The natural history of adenomas

Association between Colonoscopy Sedation Type and Polyp Detection: A Registry-based Cohort Study

BACKGROUND

Colorectal cancer is a leading cause of cancer-related death. Adenomas and serrated polyps are precursors of colorectal cancer, with serrated polyps being more difficult to detect during colonoscopy. The relationship between propofol use and polyp detection remains unclear. The authors investigated the association of propofol-based versus mild-moderate sedation on adenoma and serrated polyp detection during colonoscopy.

METHODS

This retrospective cohort study used observational data from the New Hampshire Colonoscopy Registry. Patients aged greater than 50 yr with screening or surveillance colonoscopies between January 1, 2015, and February 28, 2020, were included. Exclusions were diagnostic examinations, no sedation, missing pathology data, and poor bowel preparation. Multivariate logistic regression was used to evaluate differences in polyp detection between propofol and moderate sedation in the full sample while adjusting for covariates. Propensity score adjustment and clustering at the endoscopist level were used in a restricted sample analysis that included endoscopists and facilities with between 5% and 95% propofol sedation use.

RESULTS

A total of 54,063 colonoscopies were analyzed in the full sample and 18,998 in the restricted sample. Serrated polyp prevalence was significantly higher using propofol (9,957 of 29,312; 34.0% [95% CI, 33.4 to 34.5%]) versus moderate sedation (6,066 of 24,751; 24.5% [95% CI, 24.0 to 25.1%]) in the full sample and restricted samples (1,410 of 4,661; 30.3% [95% CI, 28.9 to 31.6%] vs. 3,690 of 14,337; 25.7% [95% CI, 25.0 to 26.5%]). In the full sample multivariate logistic regression, propofol was associated with higher neoplasm (adjusted odds ratio, 1.25 [95% CI, 1.21 to 1.29]), adenoma (odds ratio, 1.07 [95% CI, 1.03 to 1.11]), and serrated polyp detection (odds ratio, 1.51 [95% CI, 1.46 to 1.57]). In the restricted sample using inverse probability of treatment weighted propensity score adjustment and clustering at the endoscopist level, an attenuated but statistically significant effect size was observed for serrated polyps (odds ratio, 1.13 [95% CI, 1.07 to 1.19]), but not for adenomas (odds ratio, 1.00 [95% CI, 0.95 to 1.05]) or any neoplastic lesion (odds ratio, 1.03 [95% CI, 0.98 to 1.08]).

CONCLUSIONS

Propofol sedation during colonoscopy may be associated with improved detection of serrated polyps, but not adenomas.

EDITOR’S PERSPECTIVE

Adenoma characteristics in the English Bowel Cancer Screening Programme

AIM

The English Bowel Cancer Screening Programme detects colorectal cancers and premalignant polyps in a faecal occult blood test-positive population. The aim of this work is to describe the detection rates and characteristics of adenomas within the programme, identify predictive factors influencing the presence or absence of carcinoma within adenomas and identify the factors predicting the presence of advanced colonic neoplasia in different colon segments.

METHOD

The Bowel Cancer Screening System was retrospectively searched for polyps detected during colonoscopies between June 2006 and June 2012, at which time a guaiac test was being used. Data on size, location and histological features were collected, and described. Univariate and multivariate analyses were used to determine the significant factors influencing the development of carcinoma within an adenoma.

RESULTS

A total of 229 419 polyps were identified; after exclusions 136 973 adenomas from 58 334 patients were evaluated. Over half were in the rectum or sigmoid colon. Subcentimetre adenomas accounted for 69.8% of the total. The proportion of adenomas containing advanced histological features increased with increasing adenoma size up to 35 mm, then plateaued. A focus of carcinoma was found in 2282 (1.7%) adenomas, of which 95.6% were located distally. Carcinoma was identified even in diminutive adenomas (0.1%). The proportion of adenomas containing cancer was significantly higher in women than men (2.0% vs. 1.5%, p < 0.001).

CONCLUSION

This national, prospectively captured dataset adds robust information about histological features of adenomas that convey an increased risk for colorectal cancer, and identifies caecal adenomas, high-grade dysplasia, increasing adenoma size, distal location and female sex as independent risk factors associated with carcinoma.

Surveillance after colorectal polyp resection

Post-polypectomy surveillance has proven to reduce colorectal cancer (CRC) incidence in patients with high-risk polyps, but it implies a major burden on colonoscopy units. Therefore, it should be targeted to individuals with a higher risk. Different societies have published guidelines on surveillance after resection of polyps, with notable discrepancies among them, and many recommendations come from low-quality evidence based on surrogate measures, such as risk of advanced adenoma, and not CRC risk. In this review, we aimed to summarize the evidence supporting post-polypectomy surveillance, compare the recently updated major guidelines, and discuss the existing discrepancies on this topic. Briefly, patients with adenomas ≥10 mm or high-grade dysplasia and patients with serrated polyps ≥10 mm or dysplasia are generally considered to have an increased risk of metachronous CRC and require surveillance, whereas the indication of surveillance is not clearly established in patients without these high-risk features.

Bee Products and Colorectal Cancer—Active Components and Mechanism of Action

Colorectal cancer is one of the most common malignancies in the world. Lifestyle and eating patterns may have a significant impact on the prevention of this type of cancer. Bioactive food ingredients influence the gut microbiome and can have a protective effect. Bee products (honey, propolis, royal jelly, and bee venom) or pharmacologically active fractions obtained from them are widely used in many fields of medicine, pharmacy, and cosmetics. Some evidence suggests that bee products may have anti-cancer potential. The main bioactive components with anti-colon cancer potential from propolis and bee honey are polyphenols such as pinocembrin, galangin, luteolin, CAPE, Artepilin C, chrysin, caffeic, and p-coumaric acids. This review is focused on the new data on epidemiology, risk factors for colon cancer, and current reports on the potential role of bee products in the chemoprevention of this type of cancer.

Enrichment of Prevotella intermedia in human colorectal cancer and its additive effects with Fusobacterium nucleatum on the malignant transformation of colorectal adenomas

Background

Owing to the heterogeneity of microbiota among individuals and populations, only Fusobacterium nucleatum and Bacteroides fragilis have been reported to be enriched in colorectal cancer (CRC) in multiple studies. Thus, the discovery of additional bacteria contributing to CRC development in various populations can be expected. We aimed to identify bacteria associated with the progression of colorectal adenoma to carcinoma and determine the contribution of these bacteria to malignant transformation in patients of Han Chinese origin.

Methods

Microbiota composition was determined through 16S rRNA V3–V4 amplicon sequencing of autologous adenocarcinomas, adenomatous polyps, and non-neoplastic colon tissue samples (referred to as “tri-part samples”) in patients with CRC. Enriched taxa in adenocarcinoma tissues were identified through pairwise comparison. The abundance of candidate bacteria was quantified through genomic quantitative polymerase chain reaction (qPCR) in tissue samples from 116 patients. Associations of candidate bacteria with clinicopathological features and genomic and genetic alterations were evaluated through odds ratio tests. Additionally, the effects of candidate bacteria on CRC cell proliferation, migration, and invasion were evaluated through the co-culture of CRC cells with bacterial cells or with conditioned media from bacteria.

Results

Prevotella intermedia was overrepresented in adenocarcinomas compared with paired adenomatous polyps. Furthermore, co-abundance of P. intermedia and F. nucleatum was observed in tumor tissues. More notably, the coexistence of these two bacteria in adenocarcinomas was associated with lymph node involvement and distant metastasis. These two bacteria also exerted additive effects on the enhancement of the migration and invasion abilities of CRC cells. Finally, conditioned media from P. intermedia promoted the migration and invasion of CRC cells.

Conclusion

This report is the first to demonstrate that P. intermedia is enriched in colorectal adenocarcinoma tissues and enhances the migration and invasion abilities of CRC cells. Moreover, P. intermedia and F. nucleatum exert additive effects on the malignant transformation of colorectal adenomas into carcinomas. These findings can be used to identify patients at a high risk of malignant transformation of colorectal adenomas or metastasis of CRC, and they can accordingly be provided optimal clinical management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12929-022-00869-0.

Post-polypectomy colonoscopy surveillance: Can we improve the diagnostic yield?

Although adenomas and serrated polyps are the preneoplastic lesions of colorectal cancer, only few of them will eventually progress to cancer. This review provides a comprehensive overview of the present and future of post-polypectomy colonoscopy surveillance. Post-polypectomy surveillance guidelines have recently been updated and all share the aim towards more selective and less frequent surveillance. We have examined these current guidelines and compared the recommendations of each of them. To improve the diagnostic yield of post-polypectomy surveillance it is important to find predictors of metachronous polyps that better identify high-risk individuals of developing advanced neoplasia. For this reason, we have also conducted a literature review of the molecular biomarkers of metachronous advanced colorectal polyps. Finally, we have discussed future directions of post-polypectomy surveillance and identified possible strategies to improve the use of endoscopic resources with the COVID-19 pandemic.

Colorectal cancer and potential predictors of never screened for faecal occult blood test: a narrative review

Colorectal cancer (CRC) is a major public health threat. Therefore, CRC screening uptake has been a focus with the established precancerous lesion and the strong association of early detection with staging and survival of the disease. However, CRC screening is relatively low in many countries. This article briefly discussed the current situation of CRC, recommendations, and current uptake of CRC screening in various countries. Besides that, this article also highlights the potential factors that help to predict the CRC screening uptake worldwide. Identification of those factors could guide policymakers to develop an effective strategy to improve the CRC screening uptake and ultimately improve the health outcome of the population.

A literature review on large intestinal hyperelastic constitutive modeling

Impacts, traumas and strokes are spontaneously life-threatening, but chronic symptoms strangle patient every day. Colorectal tissue mechanics in such chronic situations not only regulates the physio-psychological well-being of the patient, but also confirms the level of comfort and post-operative clinical outcomes. Numerous uniaxial and multiaxial tensile experiments on healthy and affected samples have evidenced significant differences in tissue mechanical behavior and strong colorectal anisotropy across each layer in thickness direction and along the length. Furthermore, this study reviewed various forms of passive constitutive models for the highly fibrous colorectal tissue ranging from the simplest linearly elastic and the conventional isotropic hyperelastic to the most sophisticated second harmonic generation image based anisotropic mathematical formulation. Under large deformation, the isotropic description of tissue mechanics is unequivocally ineffective which demands a microstructural based tissue definition. Therefore, the information collected in this review paper would present the current state-of-the-art in colorectal biomechanics and profoundly serve as updated computational resources to develop a sophisticated characterization of colorectal tissues.

Design, Synthesis and Studies on Novel Polymeric Prodrugs of Erlotinib for Colon Drug Delivery

AIMS

In the present study, polymer-drug conjugates were synthesized based on azo-bond cleavage drug delivery approach for targeting erlotinib as an anticancer drug specifically to the colon for the proficient treatment of colon cancer.

BACKGROUND

Colon Cancer (CC) is the third commonly detected tumor worldwide and makes up about 10% of all cases of cancers. Most of the chemotherapeutic drugs available for treating colon cancer are not only toxic to cancerous cells but also to the normal healthy cells. Among the various approaches to get rid of the adverse effects of anticancer agents, prodrugs are one of the most imperative approaches.

OBJECTIVE

The objective of the study is to chemically modify the erlotinib drug through azo-bond linkage and suitable spacer which will be finally linked to the polymeric backbone to give the desired polymer linked prodrug. The azo reductase enzyme present in the colon is supposed to cleave the azo-bond specifically and augment the drug release at the colon.

METHODS

The synthesized conjugates were characterized by IR and 1H-NMR spectroscopy. The cleavage of aromatic azo-bond resulted in a potential colon-specific liberation of drug from conjugate studied in rat fecal contents. In vitro release profiles of polyphosphazene-linked conjugates of erlotinib have been studied at pH 1.2, pH 6.8 and pH 7.4. The stability study was designed to exhibit that free drug was released proficiently and unmodified from polyphosphazene-erlotinib conjugates having aromatic azo-bond in artificial colon conditions.

RESULTS

The synthesized conjugates were demonstrated to be stable in simulated upper gastrointestinal tract conditions. The drug release kinetics shows that all the polymer-drug conjugates of erlotinib follow zero-order release kinetics which indicates that the drug release from the polymeric backbone is independent of its concentration. Kinetic study of conjugates with slope (n) shows the anomalous type of release with an exponent (n) > 0.89 indicating a super case II type of release.

CONCLUSION

These studies indicate that polyphosphazene linked drug conjugates of erlotinib could be promising candidates for the site-specific treatment of colon cancer with the least detrimental side-effects.

Histomorphological analysis of gastric polyps

Introduction

Incidence of gastric carcinoma and gastric polyps is on rise all over the world. Chronic atrophic gastritis to intestinal metaplasia progressing to adenocarcinoma has been documented pathway for gastric carcinogenesis. Another pathway for gastric carcinoma is adenoma carcinoma sequence similar to colon cancer.

Aim

To study prevalence, endoscopic, and histomorphological features of gastric polyps.

Methods and Material

This was retrospective analysis of gastric polyps from 2012 to 2019 in consecutive 10,800 upper gastrointestinal endoscopies. Demographic, endoscopic, and histopathological data were obtained from hospital records. All gastric polyps were classified as per standard histologic criteria. Additional histological features noted were presence of dysplasia, focus of adenoma, or malignancy.

Results

The prevalence of gastric polyps was 434 (4%) of 10,800 upper gastrointestinal endoscopies. Majority of polyps were found in the last 4 years (277: 63.8%). Mean age was 55.4 years with male to female ratio 1:1.2. Most of the polyps (94.9%) were less than 1 cm, located in gastric antrum. Multiple polyps were seen in 20.9% cases. On histopathology, fundic gland polyps were most common (147: 33.8%), followed by hyperplastic (128: 29.4%) polyps. Adenomatous polyps were nine (2%); of these, two cases of hyperplastic polyps and one each of fundic gland polyp and benign epithelial polyp showed adenomatous foci.

Conclusion

Fundic gland polyps were the most common polyps. With rising incidence of gastric carcinoma, identification of gastric polyps on endoscopy with biopsy can prevent progression to carcinogenesis.

Epidermal growth factor receptor (EGFR) involvement in epithelial-derived cancers and its current antibody-based immunotherapies

The epidermal growth factor receptor (EGFR) is a transmembrane glycoprotein that is part of the family of tyrosine kinase receptors. The binding of EGFR to its cognate ligands leads to its autophosphorylation and subsequent activation of the signal transduction pathways involved in regulating cellular proliferation, differentiation, and survival. Accordingly, this receptor carries out both redundant and restricted functions in the germline development of mammals and in the maintenance of various adult tissues. Correspondingly, the loss of EGFR regulation results in many human diseases, with the most notable cancer. This receptor is overexpressed and/or mutated in multiple epithelial-derived tumors, and associated with poor prognosis and survival in cancer patients. Here, we discuss in detail the role of EGFR in specific epithelial-derived cancer pathologies; these include lung cancer, colorectal cancer, and squamous cell carcinomas. The development of multiple anticancer agents against EGFR diminished the progression and metastasis of tumors. Some of the most versatile therapeutic anti-EGFR agents include the monoclonal antibodies (mAbs), demonstrating success in clinical settings when used in combination with cytotoxic treatments, such as chemotherapy and/or radiation. We thus discuss the development and application of two of the most notable therapeutic mAbs, cetuximab, and panitumumab, currently utilized in various EGFR-related epithelial cancers.

Genetic analyses supporting colorectal, gastric, and prostate cancer syndromes

Colorectal cancer (CRC), prostate cancer (PrC), and gastric cancer (GC) are common worldwide, and the incidence is to a certain extent dependent on genetics. We have recently shown that in families with more than one case of CRC, the risk of other malignancies is increased. We therefore suggested the presence of not yet described CRC syndromes. In this study, we have searched for genetic susceptibility loci for potential cancer syndromes involving CRC combined with PrC and/or GC. We have performed SNP (single-nucleotide polymorphism)-based linkage analyses in 45 families with CRC, PrC, and GC. In the regions with suggested linkage, we performed exome and association haplotype analyses. Five loci generated a high logarithm of odds (HLOD) score >2, suggestive of linkage, in chromosome bands 1q31-32, 1q24-25, 6q25-26, 18p11-q11, and Xp11. Exome analysis detected no potential pathogenic sequence variants. The haplotype association study showed that one of the top five haplotypes with the lowest P value in the chromosome band 6q25 interestingly was found in the family which contributed the most to the increased HLOD at that locus. This study supports a suggested hereditary cancer syndrome involving CRC and PrC and indicates a location at 6q25. The impact of this locus needs to be confirmed in additional studies.

Patients with Non-Hodgkin's Lymphoma Are at Risk of Adenomatous Colon Polyps

BACKGROUND

Patients with non-Hodgkin's lymphoma (NHL) are frequently referred for colonoscopy to evaluate gastrointestinal symptoms during their treatment course. Here, we described the rate of colonic adenomas in patients with NHL.

METHODS

This was a retrospective study of patients with NHL who underwent colonoscopy after being diagnosed with NHL between January 2000 and December 2017.

RESULTS

Of the 17,938 patients who had been diagnosed with NHL in the study period, 2176 met the inclusion criteria. The mean age at the time of colonoscopy was 61 years. Most patients were male (61%). Overall, 1273 polyps were detected in 811 patients (37%). Sessile serrated adenomas were detected in 102 (5%) patients. The overall ADR was 12% in patients younger than 40 years of age (n = 103), 26% in patients aged 40-50 (n = 251), 34% in patients aged 51-60 (n = 630), and 43% in patients older than 60 (n = 1212). Most polyps were located in the right colon (63%), and 101 (8%) were larger than 1 cm. Villous adenomatous features were present in 1% of polyps, while high-grade dysplasia was detected in 22%. Invasive adenocarcinoma was identified in 4%. The median interval from lymphoma diagnosis to adenoma detection was 1.4 years (interquartile range 0.5-3.8 years). A repeat colonoscopy was performed in 343 patients. The overall ADR on repeat colonoscopy was 30%. Cox regression analysis revealed that age (hazards ratio 1.04; 95% confidence interval 1.03-1.05; P < 0.001) and male sex (hazards ratio 1.35; 95% confidence interval 1.13-1.60; P = 0.001) were independent factors associated with worse overall survival. By contrast, screening colonoscopy was associated with longer survival duration (hazards ratio 0.48; 95% confidence interval 0.36-0.63; P < 0.001).

CONCLUSION

The ADR in NHL patients aged 40-50 years was equivalent to that reported in the literature in non-cancer patients aged 50-70 years. Early screening colonoscopy may be warranted in NHL patients younger than 50 years. Screening colonoscopy significantly improved the overall survival of patients with NHL.

Anatomical distribution and detection rate of colorectal neoplasms according to age in the colonoscopic screening of a Korean population

Purpose

Because data as a basis for the determination of proper age and modality for screening of colorectal neoplasms is lacking, we evaluated detection rates and anatomical distribution of colorectal neoplasms according to age in healthy individuals who underwent total colonoscopy for health checkup.

Methods

A total of 16,100 cases that had received the colonoscopic examination from January to December in 2014 were analyzed. The total number of individuals who received total colonoscopy were divided by the number of individuals harboring colorectal adenoma to calculate the detection rate of colorectal adenoma. Individuals ≤50 years old were classified as young-age group and aged >50 were old-age group. Differences in anatomical locations of colorectal neoplasms were analyzed in the 2 age groups by chi-square test. Risk factors for colorectal adenoma in each age group were analyzed using univariate and multivariate logistic regression analyses.

Results

Detection rates of colorectal adenoma were 13.7% in all cases and 12.8% for those in their 40's. The main anatomical location of colorectal adenoma was proximal colon in both age groups (P < 0.001). Hyperplastic polyp was mainly distributed to the distal colon in both age groups (P < 0.001). Distal colon was the major site for colorectal cancer in the old-age group (P = 0.001). Proximal location of neoplasms was a risk factor for colorectal adenoma in both age groups with multivariate analysis.

Conclusion

These data could be the bases for earlier initiation of screening for colorectal neoplasms with total colonoscopy to detect clinically significant colorectal polyps.

Frequency of colonic adenomatous polyps in a tertiary hospital in Mumbai

INTRODUCTION

Incidence of colorectal carcinoma is increasing all over world. There is limited data on colorectal polyps from India. We evaluated the histomorphological features of colorectal polyps and determined risk stratification in adenomatous polyps.

METHODS

In 4970 consecutive colonoscopies, colorectal polyps were detected in 515 cases (10.3 %). Polyps were classified using standard histological criteria. Each polyp was evaluated for presence of dysplasia. Adenomatous polyps were classified as low-risk adenomas (1-2 tubular adenomas <10 mm) and high-risk adenomas characterized by villous histology, high-grade dysplasia, size ≥10 mm, or ≥3 adenomas.

RESULTS

Of 515 colorectal polyps, 270 (52.4 %) were adenomatous, followed by 78 (15.1 %) inflammatory, 78 (15.1 %) hyperplastic, 32 (6.2 %) hamartomatous polyps, 25 (4.8 %) benign epithelial polyps, 5 (0.9 %) cap polyps, 5 (0.9 %) lipomatous polyps, 3 (0.5 %) angiomatous polyps, 4 (0.7 %) lymphoid, and 15 (2.9 %) cases with adenocarcinoma masquerading as polyps. Mean (SD) age with colorectal polyps was 54.8 (33.0) years while for adenomatous polyps, 59.5 (14.8) years with male to female ratio of 2:1. Majority of adenomatous polyps 124 (45.9 %) were tubular adenomas present in rectosigmoid. High-grade dysplasia was found in 38 (14 %) adenomas. One hundred and fifty-five (57.4 %) were high risk of which majority were villous adenomas and nine (7.2 %) tubular adenomas.

CONCLUSION

The most common colorectal polyps found during routine colonoscopy were 270 adenomatous (52.4 %) cases. Of these, 155 (57.4 %) adenomatous polyps were high-risk category. Population prevalence data of colonic polyps in general population beyond the age of 50 years needs to be obtained.

Editorial: On the Quality of Quality Metrics: Rethinking What Defines a Good Colonoscopy

The colonoscopy quality assurance movement has focused on a variety of process metrics, including the adenoma detection rate (ADR). However, the ADR only ascertains whether or not at least one adenoma is identified. Supplemental measures that quantify all neoplasia have been proposed. In this issue of the American Journal of Gastroenterology, Aniwan and colleagues performed tandem screening colonoscopies to determine the adenoma miss rate among high-ADR endoscopists. This permitted validation of supplemental colonoscopy quality metrics. This study highlights potential limitations of ADR and the need for further refinement of colonoscopy quality metrics, although logistic challenges abound.

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.

Frequent Use of Antibiotics Is Associated with Colorectal Cancer Risk: Results of a Nested Case-Control Study

BACKGROUND

Microbiotical dysbiosis induced by a Western diet seems to be associated with an increased risk of developing colorectal cancer (CRC). Few other factors with an effect on the colonic microbiota and their association with CRC have been evaluated.

AIM

We investigated whether the use of antibiotics is associated with CRC risk.

METHODS

Data on the use of antibiotics and comedication were extracted from a health insurance database for subjects with a diagnostic-related group for CRC between 2006 and 2011 and four age- and sex-matched controls. Antibiotic use was categorized according to the number of prescriptions during a 5-year follow-up period (1-6 years prior to CRC). Multivariable conditional binary logistic regression analysis was used to estimate odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for different levels of use.

RESULTS

A total of 4029 cases (47 % male, mean age at diagnosis 71 ± 11 years) and 15,988 controls were included. Antibiotics had been prescribed to 2630 (65.3 %) cases and 10,234 (64.0 %) controls (p = 0.13). An increasing use of antibiotics was associated with an increasing risk of CRC [multivariable OR for high (≥8 prescriptions) vs. no prescriptions: 1.26, 95 % CI 1.11-1.44, p-trend <0.01]. For each increase of 5 prescriptions, the OR for CRC was 1.05 (95 % CI 1.01-1.09).

CONCLUSION

We found an association between the use of antibiotics, especially when used frequently, and the risk of developing CRC. Further studies are needed to establish under which conditions the use of antibiotics increases the risk of developing CRC.

A new technique of totally laparoscopic resection with natural orifice specimen extraction (NOSE) for large rectal adenoma

There is no consensus about the best technique to use for the surgical treatment for large rectal adenomas. The advent of laparoscopic surgery has led to the development of several new methods for the treatment of gastrointestinal tumors. This study was designed to introduce an innovative technique of totally laparoscopic resection with natural orifice specimen extraction (NOSE) for large rectal adenomas and to assess the feasibility and safety of the technique. Between February 2011 and January 2014, we performed totally laparoscopic resection with NOSE on 18 patients with a large rectal adenoma. This new technique was successful in all 18 patients. The average size of the adenoma was 4.2 cm. Mean operation time was 108.4 min, and mean intraoperative blood loss was 36.6 ml. The mean time to passing of the first flatus was 2.3 days, and the mean postoperative hospital stay was 7.2 days. Only one patient needed analgesics after the operation. All patients were able to walk within the first 2 days. There were no cases of morbidity and recurrence. Totally laparoscopic resection with NOSE appears to be suitable for selected patients with a large adenoma located in mid- or low rectum.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Modeling the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA)

Several colorectal cancer (CRC) screening models have been developed describing the progression of adenomas to CRC. Currently, there is increasing evidence that serrated lesions can also develop into CRC. It is not clear whether screening tests have the same test characteristics for serrated lesions as for adenomas, but lower sensitivities have been suggested. Models that ignore this type of colorectal lesions may provide overly optimistic predictions of the screen-induced reduction in CRC incidence. To address this issue, we have developed the Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) model that includes the adenoma-carcinoma pathway and the serrated pathway to CRC as well as characteristics of colorectal lesions. The model structure and the calibration procedure are described in detail. Calibration resulted in 19 parameter sets for the adenoma-carcinoma pathway and 13 for the serrated pathway that match the age- and sex-specific adenoma and serrated lesion prevalence in the COlonoscopy versus COlonography Screening (COCOS) trial, Dutch CRC incidence and mortality rates, and a number of other intermediate outcomes concerning characteristics of colorectal lesions. As an example, we simulated outcomes for a biennial fecal immunochemical test screening program and a hypothetical one-time colonoscopy screening program. Inclusion of the serrated pathway influenced the predicted effectiveness of screening when serrated lesions are associated with lower screening test sensitivity or when they are not removed. To our knowledge, this is the first model that explicitly includes the serrated pathway and characteristics of colorectal lesions. It is suitable for the evaluation of the (cost)effectiveness of potential screening strategies for CRC.

Is There an Indication for Surgical Resection in Colorectal Adenoma?

BACKGROUND

Due to the adenoma-carcinoma sequence, complete removal of colorectal polyps is essential.

METHOD

This article analyzes the role of surgery in the removal of colorectal adenoma.

RESULTS

Nowadays, most adenomas are removed properly by endoscopic methods. Also in the resection of giant polyps and recurrent adenoma endoscopic data is convincing. Therefore, surgical resection of colorectal adenomas is required in the case of endoscopic inaccessibility. Reasons for this may be the location of the polyp, incomplete endoscopic resection, or suspected malignancy. Endoscopic or limited surgical resection of malignant adenomas is acceptable only if 'low-risk' criteria are fulfilled. Otherwise oncologic radical resection is recommended. In general, radical resection is also necessary in the case of polyps that are not suitable for endoscopic removal, because here the rate of colorectal carcinoma is high.

CONCLUSION

If a surgical approach is necessary, minimally invasive surgery in the hands of an experienced laparoscopic surgeon is a suitable option. Adenomas in the lower two thirds of the rectum are suitable for transanal full-thickness resection. This is done by conventional resection or transanal endoscopic microsurgery. The histopathological preparation of these specimens provides diagnostic and therapeutic benefits, particularly compared to piecemeal resection of early carcinoma.

Characteristics and survival of interval and sporadic colorectal cancer patients: a nationwide population-based cohort study

OBJECTIVES

Colorectal cancers (CRCs) diagnosed relatively soon after a colonoscopy are referred to as interval CRCs. It is not clear whether interval CRCs arise from prevalent lesions missed at colonoscopy or represent specific aggressive biology leading to poor survival.

METHODS

Using Danish population-based medical registries (2000-2009), we investigated patients with "interval" CRC diagnosed within 1-5 years of a colonoscopy, and compared them with cases with colonoscopy ≥10 years before diagnosis and to "sporadic" CRCs with no colonoscopy before diagnosis. Multivariate logistic regression was used to explore the association between clinical, demographic, and comorbidity characteristics and interval CRC. We assessed survival using Kaplan-Meier methods and mortality rate ratios (MRRs) using Cox regression, adjusting for covariates including the Charlson Comorbidity Index (CCI 0, 1-2, 3+).

RESULTS

The comparison of the 982 interval CRCs to the 358 patients with CRC ≥10 years after colonoscopy revealed nearly similar characteristics and mortality. In the comparison with the 35,704 sporadic CRCs, interval cases were slightly older (74 vs. 71 years), more likely to be female (54 vs. 48%), have comorbidities (CCI3+: 28 vs. 15%), have proximal tumors (38 vs. 22%), and tumors with mucinous histology (9.1 vs. 7.0%), but stage was similar (metastatic 23 vs. 24%). In logistic regression analysis, female sex, localized stage at diagnosis, proximal tumor location, and high comorbidity burden were factors independently associated with interval CRC. The 1-year survival was 68% (95% confidence interval (CI): 65%, 71%) in interval and 71% (95% CI: 70%, 71%) in sporadic cases, with an adjusted MRR of 0.92 (95% CI 0.82, 1.0). After 5 years, survival was 41% (95% CI: 37%, 44%) in interval and 43% (95% CI: 42%, 43%) in sporadic cases, and the adjusted 2-5 year MRR was 1.0 (95% CI 0.88, 1.2).

CONCLUSIONS

Clinical characteristics and survival among interval CRCs did not suggest aggressive biology, but rather that the majority represented missed lesions.

The natural history of colorectal adenomas and early cancer

Adenomas represent the morphological precursors of the vast majority of colorectal cancers: although every adenoma has the capacity of malignant evolution, most adenomas stabilize their progression or even regress. Pathological factors are predictive of the natural history of adenomas in terms of potential and time interval for becoming malignant. Regression of adenomas is histologically well established, but it is thought to be a dynamic process, with cycling phases of regression and growth. Colorectal carcinoma invading the submucosa but not the muscular layer represents the earliest form of clinically relevant colorectal cancer. Grade of differentiation of carcinoma, lymphovascular invasion, and state of the resection margin predict the risk of metastasis. Microstaging of invasive cancer together with tumuor budding allow the metastatic risk to be further stratified into minimal, low, and high. Two distinct profiles are identifiable in the natural history of cancerous adenomas: blocking the growth of early cancer and allowing its progression towards advanced cancer. Thus, biomarkers to distinguish between progressive and non-progressive pT1 neoplasia are needed.

Human de novo papillary renal-cell carcinomas in a kidney graft: evidence of recipient origin with adenoma-carcinoma sequence

Papillary renal-cell carcinoma (pRCC) is unusual for its occurrence in kidneys with chronic dysfunction, for its frequent multifocality and for its common association with papillary adenoma, a benign renal lesion morphologically indistinguishable from pRCC. Concomitant development of papillary adenoma and pRCC in five transplanted kidneys, where donor and recipient characteristics are well established, provided a unique opportunity for molecular studies of de novo pRCC carcinogenesis. We aimed to study this tumor type to determine whether or not the different papillary tumors have the same origin, and whether or not papillary adenomas are precursor lesions of pRCC. We performed XY-FISH in sex-mismatched kidney transplants, and polymorphic microsatellite DNA and high-resolution melting of mitochondrial DNA analyzes in all five patients on laser-microdissected tumor cells, then compared these molecular profiles to donor and recipient profiles. This study (i) identified the recipient origin of de novo papillary adenomas and pRCCs in a kidney transplant, (ii) demonstrated an identical origin for precursor cells of papillary adenomas and pRCCs and (iii) showed additional genetic alterations in pRCCs compared to papillary adenomas. This molecular approach of papillary tumors developed in transplanted kidney identified successive steps in carcinogenesis of human de novo papillary renal-cell carcinoma.

Safety and long-term results of endoscopic transanal resection in treating rectal adenomas: 15 years' experience

BACKGROUND

Endoscopic transanal resection (ETAR) is a scarcely used technique to treat large or sessile rectal adenomas not amenable to polypectomy. The purpose of this study was to evaluate safety and long-term results of ETAR in treating rectal adenomas in three hospitals over 15 years.

METHODS

Patients who underwent ETAR during 1996-2010 were retrospectively analyzed with respect to patient, adenoma, and operative characteristics, earlier operations, complications, follow-up time, recurrence rates, recurrence treatment, and cancer incidence.

RESULTS

Ninety-two patients underwent a total 111 ETARs to treat rectal adenoma. The mean age of patients was 71 years, and the median ASA class 3. Twenty-eight patients previously had received other treatments for rectal adenoma. Incidental carcinoma was found in eight patients. Sixty-seven adenomas were treated with only one ETAR and 17 with two or three ETARs. Sixty-seven patients did not have a recurrence, whereas 14 patients had an adenoma recurrence and 3 patients developed invasive carcinoma during a mean follow-up of 30 months. Complications occurred in 14 patients; all were minor, except for one explorative laparotomy without findings. No mortalities or conversions to open surgery occurred.

CONCLUSIONS

ETAR is a minimally invasive and safe technique with inexpensive instrumentation to treat rectal adenomas that are not amenable to polypectomy. Adenoma recurrence rate was 15% and cancer incidence 3% in follow-up.

Investigating the frail elderly patient with lower bowel symptoms: what do we do now and can we improve?

AIMS

To assess the utility of flexible sigmoidoscopy (FS) and minimal preparation CT (MPCT) in investigating lower gastrointestinal (LGI) symptoms in elderly patients who are too frail to undergo colonoscopy or spiral CT.

METHODS

All FS examinations performed in patients aged over 70 between 1 January and 31 December 2008 were analysed. Predictors of usefulness were determined using multivariable analysis. In patients who also underwent MPCT, we analyzed the correlation between FS and MPCT.

RESULTS

426 FS were performed. Bowel preparation was inadequate in 24% of procedures. Indications in which FS was useful were: radiological abnormality (odds ratio [OR] 9.32), history of polyps (OR 4.54) and rectal bleeding (OR 1.73). Indications for which FS was least useful were: change in bowel habit (OR 0.22), diarrhoea (OR 0.46) and constipation (OR 0.38).

CONCLUSIONS

LGI investigation in frail elderly patients can be rationalised according to indication. Performing FS and MPCT together is not always necessary.

Adenoma detection rate is necessary but insufficient for distinguishing high versus low endoscopist performance

BACKGROUND

Endoscopist quality is benchmarked by the adenoma detection rate (ADR)-the proportion of cases with 1 or more adenomas removed. However, the ADR rewards the same credit for 1 versus more than 1 adenoma.

OBJECTIVE

We evaluated whether 2 endoscopist groups could have a similar ADR but detect significantly different total adenomas.

DESIGN

We retrospectively measured the ADR and multiple measures of total adenoma yield, including a metric called ADR-Plus, the mean number of incremental adenomas after the first. We plotted ADR versus ADR-Plus to create 4 adenoma detection patterns: (1) optimal (↑ADR/↑ADR-Plus); (2) one and done (↑ADR/↓ADR-Plus); (3) all or none (↓ADR/↑ADR-Plus); (4) none and done (↓ADR/↓ADR-Plus).

SETTING

Tertiary-care teaching hospital and 3 nonteaching facilities servicing the same patient pool.

PATIENTS

A total of 3318 VA patients who underwent screening between 2005 and 2009.

MAIN OUTCOME MEASUREMENTS

ADR, mean total adenomas detected, advanced adenomas detected, ADR-Plus.

RESULTS

The ADR was 28.8% and 25.7% in the teaching (n = 1218) and nonteaching groups (n = 2100), respectively (P = .052). Although ADRs were relatively similar, the teaching site achieved 23.5%, 28.7%, and 29.5% higher mean total adenomas, advanced adenomas, and ADR-Plus versus nonteaching sites (P < .001). By coupling ADR with ADR-Plus, we identified more teaching endoscopists as optimal (57.1% vs 8.3%; P = .02), and more nonteaching endoscopists in the none and done category (42% vs 0%; P = .047).

LIMITATIONS

External generalizability, nonrandomized study.

CONCLUSION

We found minimal ADR differences between the 2 endoscopist groups, but substantial differences in total adenomas; the ADR missed this difference. Coupling the ADR with other total adenoma metrics (eg, ADR-Plus) provides a more comprehensive assessment of adenoma clearance; implementing both would better distinguish high- from low-performing endoscopists.

Risk of colorectal adenomas in women with prior breast cancer

BACKGROUND AND AIMS

Longer life expectancy in patients with prior breast cancer may increase their risk of developing other primary cancers, including colorectal cancer (CRC). Whether the risk of developing CRC in this patient population is higher in comparison to those with no prior cancer remains unclear. The purpose of this study was to compare the prevalence of colorectal adenomas and any CRC in breast cancer survivors with those who have no history of prior cancer and assess any difference with use of antiestrogen therapy.

METHODS

We compared the prevalence of colorectal cancer and adenomas in breast cancer survivors with that of a group of matched controls. Eligible survivors were ≤85 years of age; had initially been diagnosed with stage 0, I, II, or III breast cancer; had completed all cancer treatments with the exception of adjuvant antiestrogen therapy; and had no evidence of recurrence on follow-up. We used the screening colonoscopy database at our institution to identify age-, sex-, and race-matched controls with no history of cancer.

RESULTS

We identified 302 study-eligible breast cancer survivors and 302 matched controls. No colorectal cancers were found in either group. Forty-one breast cancer survivors and 30 controls had tubular adenomas; four survivors and three controls had villous adenoma; and eight survivors and ten controls had advanced adenoma. Multivariate regression analysis revealed that adjuvant antiestrogen therapy was not significantly associated with an increased risk of advanced adenoma.

CONCLUSIONS

The prevalence of colorectal adenomas in breast cancer survivors and controls was similar. Breast cancer survivors, including those receiving adjuvant antiestrogen therapies may follow the colorectal screening guidelines used for average-risk population.

Effects of phenotypes in heterocyclic aromatic amine (HCA) metabolism-related genes on the association of HCA intake with the risk of colorectal adenomas

BACKGROUND

Heterocyclic aromatic amines (HCA), formed by high-temperature cooking of meat, are well-known risk factors for colorectal cancer (CRC). Enzymes metabolizing HCAs may influence the risk of CRC depending on the enzyme activity level. We aimed to assess effect modification by polymorphisms in the HCA-metabolizing genes on the association of HCA intake with colorectal adenoma (CRA) risk, which are precursors of CRC.

METHODS

A case-control study nested in the EPIC-Heidelberg cohort was conducted. Between 1994 and 2005, 413 adenoma cases were identified and 796 controls were matched to cases. Genotypes were determined and used to predict phenotypes (i.e., enzyme activities). Odds ratios (OR) and corresponding 95 % confidence intervals (CI) were calculated by logistic regression analysis.

RESULTS

CRA risk was positively associated with PhIP, MeIQx, and DiMeIQx (p trend = 0.006, 0.022, and 0.045, respectively) intake. SULT1A1 phenotypes modified the effect of MeIQx on CRA risk (p (Interaction) > 0.01) such that the association of MeIQx intake with CRA was stronger for slow than for normal phenotypes. Other modifying effects by phenotypes did not reach statistical significance.

CONCLUSIONS

HCA intake is positively associated with CRA risk, regardless of phenotypes involved in the metabolizing process. Due to the number of comparisons made in the analysis, the modifying effect of SULT1A1 on the association of HCA intake with CRA risk may be due to chance.

Prevalence of colonic neoplasia and advanced lesions in the normal population: a prospective population-based colonoscopy study

OBJECTIVE

There are few prospective studies of the prevalence of colonic neoplasia in the normal population. In order to properly evaluate screening-protocols for colorectal cancer in risk groups (e.g., older subjects or those with a family history), it is essential to know the prevalence of adenomas and cancer in the normal population.

METHODS

A prospective population-based colonoscopy study on 745 individuals born in Sweden aged 19-70 years was conducted (mean age 51.1 years). All polyps seen were retrieved and examined.

RESULTS

Out of the 745 individuals 27% had polyps, regardless of kind. Adenomas were found in 10% of the individuals and finding of adenomas was positively correlated to higher age. Men had adenomas in 15% and women in 6% of the cases. Women had a right-sided dominance of adenomas. Hyperplastic polyps were seen in 21% of the individuals. The presence of hyperplastic polyps was significantly positively correlated to the presence of adenomas. Advanced adenomas were seen in 2.8% of the study participants, but no cancers were detected.

CONCLUSION

One in 10 healthy subjects had an adenoma but advanced adenomas were uncommon. Men and women have a different adenoma prevalence and localization. The results provide baseline European data for evaluating colonoscopy screening-protocols for colorectal cancer risk groups, and the findings may have implications for colon cancer screening in the normal, otherwise-healthy population.

[Colorectal adenoma: pro conventional/laparoscopic resection]

The knowledge that due to the adenoma-cancer sequence polyps will develop sooner or later into invasive cancer demands the complete removal of colorectal polyps. The majority of polyps can be endoscopically removed. The indications for surgical removal of polyps are a previous incomplete endoscopic resection, location not amenable to endoscopic removal and lesions which are macroscopically highly suspicious for malignancy and cannot be detached by submucosal saline injection. If a surgical approach is indicated minimally invasive surgery in the hands of an experienced laparoscopic surgeon is a suitable option. Adenomas suspicious for malignancy in the lower two thirds of the rectum should not be treated by time-consuming endoscopic submucosal dissection (ESD) and can be quickly and safely removed transanally, conventionally or by transanal endoscopic microsurgery (TEM) by a full thickness én bloc resection. This allows the pathologist to determine the depth of invasion and the completeness of resection in terms of the circumferential margin and a definitive radical surgical approach is only necessary in high risk situations.