Should we perform sigmoidoscopy for colorectal cancer screening in people under 45 years?

BACKGROUND

The strategy for preventing colorectal cancer is screening by colonoscopy, which offers a direct way for detection and removal of adenomatous polyps (APs). American College of Gastroenterology guidelines recommend that people aged ≥ 45 years should undergo colonoscopy; however, how to deal with people aged ≤ 45 years is still unknown.

AIM

To compare the prevalence of APs and high-grade neoplasia between the left and right colon in patients ≤ 45 years.

METHODS

A retrospective observational study was conducted at a single tertiary III hospital in China. This study included patients aged 18-45 years with undergoing initial colonoscopy dissection and pathological diagnosis AP or high-grade neoplasia between February 2014 and January 2021. The number of APs in the entire colon while screening and post-polypectomy surveillance in following 1-3 years were evaluated.

RESULTS

A total of 3053 cases were included. The prevalence of APs in the left and right colon was 55.0% and 41.6%, respectively (OR 1.7, 95%CI 1.6-2.4; P < 0.05). For APs with high-grade neoplasia, the prevalence was 2.7% and 0.9%, respectively (OR 3.0, 95%CI 2.0-4.6; P < 0.05). Therefore, the prevalence of APs and high-grade neoplasia in the left colon was significantly higher than in the right colon in patients aged ≤ 45 years. There were 327 patients who voluntarily participated in post-polypectomy surveillance in following 1-3 years, and APs were found in 216 cases (66.1%); 170 cases had 1-3 polyps (52.0%) and 46 cases had > 3 polyps (14.1%; OR 0.3, 95%CI 0.1-0.6; P < 0.05).

CONCLUSION

This study suggests that flexible sigmoidoscopy would be an optimal approach for initial screening in people aged ≤ 45 years and would be a more cost-effective and safe strategy.

The frequency of colorectal lesions in the first-degree relatives of patients with colorectal lesions among PERSIAN Guilan Cohort Study population (PGCS)

BACKGROUND

This study aimed to investigate the frequency of colorectal lesions in the first-degree relatives of patients with colorectal lesions among the Prospective Epidemiological Research Studies in Iran (PERSIAN )Guilan Cohort Study (PGCS) population.

METHODS

In this cross-sectional study, 162 first-degree relatives with a history of colorectal lesions were randomly selected from 52 participants in PGCS. All subjects underwent total colonoscopy by a gastroenterologist, and a pathologist evaluated colorectal biopsies. Also, individuals' demographic information, clinical data, and dietary habits were recorded.

RESULTS

The mean age of the participants was 56.55 ± 7.04. Of 86 colon polyps, 52 neoplastic and 34 non-neoplastic polyps were observed in 56 patients (34.6%). Individuals with age > 60 years had 3.29-fold increased odds of developing colorectal polyps (OR = 3.29, 95% CI: 1.13-9.56, P = 0.029). The smokers were 2.73 times more susceptible to developing colorectal polyps than non-smokers (OR = 2.73, 95% CI: 1.24-6.02, P = 0.013). Moreover, consumption of vegetables more than three times per day was associated with decreased OR of colorectal polyp development (OR = 0.43, CI: 0.19-0.98, P = 0.045).

CONCLUSIONS

Considering the high prevalence of neoplastic colorectal polyps among the first-degree relatives of patients with colorectal lesions, early screening is recommended for individuals with a family history of colorectal lesions.

Solobacterium moorei promotes the progression of adenomatous polyps by causing inflammation and disrupting the intestinal barrier

BACKGROUND

Adenomatous polyps (APs) with inflammation are risk factors for colorectal cancer. However, the role of inflammation-related gut microbiota in promoting the progression of APs is unknown.

METHODS

Sequencing of the 16S rRNA gene was conducted to identify characteristic bacteria in AP tissues and normal mucosa. Then, the roles of inflammation-related bacteria were clarified by Spearman correlation analysis. Furthermore, colorectal HT-29 cells, normal colon NCM460 cells, and azoxymethane-treated mice were used to investigate the effects of the characteristic bacteria on progression of APs.

RESULTS

The expression levels of inflammation-related markers (diamine oxidase, D-lactate, C-reactive protein, tumor necrosis factor-α, interleukin-6 and interleukin-1β) were increased, whereas the expression levels of anti-inflammatory factors (interleukin-4 and interleukin-10) were significantly decreased in AP patients as compared to healthy controls. Solobacterium moorei (S. moorei) was enriched in AP tissues and fecal samples, and significantly positively correlated with serum inflammation-related markers. In vitro, S. moorei preferentially attached to HT-29 cells and stimulated cell proliferation and production of pro-inflammatory factors. In vivo, the incidence of intestinal dysplasia was significantly increased in the S. moorei group. Gavage of mice with S. moorei upregulated production of pro-inflammatory factors, suppressed proliferation of CD4+ and CD8+cells, and disrupted the integrity of the intestinal barrier, thereby accelerating progression of APs.

CONCLUSIONS

S. moorei accelerated the progression of AP in mice via activation of the NF-κB signaling pathway, chronic low-grade inflammation, and intestinal barrier disruption. Targeted reduction of S. moorei presents a potential strategy to prevent the progression of APs.

The incremental yield of adenoma detection with I-Scan versus high-definition white light colonoscopy-a systematic review and meta-analysis of randomized studies

INTRODUCTION

The incremental yield of I-Scan virtual chromoendoscopy compared to high-definition white light endoscopy (HD-WLE) in detection of colorectal adenomas has not been thoroughly elucidated.

METHODS

A systematic search from inception to April 2023 was conducted to identify randomized controlled trials (RCTs) comparing I-Scan to HD-WLE for detection of adenomas. A random effects model was used to compute risk difference (RD) with corresponding 95% confidence intervals in adenoma detection rate (ADR). Influence analysis was done to assess robustness of findings. The number needed to diagnose was computed. Heterogeneity was assessed using the I2 statistic and explored further by subgroup analyses defined a priori. Certainty in effect estimates was assessed using the GRADE approach.

RESULTS

We identified four studies (I-Scan n = 730, HD-WLE n = 765). I-Scan increased adenoma detection by 9% (risk difference (RD), 0.09; 0.04, 0.14; I2 02%; certainty, low). Influence analysis revealed that the gain in yield remained statistically significant with exclusion of all but one study. The number needed to capture one additional adenomatous polyp with I-Scan use was 11.2. I-Scan 1 use was associated with a statistically significant gain in ADR, whereas no significant difference in ADR was noted with I-Scan use on subgroup analysis.

DISCUSSION

In conclusion, I-Scan increases the yield of adenoma detection by 9% compared to HD-WLE, with low certainty in the estimate of this effect. Data on the gain in yield of detecting large polyps, sessile serrated lesions, and on the impact of formally training endoscopists and trainees in I-Scan use and similar technology on adenoma detection rate are needed.

Hierarchical contribution of individual lifestyle factors and their interactions on adenomatous and serrated polyp risk

BACKGROUND

Individual colorectal polyp risk factors are well characterized; however, insights into their pathway-specific interactions are scarce. We aimed to identify the impact of individual risk factors and their joint effects on adenomatous (AP) and serrated polyp (SP) risk.

METHODS

We collected information on 363 lifestyle and metabolic parameters from 1597 colonoscopy participants, resulting in over 521,000 data points. We used multivariate statistics and machine-learning approaches to assess associations of single variables and their interactions with AP and SP risk.

RESULTS

Individual factors and their interactions showed common and polyp subtype-specific effects. Abdominal obesity, high body mass index (BMI), metabolic syndrome, and red meat consumption globally increased polyp risk. Age, gender, and western diet associated with AP risk, while smoking was associated with SP risk. CRC family history was associated with advanced adenomas and diabetes with sessile serrated lesions. Regarding lifestyle factor interactions, no lifestyle or dietary adjustments mitigated the adverse smoking effect on SP risk, whereas its negative effect was exacerbated by alcohol in the conventional pathway. The adverse effect of red meat on SP risk was not ameliorated by any factor, but was further exacerbated by western diet along the conventional pathway. No modification of any factor reduced the negative impact of metabolic syndrome on AP risk, whereas increased fatless fish or meat substitutes' intake mitigated its effect on SP risk.

CONCLUSIONS

Individual risk factors and their interactions for polyp formation along the adenomatous and serrated pathways are strongly heterogeneous. Our findings may facilitate tailored lifestyle recommendations and contribute to a better understanding of how risk factor combinations impact colorectal carcinogenesis.

Expanding endoscopic boundaries: Endoscopic resection of large appendiceal orifice polyps with endoscopic mucosal resection and endoscopic submucosal dissection

BACKGROUND

Large appendiceal orifice polyps are traditionally treated surgically. Recently, endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) have been utilized as alternative resection techniques.

AIM

To evaluate the efficacy and safety of endoscopic resection techniques for the management of large appendiceal orifice polyps.

METHODS

This was a retrospective observational study conducted to assess the feasibility and safety of EMR and ESD for large appendiceal orifice polyps. This project was approved by the Baylor College of Medicine Institutional Review Board. Patients who underwent endoscopic resection of appendiceal orifice polyps ≥ 1 cm from 2015 to 2022 at a tertiary referral endoscopy center in the United States were enrolled. The main outcomes of this study included en bloc resection, R0 resection, post resection adverse events, and polyp recurrence.

RESULTS

A total of 19 patients were identified. Most patients were female (53%) and Caucasian (95%). The mean age was 63.3 ± 10.8 years, and the average body mass index was 28.8 ± 6.4. The mean polyp size was 25.5 ± 14.2 mm. 74% of polyps were localized to the appendix (at or inside the appendiceal orifice) and the remaining extended into the cecum. 68% of polyps occupied ≥ 50% of the appendiceal orifice circumference. The mean procedure duration was 61.6 ± 37.9 minutes. Polyps were resected via endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid procedures in 5, 6, and 8 patients, respectively. Final pathology was remarkable for tubular adenoma (n = 10) [one with high grade dysplasia], sessile serrated adenoma (n = 7), and tubulovillous adenoma (n = 2) [two with high grade dysplasia]. En bloc resection was achieved in 84% with an 88% R0 resection rate. Despite the large polyp sizes and challenging procedures, 89% (n = 17) of patients were discharged on the same day as their procedure. Two patients were admitted for post-procedure observation for conservative pain management. Eight patients underwent repeat colonoscopy without evidence of residual or recurrent adenomatous polyps.

CONCLUSION

Our study highlights how endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid procedures are all appropriate techniques with minimal adverse effects, further validating the utility of endoscopic procedures in the management of large appendiceal polyps.

Accuracy in optical diagnosis for polyps between 5 and 15 mm and its implications on surveillance. A prospective, multicenter study. (POPS study)

BACKGROUND AND AIMS

Polyps histology and diameter up to 1 cm determine whether a patient needs a colonoscopy after 3 years or less, or far ahead. Endoscopists' and pathologists' size estimations can be imprecise. Our aim was to assess endoscopist ability to correctly recommend surveillance colonoscopies for patients with polyps around the 10 mm threshold, based on its endoscopic sizing and optical diagnosis by NBI.

METHODS

NBI-assisted diagnosis and endoscopist estimation of polyp size were compared with reference standard, considering this as the post resection polyp measurements by the nurse assistant and the pathologic results, in a prospective, multicenter, real life study, that recruited adults undergoing colonoscopy in five hospitals. By comparing the endoscopic and pathologist size estimation, with polyps' measurement after resection, and optical and histological diagnoses in patients with polyps between 5 and 15 mm, sensitivity was assessed at the patient level by means of two characteristics: the presence of adenoma, and the surveillance interval. Surveillance intervals were established by the endoscopist, based on optical diagnosis, and by another gastroenterologist, grounded on the pathologic report. Determinants of accuracy were explored at the polyp level.

RESULTS

532 polyps were resected in 451 patients. Size estimation was more precise for the endoscopist. Endoscopist sensitivity for the presence of adenoma or carcinoma was 98.7%. Considering the presence of high-grade dysplasia or cancer, sensitivity was 82.6% for the endoscopic optical diagnosis. Sensitivity for a correct 3-year surveillance interval was 91.5%, specificity 82.3%, with a PPV of 93.2% and NPV of 78.5% for the endoscopist. 6.51% of patients would have had their follow-up colonoscopy delayed, whereas 22 (4.8%) would have it been performed earlier, had endoscopist recommendations been followed.

CONCLUSION

Our study observes that NBI optical diagnosis can be recommended in routine practice to establish surveillance intervals for polyps between 5 and 15 mm.

CLINICAL TRIALS REGISTRATION NUMBER

NCT04232176.

胃腺瘤性息肉的内镜和病理特点及癌变的危险因素分析

OBJECTIVE

To investigate the endoscopic and pathological characteristics of gastric adenomatous polyps and to assess the potential risk factors for canceration of gastric adenomatous polyps.

METHODS

The endoscopic and pathological characteristics of the patients with gastric adenomatous polyps from January 1, 2005 to December 31, 2019 were summarized retrospectively, and the risk factors of canceration were analyzed.

RESULTS

A total of 125 patients with gastric adenomatous polyps were included, 51.20% of whom were females. The average age was (66.7±12.3) years. 64.80% of patients with gastric adenomatous polyps equal or more than 65 years old, and only 5.60% of the patients less than 45 years old. Adenomatous polyps were mostly distributed in the corpus and antrum with 40.80% and 32.80%, respectively. The majority of them were single (90.40%) and sessile (76.81%). 65.4% of adenomatous polyps were no more than 1.0 cm in diameter, and 23.20% of patients with adenomatous polyps were combined with hyperplastic polyps and/or fundus glandular polyps, and 1.60% had both pathological types of polyps. 58.62% (17/29) patients with hyperplastic polyps and/or fundus glandular polyps had multiple polyps. 1.60% (2/125) of the patients had gastric neuroendocrine tumor of G1 stage. Synchronous gastric cancer was detected in 13.60% (17/125) of the patients with adenomatous polyps, and the proportion of low-grade intraepithelial neoplasia was 18.40% (23/125). The main types of synchronous gastric cancer were progressive (70.59%) and undifferentiated (66.67%). Chronic atrophic gastritis with intestinal metaplasia was found in 52.80% of the patients, and autoimmune gastritis accounted for 11.20%. The positive rate of Helicobacter pylori was 21.60%. The canceration rate of gastric adenomatous polyps was 20.80%. The cancer was mainly differentiated, but there was sigmoid ring cell carcinoma as well. Diameter of >1.0 cm (OR=5.092, 95%CI: 1.447-17.923, P=0.011), uneven surface morphology and erosion (OR=13.749, 95%CI: 1.072-176.339, P=0.044) were independent risk factors of adenomatous polyps.

CONCLUSION

The synchronous gastric cancer is common and the canceration of gastric adenomatous polyps is high with diameter and surface morphology as independent risk factors. We should pay attention to the identification of the pathological types of polyps and the evaluation of the whole gastric mucosa during the endoscopic examination.

Genetic testing for assessment of lynch syndrome in young patients with polyps

BACKGROUND

Routine screening for establishing Lynch syndrome (LS) in young individuals diagnosed with adenomas is not recommended due to its low yield, and limited sensitivity of the employment of immunohistochemistry for DNA mismatch-repair proteins on polyps. Hence we aimed to evaluate the yield of germline mutational analysis in diagnosis of LS in a young Israeli cohort with colorectal adenomatous polyps.

METHODS

Data were retrospectively collected on consecutive patients, age ≤ 45 years, who underwent colonoscopy with removal of at least one adenoma during 2015-2020, and subsequently genetic testing by multigene panel or LS-Jewish founder mutation panel.

RESULTS

Overall, 92 patients were included (median age 35 years, range 23-45 years), of whom 79 (85.8%) underwent multigene panel genotyping, and 13 (14.2%) analysis for Jewish founder LS gene mutations. Altogether, 18 patients were identified with pathogenic mutations in actionable genes, including LS-associated genes in 6 (6.5%), BRCA2 in 2 (2.5%), GREM1 in 1(1.2%), and low-penetrance genes- APC I1307K and CHEK2- in 9 (11.4%) patients. Compared with non-LS patients, LS-carriers had a significantly higher median PREMM5 score (2.6 vs. 1.3; P = 0.04).

CONCLUSIONS

Young individuals diagnosed with adenomatous polyps should be offered genetic testing when fulfilling clinical guidelines for LS, but weight should also be given to adenoma characteristics in the PREMM5 score.

Fecal metabolomic profiles: A comparative study of patients with colorectal cancer vs adenomatous polyps

BACKGROUND

Colorectal cancer (CRC), the third most common cause of death in both males and females worldwide, shows a positive response to therapy and usually a better prognosis when detected at an early stage. However, the survival rate declines when the diagnosis is late and the tumor spreads to other organs. Currently, the measures widely used in the clinic are fecal occult blood test and evaluation of serum tumor markers, but the lack of sensitivity and specificity of these markers restricts their use for CRC diagnosis. Due to its high sensitivity and precision, colonoscopy is currently the gold-standard screening technique for CRC, but it is a costly and invasive procedure. Therefore, the implementation of custom-made methodologies including those with minimal invasiveness, protection, and reproducibility is highly desirable. With regard to other screening methods, the screening of fecal samples has several benefits, and metabolomics is a successful method to classify the metabolite shift in living systems as a reaction to pathophysiological influences, genetic modifications, and environmental factors.

AIM

To characterize the variation groups and potentially recognize some diagnostic markers, we compared with healthy controls (HCs) the fecal nuclear magnetic resonance (NMR) metabolomic profiles of patients with CRC or adenomatous polyposis (AP).

METHODS

Proton nuclear magnetic resonance spectroscopy was used in combination with multivariate and univariate statistical approaches, to define the fecal metabolic profiles of 32 CRC patients, 16 AP patients, and 38 HCs well matched in age, sex, and body mass index.

RESULTS

NMR metabolomic analyses revealed that fecal sample profiles differed among CRC patients, AP patients, and HCs, and some discriminatory metabolites including acetate, butyrate, propionate, 3-hydroxyphenylacetic acid, valine, tyrosine and leucine were identified.

CONCLUSION

In conclusion, we are confident that our data can be a forerunner for future studies on CRC management, especially the diagnosis and evaluation of the effectiveness of treatments.

Detection Rate of Colorectal Polyps in Symptomatic Candidates of Colonoscopy: When Should We Do a Total Colonoscopy?

BACKGROUND The incidence of colorectal cancer is increasing in the northeast of Iran. Colorectal polyps are among the proposed risk factors noted, especially in the elder population. This study was designed to study the diagnosed cases of intestinal polyps detected from 2011 to 2016 in the northeast of Iran. METHODS The population consisted of symptomatic candidates referred to the colonoscopy center in Gorgan city. Based on the available colonoscopy and pathology reports, 1706 cases were enrolled after the exclusion of cases without sufficient data. RESULTS Among 1709 (55.5% males and 44.5% females) cases, 1405 cases with 1912 polyps were detected. Among them, 345 (25%) aged less than 50 years. Tubular adenoma (N = 826, 43.2%) and hyperplastic polyps (N = 519, 27.1%) were the top two histological findings. Out of 1405 patients with polyps, 660 (39.6%) polyps were detected in proximal colon (15.6% in proximal and 24% in both proximal and distal). Malignancies were detected in 13.2% (0.8% malignant polyps and 12.4% malignant masses). CONCLUSION A considerable number of colorectal adenomas in proximal colon and in patients younger than 50 years old, suggesting to schedule colorectal cancer screening from at least 10 years younger and continuing colonoscopy up to the proximal area.

A case-control study of Dietary Approaches to Stop Hypertension (DASH) diets, colorectal cancer and adenomas among Iranian population

Background and aims

Colorectal cancer (CRC) is the third most common cancer, worldwide. Recently, much attention has been given to the association between Dietary Approaches to Stop Hypertension (DASH) and CRC, however, data on colorectal adenomas (CRAs) as its precursor are scarce. Thus, the purpose of this case-control study was to investigate the association of DASH score with the risk of CRC and CRA in Iranian adults.

Method

A total of 499 participants, including 129 CRC and 130 CRA cases, along with 240 controls, were asked about their dietary intake via a validated questionnaire. The DASH score was then calculated based on a priori methods and categorized in quartiles. Multivariate logistic regression was performed to assess the association of DASH score and the risk of CRC and CRA.

Results

After adjusting for confounding variables, adherence to the DASH diet was associated with a reduction in the risk of CRC and CRA, respectively (OR of 4th versus 1st quartile = 0.04, 95% CI: 0.01–0.11, OR = 0.10, 95% CI: 0.04–0.22). Also, subgroup analysis based on gender showed that women and men with a higher DASH score had a significantly lower risk of CRC and CRAs.

Conclusion

The results of this study demonstrated that adherence to a DASH dietary pattern could reduce the risk of CRC and CRA in men and women. Promoting a DASH eating plan can be helpful in reducing the risk of CRC.

Latest Generation High-Definition Colonoscopy Increases Adenoma Detection Rate by Trainee Endoscopists

BACKGROUND

Adenoma detection rate (ADR) is an important quality indicator of colonoscopy. High-definition (HD) colonoscopy has been reported to increase ADR compared to standard-definition (SD) colonoscopy. Although there are few reports comparing the latest generation and the previous generation of HD colonoscopy equipment, there are reports that the latest generation colonoscopy equipment improves ADR. However, there are no reports on the impact of the latest generation HD colonoscopy on the ADR of trainee endoscopists.

AIMS

The aim of this study was to investigate whether the latest generation HD colonoscopy increases the ADR of trainee endoscopists compared with the previous generation HD colonoscopy.

METHOD

We conducted a retrospective review of medical records of patients aged 40-79 years old, who underwent screening or surveillance colonoscopy performed by nine gastroenterology fellows at Dong-A University Hospital from March 2019 to February 2020. We calculated the overall ratios of the ADR: the ADRs of the group using the older generation HD colonoscopy equipment and the group using the latest HD colonoscopy equipment. Polyp detection rate (PDR), sessile serrated polyp detection rate (SSPDR), and advanced neoplasia detection rate (ANDR) were calculated for each group. Factors related to adenoma detection were identified using logistic regression analysis.

RESULTS

Altogether, 2189 patients were included in the study (the older HD colonoscopy group comprising 1183 and the latest HD colonoscopy group comprising 1006). We found that PDR (45.98 vs. 51.69%, p = 0.008) and ADR (35.67 vs. 40.85%, p = 0.013) were significantly higher in the latest generation HD colonoscopy group. The generational differences were not statistically significant for SSPDR (1.94 vs. 2.78%, p = 0.195) or ANDR (4.65 vs. 4.97%, p = 0.726). In the multivariate regression analysis, age, male sex, the latest generation HD colonoscopy, and long withdrawal time were the most significant factors affecting adenoma detection.

CONCLUSIONS

The latest generation HD colonoscopy improved PDR and ADR by trainee endoscopists. These findings suggest that latest generation, higher-resolution colonoscopy equipment can improve the quality of colonoscopy for less experienced endoscopists.

Incidence of Colorectal Cancer and Adenomatous Polyps After a Two-Step Screening in Isfahan Province, Iran in 2018

PURPOSE

The aim of this study was to estimate the incidence of colorectal cancers in Iran. The results of this study are based on a screening program that is being implemented in Isfahan province.

MATERIAL AND METHODS

In this study, about 137,000 people were screened for colorectal cancer and adenomatous polyps in 2 steps during the year 2018.

RESULTS

Based on the findings of this study, the incidence of adenomatous polyps was reported to be 389 (95% CI, 365-422) per 100,000 population. The incidence of adenomatous polyps was reported to be 483 (95% CI, 446-520) and 316 (95% CI, 286-346) in men and women, respectively (p < 0.001). Also, the incidence of colorectal cancer was reported to be 33 (95% CI, 23-42) per 100,000 population. The incidence of colorectal cancer in men and women was reported to be 41 (95% CI, 30-51) and 26 (95% CI, 17-34), respectively, indicating a statistically non-significant difference (p = 0.29).

CONCLUSION

Based on the result of this study, despite a low participation rate of the target population in the screening program, the incidence of adenomatous polyps and colorectal cancer is relatively high in the average-risk population.

Are the current colonoscopy recommendations for interval surveillance in patients with polyps enough? Machine learning-augmented propensity score cohort analysis of 1840 patients

BACKGROUND

Colonoscopy remains the gold standard for screening and surveillance of colorectal neoplasms, and is associated with a lower risk of colorectal cancer (CRC)-related mortality. The current interval surveillance recommendations in patients with previous adenomas lack sufficient evidence. The prevalence of subsequent adenomas, and especially high-risk adenomas, during surveillance is not well known.

METHODS

The primary outcome of this study was to determine the prevalence of polyps upon surveillance colonoscopy in patients who have a history of adenomas on initial average-risk-screening colonoscopy, but then have a normal initial surveillance (second) colonoscopy between 2003 and 2017. This is the first known retrospective cohort study of adenoma detection rate (ADR) with sub-group analysis of patients with serial surveillance colonoscopies by abnormal and high-risk surveillance findings separately by prior abnormal colonoscopies and correct surveillance strategies based on the recent March 2020 updated guidelines. After ADR calculation, machine learning-augmented propensity score adjusted multivariable regression with augmented inverse-probability weighting propensity (AIPW) score analysis was used to assess the relationship between guideline adherence, as well as abnormal and high-risk surveillance findings.

RESULTS

A total of 1840 patients with pathologically confirmed adenomas or cancer on an initial average-risk-screening (first) colonoscopy met study criteria. 837 (45.5%) had confirmed adenomas on second colonoscopy, and 1003 (54.5%) had normal findings. Of 837 patients with polyps on both first and second colonoscopy, 423 (50.5%) had adenomas on third colonoscopy. Of the 1003 patients without polyps on second colonoscopy, 406 (40.5%) had confirmed adenomas on third colonoscopy. Guideline adherence was low at 9.18%, though was associated in propensity score adjusted multivariable regression with increased odds of an abnormal third (but not high-risk) colonoscopy, with comparable AIPW results.

CONCLUSION

This 14-year study demonstrates the ADR to be > 40% on the third colonoscopy for patients with adenomas on initial screening colonoscopy, who then have a normal second colonoscopy. Through advanced machine learning and propensity score analysis, we showed that correct adherence is associated with higher odds of abnormal, but not high-risk abnormal 3rd colonoscopy, with evidence that high-risk surveillance findings are reduced by providers shortening the time between surveillance colonoscopies in contrast to the guidelines for those for whom there is presumed greater clinical suspicion of eventual cancer. Larger prospective trials are needed to guide optimal surveillance for these patients.

Polygenic risk score is a predictor of adenomatous polyps at screening colonoscopy

Background

Single nucleotide polymorphism (SNP)-based polygenic risk scoring is predictive of colorectal cancer (CRC) risk. However, few studies have investigated the association of genetic risk score (GRS) with detection of adenomatous polyps at screening colonoscopy.

Methods

We randomly selected 1769 Caucasian subjects who underwent screening colonoscopy from the Genomic Health Initiative (GHI), a biobank of NorthShore University HealthSystem. Outcomes from initial screening colonoscopy were recorded. Twenty-two CRC risk-associated SNPs were obtained from the Affymetrix™ SNP array and used to calculate an odds ratio (OR)-weighted and population-standardized GRS. Subjects with GRS of < 0.5, 0.5–1.5, and > 1.5 were categorized as low, average and elevated risk.

Results

Among 1,769 subjects, 520 (29%) had 1 or more adenomatous polyps. GRS was significantly higher in subjects with adenomatous polyps than those without; mean (95% confidence interval) was 1.02 (1.00–1.05) and 0.97 (0.95–0.99), respectively, p < 0.001. The association remained significant after adjusting for age, gender, body mass index, and family history, p < 0.001. The detection rate of adenomatous polyps was 10.8%, 29.0% and 39.7% in subjects with low, average and elevated GRS, respectively, p-trend < 0.001. Higher GRS was also associated with early age diagnosis of adenomatous polyps, p < 0.001. In contrast, positive family history was not associated with risk and age of adenomatous polyps.

Conclusions

GRS was significantly associated with adenomatous polyps in subjects undergoing screening colonoscopy. This result may help in stratifying average risk patients and facilitating personalized colonoscopy screening strategies.

Screening colonoscopy: The present and the future

In the United States, colorectal cancer (CRC) is the second leading cause of mortality in men and women. We are now seeing an increasing number of patients with advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age, which requires earlier screening. With the increasing need for CRC screening through colonoscopy, and thus endoscopists, easier and simpler techniques are needed to train proficient endoscopists. The most widely used approach by endoscopists is air insufflation colonoscopy, where air distends the colon to allow visualization of the colonic mucosa. This technique is un-comfortable for patients and requires an anesthetist to administer sedation. In addition, patients commonly complain about discomfort post-op as air escapes into the small bowel and cannot be adequately removed. Current research into the use of water insufflation colonoscopies has proved promising in reducing the need for sedation, decreasing discomfort, and increasing the visibility of the colonic mucosa. Future direction into water insufflation colonoscopies which have shown to be simpler and easier to teach may increase the number of proficient endoscopists in training to serve our aging population.

Endometrial polyps: Is the prediction of spontaneous regression possible?

Objective

Endometrial polyps have been considered as a hyperplastic growth of endometrial stromal and glandular tissues. Even asymptomatic polyps in premenopausal women are usually removed as soon as they are diagnosed, although it is still unknown how often endometrial polyps disappear spontaneously. The aim of this study was to investigate the regression rate of endometrial polyps and the possible factors related to their spontaneous regression.

Methods

A total of 197 women with endometrial polyps were treated with operative hysteroscopy between January 2017 and April 2019 at our tertiary center. Of these, 123 patients who preferred conservative follow-up were enrolled in the study. Clinical and pathological data were obtained from electronic medical records.

Results

Patients with endometrial polyps were followed up for a median period of 62 days (range 30–360 days). Most women with endometrial polyps (84%) were reported to have gynecologic symptoms. Spontaneous polyp regression was observed in 28 (23%) patients who underwent surgery reevaluation. Patient age (<45 years), premenopausal period, and polyp size (<2 cm) were found to be associated with spontaneous endometrial polyp regression (P<0.05). We also observed more polyp regression in women with abnormal uterine bleeding (P=0.05). Second-look hysteroscopy showed that all postmenopausal women had persistent endometrial polyps.

Conclusion

Patient age (<45 years), premenopausal period, polyp size (<2 cm), and abnormal uterine bleeding may be associated with spontaneous endometrial polyp regression.

Risk Factors for Recurrent Colorectal Polyps

The recurrence of colorectal polyps is caused by various factors and leads to the carcinogenesis of colorectal cancer, which ranks third in incidence and fourth in mortality among cancers worldwide. The potential risk factors for colorectal polyp recurrence have been demonstrated in multiple trials. However, an article that pools and summarizes the various results is needed. This review enumerates and analyzes some risk factors in terms of patient characteristics, procedural operations, polyp characteristics, and dietary aspects to propose some effective prophylactic measures. This review aimed to provide a reference for clinical application and guide patients to prevent colorectal polyp recurrence in a more effective manner.

Yogurt consumption and colorectal polyps

Diet modifies the risk of colorectal cancer (CRC), and inconclusive evidence suggests that yogurt may protect against CRC. We analysed the data collected from two separate colonoscopy-based case-control studies. The Tennessee Colorectal Polyp Study (TCPS) and Johns Hopkins Biofilm Study included 5446 and 1061 participants, respectively, diagnosed with hyperplastic polyp (HP), sessile serrated polyp, adenomatous polyp (AP) or without any polyps. Multinomial logistic regression models were used to derive OR and 95 % CI to evaluate comparisons between cases and polyp-free controls and case-case comparisons between different polyp types. We evaluated the association between frequency of yogurt intake and probiotic use with the diagnosis of colorectal polyps. In the TCPS, daily yogurt intake v. no/rare intake was associated with decreased odds of HP (OR 0·54; 95 % CI 0·31, 0·95) and weekly yogurt intake was associated with decreased odds of AP among women (OR 0·73; 95 % CI 0·55, 0·98). In the Biofilm Study, both weekly yogurt intake and probiotic use were associated with a non-significant reduction in odds of overall AP (OR 0·75; 95 % CI 0·54, 1·04) and (OR 0·72; 95 % CI 0·49, 1·06) in comparison with no use, respectively. In summary, yogurt intake may be associated with decreased odds of HP and AP and probiotic use may be associated with decreased odds of AP. Further prospective studies are needed to verify these associations.

Gastric cancer and adenomatous colorectal polyp concomitant with pyogenic liver abscess and bacteremia

Synchronous gastric cancer and adenomatous colorectal polyp in patients with Klebsiella pneumoniae-induced pyogenic liver abscess (KP-PLA) and bacteremia is a rare presentation. A 58-year-old man with a 6-month history of diabetes mellitus (DM) presented with febrile sensation and dull abdominal pain in the right upper quadrant of the abdomen. Subsequent to laboratory test results and abdominal computed tomography findings, KP-PLA with bacteremia was diagnosed. After intravenous antibiotic administration, his symptoms improved, and upper endoscopy and colonoscopy were performed to evaluate the cause of KP-PLA. Biopsy specimens of the prepyloric anterior wall revealed a moderately differentiated adenocarcinoma. Endoscopic mucosal resection of the colon revealed high-grade dysplasia. Early gastric cancer (EGC) and adenomatous colorectal polyps with high-grade dysplasia concomitant with KP-PLA and bacteremia were diagnosed in our patient who had DM. Intravenous antibiotic treatment for KP-PLA, subtotal gastrectomy for EGC, and colonoscopic mucosal resection for the colon polyp were performed. After 25 days of hospitalization, subtotal gastrectomy with adjacent lymph node dissection was performed. Follow-up ultrasound imaging showed resolution of the abscess 5 weeks post-antibiotic treatment, as well as no tumor metastasis. Upper gastrointestinal endoscopy and colonoscopy should be performed to evaluate gastric cancer in patients with PLA or bacteremia, accompanied with DM or an immunocompromised condition.

Colorectal epithelial neoplasm associated with gut-associated lymphoid tissue

BACKGROUND

Colorectal epithelial neoplasm extending into the submucosal gut-associated lymphoid tissue (GALT) can cause difficulties in the differential diagnosis. Regarding GALT-associated epithelial neoplasms, a few studies favor the term "GALT carcinoma" while other studies have mentioned the term "GALT-associated pseudoinvasion/epithelial misplacement (PEM)".

METHODS

The clinicopathologic characteristics of 11 cases of colorectal epithelial neoplasm associated with submucosal GALT diagnosed via endoscopic submucosal dissection were studied.

RESULTS

Eight cases (72.7%) were in males. The median age was 59 years, and age ranged from 53 to 73. All cases had a submucosal tumor component more compatible with GALT-associated PEM. Eight cases (72.7%) were located in the right colon. Ten cases (90.9%) had a non-protruding endoscopic appearance. Nine cases (81.8%) showed continuity between the submucosal and surface adenomatous components. Nine cases showed (81.8%) focal defects or discontinuation of the muscularis mucosae adjacent to the submucosal GALT. No case showed hemosiderin deposits in the submucosa or desmoplastic reaction. No case showed single tumor cells or small clusters of tumor cells in the submucosal GALT. Seven cases (63.6%) showed goblet cells in the submucosa. No cases showed oncocytic columnar cells lining submucosal glands.

CONCLUSIONS

Our experience suggests that pathologists should be aware of the differential diagnosis of GALT-associated submucosal extension by colorectal adenomatous neoplasm. Further studies are needed to validate classification of GALT-associated epithelial neoplasms.

Applying simple linear combination, multiple logistic and factor analysis methods for candidate fecal bacteria as novel biomarkers for early detection of adenomatous polyps and colon cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer, and presents a considerable disease burden, worldwide. Recently, the gut microbiota has been proposed as a potential risk factor for CRC, and even adenomatous polyps (AP). Here, the aim of this study was to investigate the role of selected gut bacteria as fecal bacterial biomarkers, in early detection of CRC and AP.

MATERIAL AND METHODS

Fecal samples (n = 93) were collected from Taleghani Hospital, Tehran, Iran, between 2015 and 2017, from normal controls (NC), AP cases and CRC stage I patients, who were undergoing screening for colonoscopy. Absolute quantitative real time PCR (qPCR) assays were established for the quantification of bacterial marker candidates, in all cases and control groups. In order to evaluate the diagnostic value of bacterial candidates in distinguishing CRC from a polyp, receiver operating characteristic curve (ROC) was performed. Multiple logistic regressions were used to find the best combinations of the bacterial candidates, then, combinations were analyzed based on three methods, including linear combination, multiple logistic and factor analysis models.

RESULTS

According to the logistic model, combination of Fusobacterium nucleatum, Enterococcus feacalis, Streptococcus bovis, Enterotoxigenic Bacteroides fragilis (ETBF) and Porphyromonas spp. showed improved diagnostic performance, compared to each bacterium alone, as area under the receiver operating characteristic (AUROC) increases to 0.97, with 95% confidence interval. It was found that a simple linear combination was an appropriate model for discriminating AP and CRC cases, compared to the NC, with a sensitivity of 91.4% and specificity of 93.5%.

CONCLUSION

Our results indicated that based on fecal bacterial candidates, statistical simple linear combination model and ROC curve analysis, early detection of AP and CRC might be possible.

Self-Formation Assessed by Cumulative Summation Test Does Not Reach Recommended Thresholds for Optical Diagnosis of Colorectal Polyps ≤ 7 mm

BACKGROUND AND AIMS

Accurate optical diagnosis of diminutive polyps would allow implementing a resect and discard strategy. We evaluated the learning curve of a single training session followed by self-education in subjects with no endoscopic experience.

METHODS

Learning curves were evaluated in 38 subjects employing learning curve-cumulative summation (LC-CUSUM) tests, with each participant attending one training session regarding narrow band imaging and optical diagnosis and then individually assessing 100 lesions, receiving feedback after each diagnosis. Diagnostic accuracy was subsequently evaluated in 180 patients with lesions ≤ 7 mm. Evaluators predicted each polyp's histology and recommended a surveillance interval. Determinants of accuracy were explored using regression analysis.

RESULTS

According to the LC-CUSUM curve, 20 evaluators (52.6%) reached diagnostic competence after 57 lesions (IQR 55-76.5). During the diagnostic performance assessment, 11,666 diagnoses and 6840 follow-up recommendations were generated. Considering high confidence diagnoses, accuracy was 81.3% (80.5-82.1%), negative predictive value (NPV) for rectosigmoid adenomas 78.6% (76.4-80.6%), and sensitivity for adenomas 86.6% (85.8-87.4%). Two (5.3%) evaluators reached a ≥ 90% accuracy, 3 (7.9%) presented a NPV for rectosigmoid adenomas ≥ 90%, and 18 (47.4%) a sensitivity for adenomas ≥ 90%. Multivariable logistic regression showed high confidence and size ≥ 5 mm as the strongest predictors of accuracy. Fifteen (39.5%) evaluators recommended a correct or reduced follow-up interval in over 90% of subjects.

CONCLUSIONS

Self-formation after a single training session did not allow most evaluators to reach the required accuracy. LC-CUSUM tests did not identify competent evaluators. Despite these results, 86.7% of follow-up intervals would have been corrected or reduced.

Predicting the presence of adenomatous polyps during colonoscopy with National Cancer Institute Colorectal Cancer Risk-Assessment Tool

AIM

To evaluate the National Cancer Institute (NCI) Colorectal Cancer (CRC) Risk Assessment Tool as a predictor for the presence of adenomatous polyps (AP) found during screening or surveillance colonoscopy.

METHODS

This is a retrospective single center observational study. We collected data of adenomatous polyps in each colonoscopy and then evaluated the lifetime CRC risk. We calculated the AP prevalence across risk score quintiles, odds ratios of the prevalence of AP across risk score quintiles, area under curves (AUCs) and Youden’s indexes to assess the optimal risk score cut off value for AP prevalence status.

RESULTS

The prevalence of AP gradually increased throughout the five risk score quintiles: i.e., 27.63% in the first and 51.35% in the fifth quintile. The odd ratios of AP prevalence in the fifth quintile compared to the first and second quintile were 2.76 [confidence interval (CI): 1.71-4.47] and 2.09 (CI: 1.32-3.30). The AUC for all patients was 0.62 (CI: 0.58-0.66). Youden’s Index indicated the optimal risk score cutoff value discriminating AP prevalence status was 3.60.

CONCLUSION

Patients with the higher NCI risk score have higher risk of AP and subsequent CRC; therefore, measures to increase the effectiveness of CRC detection in these patients include longer withdrawal time, early surveillance colonoscopy, and choosing flexible colonoscopy over other CRC screening modalities.

Gastrointestinal lesions in chronic kidney disease patients with anaemia

INTRODUCTION

Despite the frequency with which anaemia is present in patients with chronic kidney disease (CKD), its relationship with gastrointestinal lesions has not been studied.

METHOD

A cross-sectional, analytical, observational study involving one year of recruitment was carried out to determine the prevalence of endoscopic gastrointestinal lesions and associated risk factors in asymptomatic patients with chronic kidney disease stages 1-5 and anaemia who had a positive qualitative immunochemical faecal occult blood test.

RESULTS

A total of 9,658 patients with CKD were analysed, of which 286 (2.9%) had anaemia; 198 had a positive faecal occult blood test (47% male, 71.1±11.8 years). The endoscopic study revealed 255 lesions, with at least one lesion in 68.2% of patients, with the most prevalent being: adenomatous colorectal polyps (39.6%), acute lesions of the gastric mucosa (22.6%), neoplastic lesions 15.1%), angiodysplasia (14.4%), oesophagitis (8.4%), inflammatory bowel disease (4.8%) and ischaemic colitis (3.1%). Uraemia and acetylsalicylic acid were identified as risk factors for acute gastric mucosal lesions. Angiodysplasia was associated with alcoholism, a more advanced stage of chronic kidney disease, anaemia, and lack of response to erythropoiesis-stimulating agents. Age and refractory anaemia were risk factors for adenomatous polyps and colorectal cancer.

CONCLUSION

Renal patients with anaemia could benefit from an endoscopic study due to their high prevalence of gastrointestinal lesions, particularly adenomatous polyps and colorectal cancer, which are more common in those over 50 years of age with CKD stages 3-5.

Mis-sizing of Adenomatous Polyps is Common among Endoscopists and Impacts Colorectal Cancer Screening Recommendations

Background/Aims

To determine the accuracy of identifying ≥6-mm adenomatous polyps during colonoscopy and define its impact on subsequent interval screening.

Methods

We conducted a retrospective study of patients who underwent colonoscopies at Banner University Medical Center, Tucson from 2011 to 2015. All patients with ≥6-mm adenomatous polyps based on their colonoscopy report were included. Adenomatous polyps were excluded if they did not meet the criteria. Discrepancies in the polyp size were determined by calculating the percentage of size variation (SV). Clinical mis-sizing was defined as SV >33%.

Results

The polyps analyzed were predominantly <10 mm in size. Approximately 13% of the examined polyps met the inclusion criteria, and 40.7% of the adenomas were ≥10 mm. A total of 189 ≥6-mm adenomatous polyps were collected from 10 different gastroenterologists and a colorectal surgeon. Adenomatous polyps were clinically mis-sized in 56.6% of cases and overestimated in 71.4%. Among the adenomas reviewed, 22% of mis-sized polyps and 11% of non-mis-sized polyps resulted in an inappropriate surveillance interval.

Conclusions

We found that more than half of ≥6-mm adenomatous polyps are mis-sized and that there is a tendency to overestimate adenoma size among endoscopists. This frequently leads to inappropriate intervals of surveillance colonoscopy.

Low frequency of polyps in colonic regions with diverticulosis

PURPOSE

Conflicting evidence exists regarding any association between diverticulosis and adenomatous polyps. We evaluated the prevalence of polyps and cancer in colonic regions containing diverticula.

METHODS

Six hundred consecutive colonoscopy reports from a single endoscopist were reviewed to determine prevalence and location of diverticulosis and polyps. Additionally, pathology reports of 88 colon cancer resection specimens were reviewed for the presence of diverticulosis, and compared with expected prevalence of diverticulosis in that colonic region based on the collected colonoscopy data.

RESULTS

Overall, rates of detected polyps were comparable between patients with and without diverticulosis. However, analyzing the data by colonic segment containing diverticulosis, the prevalence of adenomatous polyps was reduced in regions of diverticulosis compared to the same colonic segment unaffected by diverticulosis (7 vs. 17% for rectosigmoid (p = 0.005); 5 vs. 18% for descending (p < 0.0001); and 17 vs. 27% for ascending colon (p = 0.0495)). Among colon cancer resection specimens, the prevalence of diverticulosis was significantly reduced in the rectosigmoid and ascending colon, compared with expected rates of diverticulosis in those regions. (13 vs. 42% in rectosigmoid (p = 0.0006); 3 vs. 17% in ascending colon (p = 0.043)).

CONCLUSION

Despite similar overall frequency of polyps in patients with and without diverticulosis, polyps were significantly less likely in the colonic segment affected by diverticulosis. Additionally, the frequency of diverticulosis in areas of cancer in the rectosigmoid and ascending colon was significantly lower than expected compared with the expected frequency of diverticulosis for those colonic regions. These observations suggest a true negative association between colonic neoplasia and diverticulosis.

Epidemiology and risk factors of colorectal polyps

The lifetime risk of colorectal cancer (CRC) in the Western world is around 5%. CRC commonly develops from precursor lesions termed polyps, classified as adenomatous or serrated polyps according to growth pattern. Despite the well-known connection between polyps and cancer, most polyps will never develop into CRC. For those that do, the time until CRC development is generally thought of as >10 years. This gives opportunity for interventional strategies to prevent transformation into cancer. This article aims to provide an overview of the epidemiology of and risk factors for colorectal polyps in the average risk population, and will encompass the effect of age, gender, ethnicity, smoking, obesity, alcohol, physical activity, NSAIDs and dietary factors on colorectal polyps.

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.

Clinical validation of a novel urine-based metabolomic test for the detection of colonic polyps on Chinese population

PURPOSE

Colorectal cancer is the fifth leading cause of cancer-related deaths in China. When detected early, with the removal of adenomatous polyps, precursors of colorectal cancer, it is preventable. The aim of this study was to evaluate a novel urine-based metabolomic diagnostic test for the detection of adenomatous polyps, PolypDx™, that was originally developed and validated using 1000 samples from Canadian Cohort, on Chinese population.

METHODS

Prospective urine samples were collected from 1000 participants undergoing colonoscopy examination, from March 2013 to July 2014 at Minhang District, Shanghai Centre for Disease Control and Prevention. One-dimensional nuclear magnetic resonance spectra of urine metabolites were analyzed to determine the concentrations of three key metabolites used in PolypDx™. The predicted results were then compared to the gold standard for colorectal cancer diagnostic, colonoscopy. Area under curve (AUC) was calculated specifically for the Chinese population and compared with the Canadian dataset. Sensitivity and specificity of this urine-based metabolomic diagnostic test were also compared with three commercially available fecal-based tests.

RESULTS

An AUC of 0.717 for PolypDx™ was calculated on Chinese dataset which is slightly lower than the AUC on the Canadian dataset. A sensitivity of 82.6% and a specificity of 42.4% were achieved on Chinese dataset.

CONCLUSIONS

Here, we validated a novel urine-based metabolomic diagnostic test for the detection of adenomatous polyps, PolypDx™, on Chinese population through a sample size of 1000 participants with a greater level of sensitivity than fecal-based tests.

Is early colonoscopy after CT-diagnosed diverticulitis still necessary?

PURPOSE

WHO GLOBOCAN 2012 data showed that Australia and New Zealand have the highest incidence rates of colorectal cancer in the world (Ferlay et al. 1). Current guidelines recommend that patients admitted for an episode of acute diverticulitis require an early follow-up colonoscopy to rule out colorectal malignancy as reported by Fozard et al. (Colorectal Dis 13:1-11, 2011). Recent studies however have indicated that this may not be warranted (Brar et al. Dis Colon rectum 56:1259-1264, 2013). This study aimed to review the current practice by looking at our institution's rate of colorectal malignancy diagnosed after an episode of acute diverticulitis.

METHODS

We conducted a retrospective analysis of patients who presented with acute diverticulitis at our institution between 2011 and 2013. Included in the study were patients who received follow-up colonic evaluation in the next 12 months after admission. Patients who had a colonoscopy in the last year prior to emergency presentation were excluded. The primary outcome measure was the incidence of histologically confirmed colorectal carcinoma diagnosed on follow-up colonoscopy. Secondary outcome measures were incidence of low-grade or advanced adenoma on follow-up colonic evaluation.

RESULTS

A total of 523 cases of acute diverticulitis were diagnosed on CT scan. Out of 351 patients with uncomplicated diverticulitis, 196 had follow-up colonoscopy, with one case of colorectal malignancy recorded. Low-grade and advanced adenomas were found on 10.7 and 2.0% of colonoscopies performed respectively in this subgroup. Seventy-four out of 172 patients with complicated diverticulitis had follow-up evaluation, with four cases of colorectal malignancy discovered. Low-grade and advanced adenomas were found on 6.75 and 5.41% of colonoscopies performed respectively in this subgroup.

CONCLUSION

Routine interval colonoscopy following an episode of conservatively managed uncomplicated diverticulitis may not be necessary. Interval colonoscopy is still indicated in patients with complicated diverticulitis. Further collaborative study across different institutions may be warranted to gain better statistical significance.

Clinical and pathologic features of colorectal polyps: Analysis of 313 cases

AIM: To investigate the clinical and pathological features of colorectal polyps, and to provide reference for clinical diagnosis and treatment.

METHODS: The clinical records of 313 cases of colorectal polyps treated from September 2011 to September 2014 at Nanjing First Hospital were retrospectively analyzed. All patients received colonoscopy, and were confirmed to have colon polyps through endoscopic and histopathological examinations.

RESULTS: The incidence of adenomatous polyps was 72.8%. There was no significant difference in clinical characteristics between adenomatous and non-adenomatous polyps (P > 0.05). The occurrence of colorectal polyps was not correlated with sex, Yamada type, growth location and number of polyps (P > 0.05). The incidence of adenomatous polyps in different age groups and in polyps with different diameters was statistically significant (P < 0.05). The extent of the tumor was not associated with sex, age, location of growth or number of polyps, but there were significant differences in the degree of tumor variation when stratified by the Yamada type and the diameter of polyps (P < 0.05).

CONCLUSION: Colorectal polyps have no specific clinical manifestations. Most of colorectal polyps are located in the left colon. There is no significant difference in the incidence of adenomatous polyps between males and females, but the incidence rate is higher in patients with polyps whose diameter is > 1 cm. The number of polyps has no effect on the incidence of adenoma.

Gastric polyps: Association with Helicobacter pylori status and the pathology of the surrounding mucosa, a cross sectional study

AIM: To assess the endoscopic characteristics of gastric polyps and their association with Helicobacter pylori (H. pylori) status in a predominantly Hispanic population.

METHODS: We conducted a retrospective study of all esophagogastroduodenoscopies performed at our institution. Demographic, endoscopic and histopathological data were reviewed. Categorization of patients into Hispanic and Non-Hispanic was based on self-identification. Patients without resection/biopsy were not included in the analysis. Identification of polyps type was based on histological examination. One way analysis of variance was used to compare continuous variables among different polyp types and Fisher’s exact test was used compare categorical variables among polyp types. Unadjusted and adjusted comparisons of demographic and clinical characteristics were performed according to the H. pylori status and polyp type using logistic regressions.

RESULTS: Of 7090 patients who had upper endoscopy, 335 patients had gastric polyps (4.7%). Resection or biopsy of gastric polyps was performed in 296 patients (88.4%) with a total of 442 polyps removed or biopsied. Of 296 patients, 87 (29%) had hyperplastic polyps, 82 (28%) had fundic gland polyps and 5 (1.7%) had adenomatous polyps. Hyperplastic polyps were significantly associated with positive H. pylori status compared with fundic gland polyps (OR = 4.621; 95%CI: 1.92-11.13, P = 0.001). Hyperplastic polyps were also found to be significantly associated with portal hypertensive gastropathy compared with fundic gland polyps (OR = 6.903; 95%CI: 1.41-33.93, P = 0.0174). Out of 296 patients, 30 (10.1%) had a follow-up endoscopy with a mean duration of 26 ± 16.3 mo. Interval development of cancer was not noted in any of the patients during follow up period.

CONCLUSION: Gastric hyperplastic polyps were significantly associated with positive H. pylori status and portal hypertensive gastropathy as compared with fundic gland polyps.

Folate status, folate-related genes and serum miR-21 expression: Implications for miR-21 as a biomarker

BACKGROUND

Free circulating microRNA (miRNA) in serum may be valuable biomarkers for disease diagnosis and prognosis. miR-21, the archetypal oncogenic miRNA, has been proposed as a biomarker for colorectal cancer and its benign precursor, adenomatous polyps. However, it is now becoming clear that circulating miRNA profiles may be sensitive to lifestyle and environmental influences. Dietary components involved in one-carbon metabolism are particularly well placed to modulate miRNA expression through an influence on DNA methylation pathways.

METHODS

We investigated the role of methyl group donors (folate, B12, cysteine, homocysteine), polymorphisms of the enzymes of one-carbon metabolism, and serum miR-21 expression in a primary case-control cohort (colonoscopy confirmed adenomatous colon polyps vs controls; n = 253) and a secondary cross-sectional cohort (over 65s; n = 649). The relationships between these parameters and serum miR-21 levels were assessed, stratified by gender.

CONCLUSIONS

Serum miR-21 expression was related to occurrence of adenomatous polyps in females, but not males. Folate levels and MTHFR-C677T genotype was associated with miR-21 expression in both genders. Additionally, DHFR-19 del and MSR-A66G were associated with miR-21 expression in females and males, respectively. Stimulation with excess folate increased expression of miR-21 in colon cancer cell lines.

GENERAL SIGNIFICANCE

This study demonstrates that serum miR-21 expression correlates with folate status and related genetic status. This may have consequences for the proposed use of miR-21 as a colorectal cancer biomarker.

Tumor-Associated Macrophage (TAM) and Angiogenesis in Human Colon Carcinoma

AIM:

This study aimed to clarify how macrophages affect prognosis in cancer colon and their association with tumor angiogenesis.

MATERIAL AND METHODS:

Forty four biopsies of colon carcinoma and 15 of benign adenomatous polyps were investigated for macrophages infiltration and microvessels density using immunohistochemistry and image morphometric analysis. Macrophages and blood vessels were stained immunohistochemically by CD68 and F-VIII markers respectively. The morphometric analysis was carried out on the immunohistochemically stained slides using the Leica Qwin 500 Image Analyzer. Both of macrophages infiltration and microvessels density were correlated with histological tumor grade, stage and lymph node metastases and were correlated with each others.

RESULTS:

Macrophage infiltration was significantly higher in malignant cases than in benign polyps. High macrophage infiltration and hypervascularity were significantly correlated with T-staging and lymph nodes metastasis. A significant correlation was found between macrophage infiltration and microvessels densitie in malignant tumors where hypervascularity was significantly correlated with high macrophages infiltration.

CONCLUSION:

The significant correlation between macrophage infiltration and tumor angiogenesis suggests an interaction between macrophages and cancer cells stimulating microvessels formation, tumor invasion and metastasis in colon cancer. We recommend that macrophages infiltration should be evaluated to investigate their clinical value in development of individualized therapeutic regimens for management of colon carcinoma.

Retrospective study of colorectal cancer in Zimbabwe: Colonoscopic and clinical correlates

AIM: To compare differences in the frequency of colorectal cancer at colonoscopy in Zimbabwe according to ethnicity.

METHODS: All lower gastrointestinal endoscopic procedures performed between January 2006 and December 2011 at a gastroenterology clinic in Harare, Zimbabwe were reviewed. The demographic characteristics, clinical indications, differences in bowel preparation and the endoscopic and histological diagnoses were compared between different ethnic groups with emphasis on colorectal cancer. The clinical and demographic characteristics and the endoscopic findings were compared using the student t-test and the χ² test, while the clinical indications associated with a diagnosis of colorectal cancer were determined by logistic regression.

RESULTS: All colonoscopies and sigmoidoscopies performed in 1236 Caucasians, 460 black Africans and 109 Asians were analysed. Colorectal cancer was diagnosed more frequently in the black African patients compared to Caucasians or Asians (10% vs 3%, 10% vs 2%, P < 0.001). However, polyps were less common among black Africans (5%) compared to both Caucasians (8%) and Asians (9%) (P = 0.03). Among patients with colorectal cancer, black Africans tended to be younger than Caucasians, who were over-represented in the oldest age category; 32 % vs 2% were less than 50 years and 41% vs 78% were older than 60 years (P < 0.001). Anaemia and weight loss were associated with colorectal cancer in both black African [odds ratio (OR): 2.73 (95%CI: 1.33-5.61) and 3.09 (1.35-7.07)] and Caucasian patients [OR: 6.65 (95%CI: 2.93-15.09) and 3.47 (1.52-7.94)].

CONCLUSION: The likelihood of diagnosing colorectal cancer in patients referred for colonoscopy in Zimbabwe is at least as likely among black Africans as it is among Caucasians.

Early precursor of mixed endocrine-exocrine tumors of the gastrointestinal tract: histologic and molecular correlations

BACKGROUND

Mixed endocrine-exocrine tumors display histologic features of endocrine and glandular differentiation. Unlike in collision tumors, the two components are thought to arise from a monoclonal precursor. Evidence from molecular testing supports the monoclonal theory and suggests that the exocrine component may give rise to the endocrine component but not vice versa.

CASE REPORT

We report a case of an adenomatous polyp in the large intestine that had groups of endocrine cells arising from the crypt bases of the adenomatous (exocrine) epithelium. To our knowledge, ours is only the second report of an adenomatous polyp in which groups of microcarcinoid endocrine cells were recognized. The histologic findings in our case correlate with the molecular findings described in mixed endocrine-exocrine tumors.

CONCLUSION

Our description may represent the primordial stage of a mixed endocrine-exocrine neoplasm.

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.

Body mass index as a predictor of advanced colorectal neoplasia

Background:

Colorectal cancer (CRC) is the third frequent cancer in Korea. There are several risk factors including male sex, older age, smoking and family history of colon cancer. Recently, obesity is thought to be a risk factor for CRC and advanced colon polyps. Therefore, we designed a cross-sectional study to determine the association between BMI and advanced colorectal neoplasia.

Methods:

A total of 256 patients with advanced colorectal neoplasia who were diagnosed using colonoscopy between May, 2004 and December, 2011 were included in this study. Advanced colorectal neoplasia was defined large (≥1 cm) adenoma or adenocarcinoma. We compared these patients to a control group consisting of 217 subjects with normal colonoscopic findings recruited during the same period.

Results:

Of the 256 patients, there were 132 (51.6%) men, and the mean age was 56.4±12.3 years. The rate of males, alcohol drinker and current smokers was significantly higher in the advanced colorectal neoplasia compared to control group. In the subgroup analysis, the mean age and body mass index (BMI, kg/m²) of advanced colorectal neoplasia were higher than control group in the female subjects. However, there were no significant differences between two groups in the male subjects. Multiple logistic regression analysis identified overweight (BMI 23.0–24.9 kg/m², odds ratios [OR]=2.022) and obesity (BMI≥25 kg/m², OR=2.383) as independent risk factors for advanced colorectal neoplasia.

Conclusions:

We suggest that BMI should be considered as an independent risk factor for advanced colorectal neoplasia, and people with high BMI should be recommended to undergo colonocoscopy screening earlier than scheduled.

The risk of colonic adenomas and colonic cancer in obesity

Increasing body fatness has been associated with an increased burden from colorectal cancer. An increased susceptibility spanning the entire continuum from precancerous adenomatous polyps to the development of colorectal cancer, poor outcome with treatment, and reduced survival when compared to those with normal body weight has been described. It is unknown which age period and which degree and duration of excess weight are associated with increased colorectal cancer risk. It is uncertain whether weight loss can reverse this risk. If it can, how long will the new lower or normal weight be maintained to effect enduring risk reduction? Furthermore, it is controversial whether the increased burden of colorectal cancer warrants earlier and/or more frequent screening for obese persons. This article reviews the relationship between obesity and colorectal neoplasia, explores the postulated mechanism of carcinogenesis, discusses interventions to reduce the burden of disease, and suggests future directions of research.

Incidence of colorectal neoplasms among male pilots

AIM: To assess the prevalence of colorectal neoplasms (adenomas, advanced adenomas and colorectal cancers) among Israeli military and commercial airline pilots.

METHODS: Initial screening colonoscopy was performed on average-risk (no symptoms and no family history) airline pilots at the Integrated Cancer Prevention Center (ICPC) in the Tel-Aviv Medical Center. Visualized polyps were excised and sent for pathological examination. Advanced adenoma was defined as a lesion >10 mm in diameter, with high-grade dysplasia or villous histology. The results were compared with those of an age- and gender-matched random sample of healthy adults undergoing routine screening at the ICPC.

RESULTS: There were 270 pilots (mean age 55.2 ± 7.4 years) and 1150 controls (mean age 55.7 ± 7.8 years). The prevalence of colorectal neoplasms was 15.9% among the pilots and 20.6% among the controls (P = 0.097, χ² test). There were significantly more hyperplastic polyps among pilots (15.5% vs 9.4%, P = 0.004) and a trend towards fewer adenomas (14.8% vs 20.3% P = 0.06). The prevalence of advanced lesions among pilots and control groups was 5.9% and 4.7%, respectively (P = 0.49), and the prevalence of cancer was 0.7% and 0.69%, respectively (P = 0.93).

CONCLUSION: There tends to be a lower colorectal adenoma, advanced adenoma and cancer prevalence but a higher hyperplastic polyp prevalence among pilots than the general population.

Colorectal cancer disparities: Issues, controversies and solutions

Colorectal cancer (CRC) is the second leading cause of cancer related deaths in the United States. There are significant differences in CRC incidence and mortality by race with the highest burden occurring among blacks. The underlying factors contributing to CRC disparities are multiple and complex. Studies have suggested that a higher prevalence of putative risk factors for CRC, limited access to healthcare services, lower utilization of healthcare resources and increased biological susceptibilities contribute to this disparity by race. This article reviews the factors associated with the disproportionally higher burden of CRC among blacks; addresses the controversies regarding the age to begin CRC screening and the screening modality to use for blacks; and proffers solutions to eliminate CRC disparity by race.

Atypical presentation of pseudomembranous colitis localized in adenomatous polyps

The most frequent cause of pseudomembranous colitis is Clostridium difficile (C. difficile) infection. This type of colitis is characterized by an endoscopic pattern of numerous small, yellowish or whitish plaques diffusely distributed, which typically compromises the rectum extending to proximal colon. Occasionally, the pseudomembranes compromise only the transverse or right colon, but their exclusive localization over polyps has not been reported. In this case report we have described a patient with symptoms compatible with C. difficile infection and positive for C. difficile toxigenic culture. Colonoscopy examination showed two small polyps with a whitish surface, and histopathological analysis confirmed them to be pseudomembranes over tubular adenomas. The rest of the colonic mucosa was normal and no other cause was demonstrated. We suggest that this particular distribution might be due to a higher affinity for dysplastic cells such as adenomatous polyps of colon by C. difficile and/or its toxins.

Analysis of O6-methylguanine-DNA methyltransferase methylation status in sporadic colon polyps

BACKGROUND/AIM

The aim of our study was to check how MGMT methylation status together with known factors influenced the risk of colon cancer development.

MATERIALS AND METHODS

We examined patients with colon polyps. Information concerning gender, age, lifestyle, diet, anthropometry and medical information, including cancer and family history of cancer, was analyzed. Polymorphism variety of MGMT gene was investigated in another study. Genetic analysis for MGMT methylation assessment was performed for polyp tissue samples from 143 patients.

RESULTS

Positive methylation MGMT status was found in 55 patients. There was no correlation between gender and MGMT methylation status (p = 0.43). We did not find correlation between patients younger and older than 60 (p = 0.87). There was no correlation between smoking and MGMT methylation status (p = 0.36). We did not find correlation between BMI and MGMT methylation status (p = 0.86). We did not find correlation between MGMT methylation status and colon cancer in familial history (p = 0.45).

CONCLUSION

Our study showed no correlations between methylation status of MGMT polymorphisms and clinical features like age, gender, polyp localization, smoking status, or obesity. It has been shown previously that MGMT methylation status may show nonspecific methylation in colon polyps. Gene methylation status in adenoma tissues has also been associated by other authors with the adenoma's size, histology, and degree of atypia. In our study, we evaluated the gene methylation status in colon polyps and found no association with adenoma characteristics. The present study showed no correlation for MGMT methylation in polyps in different regions of colon.

Role of high definition colonoscopy in colorectal adenomatous polyp detection

AIM: To investigate the rates of polyp detection in a mixed risk population using standard definition (SDC) vs high definition colonoscopes (HDC).

METHODS: This was a retrospective cohort comparative study of 3 colonoscopists who each consecutively performed 150 SDC (307, 200 pixel) and 150 HDC (792, 576 pixels) in a community teaching hospital.

RESULTS: A total of 900 colonoscopies were evaluated (mean age 56, 46.8% men), 450 with each resolution. Polyps of any type were detected in 46.0% of patients using SDC and 43.3% with HDC (P = 0.42). There was no significant difference between the overall number of polyps, HDC (397) and SDC (410), detected among all patients examined, (P = 0.73). One or more adenomatous polyps were detected in 24.2% of patients with HDC and 24.9% of patients with SDC colonoscopy (P = 0.82). There was no significant difference between HDC (M = 0.41) and SDC (M = 0.42) regarding adenomatous polyp (P = 0.88) or advanced adenoma (P = 0.56) detection rate among all patients examined.

CONCLUSION: HDC did not improve yield of adenomatous polyp, advanced adenoma or overall polyp detection in a population of individuals with mixed risk for colorectal cancer.

Pseudoinvasion in an adenomatous polyp of the colon mimicking invasive colon cancer

Pseudoinvasion or pseudocarcinomatous invasion in an adenomatous polyp of the colon can be unfamiliar to an endoscopist. Pseudoinvasion in an adenomatous polyp represents prolapse of the adenomatous epithelium into its stalk. In most cases its morphology does not differ from of general adenomatous polyps, but in some cases it can morphologically mimic a malignant polyp with submucosal invasion due to mass-like lesioning of its stalk. This makes it difficult for endoscopists to differentiate pseudoinvasion in an adenoma from an invasive carcinoma by conventional endoscopy; instead, endoscopic ultrasonography can provide useful information for differentiating these conditions. We report on an 82-year-old man who presented with a large pedunculated polyp with a thick stalk in the sigmoid colon, which mimicked a submucosal invasive carcinoma. The patient was diagnosed with pseudoinvasion in an adenomatous polyp after segmental resection of the sigmoid colon.