High risk features in colorectal adenomatous polyps: A multi-institutional study

High risk features in colorectal adenomatous polyps include size >1 cm and advanced histology: high-grade dysplasia and villous architecture. We investigated whether the diagnostic rates of advanced histology in colorectal adenomatous polyps were similar among institutions across the United States, and if not, could differences be explained by patient age, polyp size, and/or CRC rate. Nine academic institutions contributed data from three pathologists who had signed out at least 100 colorectal adenomatous polyps each from 2018 to 2019 taken from patients undergoing screening colonoscopy. For each case, we recorded patient age and sex, polyp size and location, concurrent CRC, and presence or absence of HGD and villous features. A total of 2700 polyps from 1886 patients (mean age: 61 years) were collected. One hundred twenty-four (5 %) of the 2700 polyps had advanced histology, including 35 (1 %) with HGD and 101 (4 %) with villous features. The diagnostic rate of advanced histology varied by institution from 1.7 % to 9.3 % (median: 4.3 %, standard deviation [SD]: 2.5 %). The rate of HGD ranged from 0 % to 3.3 % (median: 1 %, SD: 1.2 %), while the rate of villous architecture varied from 1 % to 8 % (median: 3.7 %, SD: 2.5 %). In a multivariate analysis, the factor most strongly associated with advanced histology was polyp size >1 cm with an odds ratio (OR) of 31.82 (95 % confidence interval [CI]: 20.52-50.25, p < 0.05). Inter-institutional differences in the rate of polyps >1 cm likely explain some of the diagnostic variance, but pathologic subjectivity may be another contributing factor.

Clinical and Surgical Outcomes of Endoscopic Endonasal Approach for Giant Pituitary Adenomas: Analysis of Predictive Factors

BACKGROUND

Giant pituitary adenomas (GPAs) are defined as tumors with ≥40 mm in any maximum diameter, and these tend to invade multiple intracranial compartments. Hence, treatment remains a surgical challenge.

OBJECTIVE

To describe the clinical and surgical outcomes of the endoscopic endonasal approach (EEA) for GPA in a pituitary referral center in Latin America and to analyze associated predictive factors.

METHODS

37 patients with histologically-confirmed GPA treated solely through the EEA between a 2-year period were included. Preoperative and postoperative clinical and neuroimaging findings; surgical morbidity and mortality; and binary logistic regression analysis to assess predictive factors were analyzed.

RESULTS

Preoperative visual impairment prevalence was 97.3%. Mean tumor volume was 32 cc and gross total resection rate was 40.5%. Favorable visual acuity and visual fields outcome rate was 75% and 82.9%, respectively. In the multivariate analysis, bilateral cavernous sinus invasion (P = 0.018) and postoperative cerebrospinal fluid (CSF) leak (P = 0.036) were associated with an unfavorable visual acuity outcome, while radiation therapy (P = 0.035) was for visual fields. Similarly, intraoperative CSF leak was a predictive factor for postoperative CSF leak (10.8%) (P = 0.042) and vascular injury (13.5%) (P = 0.048).

CONCLUSIONS

In this first Mexican clinical series, we demonstrated that the EEA is a safe and effective technique for GPA, although early diagnosis and prompt intervention may promote further visual function preservation without significant endocrine morbidity.

Endoscopic Approach to Duodenal Adenomas in Familial Adenomatous Polyposis: A Retrospective Cohort

Introduction

Over 90% of the patients with familial adenomatous polyposis (FAP) will develop duodenal adenomas.

Aim

The aim of this study was to evaluate the effectiveness and safety of endoscopic excision of large duodenal adenomas in FAP patients.

Methods

All FAP patients from a familial risk clinic submitted to endoscopic therapy for duodenal adenomas ≥10 mm between January 2010 and February 2021 were included.

Results

From 151 FAP families, 22 patients (50 lesions) were included: 54.5% female; median follow-up 8.5 (IQR: 5.8-12.3) years after the first endoscopy. First therapeutic endoscopy occurred at a median age of 41.0 years (IQR: 33.0-58.2). Repeat therapeutic endoscopy was required in 54.5% of patients. Median size of the largest adenoma was 15 mm (IQR: 10-18 mm); resection was piecemeal in 63.1% and en bloc in the remaining. In 2 cases, the resection was incomplete (fibrosis due to previous resection and difficult positioning). Complications occurred in 6.3% of the resected lesions (4 patients): 2 immediate (bleeding, perforation); 4 in the first week (1 bleeding, 2 mild pancreatitis, 1 perforation requiring surgery; the latter two after ampullectomy). Histology revealed low-grade dysplasia adenomas in 90.1%; no adenocarcinomas were found. One patient with Spigelman stage IV disease not amenable to endoscopic control underwent elective duodenopancreatectomy (without duodenal cancer).

Conclusion

Endoscopic surveillance and treatment of duodenal adenomas in FAP patients was safe and effective in the prevention of duodenal cancer.

What do 'false-positive' stool tests really mean? Data from the New Hampshire colonoscopy registry

We utilized the population-based New Hampshire Colonoscopy Registry to calculate false discovery rates (FDR) and positive predictive values (PPVs) using three 'positive' colonoscopy definitions. Understanding the frequency of meaningful 'true positive' mt-sDNA and Fecal Immunochemical Test (FIT) results can optimize the use of these colorectal cancer (CRC) screening tests. We calculated FDR (positive stool test followed by negative colonoscopy divided by all positive stool tests) and PPV for mt-sDNA and FIT cohorts using the following definitions: 1) DeeP-C Study (CRC, adenomas/serrated polyps ≥ 1 cm, villous/High Grade Dysplasia); 2) < 10 year US Multi-Society Task Force (USMSTF) follow-up: DeeP-C findings & ≥1 sessile serrated polyps (SSPs) < 1 cm (with/without dysplasia) or ≥ 1 tubular adenomas < 1 cm. 3) Clinically Significant: DeeP-C + USMSTF + clinically significant serrated polyps: traditional serrated adenomas, SSPs, hyperplastic polyps (HPs) > 1 cm, and 5-9 mm proximal HPs. The sample included 549 mt-sDNA + and 410 FIT + and patients (mean age 66.4, 43.0% male). Using the most limited definition of positive colonoscopy, DeeP-C, FDR was 71.9% for mt-sDNA + and 81.7% for FIT +. Using the USMSTF definition, FDR decreased substantially: mt-sDNA+:33.2% and FIT+:47.6%. Adding all CSSPs resulted in the lowest FDR: mt-sDNA+:32.2% and FIT+:47.1%. Decreasing FDRs corresponded to increasing PPVs: mt-sDNA+:28.1% and FIT+:18.3% (DeeP-C definition) and mt-sDNA+:67.8% and FIT+:52.9% (DeeP-C + USMSTF + CSSP) (Table 1). FDRs decreased substantially when the definition of positive exams included all significant precancerous findings. These data present a comprehensive understanding of false positive outcomes at colonoscopies following positive stool tests, which to our knowledge is the first such analysis.

Risk factors for sessile serrated lesions among Chinese patients undergoing colonoscopy

BACKGROUND AND AIM

Serrated polyps have been recognized as a premalignant lesion accounting for a significant proportion of colorectal cancer. Limited data are available regarding the risk factors for colorectal sessile serrated lesions (SSLs). We aimed to investigate clinical risk factors of SSLs and compared them with colorectal adenomas in a study population of Chinese individuals.

METHODS

A retrospective case-control study was performed in an academic tertiary-referral center in Hong Kong. Subjects with SSLs and adenomas were identified from the hospital pathology database from January 2010 to December 2020, and additional clinical data were retrieved from the electronic patient record system. We compared clinical features and risk factors of SSL patients with those without these lesions.

RESULTS

A total of 2295 subjects were included in the study, including 459 subjects with SSLs, 918 subjects with adenomas, and 918 subjects with normal colonoscopy. By multivariable logistic regression, compared with normal subjects, patients with SSLs only were significantly more likely to have dyslipidemia (adjusted OR: 1.431, 95% CI 1.008-2.030) and diabetes mellitus (adjusted OR: 2.119, 95% CI 1.439-3.122).

CONCLUSIONS

Dyslipidemia and diabetes were independent risk factors for SSLs. Our findings suggest these metabolic factors may be important for the risk of SSLs. The findings may improve our understanding of SSLs and shed light on patient selection for screening and risk stratification.

Impact of Clinical and Endoscopic Features on the Development of Metachronous Colorectal Advanced Serrated Lesions

BACKGROUND AND AIMS

High-risk adenomas predict metachronous advanced adenomatous neoplasia. Limited data exist on predictors of metachronous advanced serrated lesions (mASLs). We analyzed clinical and endoscopic predictors of mASLs.

METHODS

In this retrospective cohort study, adults with >1 outpatient colonoscopy between 2008 and 2019 at a tertiary center were included. Serrated lesions (SLs) included sessile SLs (SSLs), traditional serrated adenomas (TSAs), and hyperplastic polyps (HPs). Patient and endoscopic characteristics were obtained using electronic medical records. Five-year cumulative incidence of mASL (HP ≥10 mm, SSL ≥10 mm or with dysplasia, any TSA) and factors associated with mASL were evaluated using Kaplan-Meier estimates and Cox proportional hazards models.

RESULTS

A total of 4990 patients were included and 45.4% were women. Mean age was 60.9 ± 9.2 years and median follow-up time was 3.7 years. Female sex and active smoking were associated with mASL. Endoscopically, any SSL and TSA were associated with mASL. The 5-year cumulative incidence for mASL was 26% (95% confidence interval [CI], 18%-32%) for SSL ≥10 mm, 17% (95% CI, 3.5%-29%) for HP ≥10 mm, 21% (95% CI, 0%-42%) for 3-4 SSLs <10 mm, 18% (95% CI, 0%-38%) for TSA, and 27% (95% CI, 3.6%-45%) for SSL with low-grade dysplasia. Baseline synchronous nonadvanced SL and nonadvanced adenoma were not associated with mASL.

CONCLUSIONS

Our data support current recommendations for a 3-year surveillance interval in patients with baseline SSL ≥10 mm, SSL with dysplasia, and TSA. A 3-year interval may be more appropriate than 3-5 years for patients with baseline HP ≥10 mm or 3-4 SSLs <10 mm. Patients with synchronous nonadvanced SLs and adenomas do not appear to be at increased risk of mASL.

Performance of artificial intelligence in the characterization of colorectal lesions

Background

Image-enhanced endoscopy (IEE) has been used in the differentiation between neoplastic and non-neoplastic colorectal lesions through microvasculature analysis. This study aimed to evaluate the computer-aided diagnosis (CADx) mode of the CAD EYE system for the optical diagnosis of colorectal lesions and compare it with the performance of an expert, in addition to evaluating the computer-aided detection (CADe) mode in terms of polyp detection rate (PDR) and adenoma detection rate (ADR).

Methods

A prospective study was conducted to evaluate the performance of CAD EYE using blue light imaging (BLI), dichotomizing lesions into hyperplastic and neoplastic, and of an expert based on the Japan Narrow-Band Imaging Expert Team (JNET) classification for the characterization of lesions. After white light imaging (WLI) diagnosis, magnification was used on all lesions, which were removed and examined histologically. Diagnostic criteria were evaluated, and PDR and ADR were calculated.

Results

A total of 110 lesions (80 (72.7%) dysplastic lesions and 30 (27.3%) nondysplastic lesions) were evaluated in 52 patients, with a mean lesion size of 4.3 mm. Artificial intelligence (AI) analysis showed 81.8% accuracy, 76.3% sensitivity, 96.7% specificity, 98.5% positive predictive value (PPV), and 60.4% negative predictive value (NPV). The kappa value was 0.61, and the area under the receiver operating characteristic curve (AUC) was 0.87. Expert analysis showed 93.6% accuracy, 92.5% sensitivity, 96.7% specificity, 98.7% PPV, and 82.9% NPV. The kappa value was 0.85, and the AUC was 0.95. Overall, PDR was 67.6% and ADR was 45.9%.

Conclusions

The CADx mode showed good accuracy in characterizing colorectal lesions, but the expert assessment was superior in almost all diagnostic criteria. PDR and ADR were high.

Risk Factors for Metachronous Colorectal Cancer or Advanced Adenomas After Endoscopic Resection of High-risk Adenomas

BACKGROUND & AIMS

Among the characteristics of high-risk adenomas (HRAs), some may predict a higher risk of metachronous advanced lesions. Our aim was to assess which HRA characteristics are associated with high risk of metachronous colorectal cancer (CRC) or advanced adenomas (AAs).

METHODS

We systematically searched Pubmed, EMBASE, and Cochrane for cohort studies and clinical trials of CRC or AA incidence at surveillance stratified by baseline lesion size, histology, and multiplicity. We calculated pooled relative risks (RRs) using a random-effects model. Heterogeneity was assessed with the I² statistic.

RESULTS

Fifty-five studies were included, with 936,540 patients with mean follow-up 5.4 ± 2.9 years. CRC incidence per 1000 person-years was 2.6 (2.1-3.0) for adenomas ≥20 mm, 2.7 (2.2-3.2) for high-grade dysplasia (HGD), 2.0 (1.8-2.3) for villous component, 0.8 (0.1-1.4) for ≥5 adenomas, 1.0 (0.7-1.2) for ≥3 adenomas. Metachronous CRC risk was higher in adenomas ≥20 mm vs 10 to 19 mm (RR, 2.08; 95% confidence interval [CI], 1.20-3.61), HGD vs low-grade dysplasia (RR, 2.89; 95% CI, 1.88-4.44), villous vs tubular (RR, 1.75; 95% CI, 1.33-2.31). No significant differences in CRC risk were found in ≥3 adenomas vs 1 to 2 (RR, 1.24; 95% CI, 0.84-1.83), nor in ≥5 adenomas vs 3 to 4 (RR, 0.79; 95% CI, 0.30-2.11). Compared with normal colonoscopy, RR for CRC risk was 2.61 (95% CI, 2.06-3.32) for ≥10mm, 6.62 (95% CI, 4.60-9.52) for HGD, 3.58 (95% CI, 2.24-5.73) for villous component, and 2.03 (95% CI, 1.40-2.94) for ≥3 adenomas. Similar trends were seen for metachronous AAs.

CONCLUSION

Metachronous CRC risk is highest in patients with baseline adenomas with ≥20 mm or HGD. Multiplicity does not seem to be associated with substantially higher CRC risk in the near term.

Subsequent participation in organized FIT based screening following screen-derived colonoscopy - A Danish nationwide cohort study

Introduction

In the Danish National Colorectal Cancer (CRC) screening program, participants with screen-detected low-risk adenomas are invited to a new faecal immunochemical test (FIT) screening after two years. However, participation rate in next FIT screening is unknown. We aimed to investigate this subsequent participation rate within the Danish CRC screening program.

Methods

This nationwide register-based study included participants aged 50-72 years registered with FIT screening in the Danish CRC screening program between January 1, 2016, and June 30, 2017. Participants were included if their index FIT was negative or if it was positive and the subsequent colonoscopy detected low-risk adenomas. Invitees were categorized as subsequent participants if they returned a FIT within 135 days following the invitation to screening. We estimated the relative risk for participation depending on screening outcome, age, and sex.

Result

415,107 with a negative result and 5,550 with low-risk adenomas were included. 86.0% (85.9;86.1) of the invitees with a negative result participated in the subsequent screening, while 71.8% (70.6;73.0) of the invitees with low-risk adenomas participated subsequently. The risk of participation in the subsequent screening was significantly lower among all age groups of men and women with low-risk adenomas compared to similar groups with negative results.

Conclusion

Invitees with low-risk adenomas detected at their initial colonoscopy are less likely to participate in the subsequent screening than invitees with negative results. This association was found in all age groups and for both sexes. Further studies are necessary to assess whether non-attendance is more pronounced in specific subgroups.

Cushing's disease in children: unique features and update on genetics

In this brief report, we review the unique characteristics of Cushing disease (CD) in children, as well as the most important new genetic discoveries associated with childhood CD. We often forget it, but CD refers to Cushing syndrome caused by pituitary corticotroph adenomas only. Thus, here we only refer to the new discoveries associated with pituitary tumors. There is indeed a wealth of new information on clinical features, outcomes, and genetic determinants of CD in children!

The efficacy of chemopreventive agents on the incidence of colorectal adenomas: A systematic review and network meta-analysis

Colorectal cancer (CRC) is the fourth most common cancer and third leading cause of cancer-related death worldwide. Use of chemopreventive agents (CPAs) to reduce the incidence of precursor colorectal adenomas could lower the future burden of CRC. Many classes of potential CPAs have been investigated. To identify the most effective CPAs, we conducted a systematic review and a network meta-analysis (NMA). An electronic search was performed through August 2020 to identify all randomized controlled trials (RCTs) assessing the efficacy of CPAs in reducing the incidence of colorectal adenomas at the time of surveillance colonoscopy among patients who had previously undergone polypectomy during an index colonoscopy. In total, 33 RCTs were included in the NMA, which was conducted under a Bayesian inference framework. Random effects models were used with adjustment for follow-up length and control group event rates to yield relative risks (RRs) and 95% credible intervals (CrIs). Our full network consisted of 13 interventions in addition to a placebo arm. Of 20,925 included patients, 7766 had an adenoma. Compared to placebo, the combination of difluoromethylornithine (DFMO) + Sulindac (RR 0.24, CrI 0.10-0.55) demonstrated a protective effect, while aspirin had a RR of 0.77 (CrI 0.60-1.00), celecoxib 800 mg had a RR of 0.56 (CrI 0.31-1.01) and metformin had a RR of 0.56 (CrI 0.22-1.39). Our results suggest that select CPAs may be efficacious in preventing the development of adenomas. Further studies are needed to identify those patients most likely to benefit and the minimum effective dosages of CPAs.

Computer-Aided Detection Improves Adenomas per Colonoscopy for Screening and Surveillance Colonoscopy: A Randomized Trial

BACKGROUND & AIMS

Colonoscopy for colorectal cancer screening is endoscopist dependent, and colonoscopy quality improvement programs aim to improve efficacy. This study evaluated the clinical benefit and safety of using a computer-aided detection (CADe) device in colonoscopy procedures.

METHODS

This randomized study prospectively evaluated the use of a CADe device at 5 academic and community centers by US board-certified gastroenterologists (n = 22). Participants aged ≥40 scheduled for screening or surveillance (≥3 years) colonoscopy were included; exclusion criteria included incomplete procedure, diagnostic indication, inflammatory bowel disease, and familial adenomatous polyposis. Patients were randomized by endoscopist to the standard or CADe colonoscopy arm using computer-generated, random-block method. The 2 primary endpoints were adenomas per colonoscopy (APC), the total number of adenomas resected divided by the total number of colonoscopies; and true histology rate (THR), the proportion of resections with clinically significant histology divided by the total number of polyp resections. The primary analysis used a modified intention-to-treat approach.

RESULTS

Between January and September 2021, 1440 participants were enrolled to be randomized. After exclusion of participants who did not meet the eligibility criteria, 677 in the standard arm and 682 in the CADe arm were included in a modified intention-to-treat analysis. APC increased significantly with use of the CADe device (standard vs CADe: 0.83 vs 1.05, P = .002; total number of adenomas, 562 vs 719). There was no decrease in THR with use of the CADe device (standard vs CADe: 71.7% vs 67.4%, P for noninferiority < .001; total number of non-neoplastic lesions, 284 vs 375). Adenoma detection rate was 43.9% and 47.8% in the standard and CADe arms, respectively (P = .065).

CONCLUSIONS

For experienced endoscopists performing screening and surveillance colonoscopies in the United States, the CADe device statistically improved overall adenoma detection (APC) without a concomitant increase in resection of non-neoplastic lesions (THR).

CLINICALTRIALS

gov registration: NCT04754347.

Yield of Surveillance Colonoscopy in Older Adults with a History of Polyps: A Systematic Review and Meta-Analysis

BACKGROUND

The benefit of surveillance colonoscopy in older adults is not well described.

AIMS

To quantify the detection of colorectal cancer (CRC) and advanced polyps during surveillance colonoscopy in older adults with a history of colon polyps.

METHODS

We conducted a systematic review (MEDLINE, Cochrane Library, Web of Science, and Embase) for all published studies through May 2020 in adults age > 70 undergoing surveillance colonoscopy. The main outcome was CRC and advanced polyps detection. We performed meta-analysis to pool results by age (>70 vs. 50-70).

RESULTS

The search identified 6239 studies, of which 569 underwent full-text review and 64 data abstraction, of which 19 were included. The risk of detecting CRC (N = 11) was higher in those >70 compared to 50-70 (risk ratio 1.5 (95% CI 1.1-2.2); risk difference 0.8% (95% CI -0.2%-1.8%)). Similarly, the risk of detecting advanced polyps (N = 8) was higher in those >70 compared to 50-70 (risk ratio 1.3 (95% CI 1.2-1.3), risk difference 2.7% (95% CI 1.3%-4.0%)). Most studies did not stratify results by baseline polyp risk.

CONCLUSIONS

The detection of CRC and advanced polyps during surveillance colonoscopy in older individuals was higher than in younger controls; however, the absolute risk increase for both was small. These differences must be weighed against competing medical problems and limited life expectancy in older adults when making decisions about surveillance colonoscopy. More primary data on the risks of CRC and advanced polyps accounting for number of past colonoscopies, prior polyp risk, and duration of time since last polyp are needed.

Risk Factors for Colorectal Polyps and Cancer

Colorectal cancer (CRC) is a common malignancy in the U.S. and worldwide. Most CRC cases arise from precancerous adenomatous and serrated polyps. Established risk factors for conventional adenomas and CRC include age, male sex, family history, obesity and physical inactivity, and red meat intake. White race and tobacco and alcohol use are important risk factors for serrated polyps, which have a distinct risk factor profile compared to conventional adenomas. A history of abdominopelvic radiation, acromegaly, hereditary hemochromatosis, or prior ureterosigmoidostomy also increases CRC risk. Understanding these risk factors allows for targeted screening of high-risk groups to reduce CRC incidence.

Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives

Inflammatory bowel disease-related colorectal cancer (IBD-CRC) is one of the most serious complications of IBD contributing to significant mortality in this cohort of patients. IBD is often associated with diet and lifestyle-related gut microbial dysbiosis, the interaction of genetic and environmental factors, leading to chronic gut inflammation. According to the “common ground hypothesis”, microbial dysbiosis and intestinal barrier impairment are at the core of the chronic inflammatory process associated with IBD-CRC. Among the many underlying factors known to increase the risk of IBD-CRC, perhaps the most important factor is chronic persistent inflammation. The persistent inflammation in the colon results in increased proliferation of cells necessary for repair but this also increases the risk of dysplastic changes due to chromosomal and microsatellite instability. Multiple pathways have been identified, regulated by many positive and negative factors involved in the development of cancer, which in this case follows the ‘inflammation-dysplasia-carcinoma’ sequence. Strategies to lower this risk are extremely important to reduce morbidity and mortality due to IBD-CRC, among which colonoscopic surveillance is the most widely accepted and implemented modality, forming part of many national and international guidelines. However, the effectiveness of surveillance in IBD has been a topic of much debate in recent years for multiple reasons — cost-benefit to health systems, resource requirements, and also because of studies showing conflicting long-term data. Our review provides a comprehensive overview of past, present, and future perspectives of IBD-CRC. We explore and analyse evidence from studies over decades and current best practices followed globally. In the future directions section, we cover emerging novel endoscopic techniques and artificial intelligence that could play an important role in managing the risk of IBD-CRC.

High-risk pituitary adenomas and strategies for predicting response to treatment

High-risk pituitary adenomas are aggressive. They show clinical and imaging features similar to those of carcinomas, including infiltration of the surrounding brain structures, but lack cerebrospinal or systemic metastases. In addition, they display distinct behavior, including tendency for fast growth and frequent recurrences, which are difficult to control. The term "high-risk" adenoma was first introduced in the 4th edition of the World Health Organization Classification of Endocrine Tumors in 2017. Five defined adenoma types belong to this category, including sparsely granulated somatotroph, lactotroph in men, Crooke cell, silent corticotroph, and plurihormonal PIT-1 positive adenomas. The morphological and immunohistochemical characteristics of high-risk adenomas are herein described in detail. In addition, the clinical features and the treatment options are presented. This review focuses on predictive markers assessed by immunohistochemistry, which help clinicians to design the appropriate treatment strategies for high-risk adenomas. Somatostatin receptor status predicts effectiveness of postsurgical treatment with somatostatin analogs, and MGMT expression predicts response to treatment with temozolomide. This comprehensive review presents the clinical and pathological features of high-risk pituitary adenomas, underlines the contribution of immunohistochemistry, and emphasizes the leading role of pathology in the design of optimal clinical management.

A clinicoradiological analysis of silent corticotroph adenomas after the introduction of pituitary-specific transcription factors

BACKGROUND

Silent corticotroph adenomas (SCAs) are a rare subtype of non-functional pituitary adenoma. While it has been suggested that they are more aggressive and recur more frequently following excision, there is limited literature on the optimum treatment strategy for these tumors, especially regarding the role of radiation therapy in incompletely resected tumors.

METHOD

We assimilated data from 62 SCAs and 238 other non-functional adenomas (ONAs), defined according to the WHO 2017 criteria that incorporates transcription factor analysis. We compared their clinicoradiological characteristics, such as hormonal levels, tumor configuration, size, and invasiveness. For 52 SCAs and 205 ONAs with serial follow-up imaging, we studied outcomes for progression after subtotal resection with or without radiation therapy or recurrence after gross total resection. Kaplan Meier analysis for recurrence or progression was used to determine the need for a differential treatment strategy for SCAs compared with other non-functional adenomas specifically concerning the role of radiotherapy.

RESULTS

Patients with SCAs present at a younger age than ONAs (43.9 years vs. 48.2 years, p = 0.014), with larger (14.9 cc vs. 9.7 cc, p = 0.006) and more invasive adenomas (61.2% vs. 45.8%, p = 0.021). Overall, SCAs are more likely to recur or progress (48.7 vs. 15.7%, p < 0.001) following excision than ONAs, with significantly poorer event-free survival (Log rank test p < 0.001). Early adjuvant radiotherapy provides favorable outcomes among SCAs with postoperative residual tumor, on par with ONAs. Multivariate analysis identified male gender (HR: 2.217; p = 0.017), MIB index ≥ 3% (HR: 2.116; p = 0.012), and SCA tumor pathology (HR: 3.787; p < 0.001) as factors predicting recurrence.

CONCLUSIONS

Based on the results of this retrospective, single-center review of 300 non-functional adenomas, we conclude that silent corticotroph adenomas are an aggressive subtype of non-functional pituitary adenomas that are larger, more likely to be invasive, and tend to recur more frequently after a subtotal excision compared with other non-functional adenomas. A gross total resection must be attempted whenever possible and earlier adjuvant radiation is recommended when re-surgery for residual tumor is difficult.

Toxic adenoma: to biopsy or not to biopsy?

Toxic adenoma nodules rarely harbour cancer. Fine-needle aspiration (FNA) is often not done because of the rarity of these lesions being cancer, the difficulty in interpreting cytology in hyperthyroid patients and the rare precipitation of thyrotoxicosis. We present two young, Caucasian female patients aged 29 and 13 years who were each diagnosed with a toxic nodule categorised as benign and indeterminate respectively. They underwent hemithyroidectomy after being rendered euthyroid, however their histology unexpectedly revealed differentiated follicular cancer. Despite thyroid cancer being rare in patients with toxic adenomas, it should be considered when planning treatment, especially if there are risk factors for cancer, or suspicious features on ultrasound examination. A review of the literature shows that compared with adenomas in euthyroid patients, patients in this group are generally younger and predominately female. If an FNA is considered, it should be performed after the patient is rendered euthyroid.

The Importance of Long Term Follow Up After Endoscopic Pituitary Surgery: Durability of Results and Tumor Recurrence

Introduction

Endoscopic endonasal approach (EEA) has become the preferred surgical approach for resection of pituitary adenomas in most centers. This technique has a number of advantages such as improved visualization and maneuverability, when compared to microscopic transsphenoidal approach. However, the long-term results of this approach are still scarce. Ten years ago, we published our initial series of patients having undergone an endoscopic removal of their pituitary adenomas reporting favorable short-term results. This project aims to revisit the results of that series, addressing the long-term results regarding recurrence of pituitary adenomas.

Methods

A retrospective analysis of consecutive, endoscopically managed pituitary adenomas in a single center from 2004-2007. Only patients with >5 years of follow up (FU) and complete follow up data were included in this study. Recurrences were defined as evidence of any new tumor growth or enlargement of previously noted residual adenoma and/or biochemical recurrence of disease activity, in cases of functioning adenomas.

Results

A total of 98 patients matched the inclusion criteria for this study. The median follow-up period was 144 months. Nonfunctioning adenoma was the most common subtype (n = 66, 67.3%), followed by GH-secreting tumors (n = 19, 19.4%), ACTH-secreting tumors (n = 7, 7.1%), prolactinomas (n = 4, 4.1%) and TSH-secreting adenomas (n = 2, 2%). Age ranges from 23 to 82 years, with median age of 53 years. Preoperative visual deficits were observed in 46 patients (46.9%) and hormonal deficits were identified in 31% of cases. 22.4% of patients had undergone a previous pituitary adenomas resection prior to treatment in our center. Surgery achieved gross total resection (GTR) and near total resection (NTR) in 89 cases (90.8%) (56.1% and 34.7%, respectively). A total of 37 cases had recurrences during FU (mean recurrence free survival: 80 months). Recurrences were observed in 34% of patients who had had GTR while recurrences were observed in 39.5% of cases that underwent subtotal resection. Most recurrences occurred after 5 years of FU and univariate analysis demonstrated previous surgery (P = 0.005), cavernous sinus invasion (P = 0.05) and Ki-67 >5% (P = 0.01) to be factors associated with higher chance of recurrence. Multivariate Cox-regression analysis demonstrate that previous surgery and Ki-67 >5% are factors associated with recurrences. Surgery and/or radiation were utilized for management of recurrences in 29/37 cases.

Conclusion

Long-term FU analysis demonstrates that progression/recurrence of previously resected adenomas is observed in a significant number of patients, especially in those with previous/multiple surgical resections, elevated ki-67 and cavernous sinus invasion. Short-term FU may shadow real tumor control rates achieved after EEA and underscores the importance of long-term FU in these patients. Therefore, long-term FU should be pursued in all cases.

Prophylactic clipping to prevent delayed colonic post-polypectomy bleeding: meta-analysis of randomized and observational studies

BACKGROUND AND AIMS

Delayed post-polypectomy bleeding (DPPB) is a commonly described adverse event following polypectomy. Prophylactic clipping may prevent DPPB in some patient subgroups. We performed a meta-analysis to assess both the efficacy and real-world effectiveness of prophylactic clipping.

METHODS

We performed a database search through March 2020 for clinical trials or observational studies assessing prophylactic clipping and DPPB. Pooled risk ratios (RR) were calculated using random effects models. Subgroup, sensitivity, and meta-regression analyses were performed to elucidate clinical or methodological factors associated with effects on outcomes.

RESULTS

A total of 2771 citations were screened, with 11 randomized controlled trials (RCTs) and 9 observational studies included, representing 24,670 colonoscopies. DPPB occurred in 2.0% of patients overall. The pooled RR of DPPB was 0.47 (95% CI 0.29-0.77) from RCTs enrolling only patients with polyps ≥ 20 mm. Remaining pooled RCT data did not demonstrate a benefit for clipping. The pooled RR of DPPB was 0.96 (95% CI 0.61-1.51) from observational studies including all polyp sizes. For patients with proximal polyps of any size, the RR was 0.73 (95% CI 0.33-1.62) from RCTs. Meta-regression confirmed that polyp size ≥ 20 mm significantly influenced the effect of clipping on DPPB.

CONCLUSION

Pooled evidence demonstrates a benefit when clipping polyps measuring ≥ 20 mm, especially in the proximal colon. In lower-risk subgroups, prophylactic clipping likely results in little to no difference in DPPB.

Variation rs9929218 and risk of the colorectal Cancer and adenomas: A meta-analysis

BACKGROUNDS

Genome-wide association studies (GWAS) have identified multiple common CRC-related (colorectal cancer) SNPs (single nucleotide polymorphisms) including the Cadherin 1(CDH1) rs9929218 may act by increasing the risk of colorectal cancer, colorectal adenoma, or both. These studies, however, reported inconsistent associations.

METHODS

To derive a more accurate approximation of the connection, we carried out a meta-analysis of 12 published pieces of research including 11,590 controls and 8192 cases. We used odds ratios (ORs) and 95% confidence intervals (CIs) to evaluate the associations' strength.

RESULTS

Meta-analysis implied considerable association between CRC and rs9929218 (OR = 1.21, 95%CI 1.04-1.42 for GG versus AA; OR = 1.22, 95%CI 1.05-1.42 for GG/AG versus AA). In the subgroup analyses, significantly increased risks were found among Europeans.

CONCLUSIONS

In summary, our meta-analysis studies in different populations confirmed that SNP rs9929218 is significantly associated with CRC risk and that this variant may have a greater impact on Europeans.

Advanced adenomas may be a red flag for hereditary cancer syndromes

Background

16–25% of colorectal cancers (CRCs) diagnosed under age 50 are associated with hereditary cancer syndromes. Advanced adenomas are considered precursors to CRC. Although polyp removal prevents cancer, polypectomy does not change underlying genetic risk. Patients with isolated advanced polyps do not currently qualify for genetic testing unless they have a personal or family history of cancer.

Aim

Describe the prevalence of hereditary cancer syndromes among patients with advanced colorectal polyps.

Methods

We performed a single center retrospective review from 2015 to 2019 of patients who underwent germline genetic testing with indication for testing listed as colorectal polyp. We excluded patients with a personal history of CRC and those with ≥10 cumulative polyps. We collected patient demographics, polyp characteristics, family history data and genetic testing results from the medical record. Discrete variables were reported as frequency and percentages and continuous variables reported as mean with range.

Results

A total of 42 patients underwent genetic testing due to a personal history of advanced adenoma. 17% of patients met current genetic testing criteria. All patients underwent multi-gene panel testing. Two patients (4.8%) had a germline pathogenic mutation (one in MLH1 and one in CHEK2). The patient with an MLH1 mutation met current criteria for genetic testing (PREMM5 score 5.8), however the patient with the CHEK2 mutation did not. Both mutation carriers had a personal history of synchronous or metachronous advanced adenomas. 38% had a variant of uncertain significance.

Conclusions

5% of patients with advanced adenomas in our retrospective series had a pathogenic germline mutation in a cancer predisposition gene. Though the patient with a pathogenic mutation in MLH1 met current clinical criteria for genetic testing, this was not recognized prior to referral; he was referred based on a personal history of advanced adenoma. Advanced polyps may be a red flag to identify patients who are at risk for hereditary cancer syndromes.

Progastrin production transitions from Bmi1+/Prox1+ to Lgr5high cells during early intestinal tumorigenesis

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Secretion of progastrin is a signature event of early malignant transformation in the colon.

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In the healthy epithelium, progastrin is produced by a subset of enteroendocrine cells expressing both Bmi1 and Prox1.

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LGR5-high intestinal stem cells are a primary source of progastrin production in early mouse and human intestinal adenomas.

Progastrin is an unprocessed soluble peptide precursor with a well-described tumor-promoting role in colorectal cancer. It is expressed at small levels in the healthy intestinal mucosa, and its expression is enhanced at early stages of intestinal tumor development, with high levels of this peptide in hyperplastic intestinal polyps being associated with poor neoplasm-free survival in patients. Yet, the precise type of progastrin-producing cells in the healthy intestinal mucosa and in early adenomas remains unclear. Here, we used a combination of immunostaining, RNAscope labelling and retrospective analysis of single cell RNAseq results to demonstrate that progastrin is produced within intestinal crypts by a subset of Bmi1⁺/Prox1⁺/LGR5^low endocrine cells, previously shown to act as replacement stem cells in case of mucosal injury. In contrast, our findings indicate that intestinal stem cells, specified by expression of the Wnt signaling target LGR5, become the main source of progastrin production in early mouse and human intestinal adenomas. Collectively our results suggest that the previously identified feed-forward mechanisms between progastrin and Wnt signaling is a hallmark of early neoplastic transformation in mouse and human colonic adenomas.

Helicobacter pylori infection with atrophic gastritis: An independent risk factor for colorectal adenomas

BACKGROUND

The significance of Helicobacter pylori (H. pylori) infection and atrophic gastritis (AG) in the prevalence of colorectal adenomas has been examined in a limited number of studies. However, these studies reported disputed conclusions.

AIM

To investigate whether H. pylori infection, AG, and H. pylori-related AG increase the risk of colorectal adenomas.

METHODS

This retrospective cross-sectional study included 6018 health-check individuals. The relevant data for physical examination, laboratory testing, ¹³C-urea breath testing, gastroscopy, colonoscopy and histopathological examination of gastric and colorectal biopsies were recorded. Univariate and multivariate logistic regression analyses were performed to determine the association between H. pylori-related AG and colorectal adenomas.

RESULTS

Overall, 1012 subjects (16.8%) were diagnosed with colorectal adenomas, of whom 143 (2.4%) had advanced adenomas. Among the enrolled patients, the prevalence of H. pylori infection and AG was observed as 49.5% (2981/6018) and 10.0% (602/6018), respectively. Subjects with H. pylori infection had an elevated risk of colorectal adenomas (adjusted odds ratio [OR] of 1.220, 95% confidence interval (CI): 1.053-1.413, P = 0.008) but no increased risk of advance adenomas (adjusted OR = 1.303, 95%CI: 0.922-1.842, P = 0.134). AG was significantly correlated to an increased risk of colorectal adenomas (unadjusted OR = 1.668, 95%CI: 1.352-2.059, P < 0.001; adjusted OR = 1.237, 95%CI: 0.988-1.549, P = 0.064). H. pylori infection accompanied by AG was significantly associated with an increased risk of adenomas (adjusted OR = 1.491, 95%CI: 1.103-2.015, P = 0.009) and advanced adenomas (adjusted OR = 1.910, 95%CI: 1.022-3.572, P = 0.043).

CONCLUSION

H. pylori-related AG was associated with a high risk of colorectal adenomas and advanced adenomas in Chinese individuals.

Evaluation of colonoscopy data for colorectal polyps and associated histopathological findings

Background

Adenomas of colon and rectal are frequent colonoscopically found benign lesions. The aim of this study is to evaluate the incidence of polyps among patients referred for colonoscopy and associated histopathological findings.

Methods

In this retrospective study, patients referred for colonoscopy at Shahid Madani Hospital from were enrolled. The records of the patients were evaluated for demographic data, polyp status along with size and location and type and histopathological findings of the polyps. The data obtained were statistically analyzed using SPSSv22.

Results

Among 1600 patients who underwent colonoscopy, 260 were positive with polyps. The main symptom among these patients was lower gastrointestinal bleeding 44.2%. The average size of the polyps was 5.68 ± 2.66 and the incidence was significantly greatest among the age group of 51–65 years, p < 0.01. The commonest sites polyps were sigmoid and descending colon, 28.6% and 23.2%, respectively. Adenomatous polyps were the most frequent type, 58.3%. The morphology and pathology of the polyps were significantly associated with each other, p < 0.01.

Conclusion

Our study evaluates the retrospective data for polyp findings among colonoscopy patients. Early diagnosis of polyps can provide better therapeutic outcomes.

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Adenomas of colon and rectal are frequent colonoscopically found benign lesions.

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Surveillance of colonoscopy could have been compromised since several physicians were included in the study.

Middle ear adenomatous neuroendocrine tumors: suggestion for surgical strategy

Introduction

Middle ear adenomatous neuroendocrine tumors are extremely rare neoplasms with epithelial and neuroendocrine differentiation, accounting for fewer than 2% of all middle and inner ear tumors. Universal standard surgical procedures for different stages of these tumors remain elusive due to the limitation of the small number of case reports or investigations.

Objective(s)

This study intends to investigate proper surgical strategies for patients with middle ear adenomatous neuroendocrine tumors.

Methods

Six patients with middle ear adenomatous neuroendocrine tumors who were treated at the Second Affiliated Hospital of Nanchang University (Nanchang, China) and the Eye, Ear, Nose, and Throat Hospital of Fudan University (Shanghai, China) respectively. Clinical characteristics and management strategies of patients were reviewed. The mean follow-up time was 63.7 months (range, 13–153 months). All the information was collected from medical records and prognosis postoperatively.

Results

Three patients underwent canal wall-up tympanomastoidectomy, including one patient with recurrence who underwent a previous tympanotomy; the other three patients underwent lateral temporal bone resection All of these patients were followed up with no evidence of recurrence or metastasis. Patients underwent canal wall-up surgery treatment accompanied with hearing function preservation measurements during follow-up periods.

Conclusions

Complete surgical resection provided good results for patients with middle ear adenomatous neuroendocrine tumors. The ossicular chain should be removed. Because of the propensity for local recurrence and invasiveness, as well as regional or distant metastasis of these tumors, it is necessary to schedule long-term follow-up and an observation plan postoperatively.

Optical imaging technology in colonoscopy: Is there a role for photometric stereo?

Colonoscopy screening for the detection and removal of colonic adenomas is central to efforts to reduce the morbidity and mortality of colorectal cancer. However, up to a third of adenomas may be missed at colonoscopy, and the majority of post-colonoscopy colorectal cancers are thought to arise from these. Adenomas have three-dimensional surface topographic features that differentiate them from adjacent normal mucosa. However, these topographic features are not enhanced by white light colonoscopy, and the endoscopist must infer these from two-dimensional cues. This may contribute to the number of missed lesions. A variety of optical imaging technologies have been developed commercially to enhance surface topography. However, existing techniques enhance surface topography indirectly, and in two dimensions, and the evidence does not wholly support their use in routine clinical practice. In this narrative review, co-authored by gastroenterologists and engineers, we summarise the evidence for the impact of established optical imaging technologies on adenoma detection rate, and review the development of photometric stereo (PS) for colonoscopy. PS is a machine vision technique able to capture a dense array of surface normals to render three-dimensional reconstructions of surface topography. This imaging technique has several potential clinical applications in colonoscopy, including adenoma detection, polyp classification, and facilitating polypectomy, an inherently three-dimensional task. However, the development of PS for colonoscopy is at an early stage. We consider the progress that has been made with PS to date and identify the obstacles that need to be overcome prior to clinical application.

Diagnostic Yield of Colonoscopy in Young Adults with Lower Gastrointestinal Symptoms in a Multicenter Midwest Cohort

BACKGROUND/AIMS

Serious gastrointestinal (GI) pathologies are common in older adults compared to young adults (≤40 years). Data on the diagnostic yield (DY) of colonoscopy in young adults with lower GI symptoms are lacking. We aimed to evaluate the overall DY of colonoscopy; and the DY stratified by the presence or absence of bright red blood per rectum (BRBPR) in young adults ≤40 years.

METHODS

We reviewed diagnostic colonoscopies performed in young adults by 18 gastroenterologists at 2 different institutions from -October 2016 to April 2019. Patients with familial colorectal cancer (CRC) syndromes were excluded. DY was calculated based on the proportion of abnormal colonoscopy defined as having inflammatory bowel disease (IBD), microscopic colitis (MC), advanced adenoma, or CRC.

RESULTS

We included 454 patients, mean (SD) age was 31 (3) years, 162 (36%) were males and mean (SD) BMI was 30 (8.5). BRBPR was the indication for colonoscopy in 194 (43%) patients, 260 (57%) patients had colonoscopy for other lower GI symptoms (abdominal pain, chronic diarrhea, constipation) but without BRBPR. Overall DY of colonoscopy in young adults with lower GI symptoms was 15%; IBD was seen in 43 (10%) patients, MC 10 (2%), and advanced neoplasia/CRC 20 (4%). Overall DY in patients with BRBPR was significantly higher than in patients without BRBPR (22 vs. 11%, p = 0.001). The DY for IBD was also higher in young adults with BRBPR versus without BRBPR (15 vs. 6%, p = 0.003). The DY of patients with both BRBPR and abdominal pain was 34%, for BRBPR and diarrhea was 40%, and for all 3 symptoms of BRBPR, diarrhea, and abdominal pain was 52%.

CONCLUSIONS

Significant proportion of young adults with BRBPR have abnormal pathology (22%) justifying evaluation by colonoscopy. For other lower GI symptoms without BRBPR, the necessity of endoscopic evaluation should be determined clinically on a case-to-case basis due to the low overall DY.

Pituitary Adenomas: What Are the Key Features? What Are the Current Treatments? Where Is the Future Taking Us?

Pituitary tumors are a heterogeneous group of lesions (usually benign) and proper understanding of the anatomy, physiology, and pathology of the hypothalamic/pituitary region is essential to make an accurate diagnosis and define the essential treatment options (i.e., surgery, medical therapies, and radiotherapy, alone or in combination). Surgery is the primary treatment for acromegaly, Cushing disease, thyroid-stimulating hormone-secreting adenomas, resistant prolactinomas, and nonfunctioning pituitary adenomas causing mass effect. Medical and radiation therapy are reserved in cases in which surgery is not possible or does not provide a complete cure. In the last decades, tremendous innovations (i.e., targeted drugs and refined surgical tools and techniques) have expanded the treatment strategies for pituitary adenomas. We herein report the current indications for and depiction of the surgical techniques in pituitary surgery, review current medical treatments, and provide a glimpse of future possibilities.

Colorectal polyp prevalence and aspirational detection targets determined using high definition colonoscopy and a high level detector in 2017

BACKGROUND

Colorectal adenoma prevalence can be determined by autopsy studies, or imaging studies such as colonoscopy. We describe the prevalence of colorectal adenomas determined by a single high detecting colonoscopist using high definition colonoscopes.

METHODS

We conducted a cross-sectional study of consecutive patients aged ≥18 years undergoing colonoscopy with a high level detector for the indications of screening, surveillance, and diagnostic reasons from December 29, 2016 to January 12, 2018.

RESULTS

During the study period, 1172 eligible patients underwent colonoscopy. Women comprised 55% (n = 646) and the majority (89%, n = 1038) were aged ≥50 years (mean age, 62.1 years). In persons aged ≥50 years undergoing screening, the prevalence of ≥1 conventional adenoma was 48.5% and ≥1 sessile serrated polyp was 15.3%. Diminutive polyps (1-5 mm in size) comprised three-quarters of all resected polyps (2236/2986). Among 246 patients (21%), 1050 hyperplastic appearing polyps were not resected from the recto-sigmoid. Adenoma prevalence was strongly associated with age and indication but serrated lesion prevalence was not.

CONCLUSIONS

The true prevalence of precancerous lesions in the colorectum determined by modern colonoscopy exceeds determination by autopsy studies. These data help define aspirational detection targets for colonoscopy. The economic burden associated with colonoscopic resection of tiny lesions is substantial.

A Review of the Management of Sporadic Colorectal Adenomas in Young People: Is Surveillance Wasted on the Young?

The national incidence of colorectal cancer is increasing in people younger than 50 years old. Although diagnostic colonoscopy is detecting more sporadic adenomas in young adults, there are no guidelines for post-polypectomy surveillance. The aim of this review was to survey the medical literature on the prevalence of sporadic adenomas in young adults, subsequent risk of metachronous neoplasia, and lastly to provide several concluding recommendations for clinical practice. We found that the prevalence of sporadic adenomas in young adults is greater than initially estimated and dependent upon factors such as colonoscopy indication and age. The incidence of metachronous colorectal neoplasia following polypectomy is unclear but does not appear to be greater than that of older adults. Risk factors for metachronous neoplasia include findings on index colonoscopy, male gender, smoking status, and certain medical comorbidities. Upon finding a colorectal adenoma in a young person, we suggest that a detailed family history be obtained to confirm that it is truly sporadic. Testing adenomas for evidence of Lynch syndrome is low yield. Strategies to inform surveillance intervals may include an assessment of risk factors for metachronous neoplasia, although surveillance intervals shorter than those recommended in current guidelines are not warranted. Future research should focus on obtaining long-term, prospective data on the incidence of metachronous neoplasia in diverse patient populations.

Management of Giant Pituitary Adenomas: Role and Outcome of the Endoscopic Endonasal Surgical Approach

Giant adenomas represent a significant surgical challenge. Although traditionally several transcranial and transsphenoidal microscopic approaches have had a central role in their management, in the last 2 decades here have been increasing reports of the endoscopic endonasal approach for giant adenomas, citing its improved resection rates and lower complication profile. However, its role as the preferred approach has not been fully established and there is currently a paucity of evidence-based recommendations available in the literature. This article reviews the current literature and attempts to define the role and outcomes of the endoscopic endonasal surgical approach for giant pituitary adenomas.

Risk of metachronous advanced lesions after resection of diminutive and small, non-advanced adenomas

BACKGROUND AND AIMS

Current post-polypectomy surveillance interval guidelines do not discriminate between 1-2 diminutive (1-5mm) and small (6-9mm) non-advanced adenomas. This study compared the risk for metachronous advanced lesions in these groups.

METHODS

Patients with 1-2 diminutive, non-advanced adenomas and no further advanced lesions, and patients with no polyps at baseline colonoscopy were retrospectively analyzed to determine the rate of metachronous advanced lesions. These were defined as the combined rate of colon cancer, advanced adenoma and ≥ 3 non-advanced adenomas at surveillance colonoscopy. Polyp size was measured either subjectively by the endoscopist or by pathology-based measurements.

RESULTS

Among patients with diminutive (n = 395) and small polyps (n = 110), advanced lesions were found in 68 patients (17.2%) and 16 patients (14.5%), respectively (P = 0.53), during a mean follow-up of 4.3 ± 0.9 years. In contrast, advanced lesions were observed in 33 patients (6.6%) in the no polyp group (n = 505), significantly lower than diminutive (P = 0.000) and small polyp groups (P = 0.002), despite a mean follow-up duration of 6.1 ± 1.9 years. The rate of metachronous advanced lesions was also similar between patients with 1-3mm polyps (16%) versus 7-9mm polyps (15.8%).

CONCLUSIONS

Our findings suggest that among patients who underwent polypectomy of up to 2 non-advanced adenomas, those with diminutive and small polyps have the same risk of metachronous advanced lesions; thus, supporting uniform recommendations for surveillance colonoscopy for these lesions.

Claudin-7 gene knockout causes destruction of intestinal structure and animal death in mice

BACKGROUND

Claudin-7, one of the important components of cellular tight junctions, is currently considered to be expressed abnormally in colorectal inflammation and colorectal cancer. However, there is currently no effective animal model to study its specific mechanism. Therefore, we constructed three lines of Claudin-7 knockout mice using the Cre/LoxP system.

AIM

To determine the function of the tumor suppressor gene Claudin-7 by generating three lines of Claudin-7 gene knockout mice.

METHODS

We crossed Claudin-7-floxed mice with CMV-Cre, vil1-Cre, and villin-CreERT2 transgenic mice, and the offspring were self-crossed to obtain conventional Claudin-7 knockout mice, conditional (intestinal specific) Claudin-7 knockout mice, and inducible conditional Claudin-7 knockout mice. Intraperitoneal injection of tamoxifen into the inducible conditional Claudin-7 knockout mice can induce the knockout of Claudin-7. PCR and agarose gel electrophoresis were used to identify mouse genotypes, and Western blot was used to confirm the knockout of Claudin-7. The mental state, body length, and survival time of these mice were observed. The dying mice were sacrificed, and hematoxylin-eosin (HE) staining and immunohistochemical staining were performed to observe changes in intestinal structure and proliferation markers.

RESULTS

We generated Claudin-7-floxed mice and three lines of Claudin-7 gene knockout mice using the Cre/LoxP system successfully. Conventional and intestinal specific Claudin-7 knockout mice were stunted and died during the perinatal period, and intestinal HE staining in these mice revealed mucosal gland structure disappearance and connective tissue hyperplasia with extensive inflammatory cell infiltration. The inducible conditional Claudin-7 knockout mice had a normal phenotype at birth, but after the induction with tamoxifen, they exhibited a dying state. Intestinal HE staining showed significant inflammatory cell infiltration, and atypical hyperplasia and adenoma were also observed. Intestinal immunohistochemistry analysis showed abnormal expression and distribution of Ki67, and the normal intestinal proliferation balance was disrupted. The intestinal crypt size in inducible conditional Claudin-7 knockout mice was increased compared with control mice (small intestine: 54.1 ± 2.96 vs 38.4 ± 1.63; large intestine: 44.7 ± 1.93 vs 27.4 ± 0.60; P < 0.001).

CONCLUSION

The knockout of Claudin-7 in vivo causes extensive inflammation, atypical hyperplasia, and adenoma in intestinal tissue as well as animal death in mice. Claudin-7 may act as a tumor suppressor gene in the development of colorectal cancer.

The role of inherited genetic variants in colorectal polyposis syndromes

Colorectal carcinoma (CRC) is the third most common cancer in men and the second most common cancer in women across the world. Most CRCs occur sporadically, but in 15-35% of cases, hereditary factors are important. Some patients with an inherited predisposition to CRC will be diagnosed with a "genetic polyposis syndrome" such as familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), polymerase proofreading associated polyposis (PPAP), NTHL1-associated polyposis, MSH3-associated polyposis or a hamartomatous polyposis syndrome. Individuals with ≥10 colorectal polyps have traditionally been referred for genetic diagnostic testing to identify APC and MUTYH mutations which cause FAP and MAP respectively. Mutations are found in most patients with >100 adenomas but in only a minority of those with 10-100 adenomas. The reasons that diagnostic laboratories are not identifying pathogenic variants include mutations occurring outside of the open reading frames of genes, individuals exhibiting generalized mosaicism and the involvement of additional genes. It is important to identify patients with an inherited polyposis syndrome, and to define the mutations causing their polyposis, so that the individuals and their relatives can be managed appropriately.

A motivational phone call improves participation to screening colonoscopy for those with a positive FIT in a national screening programme (NCT 03276091)

BACKGROUND

A large proportion of individuals with a positive faecal immunologic test (FIT) will never undergo the recommended colonoscopy despite a full sequence of reminders.

AIMS

This prospective study aimed to recruit refractory individuals by a motivational personalised phone call given by a screening physician.

METHODS

We evaluated the impact of a motivational phone call given by a physician of the screening organisation in order to convince patients with positive FIT to undergo a colonoscopy.

RESULTS

115 individuals with a positive FIT were targeted. After GP phone call, it was ascertained that 15 had had a colonoscopy, one died, one moved outside the region, and the GP refused the study phone call for 13. Finally, we attempted to call 85 individuals; 24 could not be reached, 5 colonoscopies had been performed, and thus 56 individuals were included. The main reason for colonoscopy refusal (33.9%) was wrong advice from the GP or the gastroenterologist. Among those included, 33.9% (19/56) underwent the colonoscopy within 22.7 months after FIT; 1 invasive cancer, 18 adenomas and 9 serrated sessile lesions were found.

CONCLUSION

Motivational phone call performed by a physician from the screening organisation is effective to recruit a third of refractory individuals. Education for GPs and gastroenterologists is necessary to increase participation to colonoscopy and to avoid the performance of an inappropriate secondary FIT.

TRIAL REGISTRATION

NCT 03276091.

IGF-1 Gene Therapy as a Potentially Useful Therapy for Spontaneous Prolactinomas in Senile Rats

BACKGROUND

Insulin-like Growth Factor1 (IGF1) is a powerful neuroprotective molecule. We have previously shown that short-term hypothalamic IGF1 gene therapy restores tuberoinfundibular dopaminergic neuron function in aging female rats.

OBJECTIVE

Our aim was to implement long-term IGF-I gene therapy in pituitary prolactinomas in senile female rats.

METHODS

Here, we assessed the long-term effect of IGF1 gene therapy in the hypothalamus of young (4 mo.) and aging (24 mo.) female rats carrying spontaneous pituitary prolactinomas. We constructed and injected a Helper-Dependent (HD) adenovector expressing the gene for rat IGF1 or the reporter red fluorescent protein DsRed. Ninety-one days post vector injection, all rats were sacrificed and their brains and pituitaries fixed. Serum prolactin (PRL), Estrogen (E2) and progesterone (P4), as well as hypothalamic IGF1 content, were measured by RIA. Anterior pituitaries were immunostained with an anti-rat PRL antibody and submitted to morphometric analysis.

RESULTS

DsRed expression in the Mediobasal Hypothalamus (MBH) was strong after the treatment in the DsRed group while IGF1 content in the MBH was higher in the IGF1 group. The IGF1 treatment affected neither pituitary weight nor PRL, E2 or P4 serum levels in the young rats. In the old rats, IGF1 gene therapy reduced gland weight as compared with intact counterparts and tended to reduce PRL levels as compared with intact counterparts. The treatment significantly rescued the phenotype of the lactotropic cell population in the senile adenomas.

CONCLUSION

We conclude that long-term hypothalamic IGF1 gene therapy is effective to rescue spontaneous prolactinomas in aging female rats.

[Prevalencia y factores de riesgo para lesiones premalignas en pacientes menores de 55 años sometidos a colonoscopia en un hospital de tercer nivel]

Antecedentes

El cáncer colorrectal es causa importante de mortalidad y la colonoscopia es efectiva para reducir su incidencia y mejorar la supervivencia con la resección de las lesiones precursoras.

Objetivo

Determinar la prevalencia, las características y la histología de las lesiones en pacientes < 55 años en un hospital de tercer nivel.

Método

Se realizó un estudio retrospectivo y observacional de enero de 2010 a diciembre de 2014 en el Hospital de Especialidades del Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, con el reporte de 555 colonoscopias y los datos clínicos de las historias hospitalarias de los pacientes incluidos en el estudio.

Resultados

Los hallazgos fueron lesiones premalignas en el 40% de los pacientes, con pólipos en 98 casos y con un tamaño de 5.2 mm; de ellos, el 54% se localizaron en el colon, el 24% en el sigmoides, el 27% en el recto y el 1% en el ano. En los reportes se observó una prevalencia del 63% de pólipos neoplásicos (riesgo relativo [RR]: 2.3; intervalo de confianza del 95% [IC 95%]: 1.5-3.7) en pacientes con antecedente de tabaquismo, y del 42% (RR: 1.8; IC 95%: 1.2-2.6) con antecedente de consumo de alcohol.

Conclusiones

La prevalencia de lesiones premalignas es similar para los menores de 55 años. Esto indica la importancia del diagnóstico oportuno y de evitar la progresión. Sería conveniente extender el seguimiento a hospitales de segundo nivel en pacientes con factores de riesgo para ampliar lo reportado y contribuir a mejorar los resultados en la sanidad pública.

Background

Colorectal cancer is an important cause of mortality, colonoscopy is effective to reduce its incidence and improve survival with the resection of premalignant lesions.

Objective

To determine the prevalence, characteristics and histology of lesions in patients younger than 55 years of age in a tertiary hospital.

Method

This is a retrospective observational study, we colected data at the Hospital de Especialidades del Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, with the report of 555 colonoscopies, and clinical data from the hospital archives of medic histories of selected patients.

Results

Premalignant lesions were found on 40% of the patients. The findings were polyps in 98 cases with a size of 5.2 mm; 54% were located in the colon, 24% in the sigmoid, 27% in the rectum and 1% in the anus. A prevalence of 63% of neoplastic polyps was observed (RR: 2.3; 95% CI: 1.5-3.7) in smokers; and 42% (RR: 1.8; 95% CI: 1.2-2.6) in patients with alcohol consumption.

Conclusions

The prevalence for premalignant lesions is similar for patients under 55 years of age. This highlights the importance of early diagnosis and avoiding progression. It would be convenient to extend the follow-up to second-level hospitals in patients with risk factors to contribute to improvement of public health system outcomes.

Colorectal cancer surveillance in Portuguese families with lynch syndrome: a cohort study

PURPOSE

Lynch syndrome (LS) is associated with a high risk of colorectal cancer (CRC). The aim of this study was to assess the cumulative risk for the development of colorectal adenomas or carcinomas in a LS CRC surveillance program and to audit the quality of the endoscopic procedures.

METHODS

We evaluated 147 asymptomatic LS mutation carriers, without previous CRC, in a surveillance program with colonoscopy every 12-18 months, between 2005 and 2016. Data was obtained by retrospective review of colonoscopy reports and hospital clinical files. The main outcome was assessed using Kaplan-Meier curves. Logistic regression was used to study the risk of developing adenomas.

RESULTS

Patients were under surveillance for 1092 observation years (mean, 7.7 years/patient). Most exams presented adequate bowel preparation (83.5%) and 99.2% achieved cecal intubation. The estimated risk for adenomas at age 60 was 75.6% in men (95%CI, 60.5-88.3) and 65.5% in women (95%CI, 50.8-79.7). Male gender (OR 2.4; 95%CI, 1.2-4.9; p = 0.018) and age at start of surveillance > 40 years (OR 3.7; 95%CI, 1.8-7.7; p < 0.001) were independent risk factors for adenoma detection. CRC was diagnosed in 11 patients with an estimated cumulative risk at age 60 of 18.4% (95%CI, 9.2-34.8%); 72.7% of CRC were classified as stage I; no patient died from CRC.

CONCLUSION

A colonoscopic surveillance program in LS patients allowed the detection of adenomas in a large group of mutation carriers and diagnosis of early-stage carcinomas. Our findings may help other teams to adopt similar strategies or to refer patients early to specialized centers.

Telomere length differences between colorectal polyp subtypes: a colonoscopy-based case-control study

Background

Short telomeres have been associated with increased risk of many cancers, particularly cancers of the gastrointestinal tract including esophagus and stomach. However, the association between telomere length (TL) and colorectal cancer and its precursors, colorectal polyps, is not clear.

Methods

We investigated the relationship between TL and risk of colorectal polyp subtypes in a colonoscopy-based study in western Washington. Participants were 35–79 year-old enrollees at an integrated health care system, who underwent a colonoscopy between 1998 and 2007 (n = 190), completed a self-administered questionnaire, provided blood samples, and were distinguished as having adenomas, serrated polyps, or as polyp-free controls through a standardized pathology review. Telomere length (T) relative to a single copy gene (S) was measured in circulating leukocytes from stored buffy coat samples using quantitative polymerase chain reaction. Multivariable polytomous logistic regression was used to compare case groups with polyp-free controls and other case groups; adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated.

Results

TL in the shortest tertile (T/S ratio < 0.58) was associated with increased risk of adenomas and serrated polyps [OR (95%CI) were 1.77(0.81–3.88) and 2.98(1.15–7.77), respectively). When evaluated by lesion severity within each pathway, short TL was more strongly associated with advanced adenomas and sessile serrated polyps [OR (95% CI) = 1.90(0.76–4.73) and 3.82(0.86–16.86), respectively], although the associations were not statistically significant.

Conclusions

Our results suggest that short TL may be associated with an increased risk of colorectal polyps in both the adenoma-carcinoma and serrated pathways. The risk was particularly notable for sessile serrated polyps, although the association was not statistically significant and sample size was limited.

Adenoma detection rate metrics in colorectal cancer surveillance colonoscopy

BACKGROUND

A target goal for screening adenoma detection rate (S-ADR) of ≥ 25% has been set to define high-quality colonoscopy performance. However, there is no current accepted target goal for ADR in colorectal cancer (CRC) surveillance. This makes quality assessment challenging when physicians perform cancer surveillance colonoscopy but minimal screening procedures.

METHODS

In this cohort study, consecutive colonoscopies performed at either Rush University Medical Center or Rush Oak Park Hospital by a gastroenterologist or colorectal surgeon in average risk screening population and CRC surveillance population were reviewed retrospectively from 2006 to 2012 and prospectively from 2013 to 2016. ADR in first surveillance colonoscopy following surgical resection of CRC (CRC-ADR) was reported in high-quality detectors (HQD) or low-quality detectors (LQD) based on achievement of 25% ADR in consecutive screening colonoscopy in average risk patients. Pearson's correlation was used to describe the association between individual S-ADR and CRC-ADR for colonoscopists.

RESULTS

There was a very strong positive correlation (r = 0.88, p = 0.002) between ADR in average risk screening and first time CRC surveillance. For HQD as defined by S-ADR ≥ 25% (n = 10 colonoscopists), the CRC-ADR was 37.7% (78/207, SD 8%) which was very similar to their respective S-ADR of 33.4% (816/2440, p = 0.22). For LQD (n = 5 colonoscopists), the CRC-ADR was 20.2% (40/198) which was similar to their respective S-ADR of 20.1% (119/591, p = 0.99). The CRC-ADR was significantly higher for HQD than for LQD (37.7 vs. 20.2%, p < 0.0001).

CONCLUSIONS

The major finding of this study is a defined CRC-ADR for HQD based on the ability to achieve S-ADR ≥ 25%. S-ADR strongly correlates with CRC-ADR. CRC-ADR is quite similar to the colonoscopists' respective S-ADR for both HQD and LQD. For colonoscopists who perform limited screening colonoscopies but do perform CRC surveillance colonoscopies, ADR metrics similar to S-ADR to assess quality in colonoscopy could be considered.

Could Mycobacterium avium subspecies paratuberculosis cause Crohn's disease, ulcerative colitis…and colorectal cancer?

Infectious agents are known causes of human cancers. Schistosoma japonicum and Schistosoma mansoni cause a percentage of colorectal cancers in countries where the respective Schistosoma species are prevalent. Colorectal cancer is a complication of ulcerative colitis and colonic Crohn’s disease, the two main forms of idiopathic inflammatory bowel disease (IIBD). Mycobacterium avium subspecies paratuberculosis (MAP), the cause of a chronic intestinal disease in domestic and wild ruminants, is one suspected cause of IIBD. MAP may therefore be involved in the pathogenesis of IIBD-associated colorectal cancer as well as colorectal cancer in individuals without IIBD (sporadic colorectal cancer) in countries where MAP infection of domestic livestock is prevalent and MAP’s presence in soil and water is extensive. MAP organisms have been identified in the intestines of patients with sporadic colorectal cancer and IIBD when high magnification, oil immersion light microscopy (×1000 total magnification rather than the usual ×400 total magnification) is used. Research has demonstrated MAP’s ability to invade intestinal goblet cells and cause acute and chronic goblet cell hyperplasia. Goblet cell hyperplasia is the little-recognized initial pathologic lesion of sporadic colorectal cancer, referred to as transitional mucosa, aberrant crypt foci, goblet cell hyperplastic polyps or transitional polyps. It is the even lesser-recognized initial pathologic feature of IIBD, referred to as hypermucinous mucosa, hyperplastic-like mucosal change, serrated epithelial changes, flat serrated changes, goblet cell rich mucosa or epithelial hyperplasia. Goblet cell hyperplasia is the precursor lesion of adenomas and dysplasia in the classical colorectal cancer pathway, of sessile serrated adenomas and serrated dysplasia in the serrated colorectal cancer pathway, and of flat and elevated dysplasia and dysplasia-associated lesions or masses in IIBD-associated intestinal cancers. MAP’s invasion of intestinal goblet cells may result in the initial pathologic lesion of IIBD and sporadic colorectal cancer. MAP’s persistence in infected intestines may result in the eventual development of both IIBD-associated and sporadic colorectal cancer.

Advancements in the study of miRNA regulation during the cell cycle in human pituitary adenomas

Pituitary adenomas (PAs), single-clone adenomas arising from pituitary gland cells, comprise one of the most frequent tumors found in the sella region. The prevalence of PAs is approximately 15%, third only after gliomas and meningioma among intracranial tumors. Autopsy and radiological analysis found that the incidence of PAs is approximately 22.5%. Most PAs are benign, although a few are malignant. Just 0.1% of patients with PAs develop pituitary carcinoma. However, owing to mass effects and unregulated secretion of pituitary hormones, PAs also lead to serious morbidity. The low rate of diagnosis at onset and the lack of effective treatments for patients with recurrent disease increase the morbidity rates. Therefore, there is an urgent need to ascertain the pathological mechanism of PAs for improved diagnosis and development of specific therapies. At present, the pathogenesis of PAs is poorly understood; however, disruption of the cell cycle is known to play an important role. MicroRNAs are short noncoding RNAs that regulate gene expression at the post-transcriptional level and play a role in regulating genes involved in carcinogenesis or tumor suppression. Previous studies have demonstrated a strong connection between dysregulation of microRNAs and dysregulation of the cell cycle in PAs. In this review, we summarize the recent progress in the study of microRNA dysregulation resulting in disruption of the cell cycle in PAs.

Serum MicroRNA profile in patients with colon adenomas or cancer

BACKGROUND

Colon cancer, one of the most common causes of cancer-related deaths, arises from adenomatous polyps. In these years, circulating microRNAs (miRNAs) have attracted increasing attention as novel biomarkers for colon cancers. The dysregulated circulating miRNAs in patients with colon adenomas has not been well-understood.

METHODS

Here, we aimed to identify miRNA profile in the serum of patients with colon adenomas or colon cancer by using microarray. Then we validated eight differentially expressed miRNAs (DEMs) by qRT-PCR and predicted their targets.

RESULTS

We identified 26 DEMs from Adenomas versus Normal comparison (11 up-regulations and 15 down-regulations), 72 DEMs from Cancer versus Normal comparison (19 up-regulations and 53 down-regulations) and 17 DEMs from Cancer versus Adenomas comparison (4 up-regulations and 13 down-regulations). Moreover, three DEMs identified from Cancer versus Normal comparison were included in the list of DEMs identified from Cancer versus Adenomas comparison, and may be specific diagnostic biomarkers for colon cancer. Five down-regulated miRNAs identified from Cancer versus Normal comparison were included in the list of DEMs identified from Adenomas versus Normal comparison, and may be important for the development of colon polyps and cancer.

CONCLUSIONS

We discovered 8 circulating miRNAs associated with colon adenomas and colon cancer, and these miRNAs may potentially serve as noninvasive screening biomarkers for colon cancer. Our study is useful for expanding our understanding in the development of colon adenomas and colon cancer, and thus provide novel insights into colon cancer pathogenesis and prevention.

Expression of Alpha - Methylacyl - Coenzyme A Racemase (AMACR) in Colorectal Neoplasia

INTRODUCTION

Red meat and dairy products have been implicated in colonic cancers. They are rich in branched chain fatty acids which require an enzyme Alpha-Methylacyl-Coenzyme A Racemase (AMACR) for their oxidation. Increased expression of AMACR in colorectal premalignant lesions and carcinomas suggests its possible role in carcinogenesis.

AIM

To study the expression of AMACR in colorectal neoplasia and its correlation with the histological grade, stage and nodal status of colorectal malignancy.

MATERIALS AND METHODS

All cases of colorectal neoplasms were included in the study. AMACR expression was studied in 56 cases which included 44 cases of adenocarcinoma and 12 cases of adenoma and a normal colonic mucosal tissue was used as a control. A tissue microarray was prepared by manual method. AMACR expression was studied by Immunohistochemistry (IHC) and it was correlated with the grade, stage and nodal status of the cancer. Chi-square test was used for analysis or results. The p-value of <0.05 was considered significant.

RESULTS

Out of 12 cases of adenoma 25% (3/12) were negative; 50% (6/12) showed poor expression, 25% (3/12) had moderate expression and none showed strong expression. Nearly, 34.1% (15/44) case of carcinoma were negative; 45.45% (20/44) had poor; 13.63% (6/44) had moderate and 6.81% (3/44) had a strong expression. Normal colonic tissue showed no expression. There was no significant difference of AMACR expression between adenoma and carcinoma cases. AMACR expression was found to be increased in low grade carcinomas (G1 and G2). G1 showed AMACR positivity in 62% cases and G2 showed 71.4% positivity. No association was found between AMACR expression and different American Joint Committee on Cancer (AJCC) stages and nodal status of CRC.

CONCLUSION

Increased expression of AMACR in adenomas and carcinomas as compared to non-neoplastic epithelium of colon implies that, it plays a role in colorectal neoplasia. Decreased expression of AMACR in high grade carcinomas suggests its role in differentiation of the tumour.

Reproductive factors and risk of colorectal polyps in a colonoscopy-based study in western Washington State

BACKGROUND

Oral contraceptives (OC) are associated with a decreased risk of colorectal cancers; however, a recent study reported an increased risk of small colorectal adenomas associated with OC use. To determine if these results were replicable in a different study population, we investigated the relationship between OC use and other reproductive factors and risk of colorectal polyps in a case-control study in western Washington.

METHODS

Study participants were 24-79-year-old female enrollees at an integrated health care system in western Washington who were diagnosed as having adenomas (n = 299), serrated polyps (n = 337), both types of polyps (n = 105) or as polyp-free controls (n = 615) through an index colonoscopy and completed a structured interview to collect reproductive history information. Multivariable polytomous logistic regression was used to compare case groups to controls and to each other; odds ratios (OR) and 95% confidence intervals were estimated.

RESULTS

There was no association between OC use, duration of use, or recency of use and the risk of either adenomas or serrated polyps [adjusted OR for OC ever use (95% CI) 0.85 (0.58-1.23) and 0.96 (0.66-1.40), respectively], and associations did not differ by lesion severity within the adenoma or serrated pathways. Further, no associations were observed between other reproductive factors and risk of colorectal polyp subtypes.

CONCLUSIONS

Our results suggest that reproductive factors, including OC use, are not associated with early colorectal cancer precursor lesions.

Risk factors for metachronous adenoma in the residual colon of patients undergoing curative surgery for colorectal cancer

PURPOSE

Adenoma detection in colorectal cancer survivors is poorly characterised with insufficient evidence to inform frequency of surveillance schedule. The aim of this study was to examine adenoma incidence and recurrence in patients who have undergone colorectal cancer resection with curative intent. Survival outcomes were compared to determine if the presence of adenomas could be used to identify patients at higher risk of local recurrence.

METHODS

This is a retrospective observational cohort study at a single tertiary institution between 2006 and 2012. Five hundred fifteen consecutive patients with stage I-III colorectal cancer who had preoperative colonoscopy and curative surgery were included (median follow-up 56 months (36-75 months).

RESULTS

In total, 352/515 (68%) patients underwent postoperative surveillance colonoscopy in the first 5 years after resection. Male gender was associated with greater risk of detecting synchronous adenoma at index colonoscopy or in the resection specimen (OR 2.35, p < 0.001). In the first 5 years after cancer surgery, synchronous adenoma, male gender and right sided primary tumour were independent predictors of metachronous lesions (OR 2.13, p = 0.009; OR 2.07, p = 0.027 and OR 2.34, p = 0.004, respectively). Presence of synchronous or metachronous adenoma had no impact upon incidence of local recurrence, overall or disease free survival.

CONCLUSIONS

Patients with synchronous adenoma remain at high risk of adenoma recurrence despite undergoing colonic resection and should be considered for early endoscopic surveillance. Men and those undergoing right-sided resection have a higher risk of metachronous adenoma in the long term and may benefit from more frequent endoscopic surveillance post resection.

Detection of Oncogene-Induced Senescence In Vivo

Oncogene-induced senescence or OIS is defined as a permanent state of proliferative arrest resulting from an activating oncogenic-lesion. OIS has been suggested to function as a cancer cell intrinsic mechanism to restrain tumor growth and has been implicated as a key mechanism preventing the progression of certain premalignant lesions in genetically engineered mouse models of cancer. The senescent phenotype can be defined by two criteria that include cell cycle arrest and resistance to mitogens and oncogenic transformation. While the phenotype and properties of senescent cells in vitro are well described, the morphological characteristics defining senescence in vivo have been controversial with no specific marker that definitively proves a senescent state. Indeed, many of the published in vivo markers to identify and characterize senescence in an organism are unreliable and often times have been found to be nonspecific. However, the use of multiple markers is accepted as confirmation of senescence in vivo. Here, we describe protocols for some of the most commonly used indicators of senescence in oncogenic Kras-induced lung adenomas including the detection of senescence-associated beta-galactosidase, expression of the tumor suppressor p19^ARF, the presence of senescence-associated heterochromatin foci, and in vivo BrdU uptake to confirm cell cycle arrest.

Risk of cancer in small and diminutive colorectal polyps

The prevalence of cancer in small and diminutive polyps is relevant to "resect and discard" and CT colonography reporting recommendations. We evaluated a prospectively collected colonoscopy polyp database to identify polyps <10mm and those with cancer or advanced histology (high-grade dysplasia or villous elements). Of 32,790 colonoscopies, 15,558 colonoscopies detected 42,630 polyps <10mm in size. A total of 4790 lesions were excluded as they were not conventional adenomas or serrated class lesions. There were 23,524 conventional adenomas <10mm of which 22,952 were tubular adenomas. There were 14,316 serrated class lesions of which 13,589 were hyperplastic polyps and the remainder were sessile serrated polyps. Of all conventional adenomas, 96 had high-grade dysplasia including 0.3% of adenomas ≤5mm in size and 0.8% of adenomas 6-9mm in size. Of all conventional adenomas, 2.1% of those ≤5mm in size and 5.6% of those 6-9mm in size were advanced. Among 36,107 polyps ≤5mm in size and 6523 polyps 6-9mm in size, there were no cancers. These results support the safety of resect and discard as well as current CT colonography reporting recommendations for small and diminutive polyps.