Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup

The Risk of Metachronous Advanced Colorectal Neoplasia Rises in Parallel with an Increasing Number of High-Risk Findings at Baseline

BACKGROUND/AIMS

Colorectal adenomas that are ≥10 mm have villous histology or high-grade dysplasia, or that are associated with ≥3 adenomas are considered high-risk for metachronous advanced neoplasia. We evaluated the cumulative incidence of metachronous advanced neoplasia according to the total number of high-risk findings detected on baseline colonoscopy.

METHODS

This was a retrospective cohort study performed in 862 patients who underwent removal of colorectal adenomas between 2005 and 2009. At least one surveillance colonoscopy had been conducted at Konkuk University Medical Center, Seoul, Korea.

RESULTS

The cumulative incidence of metachronous advanced neoplasia in patients with 0, 1, 2, and 3-4 high-risk findings at 1 year were 0.7%, 1.3%, 2.8%, and 8.0%; at 3 years, those were 5.9%, 11.9%, 15.5%, and 24.7%; and at 5 years, those were 8.5%, 18.7%, 26.3%, and 37.2%, respectively. In a multivariate model, the risk of metachronous advanced neoplasia was significantly higher for the multiple high-risk findings group when compared with the 0 high-risk findings group (1 high-risk (+) hazard ratio, 1.86 [95% confidence interval, 1.00-3.44]; 2 high-risk (+) 1.84 [0.88-3.84]; and 3-4 high-risk (+) 3.29 [1.54-7.01]; ptrend=0.020).

CONCLUSIONS

The presence of overlapping multiple high-risk findings was associated with an increased risk of advanced neoplasia during surveillance.

A comparison of endoscopy versus pathology sizing of colorectal adenomas and potential implications for surveillance colonoscopy

BACKGROUND AND AIMS

The aim of this study was to compare endoscopy and pathology sizing in a large population-based series of colorectal adenomas and to evaluate the implications for patient stratification into surveillance colonoscopy.

METHODS

Endoscopy and pathology sizes available from intact adenomas removed at colonoscopies performed as part of the Northern Ireland Bowel Cancer Screening Programme, from 2010 to 2015, were included in this study. Chi-squared tests were applied to compare size categories in relation to clinicopathologic parameters and colonoscopy surveillance strata according to current American Gastroenterology Association and British Society of Gastroenterology guidelines.

RESULTS

A total of 2521 adenomas from 1467 individuals were included. There was a trend toward larger endoscopy than pathology sizing in 4 of the 5 study centers, but overall sizing concordance was good. Significantly greater clustering with sizing to the nearest 5 mm was evident in endoscopy versus pathology sizing (30% vs 19%, P < .001), which may result in lower accuracy. Applying a 10-mm cut-off relevant to guidelines on risk stratification, 7.3% of all adenomas and 28.3% of those 8 to 12 mm in size had discordant endoscopy and pathology size categorization. Depending on which guidelines are applied, 4.8% to 9.1% of individuals had differing risk stratification for surveillance recommendations, with the use of pathology sizing resulting in marginally fewer recommended surveillance colonoscopies.

CONCLUSIONS

Choice of pathology or endoscopy approaches to determine adenoma size will potentially influence surveillance colonoscopy follow-up in 4.8% to 9.1% of individuals. Pathology sizing appears more accurate than endoscopy sizing, and preferential use of pathology size would result in a small, but clinically important, decreased burden on surveillance colonoscopy demand. Careful endoscopy sizing is required for adenomas removed piecemeal.

Factors Associated With Recurrence of Advanced Colorectal Adenoma After Endoscopic Resection

BACKGROUND & AIMS

Studies have identified risk factors for recurrence of advanced colorectal adenoma (ACA) after polypectomy, but the relative importance and interaction of these risk factors, and their potential impact on surveillance recommendations, are unclear. We aimed to develop a model to identify ACA features associated with risk of recurrence after polypectomy.

METHODS

In a retrospective study, we collected data from 3360 patients who underwent colonoscopy with polypectomy at University of Foggia from 2004 through 2008 and identified 746 patients with 1017 ACAs. We performed recursive partitioning analysis to identify factors associated with recurrence of ACA within 3 years after polypectomy.

RESULTS

Median ACA size was 16 mm (range, 8-34 mm) and median number was 1.5 (range, 1-2). Pedunculated, sessile, and nonpolypoid lesions accounted for 41.3%, 39.4%, and 19.3% of ACAs detected, respectively. Factors independently associated with local recurrence of ACA and metachronous distant polyps within 3 years after polypectomy included size and number of ACAs and grade of dysplasia. The recurrence rate was 4.2% in patients with a single ACA ≤15 mm without high-grade dysplasia (HGD), 21.3% in patients with HGD ≤15 mm, ACA without HGD >15 mm, or multiple ACAs without HGD ≤15 mm, and 57.9% in patients with HGD >15 mm.

CONCLUSIONS

In this retrospective analysis of 746 patients with ACA who underwent polypectomy and surveillance colonoscopy within 3 years, the recurrence rate was highest in those with HGD ≥15 mm. These patients might benefit from more intensive surveillance, whereas patients with a single ACA without HGD ≤15 mm are at lower risk for and could be considered for longer follow-up intervals.

Optimal Colonoscopy Surveillance Interval after Polypectomy

The detection and removal of adenomatous polyps and postpolypectomy surveillance are considered important for the control of colorectal cancer (CRC). Surveillance using colonoscopy is an effective tool for preventing CRC after colorectal polypectomy, especially if compliance is good. In current practice, the intervals between colonoscopies after polypectomy are variable. Different recommendations for recognizing at risk groups and defining surveillance intervals after an initial finding of colorectal adenomas have been published. However, high-grade dysplasia and the number and size of adenomas are known major cancer predictors. Based on this, a subgroup of patients that may benefit from intensive surveillance colonoscopy can be identified.

Risk of Advanced Colorectal Neoplasia According to the Number of High-Risk Findings at Index Colonoscopy: A Korean Association for the Study of Intestinal Disease (KASID) Study

BACKGROUND

Data regarding outcomes for patients with multiple findings for high-risk adenomas are scarce.

AIM

To compare the risk for colorectal neoplasm (CRN) recurrence according to the number of high-risk findings.

METHODS

This was a retrospective and multicenter study. Patients who had one or more high-risk adenomas at the index colonoscopy and underwent follow-up colonoscopy 2.5 or more years after the index colonoscopy were included. The number of high-risk findings was defined as follows: number of adenomas larger than 1 cm + number of adenomas with HGD + number of adenomas with a villous component + existence (counted as 1) or nonexistence (counted as 0) of three or more adenomas.

RESULTS

A total of 1646 patients were included, and the mean duration between index and follow-up colonoscopy was approximately 4 years. The cumulative incidence rate of recurrent advanced CRN in patients with three or more high-risk findings was higher than that in patients with one or two high-risk findings (p < 0.001). However, the difference in 3-year cumulative incidence rates of recurrent advanced CRN between the two groups was not great, although it was statistically significant (4.8 vs. 2.3 %, p = 0.039).

CONCLUSIONS

A 3-year surveillance interval for patients with multiple high-risk findings, regardless of the number of high-risk findings, appears reasonable.

Different risk factors for advanced colorectal neoplasm in young adults

AIM: To compare the risk of developing advanced colorectal neoplasm (ACRN) according to age in Koreans.

METHODS: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios (OR) for ACRN between the young-adults (YA < 50 years) and in the older-adults (OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer.

RESULTS: In the YA group, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 1.26, 95%CI: 1.02-1.55), current smoking (OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer (OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors (OR = 1.27, 95%CI: 1.06-1.54), obesity (OR = 1.23, 95%CI: 1.03-1.47), CEA (OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol (OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 2.12, 95%CI: 1.68-2.68), current smoking (OR = 1.38, 95%CI: 1.12-1.71), obesity (OR = 1.34, 95%CI: 1.09-1.65) and CEA (OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group.

CONCLUSION: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.

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

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

Surveillance colonoscopy after endoscopic treatment for colorectal neoplasia: From the standpoint of the Asia-Pacific region

Colonoscopy is considered the gold standard to detect and remove colorectal neoplasia. The efficacy of colonoscopy with polypectomy to reduce colorectal cancer incidence and mortality has been demonstrated. Recently, post-polypectomy surveillance colonoscopy has become a necessary intervention in daily practice not only in Western countries but also in the Asia-Pacific region. Therefore, it is crucial to establish new clinical practice guidelines to reduce the number of unnecessary surveillance colonoscopies in order to create space for screening colonoscopy. The Asia-Pacific Consensus group recommended that surveillance colonoscopy interval should be tailored according to risk level of index colonoscopy. However, precise guidelines on interval of surveillance cannot be given because of a lack of prospective data. According to Korean and Australian guidelines, surveillance intervals after index colonoscopy of 5 years for low-risk subjects and 3 years for high-risk subjects are recommended in Asia-Pacific regions at present. Prospective data including long-term outcomes from the Japan Polyp Study, which is a multicenter randomized control trial, would be useful to establish the Asia-Pacific consensus in the near future.

Colorectal cancer screening of the general population in East Asia

In recent years, the incidence of colorectal cancer (CRC) has been increasing, and CRC has been becoming the major cause of cancer deaths in Asian countries. Therefore, an organized screening program to reduce CRC incidence and mortality is currently implemented in each country. In the present review, we summarize the current status and future perspectives of CRC screening of the general population in East Asian and South-East Asian countries. The fecal occult blood test is widely used for CRC screening in these countries, and its effectiveness in reducing CRC incidence and mortality has been demonstrated; however, the low participation rate in CRC screening programs is a problem to be solved in every country. Improvement in the public awareness of CRC and promotion of CRC screening by physicians will help to raise the participation rate and reduce the number of deaths caused by CRC. Regarding screening colonoscopy, several studies have recently demonstrated its effectiveness in reducing CRC incidence and mortality. However, at present, CRC screening colonoscopy is not adopted as a primary population-based screening tool because of staffing constraints in relation to large population sizes, increased medical costs, and potential adverse events (e.g., perforation and drug-induced anaphylaxis). Further study is required to consider colonoscopy as CRC screening that is established in Western countries.

High incidence of metachronous advanced adenoma and cancer after endoscopic resection of colon polyps ≥20 mm in size

BACKGROUND AND AIM

There are limited studies on incidence rates of metachronous neoplastic lesions after resecting large colorectal polyps. In the present study, we analyzed metachronous lesions after endoscopic resection of colorectal polyps ≥20 mm in size.

METHODS

We retrospectively analyzed consecutive patients who underwent endoscopic resection of polyps from 2006 to 2013 at two affiliated hospitals. All patients underwent at least two total colonoscopies before follow up to ensure minimal missed polyps. Only patients who had follow-up colonoscopy annually after resection were recruited. We separated patients according to size of polyp resected; there were 239 patients in the ≥20-mm group and 330 patients in the <20-mm group. Clinical characteristics and cumulative rates of metachronous advanced adenoma and cancer in both groups were analyzed. Advanced adenoma was defined as a neoplastic lesion ≥10 mm in size and adenoma with a villous component.

RESULTS

Cumulative rate of development of metachronous advanced adenoma and cancer in the ≥20-mm group was significantly higher than in the <20-mm group (22.9% vs. 9.5%, P < 0.001) at 36 months. There was also more development of small polyps 5-9 mm in the ≥20-mm group than in the <20-mm group (45.2% vs. 28.8%, P < 0.001). With respect to metachronous lesions, there were more right-sided colonic lesions in the ≥20-mm group than in the <20-mm group (78.8% vs. 50.0%, P = 0.015).

CONCLUSION

High incidence rates of development of metachronous neoplastic lesions were detected after resection of colorectal polyps ≥20 mm in size.

Low-residue versus clear liquid diet before colonoscopy: a meta-analysis of randomized, controlled trials

BACKGROUND AND AIMS

Colonoscopy is extremely important for the identification and removal of precancerous polyps. Bowel preparation before colonoscopy is essential for adequate visualization. Traditionally, patients have been instructed to consume only clear liquids the day before a colonoscopy. However, recent studies have suggested using a low-residue diet, with varying results. We evaluated the outcomes of patients undergoing colonoscopy who consumed a clear liquid diet (CLD) versus low-residue diet (LRD) on the day before colonoscopy by a meta-analysis.

METHODS

Scopus, PubMed/MEDLINE, Cochrane databases, and CINAHL were searched (February 2015). Studies involving adult patients undergoing colonoscopy examination and comparing LRD with CLD on the day before colonoscopy were included. The analysis was conducted by using the Mantel-Haenszel or DerSimonian and Laird models with the odds ratio (OR) to assess adequate bowel preparations, tolerability, willingness to repeat diet and preparation, and adverse effects.

RESULTS

Nine studies (1686 patients) were included. Patients consuming an LRD compared with a CLD demonstrated significantly higher odds of tolerability (OR 1.92; 95% CI, 1.36-2.70; P < .01) and willingness to repeat preparation (OR 1.86; 95% CI, 1.34-2.59; P < .01) with no differences in adequate bowel preparations (OR 1.21; 95% CI, 0.64-2.28; P = .58) or adverse effects (OR 0.88; 95% CI, 0.58-1.35; P = .57).

CONCLUSION

An LRD before colonoscopy resulted in improved tolerability by patients and willingness to repeat preparation with no differences in preparation quality and adverse effects.

Early detection of cancer: past, present, and future

Screening in both healthy and high-risk populations offers the opportunity to detect cancer early and with an increased opportunity for treatment and curative intent. Currently, a defined role for screening exists in some cancer types, but each screening test has limitations, and improved screening methods are urgently needed. Unfortunately, many cancers still lack effective screening recommendations, or in some cases, the benefits from screening are marginal when weighed against the potential for harm. Here we review the current status of cancer screening: we examine the role of traditional tumor biomarkers, describe recommended imaging for early tumor surveillance, and explore the potential of promising novel cancer markers such as circulating tumor cells (CTC) and circulating tumor DNA. Consistent challenges for all of these screening tests include limited sensitivity and specificity. The risk for overdiagnosis remains a particular concern in screening, whereby lesions of no clinical consequence may be detected and thus create difficult management decisions for the clinician and patient. If treatment is pursued following overdiagnosis, patients may be exposed to morbidity from a treatment that may not provide any true benefit. The cost-effectiveness of screening tests also needs to be an ongoing focus. The improvement of genomic and surveillance technologies, which leads to more precise imaging and the ability to characterize blood-based tumor markers of greater specificity, offers opportunities for major progress in cancer screening.

Surveillance of colonic polyps: Are we getting it right?

Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. The identification of colonic polyps can reduce CRC mortality through earlier diagnosis of cancers and the removal of polyps: the precursor lesion of CRC. Following the finding and removal of colonic polyps at an initial colonoscopy, some patients are at an increased risk of developing CRC in the future. This is the rationale for post-polypectomy surveillance colonoscopy. However, not all individuals found to have colonic adenomas have a risk of CRC higher than that of the general population. This review examines the literature on post-polypectomy surveillance including current international clinical guidelines. The potential benefits of surveillance procedures must be weighed against the burden of colonoscopy: resource use, the potential for patient discomfort, and the risk of complications. Therefore surveillance colonoscopy is best utilised in a selected group of individuals at a high risk of developing cancer. Further study is needed into the specific factors conferring higher risk as well as the efficacy of surveillance in mitigating this risk. Such evidence will better inform clinicians and patients of the relative benefits of colonoscopic surveillance for the individual. In addition, the decision to continue with surveillance must be informed by the changing profile of risks and benefits of further procedures with the patient’s advancing age.

Aspirin, Calcitriol, and Calcium Do Not Prevent Adenoma Recurrence in a Randomized Controlled Trial

BACKGROUND & AIMS

Chemopreventive strategies might be used to reduce the recurrence of colorectal adenomas and the incidence of colorectal cancer. We performed a randomized, double-blind, placebo-controlled trial to determine whether a combination of acetylsalicylic acid (aspirin), calcitriol, and calcium carbonate could prevent colorectal adenoma recurrence.

METHODS

We included 1107 patients with 1 or more sporadic adenoma(s) removed from the colon or rectum at centers in Europe, Russia, or the United States, from 2004 through 2010. Inclusion criteria were 1 adenoma greater than 1 cm in diameter, more than 1 adenoma of any size, or an adenoma of any size and first-degree relatives with colorectal cancer. Subjects were assigned randomly to groups given 0.5 μg calcitriol, 75 mg acetylsalicylic acid, and 1250 mg calcium carbonate (n = 209), or placebo (n = 218), each day for 3 years. The primary outcome was adenoma recurrence assessed by colonoscopy after 3 years. Secondary outcomes were the proportion of patients with advanced adenomas, the total number of colorectal adenomas, and adenoma size and features.

RESULTS

The trial was stopped in October 2010 because of futility. In this analysis, we found no differences between groups in the rate of recurrence (odds ratio [OR], 0.95; 95% confidence interval [CI], 0.61-1.48), adverse effects, or secondary outcomes. Subgroup analyses indicated that the treatment effects may be influenced by smoking status (nonsmokers OR, 0.65; 95% CI, 0.26-1.22 vs current smokers OR, 1.70; 95% CI, 0.70-4.09; P value interaction < .05). However, the overall interaction was not significant.

CONCLUSIONS

In a prospective study, the combination of calcitriol, aspirin, and calcium carbonate did not prevent recurrence of colorectal adenomas over a 3-year period. The negative results might be owing to the effects of smoking or low doses of the tested agents. Clinicaltrials.gov number: NCT00486512.

Risk stratification and detection of new colorectal neoplasms after colorectal cancer screening with faecal occult blood test: experiences from a Danish screening cohort

BACKGROUND

Limited data exist on adenoma surveillance as recommended in the European guidelines for quality assurance in colorectal cancer (CRC) screening and diagnosis after faecal occult blood test (FOBT) screening.

OBJECTIVE

To assess the European guidelines for adenoma surveillance after CRC screening with FOBT.

MATERIALS AND METHODS

This was a population-based cohort-study of 176 782 Danish individuals aged 50-74 years invited for CRC screening in 2005-2006. Adenoma patients were stratified into risk groups (low A, medium B, high C) in accordance with the European guidelines and followed up for recurrence of new neoplasms until the end of 2011. Risk ratios (RR) between the risk groups were calculated to assess differences in the recurrence rates of neoplasms.

RESULTS

Among 84 803 screening participants, 2059 had positive FOBT, of whom 1861 underwent colonoscopy, and 709 patients had screen-detected adenomas. During a median follow-up period of 72.7 months, detection of new advanced adenomas (B+C) was significantly higher in risk group C than group A (RR 2.25, 95% confidence interval: 1.13-4.48). Nine patients were diagnosed with CRC: one in risk group A, two in B and six in C. The detection rate of CRC was higher in risk group C than A (RR 5.20, 95% confidence interval: 0.63-42.58), but not statistically significant. In risk group C, half of new advanced adenomas were detected within the first year and four of nine CRC were detected within 3 years.

CONCLUSION

Risk stratification of adenoma patients, as recommended by the European guidelines, is appropriate for postpolypectomy surveillance after FOBT screening.

Metformin use and risk of colorectal adenoma after polypectomy in patients with type 2 diabetes mellitus

BACKGROUND

Existing literature suggests that metformin, the most commonly used biguanide, may lower colorectal cancer risk. Because most colorectal cancers originate in precancerous adenomas, we examined whether metformin use lowered colorectal adenoma risk after polypectomy in patients with type-2 diabetes.

METHODS

Retrospective cohort study of 40- to 89-year-old Kaiser Permanente Northern California patients who had type 2 diabetes, and ≥1 adenoma detected at baseline colonoscopy during 2000 to 2009 and a repeat colonoscopy 1 to 10 years from baseline adenoma diagnosis through 2012. Cox models evaluated the association between metformin use during follow-up and subsequent adenoma diagnoses, controlling for age, race/ethnicity, sex, body mass index, and repeat examination indication.

RESULTS

Study included 2,412 patients followed for a median of 4.5 years; cumulatively, 1,117 (46%) patients had ≥1 adenoma at repeat colonoscopy. Compared with patients not receiving diabetes medications (n = 1,578), metformin-only use (n = 457) was associated with lower adenoma recurrence risk [adjusted HR, 0.76; 95% confidence interval (CI), 0.65-0.89], and the association was stronger with increasing total metformin dose [quartile (Q) 1: HR, 0.90; 95% CI, 0.72-1.12; Q2: HR, 0.89; 95% CI, 0.70-1.12; Q3: HR, 0.80; 95% CI, 0.63-1.01; Q4: HR, 0.50; 95% CI, 0.42-0.60, Ptrend < 0.001]. Findings were unchanged in sensitivity analyses, including evaluating only outcomes during the 3- to 10-year period from baseline.

CONCLUSION

Our study suggests a potential benefit of metformin use in lowering the risk of subsequent adenomas after polypectomy in patients with type 2 diabetes.

IMPACT

Metformin may lower colorectal cancer risk by reducing the formation of precancerous lesions, reinforcing the potential additional benefits of its use.

Practice Guideline for the Surveillance of Patients After Curative Treatment of Colon and Rectal Cancer

Current evidence suggests improved rates of curative secondary treatment following identification of recurrence among patients who participate in a surveillance program after initial curative resection of colon or rectal cancer. The newer data show that surveillance CEA, chest and liver imaging,and colonoscopy can also improve survival through early diagnosis of recurrence; thus, these modalities are now included in the current guideline. Although the optimum strategy of surveillance for office visits, CEA, chest and liver imaging, and colonoscopy is not yet defined, routine surveillance does improve the detection of recurrence that can be resected with curative intent. Recommended surveillance schedules are shown in Table 4. However, the factors to be considered when recommending surveillance include underlying risk for recurrence, patient comorbidity, and the ability to tolerate major surgery to resect recurrent disease or palliative chemotherapy, performance status, physiologic age, preference, and compliance. The success of surveillance for early detection of curable recurrence will depend on patient and provider involvement to adhere to the surveillance schedule and avoid unnecessary examination. It should be noted that, after curative resection of colorectal cancer, patients are still at risk for other common malignancies(lung, breast, cervix, prostate) for which standard screening recommendations should be observed and measures to maintain general health (risk reduction for cardiovascular disease, eg, cessation of smoking, control of blood pressure and diabetes mellitus, balanced diet, regular exercise and sleep, and flu vaccines) should be recommended.

Two Chinese pedigrees for adenomatous polyposis coli: new mutations at codon 1309 and predisposition to phenotypic variations

Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease caused by a mutation in the adenomatous polyposis coli (APC) gene. Some studies have attempted to correlate mutations at codon 1309 with classic FAP (≥100 colorectal polyps). We report two Chinese FAP pedigrees with new frameshift mutations at codon 1309, in which affected individuals manifest phenotypic variations. Comprehensive physical examinations were performed for all living individuals and the medical data of deceased patients were collected. Screening of the APC and human mutY homolog (MUTYH) genes for germline mutations was conducted by direct polymerase chain reaction (PCR) sequencing. In two pedigrees, a heterozygous deletion in exon 16 of the APC gene was present in all FAP patients but absent in the unaffected individuals. There were no changes to the MUTYH gene. The first pedigree, with a new frameshift mutation at c.3926_3930 del AAAAG (p. Glu1309Aspfs X4), exhibited obvious differences in the polyp number such that the proband manifested only three colorectal polyps, whereas another patients showed the symptoms of classic FAP. The second pedigree, also traced a new mutation at c.3922_3925 del AAAG (p. Glu1309Argfs X11). Although all of the patients presented with classic polyposis, one of them exhibited a delayed onset of colorectal cancer in his 50s. Two novel mutations at codon 1309 in two Chinese families suffering from FAP could enrich the germline mutation spectrum of the APC gene. Families of individuals might manifest different phenotypes, even with an identical codon 1309 mutation, unlike in previous studies.

Effects of metabolic syndrome and findings from baseline colonoscopies on occurrence of colorectal neoplasms

BACKGROUND & AIMS

Metabolic syndrome is associated with increased risk of colorectal neoplasm, but little is known about its effects on the occurrence of neoplasm after colonoscopy. We investigated the effects of metabolic syndrome on the risk of advanced neoplasm after colonoscopy.

METHODS

We performed a prospective study of 4483 subjects age 50 years and older who underwent screening and surveillance colonoscopies as part of an annual health check-up at National Taiwan University Hospital. Baseline demographic data and colonoscopic findings were recorded. Subjects with either advanced adenoma or 3 or more adenomas detected at baseline were classified as high risk; those with fewer than 3 nonadvanced adenomas were classified as low risk; and those without any neoplastic lesions were classified as normal. The cumulative risk of detecting an advanced neoplasm during surveillance colonoscopies (3 and 5 years later) was correlated with risk group and metabolic syndrome. Hazard ratios (HRs) were calculated for occurrence of neoplasm according to baseline colonoscopic findings and clinical risk factors, including metabolic syndrome.

RESULTS

Advanced neoplasms were detected during the surveillance colonoscopies in 1.3% of subjects in the normal group and in 2.4% of those in the low-risk group at 5 years, and in 8.5% of subjects in the high-risk group at 3 years. Subjects with metabolic syndrome had a significantly higher risk for subsequent advanced neoplasms (P < .0001). After stratification based on findings from baseline colonoscopies, the risk for neoplasm was significant in the normal (P < .001) and low-risk groups (P = .04), but not in the high-risk group (P = .48). In Cox regression analysis, metabolic syndrome had significant effects on the risk for advanced neoplasms in the normal (HR, 2.07; 95% confidence interval, 1.13-3.81) and low-risk groups (HR, 2.34; 95% confidence interval, 1.01-5.41), but not in the high-risk group.

CONCLUSIONS

Metabolic syndrome is a significant risk factor for occurrence of an advanced adenoma after a negative or low-risk finding from a baseline colonoscopy. Metabolic syndrome should be considered in risk stratification for surveillance intervals.

Controversies in colorectal cancer screening

BACKGROUND

Colorectal cancer (CRC) is one of the most common cancers worldwide and a good candidate for screening programmes. However, there is controversy concerning which of the available screening tests should be used.

SUMMARY

There is general agreement that screening for CRC in the asymptomatic population should begin at the age of 50. Several different screening methods are available which can be separated into those that mainly detect cancers: faecal occult blood tests [guaiac (FOBT) and immunochemical (FIT)], genetic stool tests, blood tests and the M2-pyruvate kinase (M2-PK) test. Methods that detect cancers and polyps are colonoscopy, sigmoidoscopy, CT-colonography (CT-C) and colon capsule endoscopy. The only tests for which a reduction in CRC mortality compared to no screening have been proven in randomized trials are FOBT and sigmoidoscopy. Several trials suggest that FIT are superior to FOBT in terms of detection rates of cancers and advanced adenomas and possibly compliance. There is indirect evidence suggesting efficacy of colonoscopy as a screening test. The role of CT-C is controversial. There is data suggesting a good sensitivity for neoplasia >9 mm with a lower sensitivity for smaller neoplasia. However, radiation exposure is considered a major limitation in some countries. Unresolved questions include the lesion cut-off for referral to colonoscopy and work-up of extracolonic findings. For other methods, like genetic stool testing using newer markers, blood tests, capsule endoscopy and M2-PK, there is currently insufficient data on screening of the asymptomatic population. Key Messages: Colorectal screening is recommended and should be performed in the form of an organized programme. If detection of early-stage cancers is the aim of a screening programme, FIT seem to be superior to FOBT. If detection and removal of adenomas is the aim of a screening programme, endoscopic methods seem to be good alternatives. Sigmoidoscopy is easier to perform but will likely only have an effect on distal cancers. Colonoscopy is more invasive but enables inspection of the whole colon. The role of CT-C, capsule endoscopy, genetic stool tests, blood tests and M2-PK is currently unknown.

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

AIM

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

METHOD

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

RESULTS

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

CONCLUSIONS

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

Screening colonoscopy: what is the most reliable modality for the detection and characterization of colorectal lesions?

Colonoscopy is considered the best modality for the detection and treatment of colorectal polyps. However, some polyps still may not be detected. Although conventional white-light endoscopy is the gold standard for the detection of colorectal polyps, up to a fifth of lesions may be missed on screening colonoscopy, especially non-polypoid colorectal neoplasms. Recently, many studies have reported on various endoscopic modalities that improve the detection and characterization of colorectal lesions. Newly developed modalities might be helpful to recognize colorectal lesions; however, careful observation is required to identify flat/depressed lesions as well as hidden polyps during screening and surveillance colonoscopy.

Public health impact of achieving 80% colorectal cancer screening rates in the United States by 2018

BACKGROUND

The National Colorectal Cancer Roundtable, a national coalition of public, private, and voluntary organizations, has recently announced an initiative to increase colorectal cancer (CRC) screening rates in the United States to 80% by 2018. The authors evaluated the potential public health benefits of achieving this goal.

METHODS

The authors simulated the 1980 through 2030 United States population of individuals aged 50 to 100 years using microsimulation modeling. Test-specific historical screening rates were based on National Health Interview Survey data for 1987 through 2013. The effects of increasing screening rates from approximately 58% in 2013 to 80% in 2018 were compared to a scenario in which the screening rate remained approximately constant. The outcomes were cancer incidence and mortality rates and numbers of CRC cases and deaths during short-term follow-up (2013-2020) and extended follow-up (2013-2030).

RESULTS

Increasing CRC screening rates to 80% by 2018 would reduce CRC incidence rates by 17% and mortality rates by 19% during short-term follow-up and by 22% and 33%, respectively, during extended follow-up. These reductions would amount to a total of 277,000 averted new cancers and 203,000 averted CRC deaths from 2013 through 2030.

CONCLUSIONS

Achieving the goal of increasing the uptake of CRC screening in the United States to 80% by 2018 may have a considerable public health impact by averting approximately 280,000 new cancer cases and 200,000 cancer deaths within <20 years. Cancer 2015;121:2281–2285. © 2015 The Authors. Cancer published by Wiley Periodicals, Inc. on behalf of American Cancer Society. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

Recently in Japan, the morbidity of colorectal polyp has been increasing. As a result, a large number of cases of colorectal polyps that are diagnosed and treated using colonoscopy has now increased, and clinical guidelines are needed for endoscopic management and surveillance after treatment.

METHODS

Three committees [the professional committee for making clinical questions (CQs) and statements by Japanese specialists, the expert panelist committee for rating statements by the modified Delphi method, and the evaluating committee by moderators] were organized. Ten specialists for colorectal polyp management extracted the specific clinical statements from articles published between 1983 and September 2011 obtained from PubMed and a secondary database, and developed the CQs and statements. Basically, statements were made according to the GRADE system. The expert panel individually rated the clinical statements using a modified Delphi approach, in which a clinical statement receiving a median score greater than seven on a nine-point scale from the panel was regarded as valid.

RESULTS

The professional committee created 91CQs and statements for the current concept and diagnosis/treatment of various colorectal polyps including epidemiology, screening, pathophysiology, definition and classification, diagnosis, treatment/management, practical treatment, complications and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumor/carcinoma).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical guidelines for management of colorectal polyps have been proposed for 2014.

Novel computer-aided diagnostic system for colorectal lesions by using endocytoscopy (with videos)

BACKGROUND

Endocytoscopy enables in vivo observation of nuclei at 450× magnification during GI endoscopy, thus allowing precise prediction of lesion pathology. However, because it requires training and experience, it may be beneficial only when performed by expert endoscopists.

OBJECTIVE

To develop and evaluate a novel computer-aided diagnosis system for endocytoscopic imaging (EC-CAD) of colorectal lesions.

DESIGN

Pilot study.

SETTING

University hospital.

PATIENTS

One hundred fifty-two patients with small colorectal polyps (≤10 mm) who had undergone endocytoscopy.

INTERVENTION

Test sets of white-light endoscopic images and endocytoscopic images from 176 small colorectal polyps (137 neoplastic and 39 non-neoplastic polyps) were assessed by EC-CAD, 2 expert endoscopists, and 2 trainee endoscopists.

MAIN OUTCOME MEASUREMENT

Sensitivity, specificity, and accuracy in predicting neoplastic change by EC-CAD comparing expert and trainee endoscopists.

RESULTS

EC-CAD had a sensitivity of 92.0% and an accuracy of 89.2%; these were comparable to those achieved by expert endoscopists (92.7% and 92.3%; P = .868 and .256, respectively) and significantly higher than those achieved by trainee endoscopists (81.8% and 80.4%; P < .001 and .002, respectively). EC-CAD achieved a specificity of 79.5%; this did not differ significantly from that achieved by the experts and trainees. EC-CAD also enabled instant diagnosis, taking only 0.3 seconds for each lesion with perfect reproducibility.

LIMITATIONS

No sample size calculation.

CONCLUSIONS

EC-CAD provides fully automated instant classification of colorectal polyps with excellent sensitivity, accuracy, and objectivity. Thus, it can be a powerful tool for facilitating decision making during routine colonoscopy.

The efficacy and safety of non-steroidal anti-inflammatory drugs in preventing the recurrence of colorectal adenoma: a meta-analysis and systematic review of randomized trials

AIM

We report a meta-analysis and systematic review of randomized trials assessing the impact of non-steroidal anti-inflammatory drugs (NSAIDs) in preventing recurrence of colorectal adenoma.

METHOD

PubMed/Medicine, EMBASE and the Cochrane Central Register of Controlled Trials databases were searched for relevant randomized double-blind placebo-controlled trials published before March 2014. Two authors independently assessed study quality and extracted data. stata software was used to investigate heterogeneity between studies, and analysis was performed using a fixed-effects model to calculate and merge data.

RESULTS

Nine studies, with 8521 subjects, were included. Results were categorized by the duration of follow-up. The relative risks of any recurrence of adenoma in patients receiving NSAIDs compared with the placebo group were 0.68 [95% confidence interval (CI) 0.63-0.73, P = 0.001] for patients with a 1-year follow-up, 0.75 (95% CI 0.68-0.83, P = 0.246) with 3 years and 1.43 (95% CI 1.14-1.79, P = 0.127) with follow-up of over 3 years. Using pooled risk ratios, NSAIDs were associated with a significant decrease in adenoma recurrence at 1 and 3 years, although this association was lost beyond 3 years of follow-up. For secondary prevention of advanced adenomas, the pooled risk ratios (compared with placebo) were 0.51 (95% CI 0.43-0.60, P = 0.026) after 1 year, 0.61 (95% CI 0.50-0.76, P = 0.887) at 3 years and 1.39 (95% CI 0.89-2.16, P = 0.829) after 3 years.

CONCLUSION

The meta-analysis indicated that oral NSAIDs may be effective in the early prevention of secondary occurrence of adenomas.

Novel risk stratification for recurrence after endoscopic resection of advanced colorectal adenoma

BACKGROUND

Advanced colorectal adenoma (ACA) refers to adenomas with the following predictive characteristics: ≥1 cm in diameter, and/or villous component, and/or high-grade dysplasia. ACA has high risk of transforming to colorectal cancer, and the recurrence rate is relatively high.

OBJECTIVE

To assess the outcomes of patients with ACA undergoing endoscopic resection and to identify risk factors for local recurrence and development of metachronous advanced neoplasm.

DESIGN

Retrospective cohort study.

SETTING

Tertiary care medical center.

PATIENTS

From 2005 to 2011, the records of 3625 patients who underwent colonoscopic polypectomy at Seoul National University Hospital were retrospectively reviewed. Patients with synchronous colorectal cancers, inflammatory bowel disease, previous colorectal resection, loss to follow-up, and incomplete resection were excluded.

INTERVENTION

Endoscopic resection for ACA.

MAIN OUTCOME MEASUREMENTS

Local recurrence and metachronous advanced neoplasm.

RESULTS

The study included 917 patients with 1206 ACAs. The median duration of follow-up was 28.5 months (interquartile range, 12.8-51.7). Independent risk factors for local recurrence included ACA with 2 or more predictive characteristics (adjusted hazard ratio [HR], 2.46; 95% confidence interval [CI], 1.11-5.48; P = .027) and piecemeal resection (adjusted HR, 6.96; 95% CI, 1.58-30.71; P = .010). Independent risk factors for metachronous advanced neoplasm were male gender (adjusted HR, 1.65; 95% CI, 1.02-2.65; P = .041), ≥3 adenomas (adjusted HR, 2.56; 95% CI, 1.72-3.82; P < .001), and ≥3 ACAs (adjusted HR, 1.44; 95% CI, 1.01-2.06; P = .045).

LIMITATIONS

Retrospective design.

CONCLUSION

ACAs with 2 or more predictive characteristics recurred locally at a higher rate than ACAs with 1 predictive characteristic. These results suggest that patients who are found to have ACAs with 2 or more predictive factors at index colonoscopy are at higher risk for local recurrence, and follow-up colonoscopy should be performed sooner.

The history of colorectal cancer screening: a personal perspective

The present explosive interest in screening for colorectal cancer (CRC), one of the most prevalent and preventable cancers, had its beginnings at a hospital in London and an Internist's office in Ohio. Demonstrated there were the concepts that CRC did not occur de-novo but arose from a premalignant polyp, that detection of the resultant cancer at an earlier stage was associated with better survival and that cancer could be detected at an early presymptomatic stage by screening. Many years later, the introduction of colonoscopy and colonoscopic polypectomy provided the opportunity for randomized trials to prove that these concepts were true. The sequence of rigorous science followed by guidelines consensus and then multilevel national efforts of screening implementation has resulted in a decline in the CRC incidence and mortality worldwide, most significantly in the USA. Campaigns have been initiated to maximize population screening and further investigate its optimal approach. Some historical details of this success story and many of the key participants are presented in this paper.

Colonoscopy: the current king of the hill in the USA

Colonoscopy is the dominant colorectal cancer screening strategy in the USA. There are no randomized controlled trials completed of screening colonoscopy, but multiple lines of evidence establish that colonoscopy reduces colorectal cancer incidence in both the proximal and distal colon. Colonoscopy is highly operator dependent, but systematic efforts to measure and improve quality are impacting performance. Colonoscopy holds a substantial advantage over other strategies for detection of serrated lesions, and a recent case-control study suggests that once-only colonoscopy or colonoscopy at 20-year intervals, by a high-level detector, could ensure lifetime protection from colorectal cancer for many patients.

Optimal timing for resuming antithrombotic agents and risk factors for delayed bleeding after endoscopic resection of colorectal tumors

Aim. To examine optimal timing for resuming antithrombotic agents and risk factors for delayed bleeding after endoscopic resection of colorectal tumors. Method. Of 1,970 polyps larger than 10 mm removed by polypectomy, endoscopic mucosal resection, or endoscopic submucosal dissection, delayed bleeding, which was designated as bleeding that occurred 6 or more hours after endoscopic treatment, occurred in 52 cases (2.6%); 156 nonbleeding cases matched for age and gender were controls in this single-institution retrospective case-control study. We investigated (1) patient-factors: resuming antithrombotic agents within 5 days following endoscopic resection, hypertension, and diabetes mellitus; and (2) tumor-factors: morphology, size, location, and resection technique by conditional logistic regression. Results. By multivariate analysis resumption of anticoagulants within 5 days was a significant risk factor for delayed bleeding (OR 10.2; 95% CI = 2.7-38.3; P = 0.0006). But resuming a thienopyridine within 5 days was not (OR 0.9; 95% CI = 0.1-2.6; P = 0.40). Other patient- and tumor-factors were not significant. Conclusion. Resuming anticoagulants within 5 days after endoscopic treatment was associated with delayed bleeding whereas resuming thienopyridines was not.

Colorectal cancer deaths attributable to nonuse of screening in the United States

PURPOSE

Screening is a major contributor to colorectal cancer (CRC) mortality reductions in the United States but is underused. We estimated the fraction of CRC deaths attributable to nonuse of screening to demonstrate the potential benefits from targeted interventions.

METHODS

The established microsimulation screening analysis colon model was used to estimate the population attributable fraction (PAF) in people aged ≥50 years. The model incorporates long-term patterns and effects of screening by age and type of screening test. PAF for 2010 was estimated using currently available data on screening uptake. PAF was also projected assuming constant future screening rates to incorporate lagged effects from past increases in screening uptake. We also computed PAF using Levin's formula to gauge how this simpler approach differs from the model-based approach.

RESULTS

There were an estimated 51,500 CRC deaths in 2010, about 63% (N ∼ 32,200) of which were attributable to nonscreening. The PAF decreases slightly to 58% in 2020. Levin's approach yielded a considerably more conservative PAF of 46% (N ∼ 23,600) for 2010.

CONCLUSIONS

Most of the current United States CRC deaths are attributable to nonscreening. This underscores the potential benefits of increasing screening uptake in the population. Traditional methods of estimating PAF underestimated screening effects compared with model-based approaches.

What level of bowel prep quality requires early repeat colonoscopy: systematic review and meta-analysis of the impact of preparation quality on adenoma detection rate

OBJECTIVES

Current guidelines recommend early repeat colonoscopy when bowel preparation quality is inadequate, defined as inability to detect polyps >5 mm, but no data link specific bowel preparation categories or scores to this definition. Nevertheless, most physicians use a shortened screening/surveillance interval in patients with intermediate-quality preparation. We determined whether different levels of bowel preparation quality are associated with differences in adenoma detection rates (ADRs: proportion of colonoscopies with ≥1 adenoma) to help guide decisions regarding early repeat colonoscopy-with primary focus on intermediate-quality preparation.

METHODS

MEDLINE and Embase were searched for studies with adenoma or polyp detection rate stratified by bowel preparation quality. Preparation quality definitions were standardized on the basis of Aronchick definitions (excellent/good/fair/poor/insufficient), and primary analyses of ADR trichotomized bowel preparation quality: high quality (excellent/good), intermediate quality (fair), and low quality (poor/insufficient). Dichotomized analyses of adequate (excellent/good/fair) vs. inadequate (poor/insufficient) were also performed.

RESULTS

Eleven studies met the inclusion criteria. The primary analysis, ADR with intermediate- vs. high-quality preparation, showed an odds ratio (OR) of 0.94 (0.80-1.10) and absolute risk difference of -1% (-3%, 2%). ADRs were significantly higher with both intermediate-quality and high-quality preparation vs. low-quality preparation: OR=1.39 (1.08-1.79) and 1.41 (1.21-1.64), with absolute risk increases of 5% for both. ADR and advanced ADR were significantly higher with adequate vs. inadequate preparation: OR=1.30 (1.19-1.42) and 1.30 (1.02-1.67). Studies did not report other relevant outcomes such as total adenomas per colonoscopy.

CONCLUSIONS

ADR is not significantly different with intermediate-quality vs. high-quality bowel preparation. Our results confirm the need for early repeat colonoscopy with low-quality bowel preparation, but suggest that patients with intermediate/fair preparation quality may be followed up at standard guideline-recommended surveillance intervals without significantly affecting quality as measured by ADR.

Minimal benefit of earlier-than-recommended repeat colonoscopy among US Medicare enrollees following a negative colonoscopy

BACKGROUND

A large proportion of US Medicare beneficiaries undergo earlier-than-recommended follow-up colonoscopies after negative screening colonoscopy. Such practice entails substantial cost and added risk.

AIMS

To compare the risk of colorectal cancer (CRC) associated with varying follow-up colonoscopy intervals following a negative colonoscopy, and to determine whether the potential benefit of a shorter colonoscopy follow-up interval would differ by gender.

METHODS

We conducted a weighted cohort study using the Surveillance, Epidemiology and End Results-Medicare linked database (1991-2006) among 932,370 Medicare enrollees who are representative of the entire US elderly population. We compared the cumulative incidence of CRC among patients who underwent follow-up colonoscopies at different intervals following a negative colonoscopy. The primary outcome was incident CRC.

RESULTS

The eligible study cohort (n = 480,864) included 106,924 patients who underwent ≥1 colonoscopy. Men were more likely to require polypectomy during their initial colonoscopy than women. Compared to the recommended 9-10 year follow-up colonoscopy interval, an interval of 5-6 years was associated with the largest CRC cumulative risk reduction [i.e. 0.17% (95% CI: 0.009-0.32%)]. The magnitude of risk reduction associated with shorter colonoscopy follow-up intervals was not significantly different between men and women.

CONCLUSIONS

Among elderly individuals who undergo a negative colonoscopy, the magnitude of reduction in the cumulative CRC risk afforded by earlier-than-recommended follow-up colonoscopy is quite small, and probably cannot justify the risk and cost of increased colonoscopy frequency. In addition, there are insufficient differences between men and women to warrant gender-specific recommendations.

Variation in polyp size estimation among endoscopists and impact on surveillance intervals

BACKGROUND

Accurate estimation of polyp size is important because it is used to determine the surveillance interval after polypectomy.

OBJECTIVE

To evaluate the variation and accuracy in polyp size estimation among endoscopists and the impact on surveillance intervals after polypectomy.

DESIGN

Web-based survey.

PARTICIPANTS

A total of 873 members of the American Society for Gastrointestinal Endoscopy.

INTERVENTIONS

Participants watched video recordings of 4 polypectomies and were asked to estimate the polyp sizes.

MAIN OUTCOME MEASUREMENTS

Proportion of participants with polyp size estimates within 20% of the correct measurement and the frequency of incorrect surveillance intervals based on inaccurate size estimates.

RESULTS

Polyp size estimates were within 20% of the correct value for 1362 (48%) of 2812 estimates (range 39%-59% for the 4 polyps). Polyp size was overestimated by >20% in 889 estimates (32%, range 15%-49%) and underestimated by >20% in 561 (20%, range 4%-46%) estimates. Incorrect surveillance intervals because of overestimation or underestimation occurred in 272 (10%) of the 2812 estimates (range 5%-14%). Participants in a private practice setting overestimated the size of 3 or of all 4 polyps by >20% more often than participants in an academic setting (difference = 7%; 95% confidence interval, 1%-11%).

LIMITATIONS

Survey design with the use of video clips.

CONCLUSION

Substantial overestimation and underestimation of polyp size occurs with visual estimation leading to incorrect surveillance intervals in 10% of cases. Our findings support routine use of measurement tools to improve polyp size estimates.

microRNA-221 and microRNA-18a identification in stool as potential biomarkers for the non-invasive diagnosis of colorectal carcinoma

BACKGROUND

The detection of microRNA (miRNA) dysregulation in stool is a novel approach for the diagnosis of colorectal carcinoma (CRC). The aim of this study is to investigate the use of miR-221 and miR-18a in stool samples as non-invasive biomarkers for CRC diagnosis.

METHODS

A miRNA expression array containing 667 miRNAs was performed to identify miRNA dysregulation in CRC tissues. We focused on miR-221 and miR-18a, two significantly upregulated miRNAs which were subsequently verified in 40 pairs of CRC tissues and 595 stool samples (198 CRCs, 199 polyps and 198 normal controls).

RESULTS

miR-221 and miR-18a were upregulated in the miRNA expression array. miR-221 and miR-18a levels were also significantly higher in 40 CRC tumours compared with their respective adjacent normal tissues. In stool samples, miR-221 and miR-18a showed a significant increasing trend from normal controls to late stages of CRC (P<0.0001). The levels of stool miR-221 and miR-18a were both significantly higher in subjects with stages I+II (miR-221: P<0.0001, miR-18a: P<0.0001) and stages III+IV of CRC (miR-221: P=0.0004, miR-18a: P<0.0001) compared with normal controls. The AUC of stool miR-221 and miR-18a were 0.73 and 0.67 for CRC patients as compared with normal controls, respectively. No significant differences in stool miR-221 and miR-18a levels were found between patients with proximal and distal CRCs. The use of antibiotics did not influence stool miRNA-221 and miRNA-18a levels.

CONCLUSIONS

Stool-based miR-221 can be used as a non-invasive biomarker for the detection of CRC.

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.

Risk of advanced lesions at first follow-up colonoscopy in high-risk groups as defined by the United Kingdom post-polypectomy surveillance guideline: data from a single U.S. center

BACKGROUND

The United Kingdom (U.K.) post-adenoma resection guidelines recommend earlier surveillance for patients with 5 or more adenomas or 3 to 4 adenomas of which one is 10 mm or larger compared with U.S. guidelines.

OBJECTIVE

To evaluate the effect of using the U.K. guideline on a U.S. cohort of adenoma patients.

DESIGN

Single-center, retrospective study.

SETTING

Indiana University Hospital and an associated ambulatory surgery center.

PATIENTS

A total of 1414 patients with baseline adenoma findings belonging to one of 5 risk categories and with a follow-up colonoscopy more than 200 days later.

INTERVENTION

Colonoscopy, polypectomy.

MAIN OUTCOME MEASUREMENTS

Incidence of advanced lesions at follow-up colonoscopy.

RESULTS

Advanced neoplasms at follow-up occurred in 16.3% of patients with 5 or more adenomas including 1 that was 10 mm or larger, 8.6% of patients with 3 or 4 adenomas including 1 that was 10 mm or larger, 5% of those with 5 or more adenomas all smaller than 10 mm, 1.8% of those with 3 or 4 adenomas all smaller than 10 mm, and 1.4% of those with 1 to 2 adenomas smaller than 10 mm. Logistic regression analyses showed that the rate of advanced lesions at first follow-up was increased in persons with 3 or more baseline adenomas and at least 1 that is 10 mm or larger compared with those with 1 to 4 small baseline adenomas.

LIMITATIONS

Single-center, retrospective study.

CONCLUSIONS

Our results indicate the U.K. guideline predicts higher risk groups for advanced neoplasia at first follow-up. Our study had inadequate power to show better prediction of incident cancer. Additional study of other databases is warranted.

Primary and secondary prevention of colorectal cancer

INTRODUCTION

Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. Colorectal cancer (CRC) is the third most frequent cancer in men, after lung and prostate cancer, and is the second most frequent cancer in women after breast cancer. It is also the third cause of death in men and women separately, and is the second most frequent cause of death by cancer if both genders are considered together. CRC represents approximately 10% of deaths by cancer. Modifiable risk factors of CRC include smoking, physical inactivity, being overweight and obesity, eating processed meat, and drinking alcohol excessively. CRC screening programs are possible only in economically developed countries. However, attention should be paid in the future to geographical areas with ageing populations and a western lifestyle.19,20 Sigmoidoscopy screening done with people aged 55–64 years has been demonstrated to reduce the incidence of CRC by 33% and mortality by CRC by 43%.

OBJECTIVE

To assess the effect on the incidence and mortality of CRC diet and lifestyle and to determine the effect of secondary prevention through early diagnosis of CRC.

METHODOLOGY: A comprehensive search of Medline and Pubmed articles related to primary and secondary prevention of CRC and subsequently, a meta-analysis of the same blocks are performed.

RESULTS

225 articles related to primary or secondary prevention of CRC were retrieved. Of these 145 were considered valid on meta-analysis: 12 on epidemiology, 56 on diet and lifestyle, and over 77 different screenings for early detection of CRC. Cancer is a worldwide problem as it will affect one in three men and one in four women during their lifetime. There is no doubt whatsoever which environmental factors, probably diet, may account for these cancer rates. Excessive alcohol consumption and cholesterol-rich diet are associated with a high risk of colon cancer. A diet poor in folic acid and vitamin B6 is also associated with a higher risk of developing colon cancer with an overexpression of p53. Eating pulses at least three times a week lowers the risk of developing colon cancer by 33%, after eating less meat, while eating brown rice at least once a week cuts the risk of CRC by 40%. These associations suggest a dose–response effect. Frequently eating cooked green vegetables, nuts, dried fruit, pulses, and brown rice has been associated with a lower risk of colorectal polyps. High calcium intake offers a protector effect against distal colon and rectal tumors as compared with the proximal colon. Higher intake of dairy products and calcium reduces the risk of colon cancer. Taking an aspirin (ASA) regularly after being diagnosed with colon cancer is associated with less risk of dying from this cancer, especially among people who have tumors with COX-2 overexpression.16 Nonetheless, these data do not contradict the data obtained on a possible genetic predisposition, even in sporadic or non-hereditary CRC. CRC is susceptible to screening because it is a serious health problem given its high incidence and its associated high morbidity/mortality.

CONCLUSIONS

(1) Cancer is a worldwide problem. (2) A modification of diet and lifestyle could reduce morbidity and mortality. (3) Early detection through screening improves prognosis and reduces mortality.

Incidence and risk factors of metachronous colorectal neoplasm after curative resection of colorectal cancer in Korean patients

OBJECTIVE

Early detection and endoscopic removal of metachronous neoplasms are important preventive strategies for patients with colorectal cancer (CRC) after curative tumor resection. We aimed to determine the incidence of and the risk factors for metachronous colorectal neoplasms after curative resection for CRC.

METHODS

We retrospectively reviewed clinical data of patients who underwent curative resection for CRC at the National Cancer Center, Korea, from July 2004 to July 2007 and were followed up for a mean duration of 40.7 months. The incidence of and the risk factors for developing metachronous neoplasms were analyzed.

RESULTS

A total of 1049 patients were included in this study. A follow-up colonoscopy showed that 454 (43.3%) patients developed metachronous neoplasms, including 46 (4.4%) with advanced adenoma or cancer. Univariate analyses revealed that age ≥ 60 years, male gender, diabetes mellitus, hypertension, synchronous adenoma, synchronous multiple adenoma and synchronous advanced adenoma were associated with the development of metachronous neoplasms. Baseline risk factors associated with metachronous advanced neoplasm were age ≥ 60 years, synchronous multiple adenoma and synchronous advanced adenoma. Multivariate analysis showed that age ≥ 60 years, synchronous adenoma and diabetes mellitus were risk factors for the development of metachronous neoplasms. The cumulative incidence of metachronous neoplasms was higher in patients with these risk factors than in those without.

CONCLUSIONS

Elder age, synchronous adenoma and diabetes mellitus are risk factors for developing metachronous neoplasia. Therefore, careful surveillance colonoscopy are necessary for these patients.

Endoscopic measurement of polyp size using a novel calibrated hood

Background. Although the size of colon polyps is an important risk factor for colorectal cancer, a standardized measurement technique has yet to be determined. In clinical practice, most endoscopists estimate polyp size by uncertain visual estimation; however, colonoscopic polypectomy is indicated for adenomatous polyps more than 5 mm in diameter. We have therefore developed a novel calibrated hood that enables accurate measurement of polyp size during colonoscopy. Method. We compared prepolypectomy estimates using the calibrated hood against measurements of preformalin-fixed samples immediately after polypectomy. Results. Sixty-five polyps removed from 44 patients were included in the present study. The mean size of polyps was significantly larger at prepolypectomy (6.06 ± 1.23 mm) than after polypectomy (5.48 ± 1.31 mm, P < 0.05). Conclusion. Accurately measuring the size of polyps during colonoscopy is important, since polyps are shrunk by polypectomy. Attaching the calibrated hood appears useful in the measurement of polyp size to determine indications for polypectomy in patients with colon polyps.

Addressing overdiagnosis and overtreatment in cancer: a prescription for change

A vast range of disorders--from indolent to fast-growing lesions--are labelled as cancer. Therefore, we believe that several changes should be made to the approach to cancer screening and care, such as use of new terminology for indolent and precancerous disorders. We propose the term indolent lesion of epithelial origin, or IDLE, for those lesions (currently labelled as cancers) and their precursors that are unlikely to cause harm if they are left untreated. Furthermore, precursors of cancer or high-risk disorders should not have the term cancer in them. The rationale for this change in approach is that indolent lesions with low malignant potential are common, and screening brings indolent lesions and their precursors to clinical attention, which leads to overdiagnosis and, if unrecognised, possible overtreatment. To minimise that potential, new strategies should be adopted to better define and manage IDLEs. Screening guidelines should be revised to lower the chance of detection of minimal-risk IDLEs and inconsequential cancers with the same energy traditionally used to increase the sensitivity of screening tests. Changing the terminology for some of the lesions currently referred to as cancer will allow physicians to shift medicolegal notions and perceived risk to reflect the evolving understanding of biology, be more judicious about when a biopsy should be done, and organise studies and registries that offer observation or less invasive approaches for indolent disease. Emphasis on avoidance of harm while assuring benefit will improve screening and treatment of patients and will be equally effective in the prevention of death from cancer.

Colorectal cancers soon after colonoscopy: a pooled multicohort analysis

OBJECTIVE

Some individuals are diagnosed with colorectal cancer (CRC) despite recent colonoscopy. We examined individuals under colonoscopic surveillance for colonic adenomas to assess possible reasons for diagnosing cancer after a recent colonoscopy with complete removal of any identified polyps.

DESIGN

Primary data were pooled from eight large (>800 patients) North American studies in which participants with adenoma(s) had a baseline colonoscopy (with intent to remove all visualised lesions) and were followed with subsequent colonoscopy. We used an algorithm based on the time from previous colonoscopy and the presence, size and histology of adenomas detected at prior exam to assign interval cancers as likely being new, missed, incompletely resected (while previously an adenoma) or due to failed biopsy detection.

RESULTS

9167 participants (mean age 62) were included in the analyses, with a median follow-up of 47.2 months. Invasive cancer was diagnosed in 58 patients (0.6%) during follow-up (1.71 per 1000 person-years follow-up). Most cancers (78%) were early stage (I or II); however, 9 (16%) resulted in death from CRC. We classified 30 cancers (52%) as probable missed lesions, 11 (19%) as possibly related to incomplete resection of an earlier, non-invasive lesion and 14 (24%) as probable new lesions. The cancer diagnosis may have been delayed in three cases (5%) because of failed biopsy detection.

CONCLUSIONS

Despite recent colonoscopy with intent to remove all neoplasia, CRC will occasionally be diagnosed. These cancers primarily seem to represent lesions that were missed or incompletely removed at the prior colonoscopy and might be avoided by increased emphasis on identifying and completely removing all neoplastic lesions at colonoscopy.

Screening strategies for colorectal cancer in asymptomatic adults

This article provides an update for the primary care community on the evidence and recommendations for colorectal cancer screening in the adult population without symptoms at average and increased risk, excluding patients with high-risk genetic syndromes. The current and possible new screening strategies are reviewed, along with clinical wisdom related to the implementation of each method.

Fasting serum insulin levels and insulin resistance are associated with colorectal adenoma in Koreans

AIMS/INTRODUCTION

Insulin has been associated with the risk of colorectal cancer (CRC). However, few studies have evaluated the association between insulin and colorectal adenoma. We investigated the relationship between fasting serum insulin levels or homeostasis model assessment of insulin resistance (HOMA-IR) and colorectal adenoma.

MATERIALS AND METHODS

We retrospectively enrolled 15,427 participants who underwent both fasting serum insulin measurement and colonoscopy for a routine health examination at Asan Medical Center from January 2007 to December 2008. Participants with a history of any cancer, previous colectomy or polypectomy, those taking antidiabetic medications, and inflammatory bowel disease, non-specific colitis, non-adenomatous polyps only or CRC on colonoscopic findings were excluded. Finally, 3,606 participants with histologically confirmed colorectal adenoma and 6,019 controls with no abnormal findings on colonoscopy were included. Participants were categorized into quartiles (Q) based on fasting serum insulin levels and HOMA-IR.

RESULTS

Fasting serum insulin and HOMA-IR were significantly higher in participants with colorectal adenomas compared with controls. Multivariate regression analysis adjusting for age, sex, smoking habits, drinking habits and family history of CRC showed that participants with higher quartiles of fasting serum insulin levels (odd ratio [OR] 1.17 for 2nd Q, 1.19 for 3rd Q, and 1.42 for 4th Q, P < 0.05) or HOMA-IR (OR 1.18 for 2nd Q and 1.45 for 4th Q, P < 0.05) showed significantly increased ORs of colorectal adenoma compared with the lowest quartiles.

CONCLUSIONS

These findings showed that increased serum insulin levels and insulin resistance were significantly associated with the presence of colorectal adenoma.