deficiencies, conducted root cause analysis, and developed practice changes. Implementing the prioritized recommendations and routinely benchmarking care were warranted to ensure effective practice to improve outcomes for colorectal cancer prevention. Achieving higher-value care has led to increased efforts to improve systems for measuring care, using these measures for quality improvement and directly linking quality outcomes to reimbursement.

Routine colonoscopy is not required in uncomplicated diverticulitis: a systematic review

BACKGROUND

It is generally accepted that patients following an episode of diverticulitis should have additional colonoscopy screening to rule out a colorectal malignancy. We aimed to investigate the rate of CRC found by colonoscopy after an attack of uncomplicated diverticulitis.

METHODS

MEDLINE, Embase, and Cochrane databases were searched systematically for clinical trials or observational studies on colonic evaluation by colonoscopy after the initial diagnosis of acute uncomplicated diverticulitis, followed by hand-searching of reference lists.

RESULTS

Nine studies met the inclusion criteria and included a total number of 2,490 patients with uncomplicated diverticulitis. Subsequent colonoscopy after an episode of uncomplicated diverticulitis was performed in 1,468 patients (59%). Seventeen patients were diagnosed with CRC, having a prevalence of 1.16% (95% confidence interval 0.72-1.9% for CRC). Hyperplastic polyps were seen in 156 patients (10.6%), low-grade adenoma in 90 patients (6.1%), and advanced adenoma was reported in 32 patients (2.2%).

CONCLUSION

Unless colonoscopy is regarded for screening in individuals aged 50 years and older, routine colonoscopy in the absence of other clinical signs of CRC is not required.

Colorectal cancer: screening and surveillance for high-risk individuals

Colorectal cancer is very common and is closely related to patient age. After age, the second most common risk factor is family history of colon cancer. In fact, it is one of the most hereditable cancers. Colon cancer is preventable and screening has demonstrated efficacy in the reduction of both the incidence and the mortality from colorectal cancer. Several screening techniques are currently available, including endoscopy and nonendoscopic-based techniques. Screening strategies vary according to the individual risk of colon cancer. This paper will focus on the screening recommendations for patients with high-risk colon cancer.

Anatomic distribution of cancers and colorectal adenomas according to age and sex and relationship between proximal and distal neoplasms in an i-FOBT-positive average-risk Italian screening cohort

BACKGROUND AND AIMS

Subsite-specific incidence rates of colorectal cancer (CRC) and adenomas may vary considerably by race, sex and age as well as due to different screening strategies. We assessed variations in the anatomical distribution of adenomas according to age and sex in an average-risk screening cohort testing positive at immunological faecal occult blood test (i-FOBT) in northern Italy.

METHODS

Data from 2,281 consecutive asymptomatic i-FOBT-positive subjects ageing 50-70 years undergone colonoscopy were reviewed. Size, number, macroscopic and histological features of all adenomas found as well as their proximal or distal location in relation to the splenic flexure were examined. Odds ratios (OR) of proximal neoplasms, according to the presence of distal neoplasms and other selected covariates were assessed by multiple logistic regression analysis.

RESULTS

A total of 2,599 neoplasms were found in 1,396 patients. Of these, 116 (5 %) were colorectal cancers, diagnosed in 106 patients. Out of 2,483 adenomas found, 1,564 (63 %) were sessile, 795 (32 %) were peduncolated and 124 (5 %) were flat-type; 54 % of all adenomas were tubular, 36 % were tubulovillous or villous, and 10 % were serrated adenomas. The majority of neoplasms (66 %) were located in the distal colon. Tumour subsite distribution was consistent in both sexes, whereas significant proximal migration of neoplasms occurred in the older age cohort. Indeed, the rate of proximal neoplasms in patients aged ≥60 years was 37 % as compared with 29 % in those ageing 50-59 years. Male gender (OR 1.84), age of 60 years or older (OR 1.44), having a family history of colorectal neoplasms (OR 1.47) and presence of at least 1 distal advanced adenoma (OR 1.63) were all significant predictors of advanced proximal neoplasms.

CONCLUSIONS

A left to right shift of colorectal adenomas with increasing age is evident in northern Italian asymptomatic i-FOBT-positive population. Advanced proximal neoplasms are not uncommon in subjects with or without distal adenomas, especially after 60 years of age. This should be carefully considered when implementing public screening strategies for CRC since the use of flexible sigmoidoscopy as a screening tool, particularly in older age groups, appears to be less effective.

Prevalence of colorectal polyps in a group of subjects at average-risk of colorectal cancer undergoing colonoscopic screening in Tehran, Iran between 2008 and 2013

BACKGROUND

Colorectal cancer (CRC) is one of the prime causes of mortality around the globe, with a significantly rising incidence in the Middle East region in recent decades. Since detection of CRC in the early stages is an important issue, and also since to date there are no comprehensive epidemiologic studies depicting the Middle East region with special attention to the average risk group, further investigation is of significant necessity in this regard.

AIM

Our aim was to investigate the prevalence of preneoplastic and neoplastic lesions of the colon in an average risk population.

MATERIALS AND METHODS

A total of 1,208 eligible asymptomatic, average- risk adults older than 40 years of age, referred to Firuzgar Hospotal in the years 2008-2012, were enrolled. They underwent colonoscopy screening and all polypoid lesions were removed and examined by an expert gastrointestinal pathologist. The lesions were classified by size, location, numbers and pathologic findings. Size of lesions was measured objectively by endoscopists.

RESULTS

The mean age of participants was 56.5±9.59 and 51.6% were male. The overall polyp detection rate was 199/1208 (16.5 %), 26 subjects having non-neoplastic polyps, including hyperplastic lesions, and 173/1208 (14.3%) having neoplastic polyps, of which 26 (2.15%) were advanced neoplasms .The prevalence of colorectal neoplasia was more common among the 50-59 age group. Advanced adenoma was more frequent among the 60-69 age group. The majority of adenomas were detected in the distal colon, but a quarter of advanced adenomas were found in the proximal colon; advance age and male gender was associated with the presence of adenoma.

CONCLUSIONS

It seems that CRC screening among average-risk population might be recommended in countries such as Iran. However, sigmioidoscopy alone would miss many colorectal adenomas. Furthermore, the 50-59 age group could be considered as an appropriate target population for this purpose in Iran.

Detection rate of colorectal adenoma or cancer in unselected colonoscopy patients: Indonesian experience in a private hospital

BACKGROUND

Colorectal cancer is currently the third most common cancer in Indonesia, yet colonoscopy--the most accepted mode of screening to date--is not done routinely and national data are still lacking.

OBJECTIVE

To determine the detection rate of colorectal cancers and adenomas in unselected patients undergoing colonoscopy for various large bowel symptoms at the Digestive Disease and GI Oncology Centre, Medistra Hospital in Jakarta, Indonesia.

MATERIALS AND METHODS

Colonoscopy data from January 2009 to December 2012 were reviewed. New patients referred for colonoscopy were included. Data collected were patient demographic and significant colonoscopy findings such as the presence of hemorrhoids, colonic polyps, colonic diverticula, inflammation, and tumor mass. Histopathological data were obtained for specimens taken by biopsy. Associations between categorical variables were analyzed using chi-square test, while mean differences were tested using the t-test.

RESULTS

A total of, 1659 cases were included in this study, 889 (53.6%) of them being men. Polyps or masses were found in 495 (29.8%) patients while malignancy was confirmed in 74 (4.5%). Patients with a polyp or mass were significantly older (60.2 vs 50.8 years; p<0.001; t-test) and their presence was significantly associated with male gender (35.0% vs 23.9%; prevalent ratio [PR] 1.71; 95% confidence interval [CI] 1.38-2.12; p<0.001) and age>50 years (39.6% vs 16.6%; PR 3.29; 95% CI 2.59-4.12; p<0.001). Neoplastic lesions was found in 257 (16.1%), comprising 180 (11.3%) adenomas, 10 (0.6%) in situ carcinomas, and 67 (4.2%) carcinomas.

CONCLUSIONS

Polyps or masses were found in 30% of colonoscopy patients and malignancies in 16.1%. These figures do not represent the nation-wide demographic status of colorectal cancer, but may reflect a potentially increasing major health problem with colorectal cancer in Indonesia.

Risk of colorectal neoplasia in patients with celiac disease: a multicenter study

BACKGROUND AND AIMS

The association of celiac disease with colorectal neoplasia is controversial. The aim of this study was to determine the risk of colorectal neoplasia among patients with celiac disease.

METHODS

We carried out a multicenter, retrospective case-control study, within four community hospitals. Celiac disease patients with a complete colonoscopy were regarded as cases and those without celiac disease as controls. For each case, two controls matched for age, sex, indication for colonoscopy and colorectal cancer family history, were randomly selected. The main outcome evaluated was risk of colorectal polyps, adenomas, advanced neoplastic lesions and cancer.

RESULTS

We identified 118 patients with celiac disease and 236 controls. The risk of polyps, adenomas and advanced neoplastic lesions was similar in both groups (OR 1.25, CI 0.71-2.18, p=0.40; OR 1.39, CI 0.73-2.63, p=0.31; and OR 1.00, CI 0.26-3.72, p=1.00, respectively). On multivariate analysis, age >75 years old, and first-grade CRC family history were associated with adenomas (OR 2.68 CI 1.03-6.98, OR 6.68 CI 1.03-47.98 respectively) and advanced neoplastic lesions (OR 15.03, CI 2.88-78.3; OR 6.46 CI 1.23-33.79, respectively). With respect to celiac disease characteristic, a low adherence to a gluten free diet was independently associated with the presence of adenomas (OR 6.78 CI 1.39-33.20 p=0.01).

CONCLUSIONS

Celiac disease was not associated with an increased risk of colorectal neoplasia. Nonadherence to a strict gluten free diet was associated with the presence of adenomas. Further studies addressing celiac disease characteristics are needed to confirm this observation.

Economic evaluation of colorectal cancer (CRC) screening

Because of its incidence and mortality colorectal cancer represents a serious public health issue in industrial countries. In order to reduce its social impact a number of screening strategies have been implemented, which allow an early diagnosis and treatment. These basically include faecal tests and studies that directly explore the colon and rectum. No strategy, whether alone or combined, has proven definitively more effective than the rest, but any such strategy is better than no screening at all. Selecting the most efficient strategy for inclusion in a population-wide program is an uncertain choice. Here we review the evidence available on the various economic evaluations, and conclude that no single method has been clearly identified as most cost-effective; further research in this setting is needed once common economic evaluation standards are established in order to alleviate the methodological heterogeneity prevailing in study results.

Noncathartic CT colonography to screen for colorectal neoplasia in subjects with a family history of colorectal cancer

PURPOSE

To prospectively assess the diagnostic performance of noncathartic computed tomographic (CT) colonography in the detection of clinically relevant colorectal lesions (≥6 mm polyps or masses) in a well-defined cohort of first-degree relatives of patients with colorectal cancer (CRC), using colonoscopy and histologic review as the standard of reference.

MATERIALS AND METHODS

Institutional review board approval was obtained, and all subjects provided written informed consent. Consecutive patients admitted with CRC (index cases) were prospectively evaluated, and those who agreed to contact their first-degree relatives who were at least 40 years old were included. Available first-degree relatives were invited to undergo noncathartic CT colonography (200 mL of diatrizoate meglumine and diatrizoate sodium). Colonoscopy was performed the following day, and findings from CT colonography were disclosed for each segment. Sensitivity, specificity, and positive and negative predictive values of CT colonography were assessed for detecting subjects with any lesion at least 6 mm, any lesion at least 10 mm, and advanced neoplasia at least 6 mm. Colonoscopy with segmental unblinding and histologic diagnosis were used as the standard of reference. Matching between findings from CT colonography and colonoscopy was allowed when lesions were located in the same or adjacent colon segments and when the size difference was 50% or less.

RESULTS

Three hundred four first-degree relatives (median age, 47 years; age range, 40-79 years; 46.7% women) identified from 221 index cases were included. Overall, CT colonography helped identify 17 of 22 subjects with polyps measuring at least 6 mm (sensitivity, 0.77; 95% confidence interval [CI]: 0.59, 0.95) and helped correctly classify as negative 278 of 282 subjects without lesions measuring at least 6 mm (specificity, 0.99; 95% CI: 0.97, 1.00). CT colonography helped detect eight of nine subjects with polyps measuring at least 10 mm as well as eight of nine subjects with advanced neoplasia measuring at least 6 mm (sensitivity, 0.89 for both). Per-subject positive and negative predictive values for lesions measuring at least 6 mm were 0.81 (17 of 21 subjects; 95% CI: 0.65, 0.97) and 0.98 (282 of 287 subjects; 95% CI: 0.96, 0.99), respectively.

CONCLUSION

Noncathartic CT colonography is an effective screening method in first-degree relatives of patients with CRC.

FIT testing: an overview

Colorectal cancer (CRC) is a common, but preventable, disease and is the second most common cause of cancer-related deaths in the U.S. CRC screening has proven effective at reducing both the incidence and mortality of this disease, using any of a number of screening tests available. The test options range from the least invasive and least expensive to more invasive and costly options. Fecal occult blood testing is the oldest, least expensive, and least invasive of these options and has evolved from the poorly sensitive standard guaiac test to the newer and diagnostically superior fecal immunochemical test (FIT) for hemoglobin. This article explores the evolutionary history of fecal occult blood testing, examines test performance characteristics among different FOBTs, and evaluates the role of the FIT in programmatic CRC screening.

Differences in detection rates of adenomas and serrated polyps in screening versus surveillance colonoscopies, based on the new hampshire colonoscopy registry

BACKGROUND & AIMS

The adenoma detection rate (ADR) is an important quality indicator originally developed for screening colonoscopies. However, it is unclear whether the ADR should be calculated using data from screening and surveillance examinations. The recommended benchmark ADR for screening examinations is 20% (15% for women and 25% for men ≥50 y). There are few data available to compare ADRs from surveillance vs screening colonoscopies. We used a population-based registry to compare ADRs from screening vs surveillance colonoscopies. The serrated polyp detection rate (SDR), a potential new quality indicator, also was examined.

METHODS

By using data from the statewide New Hampshire Colonoscopy Registry, we excluded incomplete and diagnostic colonoscopies, and those performed in patients with inflammatory bowel disease, familial syndromes, or poor bowel preparation. We calculated the ADR and SDR (number of colonoscopies with at least 1 adenoma or serrated polyp detected, respectively, divided by the number of colonoscopies) from 9100 colonoscopies. The ADR and SDR were compared by colonoscopy indication (screening, surveillance), age at colonoscopy (50-64 y, ≥65 y), and sex.

RESULTS

The ADR was significantly higher in surveillance colonoscopies (37%) than screening colonoscopies (25%; P < .001). This difference was observed for both sexes and age groups. There was a smaller difference in the SDR of screening (8%) vs surveillance colonoscopies (10%; P < .001).

CONCLUSIONS

In a population-based study, we found that addition of data from surveillance colonoscopies increased the ADR but had a smaller effect on the SDR. These findings indicate that when calculating ADR as a quality measure, endoscopists should use screening, rather than surveillance colonoscopy, data.

Association between Obesity, Serum Lipids, and Colorectal Polyps in Old Chinese People

Background. Colorectal cancer mostly arises from the polyps of colon. The aim of our study was to examine the association of body mass index (BMI) and serum lipids with the colorectal polyps in old Chinese people. Methods. The risk of developing colorectal polyps was studied in 244 subjects (212 men and 32 women, 74.63 ± 11.63 years old) who underwent colonoscopy for the first time from January 2008 to July 2012 at the Navy General Hospital, Beijing, China. According to the results of colonoscopy, all the subjects were divided into 112 normal control, 38 right colorectal polyps, 53 left colorectal polyps, and 41 both right and left colorectal polyps groups. The total plasma cholesterol, plasma triglyceride, plasma creatinine concentration, blood urinary nitrogen, and fasting glucose were determined using a multichannel analyzer. Results. There were significant differences among normal control, right colorectal polyps, left colorectal polyps, and both right and left polyps groups, which were the BMI, total cholesterol, triglycerides, creatinine, and urinary nitrogen. In binary logistic regression analysis, there were two risk factors associated with the occurrence of colorectal polyps, which included BMI and systolic blood pressure. Conclusions. Colorectal polyps were significantly associated with increased BMI, total cholesterol, and triglycerides levels.

Colonoscopy and colorectal cancer incidence and mortality

There is substantial indirect evidence for the effectiveness of colonoscopy in reducing colorectal cancer incidence and mortality. However, several recent studies have raised questions on the magnitude of effect for right-sided colorectal cancers. Well-documented variation in outcomes when colonoscopy is performed by different groups of endoscopists suggests that the recent emphasis on the quality of the procedures should lead to improved outcomes after colonoscopy including reduction in incidence and mortality due to right-sided colorectal cancers.

Interval cancers: learning from the past as we build for the future

While colonoscopy is the gold standard for the evaluation of the colon, research on post-colonoscopy colorectal cancers has increased our awareness of its limitations. In this issue of the Journal, Erichsen et al. provide evidence to suggest that post-colonoscopy colorectal cancers are most likely due to missed cancers at the time of the index colonoscopy, rather than due to aggressive tumor biology. Ultimately, studies demonstrating the shortcomings of colonoscopy are a call to action for the gastroenterology community to develop strategies and new technologies to improve the effectiveness of colonoscopy.

Advanced colorectal neoplasia risk stratification by penalized logistic regression

Colorectal cancer is the second leading cause of death from cancer in the United States. To facilitate the efficiency of colorectal cancer screening, there is a need to stratify risk for colorectal cancer among the 90% of US residents who are considered "average risk." In this article, we investigate such risk stratification rules for advanced colorectal neoplasia (colorectal cancer and advanced, precancerous polyps). We use a recently completed large cohort study of subjects who underwent a first screening colonoscopy. Logistic regression models have been used in the literature to estimate the risk of advanced colorectal neoplasia based on quantifiable risk factors. However, logistic regression may be prone to overfitting and instability in variable selection. Since most of the risk factors in our study have several categories, it was tempting to collapse these categories into fewer risk groups. We propose a penalized logistic regression method that automatically and simultaneously selects variables, groups categories, and estimates their coefficients by penalizing the [Formula: see text]-norm of both the coefficients and their differences. Hence, it encourages sparsity in the categories, i.e. grouping of the categories, and sparsity in the variables, i.e. variable selection. We apply the penalized logistic regression method to our data. The important variables are selected, with close categories simultaneously grouped, by penalized regression models with and without the interactions terms. The models are validated with 10-fold cross-validation. The receiver operating characteristic curves of the penalized regression models dominate the receiver operating characteristic curve of naive logistic regressions, indicating a superior discriminative performance.

Endoscopy and polyps-diagnostic and therapeutic advances in management

Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options.

Accuracy of narrow-band imaging in predicting colonoscopy surveillance intervals and histology of distal diminutive polyps: results from a multicenter, prospective trial

BACKGROUND

In vivo prediction of colorectal polyp histology by narrow-band imaging (NBI) could potentially avoid post-polypectomy histologic examination or resection of diminutive lesions, thereby reducing costs and risk.

OBJECTIVE

To assess whether NBI is able to predict colonoscopy surveillance intervals and histology of distal diminutive polyps according to American Society for Gastrointestinal Endoscopy (ASGE) criteria.

DESIGN

Prospective, multicenter study.

SETTING

Five endoscopic centers.

PATIENTS

Consecutive patients undergoing colonoscopy in 5 centers were included.

INTERVENTION

Participating endoscopists were required to pass a before-study qualifying examination. Histology of polyps that were <10 mm was predicted at NBI and assigned a designation of high or low confidence.

MAIN OUTCOME MEASUREMENTS

Accuracy of high-confidence NBI prediction for polyps ≤5 mm in predicting surveillance intervals and negative predictive value (NPV) for adenomatous histology in the rectosigmoid colon were compared with the ASGE thresholds (90% agreement, 90% NPV).

RESULTS

A total of 278 patients (mean age, 63 years; 58% male) were enrolled. At colonoscopy, 574 (97.3%) polyps <10 mm (429 ≤5 mm, 60% adenomatous) were retrieved for histologic analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of high confidence-NBI predictions for adenomatous histology in lesions ≤5 mm were 90%, 88%, 89%, 89%, and 89%, respectively. High-confidence characterization of polyps ≤5 mm predicted the correct surveillance interval in 92% to 99% of cases, according to the American and European guidelines. NPV of high-confidence NBI for adenomatous histology for the rectosigmoid colon lesions ≤5 mm was 92%.

LIMITATIONS

Only experienced endoscopists were included.

CONCLUSION

High-confidence prediction of histology for polyps ≤5 mm appears to be sufficiently accurate to avoid post-polypectomy histologic examination of the resected lesions as well as to allow rectosigmoid hyperplastic polyps to be left in place without resection. (

CLINICAL TRIAL REGISTRATION NUMBER

NCT01675752.).

Prevalence of colorectal cancer and its precursor lesions in symptomatic and asymptomatic patients undergoing total colonoscopy: results of a large prospective, multicenter, controlled endoscopy study

BACKGROUND

Colorectal cancer (CRC) is the second most common cancer in Germany. Screening colonoscopies have been offered in Germany since 2002. However, validation of screening programs for CRC relies on estimates up to date.

OBJECTIVE

The aim of this study was to analyze the influence of the risk factor tumor-suspicious symptoms on the prevalence of CRC and its precursor lesions in patients at least 55 years of age undergoing colonoscopy in comparison with an age-matched and sex-matched control population undergoing screening colonoscopy.

DESIGN

Multicenter, prospective, controlled colonoscopy study.

SETTING

Integrated care program of 49 gastroenterological practices in collaboration with a health insurance company and the screening colonoscopy program in Hesse, Germany.

PATIENTS

In total, 1075 symptomatic and 5375 asymptomatic participants were matched for age and sex (1 : 5) from 1 October 2008 to 30 September 2010.

MAIN OUTCOME MEASUREMENTS

Detection of CRC and its precursor lesions.

RESULTS

Overall, the prevalence of CRC was significantly equivalent in both the symptomatic (n=13/1075, 1.21%) and the control group [n=55/5375, 1.02%, 95% confidence interval (CI) for the difference: [-0.46%, 0.83%], P=0.0002, equivalence test with δ=1.5%], respectively. Advanced adenomas were observed in significantly fewer symptomatic patients (61/1075, 5.67%) compared with 432/5375 matched asymptomatic screening participants (8.03%, 95% CI for the difference: [-3.98%, -0.74%], P=0.0094, difference test). Finally, polyps were found significantly less often in symptomatic patients (n=269/1075, 25.0%) than in matched screening participants (n=1807/5375, 33.6%, 95% CI for the difference: [-11.53%, -5.66%], P<0.0001, difference test).

CONCLUSION

The results underline the importance of screening the symptom-free population at least 55 years of age to prevent CRC.

Current status of screening for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality. A well-defined precursor lesion (adenoma) and a long preclinical course make CRC a candidate for screening. This paper reviews the current evidence for the most important tests that are widely used or under development for population-based screening.

MATERIAL AND METHODS

In this narrative review, we scrutinized all papers we have been aware of, and carried out searches in PubMed and Cochrane library for relevant literature.

RESULTS

Two screening methods have been shown to reduce CRC mortality in randomised trials: repetitive faecal occult blood testing (FOBT) reduces CRC mortality by 16%; once-only flexible sigmoidoscopy (FS) by 28%. FS screening also reduces CRC incidence (by 18%), FOBT does not. Colonoscopy screening has a potentially larger effect on CRC incidence and mortality, but randomised trials are lacking. New screening methods are on the horizon but need to be tested in large clinical trials before implementation in population screening.

CONCLUSIONS

FS screening reduces CRC incidence and CRC mortality by removal of adenomas; FOBT reduces CRC mortality by early detection of cancer. Several other tests are available, but none has been evaluated in randomised trials. Screening strategies differ considerably across countries.

Quality indicators for colorectal cancer screening for colonoscopy

The growing importance of colonoscopy in the prevention of colorectal cancer has stimulated an effort to identify and track quality indicators for this procedure. Several factors have been identified so far which are readily measurable and in many cases have been associated with improved patient outcomes. There is also ample evidence of variations in performance of this procedure. As a result, gathering data about quality indicators may play a vital role in the process of continuous quality improvement. Quality indicators for colonoscopy in colorectal cancer prevention are described along with the evidence that supports their use in benchmarking, quality reporting, and continuous quality improvement.

Impact of asian ethnicity on colorectal cancer screening: a population-based analysis

OBJECTIVES

Although research shows that African Americans and Hispanics frequently receive less colorectal cancer screening (CRCS) than whites, few studies have focused on CRCS among Asians. The aims of this study were to compare CRCS between Asians and whites and to evaluate for clinical predictors of CRCS.

METHODS

From the 2007 California Health Interview Survey, we identified all Asian and white respondents who were eligible for CRCS. Logistic regression was performed to evaluate for differences in CRCS. We used stratified and interaction analyses to examine whether associations between race and CRCS were modified by insurance status, birthplace, or language skills, while controlling for other confounders.

RESULTS

Baseline characteristics were similar between Asians and whites. Only 58% of Asians and 66% of whites reported undergoing up-to-date CRCS (P < 0.01). In multivariate analyses, visiting a physician more than 5 times produced the highest odds of being up-to-date with screening. When compared with whites, Asians had decreased odds of being up-to-date with screening. Stratified analyses showed that this disparity existed mainly in the insured, but not in the uninsured, and it was not modified by place of birth or English language proficiency.

CONCLUSIONS

Despite its ability to reduce mortality, CRCS is suboptimal in our US population-based cohort of Asians when compared with whites. A contributing factor to this problem for the Chinese and Koreans may be a lack of awareness regarding CRCS, whereas the source of the problem in the Vietnamese seems to be related to healthcare access.

Colorectal cancer screening in an equal access healthcare system

INTRODUCTION

The military health system (MHS) a unique setting to analyze implementation programs as well as outcomes for colorectal cancer (CRC). Here we look at the efficacy of different CRC screening methods, attributes and results within the MHS, and current barriers to increase compliance.

MATERIALS AND METHODS

A literature search was conducted utilizing PubMed and the Cochrane library. Key-word combinations included colorectal cancer screening, racial disparity, risk factors, colorectal cancer, screening modalities, and randomized control trials. Directed searches were also performed of embedded references.

RESULTS

Despite screening guidelines from several national organizations, extensive barriers to widespread screening remain, especially for minority populations. These barriers are diverse, ranging from education and access problems to personal beliefs. Screening rates in MHS have been reported to be generally higher at 71% compared to national averages of 50-65%.

CONCLUSION

CRC screening can be highly effective at improving detection of both pre-malignant and early cancers. Improved patient education and directed efforts are needed to improve CRC screening both nationally and within the MHS.

The Diagnostic and Prognostic Role of microRNA in Colorectal Cancer - a Comprehensive review

The discovery of microRNA, a group of regulatory short RNA fragments, has added a new dimension to the diagnosis and management of neoplastic diseases. Differential expression of microRNA in a unique pattern in a wide range of tumor types enables researches to develop a microRNA-based assay for source identification of metastatic disease of unknown origin. This is just one example of many microRNA-based cancer diagnostic and prognostic assays in various phases of clinical research.

Since colorectal cancer (CRC) is a phenotypic expression of multiple molecular pathways including chromosomal instability (CIN), micro-satellite instability (MIS) and CpG islands promoter hypermethylation (CIMP), there is no one-unique pattern of microRNA expression expected in this disease and indeed, there are multiple reports published, describing different patterns of microRNA expression in CRC.

The scope of this manuscript is to provide a comprehensive review of the scientific literature describing the dysregulation of and the potential role for microRNA in the management of CRC. A Pubmed search was conducted using the following MeSH terms, "microRNA" and "colorectal cancer". Of the 493 publications screened, there were 57 papers describing dysregulation of microRNA in CRC.

Colonoscopy for colorectal cancer screening

Colorectal cancer (CRC) is the second leading cause of cancer death in the United States. Many, if not most, cases arise from premalignant lesions (adenomas) which may be identified and removed prior to becoming frankly malignant. For over a decade, colonoscopy has been the preferred modality for both CRC screening and prevention in the US. Early reports suggested that colonoscopic screening imparted a 90% risk reduction for colorectal cancer. Subsequent studies showed that estimate to be overly optimistic. While still an outstanding CRC screening and detection tool, colonoscopy has several important limitations. Some of these limitations relate to the mechanics of the procedure such as the risk of colonic perforation, bleeding, adverse consequences of sedation, and the inability to detect all colonic polyps. Other limitations reflect issues with patient perception regarding colonoscopy which, at least in part, drive patient non-adherence to recommended testing. This review examines the literature to address several important issues. First, we analyze the effect of colonoscopy on CRC incidence and mortality. Second, we consider the patient-based, periprocedural, and intraprocedural factors which may limit colonoscopy as a screening modality. Third, we explore new techniques and technologies which may enhance the efficacy of colonoscopy for adenoma detection. Finally, we discuss the short and long-term future of colonoscopy for CRC screening and the factors which may affect this future.

Risk factors associated with colorectal flat adenoma detection

OBJECTIVES

Colorectal flat adenomas have been associated with a higher risk of colorectal malignancy. We describe demographic characteristics and endoscopic findings in patients with colorectal flat adenomas.

METHODS

In total, 1934 consecutive patients undergoing colonoscopy were prospectively included. Polyp shape was classified according to the Japanese classification. Chromoendoscopy was applied whenever a flat lesion was suspected. Indications for colonoscopy, demographic data, and characteristics of neoplastic lesions were recorded. Patients were classified as follows: group 1, no adenomas (n=1250); group 2, only protruding adenomas (n=427); group 3, protruding and flat adenomas (n=118); and group 4, only flat adenomas (n=139).

RESULTS

Approximately one in every 10 patients (13.2%) had flat adenomas. Among them, concomitant protruding adenomas were identified in approximately half of the cases. In multivariate analysis, age older than 50 years [odds ratio (OR)=1.62; 95% confidence interval (CI)=1.08-2.43, P=0.02], protruding adenomas (OR=2.17; 95% CI=1.65-2.87, P<0.001), follow-up colonoscopy for polyps or cancer (OR=2.22; 95% CI=1.59-3.10, P<0.001), screening colonoscopy (OR=1.60, 95% CI=1.15-2.22, P=0.005), and specifically trained endoscopist (OR=2.02, 95% CI=1.53-2.68, P<0.001) were associated independently with flat adenoma detection.

CONCLUSION

Flat adenomas have specific demographic factors that might help to improve detection. Particularly, age older than 50 years, colorectal neoplasia surveillance, and the presence of protruding adenomas should alert endoscopists to the possible presence of these lesions. Trained endoscopists may offer a greater chance of detecting these lesions.

Increased risk of advanced neoplasms among asymptomatic siblings of patients with colorectal cancer

BACKGROUND & AIMS

Colorectal cancer (CRC) is the second-most common cancer in Hong Kong. Relatives of patients with CRC have an increased risk of colorectal neoplasm. We assessed the prevalence of advanced neoplasms among asymptomatic siblings of patients with CRC.

METHODS

Patients with CRC were identified from the Prince of Wales Hospital CRC Surgery Registry from 2001 to 2011. Colonoscopies were performed for 374 siblings of patients (age, 52.6 ± 7.4 y) and 374 age- and sex-matched siblings of healthy subjects who had normal colonoscopies and did not have a family history of CRC (controls, 52.7 ± 7.4 y). We identified individuals with advanced neoplasms (defined as cancers or adenomas of at least 10 mm in diameter, high-grade dysplasia, with villous or tubulovillous characteristics).

RESULTS

The prevalence of advanced neoplasms was 7.5% among siblings of patients and 2.9% among controls (matched odds ratio [mOR], 3.07; 95% confidence interval [CI], 1.5-6.3; P = .002). The prevalence of adenomas larger than 10 mm was higher among siblings of patients than in controls (5.9% vs 2.1%; mOR, 3.34; 95% CI, 1.45-7.66; P = .004), as was the presence of colorectal adenomas (31.0% vs 18.2%; mOR, 2.19; 95% CI, 1.52-3.17; P < .001). Six cancers were detected among siblings of patients; no cancers were detected in controls. The prevalence of advanced neoplasms among siblings of patients was higher when their index case was female (mOR, 4.95; 95% CI, 1.81-13.55) and had distally located CRC (mOR, 3.10; 95% CI, 1.34-7.14).

CONCLUSIONS

In Hong Kong, siblings of patients with CRC have a higher prevalence of advanced neoplasms, including CRC, than siblings of healthy individuals. Screening is indicated in this high-risk population. ClinicalTrials.gov number: NCT00164944.