Panchromoendoscopy Increases Detection of Polyps in Patients With Serrated Polyposis Syndrome

BACKGROUND & AIMS

Serrated polyposis syndrome (SPS), characterized by multiple and/or large proximal serrated lesions, increases the risk of colorectal cancer. Serrated lesions often are missed during colonoscopy but panchromoendoscopy can increase their detection in an average-risk population. We performed a randomized controlled study to determine the efficacy of panchromoendoscopy in detection of polyps in patients with SPS.

METHODS

Patients with SPS (n = 86 patients) underwent tandem high-definition (HD) colonoscopies from February 2015 through July 2016 at 7 centers in Spain. Patients were assigned randomly to groups that received 2 HD white-light endoscopy examinations (HD-WLE group; n = 43) or HD-WLE followed by 0.4% indigo carmine panchromoendoscopy (HD-CE group; n = 43). For each procedure, polyps detected were described, removed, and analyzed by histology. The primary outcome was additional polyp detection rate, defined as the number of polyps detected during the second inspection divided by the total number of polyps detected during the first and the second examination.

RESULTS

A total of 774 polyps were detected (362 in the HD-WLE group and 412 in the HD-CE group); 54.2% were hyperplastic, 13.8% were adenomas, and 10.9% were sessile serrated polyps. There was a significantly higher additional polyp detection rate in the HD-CE group (0.39; 95% CI, 0.35-0.44) than in the HD-WLE group (0.22; 95% CI, 0.18-0.27) (P < .001). A higher additional rate of serrated lesions proximal to the sigmoid colon were detected in the second inspection with HD-CE (0.40; 95% CI, 0.33-0.47) than with HD-WLE (0.24; 95% CI, 0.19-0.31) (P = .001). Detection of adenomas and serrated lesions greater than 10 mm did not differ significantly between groups. In a multivariate logistic regression analysis, only use of HD-CE was associated independently with increased polyp detection throughout the colon.

CONCLUSIONS

In a randomized controlled trial, we found that panchromoendoscopy increases detection of polyps (mostly of small serrated lesions) and should be considered the standard of care in patients with SPS. Studies are needed to determine the effects of this strategy on the incidence of advanced neoplasia during long-term follow-up evaluation. ClinicalTrials.gov no: NCT03476434.

Impact of moderate versus deep sedation on adenoma detection rate in index average-risk screening colonoscopies

BACKGROUND AND AIMS

The debate between moderate sedation versus deep sedation for index average-risk screening colonoscopies is well known to gastroenterologists. Ensuring the best of all metrics to perform quality colonoscopies for colon cancer prevention is paramount for both patients and physicians alike, because colon cancer remains the leading cause of cancer death and is the most-used screening tool in the United States. The aim of this study was to determine if moderate sedation versus deep sedation affects outcomes of adenoma detection rate (ADR) or polyp detection rate (PDR) in index, average-risk colonoscopies for colon cancer screening.

METHODS

A retrospective, single, tertiary care outpatient center study of 585 healthy average-risk patients who underwent index screening colonoscopy between June 1, 2015 to December 31, 2015 (moderate sedation only) and June 1, 2016,to December 31, 2016 (deep sedation only) was performed after Institutional Review Board approval. Demographic data and polyp details were collected to determine ADR and PDR. Patients who were not average risk were excluded from the study.

RESULTS

A total of 585 index average-risk screening colonoscopies were included in this study with 57.7% moderate sedation and 42.2% deep sedation. Neither ADR nor PDR was significantly different between the 2 groups (44.1% vs 38.5% [P = .18] and 71.9% vs 67.6% [P = .27], respectively).

CONCLUSIONS

In index average-risk screening colonoscopies, deep sedation appears to have no benefit compared with moderate sedation for ADR and PDR.

Mucosal microbiota of intestinal polyps reveals putative biomarkers of colorectal cancer

The human intestine retains a complex microbial ecosystem, which performs crucial functions that impact on host health. Several studies have indicated that intestinal dysbiosis may impact on the establishment of life-threatening intestinal diseases such as colorectal cancer. An adenomatous polyp is the result of abnormal tissue growth, which is benign but is considered to be associated with a high risk of developing colorectal cancer, based on its grade of dysplasia. Development of diagnostic tools that are based on surveying the gut microbiota and are aimed at early detection of colorectal cancer represent highly desirable target. For this purpose, we performed a pilot study in which we applied a metataxonomic analysis based on 16S rRNA gene sequencing approach to unveil the composition of microbial communities of intestinal polyps. Moreover, we performed a meta-analysis involving the reconstructed microbiota composition of adenomatous polyps and publicly available metagenomics datasets of colorectal cancer. These analyses allowed the identification of microbial taxa such as Faecalibacterium, Bacteroides and Romboutsia, which appear to be depleted in cancerogenic mucosa as well as in adenomatous polyps, thus representing novel microbial biomarkers associated with early tumor formation. Furthermore, an absolute quantification of Fusubacterium nucleatum in polyps further compounded the important role of this microorganism as a valuable putative microbial biomarker for early diagnosis of colorectal cancer.

Risk of Colorectal Polyps and Malignancies Among Predominantly Rural Hispanics

Colorectal cancer is the fourth most frequently diagnosed cancer. However, due to variations in diet, it was hypothesized that risk of adenomatous or hyperplastic polyps or malignancies would be lower among Hispanics. Participants (n = 1671) underwent a colonoscopy. Results were grouped into one of four groups: normal, hyperplastic polyps only, adenomatous polyps, and malignancies. As expected, Hispanics had a lower risk of hyperplastic (p = .031, OR = 0.47) and adenomatous polyps (p = .031, OR = 0.66) than non-Hispanic Whites. Comparison between malignancies was not possible as no Hispanics had a malignancy. Contrary to expectations, risk of hyperplastic and adenomatous polyps and malignancies were no different between non-Hispanic Blacks and Whites. Among rural and mostly rural populations, Hispanics had a lower risk of hyperplastic and adenomatous polyps.

Assessment of colon polyp morphology: Is education effective?

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Sex-influenced association of non-alcoholic fatty liver disease with colorectal adenomatous and hyperplastic polyps

AIM

To investigate the relationship between non-alcoholic fatty liver disease (NAFLD) and colorectal adenomatous and hyperplastic polyps.

METHODS

A retrospective cross-sectional study was conducted on 3686 individuals undergoing health checkups (2430 males and 1256 females). All subjects underwent laboratory testing, abdominal ultrasonography, colonoscopy, and an interview to ascertain the baseline characteristics and general state of health. Multinomial logistic regression analysis was performed to examine the association between NAFLD and the prevalence of colorectal adenomatous and hyperplastic polyps. Furthermore, the relationship was analyzed in different sex groups. Subgroup analysis was performed based on number, size, and location of colorectal polyps.

RESULTS

The prevalence of colorectal polyps was 38.8% in males (16.2% for adenomatous polyps and 9.8% for hyperplastic polyps) and 19.3% in females (8.4% for adenomatous polyps and 3.9% for hyperplastic polyps). When adjusting for confounding variables, NAFLD was significantly associated with the prevalence of adenomatous polyps (OR = 1.28, 95%CI: 1.05-1.51, P < 0.05) and hyperplastic polyps (OR = 1.35, 95%CI: 1.01-1.82, P < 0.05). However, upon analyzing adenomatous and hyperplastic polyps in different sex groups, the significant association remained in males (OR = 1.53, 95%CI: 1.18-2.00, P < 0.05; OR = 1.42, 95%CI: 1.04-1.95, P < 0.05) but not in females (OR = 0.44, 95%CI: 0.18-1.04, P > 0.05; OR = 1.18, 95%CI: 0.50-2.78, P > 0.05).

CONCLUSION

NAFLD is specifically associated with an increased risk of colorectal adenomatous and hyperplastic polyps in men. However, NAFLD may not be a significant factor in the prevalence of colorectal polyps in women.

New endoscopes and add-on devices to improve colonoscopy performance

Colonoscopy is the gold standard for colorectal cancer prevention; however, it is still an imperfect modality. Precancerous lesions can be lost during screening examinations, thus increasing the risk of interval cancer. A variety of factors either patient-, or endoscopist dependent or even the procedure itself may contribute to loss of lesions. Sophisticated modalities including advanced technology endoscopes and add-on devices have been developed in an effort to eliminate colonoscopy's drawbacks and maximize its ability to detect potentially culprit polyps. Novel colonoscopes aim to widen the field of view. They incorporate more than one cameras enabling simultaneous image transmission. In that way the field of view can expand up to 330°. On the other hand a plethora of add-on devices attachable on the standard colonoscope promise to detect lesions in the proximal aspect of colonic folds either by offering a retrograde view of the lumen or by straightening the haustral folds during withdrawal. In this minireview we discuss how these recent advances affect colonoscopy performance by improving its quality indicators (cecal intubation rate, adenoma detection rate) and other metrics (polyp detection rate, adenomas per colonoscopy, polyp/adenoma miss rate) associated with examination's outcomes.

Massive Gastric Juvenile Polyposis: A Clinicopathologic Study Using SMAD4 Immunohistochemistry

OBJECTIVES

Juvenile polyps involving the stomach are uncommon. Massive gastric juvenile polyposis is even rarer.

METHODS

We describe the clinicopathologic features of nine cases of massive gastric juvenile polyposis.

RESULTS

All patients had anemia; four had hypoalbuminemia. The polyps were composed predominantly of dilated crypts lined by columnar epithelium and abundant edematous stroma with mixed inflammatory infiltrates. One patient had a poorly differentiated adenocarcinoma, arising in juvenile polyp-associated intraepithelial neoplasia. A second patient had a well-differentiated intramucosal adenocarcinoma arising in a juvenile polyp with high-grade dysplasia. Three of our cases had polyposis restricted to the stomach. Six (66.6%) had loss of SMAD4 immunoreactivity, making them subject to severe bleeding and hypoproteinemia, as well as developing severe dysplasia or adenocarcinoma.

CONCLUSIONS

SMAD4 immunohistochemstry is a helpful ancillary diagnostic test in cases of suspected juvenile polyposis syndrome involving the stomach.

[THE PROGNOSTIC FACTORS ANALYSIS FOR THE REPEATED DEVELOPMENT OF GASTRIC POLYPS AFTER ENDOSCOPIC POLYPECTOMY]

There were analyzed the results of treatment of 1450 patients, to whom in surgical departments of Lugansk Regional Clinical Hospital the elective endoscopic polypectomy for solitary and multiple gastric polyps, premalignant changes, was conducted. The unfavorable prognosis signs, trustworthily impacting the gastric polyps reoccurring, were considered: quantity of gastric polyps, their dimensions, localization and presence of mucosal erosions. Reoccurrence of majority of the polyps in gastric antrum may be due to microcirculatory disorders, present in their mucosa.

Diagnostic Potential of Cell-Free and Exosomal MicroRNAs in the Identification of Patients with High-Risk Colorectal Adenomas

BACKGROUND

Although there is a growing interest in developing circulating microRNA (miRNA) as noninvasive diagnostic biomarkers for the detection of high-risk colorectal adenomas and early-stage CRCs, but the comparative diagnostic significance of serum vs. exosomal miRNAs remains unexplored.

METHODS

Based upon published literature, we performed an initial discovery step by investigating the expression of a miRNA panel in 20 normal colonic mucosa, 27 adenomas, and 19 CRC tissues. We performed subsequent validation by quantifying expression of candidate miRNAs in total serum and in exosomes from 26 adenoma patients and 47 healthy controls, and evaluated their clinical significance and potential diagnostic value in colorectal adenomas.

RESULTS

We observed that the expression of four miRNAs, miR-21, miR-29a, miR-92a, and miR-135b, was significantly higher in colorectal adenomas vs. normal colonic mucosa. During validation, expression of miR-21, miR-29a and miR-92a in serum was significantly higher in adenomas vs. healthy controls, significantly correlated with adenoma size and total adenoma number within the colorectum, and significantly discriminated patients with advanced adenomas. In contrast, although exosomal miR-21 and miR-29a levels in adenoma patients were significantly higher than those of healthy volunteers, only exosomal miR-21 significantly correlated with adenoma size and total adenoma number, and could discriminate patients with high-risk adenomas.

CONCLUSION

Compared to exosomal miRNAs, serum levels of miR-21, miR-29a and miR-92a are superior diagnostic biomarkers in patients with high-risk adenomatous polyps.

Simultaneous fingerprint and high-wavenumber fiber-optic Raman spectroscopy enhances real-time in vivo diagnosis of adenomatous polyps during colonoscopy

Colorectal cancer can be prevented if detected early (e.g., precancerous polyps-adenoma). Endoscopic differential diagnosis of hyperplastic polyps (that have little or no risk of malignant transformation) and adenomas (that have prominent malignant latency) remains an unambiguous clinical challenge. Raman spectroscopy is an optical vibrational technique capable of probing biomolecular changes of tissue associated with neoplastic transformation. This work aims to apply a fiber-optic simultaneous fingerprint (FP) and high wavenumber (HW) Raman spectroscopy technique for real-time in vivo assessment of adenomatous polyps during clinical colonoscopy. We have developed a fiber-optic Raman endoscopic technique capable of simultaneously acquiring both the FP (i.e., 800-1800 cm(-1)) and HW (i.e., 2800-3600 cm(-1)) Raman spectra from colorectal tissue subsurface (<200 µm) for real-time assessment of colorectal carcinogenesis. In vivo FP/HW Raman spectra were acquired from 50 patients with 17 colorectal polyps during clinical colonoscopy. Prominent Raman spectral differences (p < 0.001) were found between hyperplastic (n = 118 spectra), adenoma (n = 184 spectra) that could be attributed to changes in inter- and intra-cellular proteins, lipids, DNA and water structures and conformations. Simultaneous FP/HW Raman endoscopy provides a diagnostic sensitivity of 90.9% and specificity of 83.3% for differentiating adenoma from hyperplastic polyps, which is superior to either the FP or HW Raman technique alone. This study shows that simultaneous FP/HW Raman spectroscopy technique has the potential to be a clinically powerful tool for improving early diagnosis of adenomatous polyps in vivo during colonoscopic examination.

Correlation between Faecal Tumour M2 Pyruvate Kinase and Colonoscopy for the Detection of Adenomatous Neoplasia in a Secondary Care Cohort

BACKGROUND AND AIMS

Colorectal cancer screening programmes that target detection and excision of adenomatous colonic polyps have been shown to reduce colorectal cancer related mortality. Many screening programmes include an initial faecal occult blood test (FOBt) prior to colonoscopy. To refine the selection of patients for colonoscopy other faecal-based diagnostic tools have been proposed, including tumour M2-pyruvate kinase (tM2-PK). To determine whether tM2-PK quantification may have a role in diverse settings we have assessed the assay in a cohort of patients derived from both the England bowel cancer screening programme (BCSP) and symptomatic individuals presenting to secondary care.

METHOD

Patients undergoing colonoscopy provided faecal samples prior to bowel preparation. Faecal tM2-PK concentrations were measured by ELISA. Sensitivity, specificity, positive predictive value, negative predictive value and ROC analyses were calculated.

RESULTS

Ninety-six patients returned faecal samples: 50 of these with adenomas and 7 with cancer. Median age was 68. Median faecal tM2-PK concentration was 3.8 U/mL for individuals without neoplastic findings at colonoscopy, 7.7 U/mL in those with adenomas and 24.4 U/mL in subjects with colorectal cancer (both, p=0.01). ROC analysis demonstrated an AUROC of 0.66 (sensitivity 72.4%, specificity 48.7%, positive predictive value 67.7%, negative predictive value 36.7%). Amongst BCSP patients with a prior positive FOBt faecal tM2-PK was more abundant (median 6.4 U/mL, p=0.03) and its diagnostic accuracy was greater (AUROC 0.82).

CONCLUSION

Our findings confirm that faecal tM2-PK ELISA may have utility as an adjunct to FOBt in a screening context, but do not support its use in symptomatic patients.

Nonampullary duodenal adenoma: Current understanding of its diagnosis, pathogenesis, and clinical management

Nonampullary duodenal adenomas are relatively common in familial adenomatous polyposis (FAP), but nonampullary sporadic duodenal adenomas (SDAs) are rare. Emerging evidence shows that duodenal adenomas, regardless of their anatomic location and whether they are sporadic or FAP-related, share morphologic and molecular features with colorectal adenomas. The available data suggest that duodenal adenomas develop to duodenal adenocarcinomas via similar mechanisms. The optimal approach for management of duodenal adenomas remains to be determined. The techniques for endoscopic resection of duodenal adenoma include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), and argon plasma coagulation ablation. EMR may facilitate removal of large duodenal polyps. Although several studies have reported cases of successful ESD for duodenal adenomas, the procedure is technically difficult to perform safely because of the anatomical properties of the duodenum. Although current clinical practice recommends endoscopic resection of all large duodenal adenomas in patients with FAP, endoscopic treatment is usually insufficient to guarantee a polyp-free duodenum. Surgery is indicated for FAP patients with severe polyposis or nonampullary SDAs or FAP-related polyps not amenable to endoscopic resection. Further studies are needed to develop newer endoscopic techniques to guide diagnostic and therapeutic decisions for future management of nonampullary duodenal adenomas.

Obesity and Colorectal Cancer

There is strong evidence that modifiable lifestyle factors such as obesity play a key role in colorectal carcinogenesis. Epidemiologic data have consistently reported a positive association between obesity and colorectal cancer. The relative risk associated with general obesity (as assessed by BMI) is higher in men than in women and for cancer of the colon than for cancer of the rectum. Abdominal obesity (as assessed by waist circumference (WC) or waist-to-hip ratio) is associated with an increased risk of colorectal cancer in both sexes, with stronger associations for cancer of the colon than for cancer of the rectum. Plausible biological mechanisms include insulin resistance, hyperinsulinemia, chronic inflammation, altered levels of growth factors, adipocytokines and steroid hormones. In addition to its effect on colorectal cancer incidence, obesity may play a role in colorectal cancer recurrence, treatment outcomes and survival. Understanding the effects of childhood and adolescent obesity and weight change over the life course in relation to future risk of colorectal cancer is incomplete but essential for targeted preventive recommendations. This chapter summarizes the current evidence on the relationship between obesity and colorectal cancer and colorectal adenoma, a common precursor lesion.

Race and Prevalence of Large Bowel Polyps Among the Low-Income and Uninsured in South Carolina

BACKGROUND

Compared to whites, blacks have higher colorectal cancer incidence and mortality rates and are at greater risk for early-onset disease. The reasons for this racial disparity are poorly understood, but one contributing factor could be differences in access to high-quality screening and medical care.

AIMS

The present study was carried out to assess whether a racial difference in prevalence of large bowel polyps persists within a poor and uninsured population (n = 233, 124 blacks, 91 whites, 18 other) undergoing screening colonoscopy.

METHODS

Eligible patients were uninsured, asymptomatic, had no personal history of colorectal neoplasia, and were between the ages 45-64 years (blacks) or 50-64 years (whites, other). We examined the prevalence of any adenoma (conventional, serrated) and then difference in adenoma/polyp type by race and age categories.

RESULTS

Prevalence for ≥1 adenoma was 37 % (95 % CI 31-43 %) for all races combined and 36 % in blacks <50 years, 38 % in blacks ≥50 years, and 35 % in whites. When stratified by race, blacks had a higher prevalence of large conventional proximal neoplasia (8 %) compared to whites (2 %) (p value = 0.06) but a lower prevalence of any serrated-like (blacks 18 %, whites 32 %; p value = 0.02) and sessile serrated adenomas/polyps (blacks 2 %, whites 8 % Chi-square p value; p = 0.05).

CONCLUSIONS

Within this uninsured population, the overall prevalence of adenomas was high and nearly equal by race, but the racial differences observed between serrated and conventional polyp types emphasize the importance of taking polyp type into account in future research on this topic.

Interval colorectal carcinoma: An unsolved debate

Colorectal carcinoma (CRC), as the third most common new cancer diagnosis, poses a significant health risk to the population. Interval CRCs are those that appear after a negative screening test or examination. The development of interval CRCs has been shown to be multifactorial: location of exam-academic institution versus community hospital, experience of the endoscopist, quality of the procedure, age of the patient, flat versus polypoid neoplasia, genetics, hereditary gastrointestinal neoplasia, and most significantly missed or incompletely excised lesions. The rate of interval CRCs has decreased in the last decade, which has been ascribed to an increased understanding of interval disease and technological advances in the screening of high risk individuals. In this article, we aim to review the literature with regard to the multifactorial nature of interval CRCs and provide the most recent developments regarding this important gastrointestinal entity.

[THE BIOMARKERS FOR TIMELY DIAGNOSTICS OF COLORECTAL CANCER]

The colorectal cancer (CC) is one of the most widespread type of cancer all over the world. It is confirmed that the screening procedures intended for timely detection of CC and adenomatous polyps, significantly decrease mortality. The colonoscopy and analysis offeces for occult blood are widely applied as screening procedures. However, they have a number of shortcomings. The studies of the last decade revealed number of genetic and epigenetic markers potentially permitting revealing patients with CC at early stages of development of disease. The article analyzes CC-specific microRNA and their possible interactions with different transcriptional factors. These factors, being integrated into the structure of so called network s with direct signal propagation, ensure special stability of all regulatory system. The derangement of functioning of these networks quite often results in pathological alterations.

The prevalence and associated factors of colorectal neoplasms in acromegaly: a single center based study

PURPOSE

Colorectal neoplasms are well known to be a complication in cases of acromegaly; however, data on the prevalence of colorectal neoplasms in Asian patients with acromegaly are limited. Further, the factors associated with colorectal neoplasms in cases of acromegaly are controversial. Therefore, we aimed to clarify the prevalence of and factors associated with colorectal neoplasms in Japanese patients with acromegaly in a single center.

METHODS

We analyzed consecutive 57 patients who had undergone full-length colonoscopy at the time of diagnosis at Kobe University Hospital between 1986 and 2012.

RESULTS

Of the 57 patients, 22 (38.6%), 18 (31.6%) and 3 (5.3%) patients were diagnosed with hyperplastic polyps, adenomas, and adenocarcinomas, respectively and the prevalence was significantly higher than in a historical control group, Chinese patients with irritable bowel syndrome (The odds ratio was 4.0, 8.7, and 17.5, respectively). The prevalence of adenocarcinomas was also significantly higher in these patients than in the general Japanese population (odds ratio 14.5). Patients with acromegaly who had colorectal neoplasms had longer disease duration than those without colorectal neoplasms. Of note, the area under the growth hormone (GH) concentration-time curve (GH AUC) during the oral glucose tolerance test was significantly higher in patients with adenocarcinomas than in those with no colonic lesion or those with hyperplastic polyps.

CONCLUSION

Japanese patients with acromegaly exhibited an increased risk of colorectal neoplasms, especially colorectal adenocarcinomas. An increased GH AUC was associated with an increased risk for colon adenocarcinomas in patients with acromegaly.

Discovery of a 29-gene panel in peripheral blood mononuclear cells for the detection of colorectal cancer and adenomas using high throughput real-time PCR

Colorectal cancer (CRC) is the second leading cause of cancer-related death in developed countries. Early detection of CRC leads to decreased CRC mortality. A blood-based CRC screening test is highly desirable due to limited invasiveness and high acceptance rate among patients compared to currently used fecal occult blood testing and colonoscopy. Here we describe the discovery and validation of a 29-gene panel in peripheral blood mononuclear cells (PBMC) for the detection of CRC and adenomatous polyps (AP). Blood samples were prospectively collected from a multicenter, case-control clinical study. First, we profiled 93 samples with 667 candidate and 3 reference genes by high throughput real-time PCR (OpenArray system). After analysis, 160 genes were retained and tested again on 51 additional samples. Low expressed and unstable genes were discarded resulting in a final dataset of 144 samples profiled with 140 genes. To define which genes, alone or in combinations had the highest potential to discriminate AP and/or CRC from controls, data were analyzed by a combination of univariate and multivariate methods. A list of 29 potentially discriminant genes was compiled and evaluated for its predictive accuracy by penalized logistic regression and bootstrap. This method discriminated AP >1cm and CRC from controls with a sensitivity of 59% and 75%, respectively, with 91% specificity. The behavior of the 29-gene panel was validated with a LightCycler 480 real-time PCR platform, commonly adopted by clinical laboratories. In this work we identified a 29-gene panel expressed in PBMC that can be used for developing a novel minimally-invasive test for accurate detection of AP and CRC using a standard real-time PCR platform.

Trainee colonoscopists fulfil quality standards for the detection of adenomatous polyps

BACKGROUND

The detection of adenomatous lesions is a major indicator for quality and competence in colonoscopy. Little is known about adenoma detection rates (ADR) of endoscopy trainees. The aim of our study was to investigate the performance of trainee colonoscopists in detecting adenomas and to depict the shape of adenoma detection learning curves during apprenticeship.

METHODS

We retrospectively investigated a prospectively maintained database of a single tertiary referral center to reveal colonoscopies performed by trainee endoscopists during 2001 and 2013. Colonoscopy reports were chronologically retrieved and separately analyzed for each trainee. Using cumulative curves, courses of trainee's Adenoma detection rates (ADR) during apprenticeship were displayed. Additionally, procedural data including cecal intubation rate and occurrence of complications were assessed.

RESULTS

We retrospectively analyzed 4354 colonoscopies conducted by 10 trainee endoscopists (TE). A median number of 371 investigations were performed by each apprentice. Group ADR was 23%. No significant difference between aggregated ADRs at the beginning (23%) and at the end (22%) of apprenticeship could be determined (p = 0.70). However, individual learning curves showed considerable different slopes. Personal ADR values ranged between 17% and 31%. Overall cecum intubation rate was 99.0 %. Complication rates were low and fulfilled quality requirements recommended in guidelines.

CONCLUSION

From the beginning of education, trainee colonoscopists are capable to provide high-quality investigations considering the detection of adenomas as a benchmark quality indicator. Nevertheless, performance differs markedly between investigators. Therefore, individual detection rates should be reviewed regularly to reveal further need for training.

Body mass index and colon cancer screening: The road ahead

Screening for colorectal cancer (CRC) has been associated with a decreased incidence and mortality from CRC. However, patient adherence to screening is less than desirable and resources are limited even in developed countries. Better identification of individuals at a higher risk could result in improved screening efforts. Over the past few years, formulas have been developed to predict the likelihood of developing advanced colonic neoplasia in susceptible individuals but have yet to be utilized in mass screening practices. These models use a number of clinical factors that have been associated with colonic neoplasia including the body mass index (BMI). Advances in our understanding of the mechanisms by which obesity contributes to colonic neoplasia as well as clinical studies on this subject have proven the association between BMI and colonic neoplasia. However, there are still controversies on this subject as some studies have arrived at different conclusions on the influence of BMI by gender. Future studies should aim at resolving these discrepancies in order to improve the efficiency of screening strategies.

[Application of double balloon enteroscopy in diagnosis of small bowel diseases]

INTRODUCTION

Double balloon enteroscopy (DBE) is one of the newest among endoscopic techniques used in diagnosis of the digestive tract diseases--particularly in small bowel's lesions.

MATERIALS AND METHODS

The retrospective analysis of patients' data from 2008 to 2012 in the Department of Digestive Tract Diseases, UM was made. Case histories were analised and evaluated for sex, age, clinical symptoms, results of additional examinations and indications. The course of the examination, its result, complications and role in final diagnosis were also checked.

RESULTS

During the analysed period DBE was attempted 71 times DBE among 42 patients (17 women and 25 men; the age was 44.5 years ± 17.5 years). The most frequent indication for DBE was occult gastrointestinal bleeding--34 patients (80.9%). Among the other patients, the clinical image suggested Crohn's disease (4 cases--9.5%), suspicion of small bowel's neoplasm (2 patients--4.8%), familiar adenomatous polyposis with a need to make polypectomy (1 case--2.4%) and state after bariatric surgery to extract moved gastric balloon (1 patient--2.4%). Small bowel's lesions were detected in 21 patients (50%)--8 polyps, 8--aphthaes and inflammatory changes, 3--vascular lesions, 2--smoothing villi. In four cases the polypectomy was made. The anaesthetic complications appeared with two patients (4,8%). Complications being a result of performed DBE was observed in one case (2.4%).

CONCLUSIONS

Double balloon enteroscopy is safe endoscopic procedure and it plays a key role in diagnosis of patients with gastrointestinal bleeding.

Rare combination of familial adenomatous polyposis and gallbladder polyps

Familial adenomatous polyposis is associated with a high incidence of malignancies in the upper gastrointestinal tract (particularly ampullary adenocarcinomas). However, few reports have described a correlation between familial adenomatous polyposis and gallbladder neoplasms. We present a case of a 60-year-old woman with familial adenomatous polyposis who presented with an elevated mass in the neck of the gallbladder (measuring 16 mm × 8 mm in diameter) and multiple small cholecystic polyps. She had undergone a total colectomy for ascending colon cancer associated with familial adenomatous polyposis 22 years previously. The patient underwent laparoscopic cholecystectomy under a preoperative diagnosis of multifocal gallbladder polyps. Pathologic examination of the resected gallbladder revealed more than 70 adenomatous lesions, a feature consistent with adenoma of the gallbladder. This case suggests a requirement for long-term surveillance of the biliary system in addition to the gastrointestinal tract in patients with familial adenomatous polyposis.

Predictive gene signatures: molecular markers distinguishing colon adenomatous polyp and carcinoma

Cancers exhibit abnormal molecular signatures associated with disease initiation and progression. Molecular signatures could improve cancer screening, detection, drug development and selection of appropriate drug therapies for individual patients. Typically only very small amounts of tissue are available from patients for analysis and biopsy samples exhibit broad heterogeneity that cannot be captured using a single marker. This report details application of an in-house custom designed GenomeLab System multiplex gene expression assay, the hCellMarkerPlex, to assess predictive gene signatures of normal, adenomatous polyp and carcinoma colon tissue using archived tissue bank material. The hCellMarkerPlex incorporates twenty-one gene markers: epithelial (EZR, KRT18, NOX1, SLC9A2), proliferation (PCNA, CCND1, MS4A12), differentiation (B4GANLT2, CDX1, CDX2), apoptotic (CASP3, NOX1, NTN1), fibroblast (FSP1, COL1A1), structural (ACTG2, CNN1, DES), gene transcription (HDAC1), stem cell (LGR5), endothelial (VWF) and mucin production (MUC2). Gene signatures distinguished normal, adenomatous polyp and carcinoma. Individual gene targets significantly contributing to molecular tissue types, classifier genes, were further characterised using real-time PCR, in-situ hybridisation and immunohistochemistry revealing aberrant epithelial expression of MS4A12, LGR5 CDX2, NOX1 and SLC9A2 prior to development of carcinoma. Identified gene signatures identify aberrant epithelial expression of genes prior to cancer development using in-house custom designed gene expression multiplex assays. This approach may be used to assist in objective classification of disease initiation, staging, progression and therapeutic responses using biopsy material.