Factors that increase risk of colon polyps

Development and validation of a nomogram predictive model for colorectal adenoma with low-grade intraepithelial neoplasia using routine laboratory tests: A single-center case-control study in China

Background

Colorectal cancer (CRC) is the third most common cancer in the world and has a high mortality rate. Colorectal adenoma (CRA) is precancerous lesions of CRC. The purpose of the present study was to construct a nomogram predictive model for CRA with low-grade intraepithelial neoplasia (LGIN) in order to identify high-risk individuals, facilitating early diagnosis and treatment, and ultimately reducing the incidence of CRC.

Methods

We conducted a single-center case-control study. Based on the results of colonoscopy and pathology, 320 participants were divided into the CRA group and the control group, the demographic and laboratory test data were collected. A development cohort (n = 223) was used for identifying the risk factors for CRA with LGIN and to develop a predictive model, followed by an internal validation. An independent validation cohort (n = 97) was used for external validation. Receiver operating characteristic curve, calibration plot and decision curve analysis were used to evaluate discrimination ability, accuracy and clinical practicability of the model.

Results

Four predictors, namely sex, age, albumin and monocyte count, were included in the predictive model. In the development cohort, internal validation and external validation cohort, the area under the curve (AUC) of this risk predictive model were 0.946 (95%CI: 0.919-0.973), 0.909 (95 % CI: 0.869-0.940) and 0.928 (95%CI: 0.876-0.980), respectively, which demonstrated the model had a good discrimination ability. The calibration plots showed a good agreement and the decision curve analysis (DCA) suggested the predictive model had a high clinical net benefit.

Conclusion

The nomogram model exhibited good performance in predicting CRA with LGIN, which can aid in the early detection of high-risk patients, improve early treatment, and ultimately reduce the incidence of CRC.

Clinical characteristics and risk factors related to polyposis recurrence and advanced neoplasm development among patients with non-hereditary colorectal polyposis

BACKGROUND/AIMS

Patients with more than 10 cumulative polyps might involve a greater genetic risk of colorectal neoplasia development. However, few studies have investigated the risk factors of polyposis recurrence and development of advanced neoplasms among patients with non-hereditary colorectal polyposis.

METHODS

This study included patients (n=855) with 10 or more cumulative polyps diagnosed at Severance Hospital from January 2012 to September 2021. Patients with known genetic mutations related to polyposis, known hereditary polyposis syndromes, insufficient information, total colectomy, and less than 3 years of follow-up were excluded. Finally, 169 patients were included for analysis. We collected clinical data, including colonoscopy surveillance results, and performed Cox regression analyses of risk factors for polyposis recurrence and advanced neoplasm development.

RESULTS

The 169 patients were predominantly male (84.02%), with a mean age of 64.19±9.92 years. The mean number of adenomas on index colonoscopy was 15.33±8.47. Multivariable analysis revealed history of cancer except colon cancer (hazard ratio [HR], 2.23; 95% confidence interval [CI], 1.23-4.01), current smoking (HR, 2.39; 95% CI, 1.17-4.87), and detection of many polyps (≥15) on index colonoscopy (HR, 2.05; 95% CI, 1.21-3.50) were significant risk factors for recurrence of polyposis. We found no statistically significant risk factors for advanced neoplasm development during surveillance among our cohort.

CONCLUSIONS

The presence of many polyps (≥15) on index colonoscopy, history of cancer except colon cancer, and current smoking state were significant risk factors for polyposis recurrence among patients with non-hereditary colorectal polyposis.

Self-reported gastrointestinal disorders among veterans with gulf war illness with and without posttraumatic stress disorder

BACKGROUND

Gulf War Illness (GWI) is a chronic, multi-symptom disorder affecting 25%-32% of Gulf War veterans. Veterans with GWI disproportionately suffer from gastrointestinal (GI) disorders. Given the increasing evidence supporting a gut-brain axis, we explore the relationship between post-traumatic stress disorder (PTSD), GWI, and self-reported GI disorders among GW veterans.

METHODS

Veterans from the Gulf War Era Cohort and Biorepository responded to a mail-based survey (N = 1058). They were stratified by GWI (Centers for Disease Control definition) and PTSD status. This yielded three groups: GWI-, GWI+/PTSD-, and GWI+/PTSD+. Multivariable logistic regression adjusting for demographic and military characteristics examined associations between GWI/PTSD groups and GI disorders. Results were expressed as adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

KEY RESULTS

The most frequently reported GI disorders were irritable bowel syndrome (IBS), gastroesophageal reflux disease (GERD), and colon polyps (CP). The GWI+/PTSD+ group had a higher odds of these disorders than the GWI+/PTSD- group (aOR_IBS  = 3.12, 95% CI: 1.93-5.05; aOR_GERD  = 2.04, 95% CI: 1.44-2.90; aOR_CP  = 1.85, 95% CI: 1.23-2.80), which had a higher odds of these disorders than the GWI- group (aOR_IBS  = 4.38, 95% CI: 1.55-12.36; aOR_GERD  = 2.51 95% CI: 1.63-3.87; aOR_CP  = 2.57, 95% CI: 1.53-4.32).

CONCLUSIONS & INFERENCES

GW veterans with GWI and PTSD have significantly higher odds of specific self-reported GI disorders than the other groups. Given the known bidirectional influences of the gut and brain, these veterans may benefit from a holistic healthcare approach that considers biopsychosocial contributors to the assessment and management of disease.

Intestinal cancer development in response to oral infection with high-fat diet-induced Type 2 diabetes (T2D) in collaborative cross mice under different host genetic background effects

Type 2 diabetes (T2D) is a metabolic disease with an imbalance in blood glucose concentration. There are significant studies currently showing association between T2D and intestinal cancer developments. High-fat diet (HFD) plays part in the disease development of T2D, intestinal cancer and infectious diseases through many biological mechanisms, including but not limited to inflammation. Understanding the system genetics of the multimorbidity of these diseases will provide an important knowledge and platform for dissecting the complexity of these diseases. Furthermore, in this study we used some machine learning (ML) models to explore more aspects of diabetes mellitus. The ultimate aim of this project is to study the genetic factors, which underline T2D development, associated with intestinal cancer in response to a HFD consumption and oral coinfection, jointly or separately, on the same host genetic background. A cohort of 307 mice of eight different CC mouse lines in the four experimental groups was assessed. The mice were maintained on either HFD or chow diet (CHD) for 12-week period, while half of each dietary group was either coinfected with oral bacteria or uninfected. Host response to a glucose load and clearance was assessed using intraperitoneal glucose tolerance test (IPGTT) at two time points (weeks 6 and 12) during the experiment period and, subsequently, was translated to area under curve (AUC) values. At week 5 of the experiment, mice of group two and four were coinfected with Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) strains, three times a week, while keeping the other uninfected mice as a control group. At week 12, mice were killed, small intestines and colon were extracted, and subsequently, the polyp counts were assessed; as well, the intestine lengths and size were measured. Our results have shown that there is a significant variation in polyp's number in different CC lines, with a spectrum between 2.5 and 12.8 total polyps on average. There was a significant correlation between area under curve (AUC) and intestine measurements, including polyp counts, length and size. In addition, our results have shown a significant sex effect on polyp development and glucose tolerance ability with males more susceptible to HFD than females by showing higher AUC in the glucose tolerance test. The ML results showed that classification with random forest could reach the highest accuracy when all the attributes were used. These results provide an excellent platform for proceeding toward understanding the nature of the genes involved in resistance and rate of development of intestinal cancer and T2D induced by HFD and oral coinfection. Once obtained, such data can be used to predict individual risk for developing these diseases and to establish the genetically based strategy for their prevention and treatment.

Obesity and incidence of colorectal polyps: a case-controlled study

Previous essays have presented possible concordance between obesity and colorectal polyp development. However, neither for the hypothesis nor for the details general consensus exists. This study aimed to evaluate the association between higher BMI rather than the normal and colorectal polyp presentation and characteristics if any.

Methods

Eligible patients based on study criteria who were candidates for total colonoscopy examination enrolled in this case-controlled trial. Controls had normal colonoscopy reports. A positive colonoscopy for any kind of polyp was followed by a histopathological study. Demographic data also was registered, and patients were categorized according to the calculated BMI. Groups were matched by both gender and status of tobacco abuse. Finally, the outcomes of colonoscopy and histopathological studies were compared between groups.

Results

A total of 141 and 125 persons investigated, respectively, as patients and controls. Possible effects of gender, tobacco abuse, and cigarette smoking were declined by participants matching. Hence, we found no significant difference between groups regarding the latter variables (P>0.05). Colorectal polyps were found absolutely more in BMI>25 kg/m^-2 rather than in lesser values (P<0.001). However, there was no obvious difference in the incidence of colorectal polyps between groups categorized as overweight and obese (P>0.05). Namely, even weighing over could be the risk for colorectal polyp development. Additionally, it was more expected to find neoplastic adenomatous polyp(s) with high-graded dysplasia in BMI>25 kg/m^-2 (P<0.001).

Conclusion

Even little changes in BMI further than the normal values can independently increase the risk of developing dysplastic adenomatous colorectal polyp(s) significantly.

Does Finding Cecal Adenoma Increase the Risk of Discovering More and Advanced Adenomas in the Remainder of the Colon?

OBJECTIVES

Adenomatous polyps are common, occurring in up to 25% of the population older than 50 years of age in the United States. Conflicting data are present in the literature about the impact of specific adenoma locations and the prediction on the number and advanced histology of adenomas elsewhere. With this study we aimed to review the association between cecal adenoma and the risk of discovering more and advanced adenomas in the remainder of the colon.

METHODS

We performed a retrospective study of 1880 patients who received outpatient colonoscopies between June 2012 and December 2014 at the Veterans Affairs Medical Center in Oklahoma City. The data collected included patient demographics, indications for colonoscopy, smoking history, alcohol use, family history of colon cancer, quality of bowel preparation, number of adenomas, location, size of adenomas, and the histology of adenomas and colon cancer.

RESULTS

The mean age of the study population was 61.6 ± 9.4 year, with 95% of the population being men. Cecal adenomas were found in 243 (12.9%) of patients. Patients with cecal adenoma tended to be older (65 ± 7 vs 61 ± 10, P < 0.0001), more likely to be men (97% vs 94%, P = 0.06) and less likely to have a colonoscopy done for screening indication (11% vs. 13%., P = 0.03). After adjusting for age, sex, indication, and quality of bowel preparation, patients with cecal adenoma were found to have a sixfold increase in finding ≥10 other adenomas elsewhere (4.5% vs 0.8% P = 0.0009) and a threefold increase in finding advanced adenomas (17.7% vs 9.9% P = 0.002) in the remainder of the colon. Stratifying by location, the increased risk was more pronounced in the right side (24.7% vs 8.9% P ≤ 0.0001) compared with the left side.

CONCLUSIONS

Cecal adenoma is associated with an increased risk of finding more and advanced adenomas in the remainder of the colon, especially on the right side; therefore, the discovery of a cecal adenoma should prompt a more thorough evaluation of the entire colon, particularly the right colon.

Modeling age-specific incidence of colon cancer via niche competition

Cancer development is a multistep process often starting with a single cell in which a number of epigenetic and genetic alterations have accumulated thus transforming it into a tumor cell. The progeny of such a single benign tumor cell expands in the tissue and can at some point progress to malignant tumor cells until a detectable tumor is formed. The dynamics from the early phase of a single cell to a detectable tumor with billions of tumor cells are complex and still not fully resolved, not even for the well-known prototype of multistage carcinogenesis, the adenoma-adenocarcinoma sequence of colorectal cancer. Mathematical models of such carcinogenesis are frequently tested and calibrated based on reported age-specific incidence rates of cancer, but they usually require calibration of four or more parameters due to the wide range of processes these models aim to reflect. We present a cell-based model, which focuses on the competition between wild-type and tumor cells in colonic crypts, with which we are able reproduce epidemiological incidence rates of colon cancer. Additionally, the fraction of cancerous tumors with precancerous lesions predicted by the model agree with clinical estimates. The correspondence between model and reported data suggests that the fate of tumor development is majorly determined by the early phase of tumor growth and progression long before a tumor becomes detectable. Due to the focus on the early phase of tumor development, the model has only a single fit parameter, the time scale set by an effective replacement rate of stem cells in the crypt. We find this effective rate to be considerable smaller than the actual replacement rate, which implies that the time scale is limited by the processes succeeding clonal conversion of crypts.

Cancer development is a multistep process often starting with a single cell turning into a tumor cell whose progeny growths via clonal expansion into a macroscopic tumor with billions of cells. While experimental insight exists on the cellular scale and cancer registries provide statistics on detectable tumors, the complex dynamics leading from the microscopic cellular scale to a macroscopic tumor is still not fully resolved. Models of cancer biology are commonly used to explain incidence rates but usually require the fit of several biological parameters due to the complexity of the incorporated processes. We employ a cell-based model based on the competition in colonic crypts, to reproduce epidemiological age-specific incidence rates of colon cancer. Due to the focus on the early stage of tumor development, only the time scale in the model has to be calibrated. The agreement between theoretical prediction and epidemiological observation suggests that the fate of tumor development is dominated by the early phase of tumor development long before a tumor becomes detectable.

Total Vitamin D Intake and Risks of Early-Onset Colorectal Cancer and Precursors

BACKGROUND & AIMS

Vitamin D has been implicated in colorectal cancer (CRC) pathogenesis, but it remains unknown whether total vitamin D intake is associated with early-onset CRC and precursors diagnosed before age 50.

METHODS

We prospectively examined the association between total vitamin D intake and risks of early-onset CRC and precursors among women enrolled in the Nurses' Health Study II. Multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for early-onset CRC were estimated with Cox proportional hazards model. Multivariable-adjusted odds ratios (ORs) and 95% CIs for early-onset conventional adenoma and serrated polyp were estimated with logistic regression model.

RESULTS

We documented 111 incident cases of early-onset CRC during 1,250,560 person-years of follow-up (1991 to 2015). Higher total vitamin D intake was significantly associated with a reduced risk of early-onset CRC (HR for ≥450 IU/day vs <300 IU/day, 0.49; 95% CI, 0.26-0.93; P for trend = .01). The HR per 400 IU/day increase was 0.46 (95% CI, 0.26-0.83). The inverse association was significant and appeared more evident for dietary sources of vitamin D (HR per 400 IU/day increase, 0.34; 95% CI, 0.15-0.79) than supplemental vitamin D (HR per 400 IU/day increase, 0.77; 95% CI, 0.37-1.62). For CRC precursors, the ORs per 400 IU/day increase were 0.76 (95% CI, 0.65-0.88) for conventional adenoma (n = 1,439) and 0.85 (95% CI, 0.75-0.97) for serrated polyp (n = 1,878).

CONCLUSIONS

In a cohort of younger women, higher total vitamin D intake was associated with decreased risks of early-onset CRC and precursors.

Colorectal Cancer Prevention in Lung Transplant Recipients: The Need for an Enhanced Surveillance Protocol

BACKGROUND

Solid organ transplant recipients are at increased risk for noncutaneous neoplasms, including colorectal cancer (CRC). We evaluated precancerous lesions detected by post-transplant surveillance colonoscopy to infer the rate at which new adenomas develop in this population.

STUDY DESIGN

We reviewed all patients who underwent lung transplant between January 2013 and August 2017 at our institution. Those with post-transplant survival <1 year, personal history of CRC, previous lung transplant, and lack of pretransplant colonoscopy were excluded.

RESULTS

During the study period, 411 patients underwent lung transplant; 237 met inclusion criteria. Median age at transplant was 63.6 (interquartile range [IQR] 59.2-68.3) years. Most recipients were immunosuppressed with a combination of prednisone, tacrolimus, and mycophenolate mofetil. At least 1 adenoma was found in 92 patients (38.8%) pretransplant and in 118 patients (49.8%) from 1 to 5 years post-transplant, with 68.6% identified at 1 year. Most adenomas were identified proximal to the splenic flexure. Multiple (≥3) adenomas were found in 31.4% of positive colonoscopies. Within 5 years after transplant, patients with a positive pretransplant colonoscopy had significantly more positive post-transplant colonoscopies than patients with a negative pretransplant colonoscopy (63.0% vs 41.4%, p < 0.001). No de novo CRC was identified.

CONCLUSIONS

Lung transplant recipients have a significantly higher risk of adenoma formation than average-risk adults (25%-30% national detection rate). This increase occurs in the early post-transplant period (within 3 years). An enhanced CRC surveillance protocol for lung transplant recipients is needed.

An Overview of Gut Microbiota and Colon Diseases with a Focus on Adenomatous Colon Polyps

It is known and accepted that the gut microbiota composition of an organism has an impact on its health. Many studies deal with this topic, the majority discussing gastrointestinal health. Adenomatous colon polyps have a high prevalence as colon cancer precursors, but in many cases, they are hard to diagnose in their early stages. Gut microbiota composition correlated with the presence of adenomatous colon polyps may be a noninvasive and efficient tool for diagnosis with a high impact on human wellbeing and favorable health care costs. This review is meant to analyze the gut microbiota correlated with the presence of adenomatous colon polyps as the first step for early diagnosis, prophylaxis, and treatment.

Clinicopathologic Features of Colorectal Polyps in Shahid Beheshti University of Medical Sciences (SBMU)

Aim:

This study was designed to report epidemiologic findings of polyps in Iranian patients, and predict histology of polyp regarding to demographic and colonoscopic findings.

Background:

Classification of colorectal polyps had been revised in the past two decades and there is a need for polyp categorization in the Iranian Health System. Patients and methods: In this retrospective study, the medical records of patients with colonoscopic diagnosis of polyp in pathology departments of SBMU affiliated teaching hospitals were reviewed. Patient’s slides evaluated and demographics findings were assessed. The anatomical location, macroscopic appearance including size and histological assessment of all polyps were recorded.

Results:

From total number of 1106 polyps (detected in 862 patients), adenomatous polyps (638 [57.7%]) were the most prevalent findings, followed by colon mucosal tag (184[16.6%]), hyperplastic and serrated polyps (122[11%]), inflammatory polyps (110[9.9%]), hamartomatous (21[1.9%]), and malignant lesions (13[1.2%]). Multivariate logistic regression showed age (each one year increasing age; odds ratio [OR] = 1.026, 95%confidence interval [CI] = 1.016–1.036, p < 0.0001), location of polyp (right colon; OR = 1.905, 95%CI = 1.366–2.656, p < 0.0001), and polyp size of 5-10 mm (OR = 1.662, 95%CI = 1.214–2.276, p = 0.002), and polyp size of >10 mm (OR = 2.778, 95%CI = 1.750–4.411, p< 0.0001) were independently associated with neoplastic polyps. Also, polyp size of >10 mm (OR= 2.613, 95%CI= 1.083-6.307, p=0.033), tubulovillous pattern of polyp (OR= 3.508, 95%CI= 1.666-7.387, p=0.001) and villous pattern of polyp (OR= 10.444, 95%CI= 4.211-25.905, p<0.0001) were associated with high grade dysplasia in neoplastic polyps.

Conclusion:

Increased age, location of polyp (right colon), increased size of polyp and villous component of polyp could classify patients in high risk groups.

Detrimental association between betel nut chewing and colorectal polyps in adult populations

Adverse systemic effect caused by betel nut had been reported for decades. Our aim was to determine whether betel nut had detrimental impact on the development of colorectal polyps in general population. Participants who attended health examinations at the Tri-Service General Hospital (TSGH) from 2010 to 2016 were included in the study. The habit of betel nut chewing was obtained from a self-reported questionnaire. Colorectal polyps were diagnosed by colonoscopies operated by experienced physicians. A logistic regression model was used for the association between betel nut chewing with the presence of colorectal polyps. After adjustment for pertinent information such as age, gender, biochemistry data and personal history, the odd ratios (ORs) of colorectal polyps among betel nut chewers was 1.49 (95%CI: 1.14–1.94). Besides, betel nut chewers in the higher percentage body fat (PBF) group had higher risk for developing colorectal polyps with ORs of 2.07 (95%CI:1.23–3.47). Subjects with habit of betel nut chewing were associated with an increased risk of colorectal polyps in Taiwanese general population. Screening for betel nut chewing history and encouraging cessation might offer improved quality of life. A further research for this association was warranted.

Long-chain ω-6 plasma phospholipid polyunsaturated fatty acids and association with colon adenomas in adult men: a cross-sectional study

Dietary lipid intake can be associated with an increased risk for colorectal cancer depending on its composition. Carcinogenesis alters lipid metabolism to facilitate cell growth and survival. For instance, metabolites of polyunsaturated fatty acids (PUFAs) are associated with increasing colon cell proliferation. Moreover, precancerous colon lesions (i.e. adenomas) increase the risk for colorectal cancer. In this study, we investigated associations between plasma PUFAs and the number of colon polyps and polyp type (i.e. hyperplastic and adenoma). Healthy male participants (n=126) of 48-65 years of age were recruited before a routine colonoscopy screening. Plasma phospholipid (PPL) PUFAs were isolated by means of solid phase extraction and methylated. Fatty acid methyl esters were analyzed using gas chromatography. Factor analysis was used to cluster PUFAs into groups, and then generated factors and individual PUFAs were analyzed using polytomous logistic regression. In our age-adjusted and smoking-adjusted polytomous logistic regression, for each unit increase in PPL docosatetraenoic acid (DTA), individuals were 1.43 (1.00-2.06) and 1.33 (0.99-1.80) times more likely to have hyperplastic polyps and adenomas rather than no polyps, respectively. In our factor analysis, high PPL ω-6 PUFA and trans-fatty acid loading scores were associated with increased odds of adenoma presence rather than no polyps. Increases in long-chain PPL ω-6 PUFAs are associated with an increased risk for adenomas. As relative levels of DTA increase in PPLs, individuals had increased odds of having hyperplastic polyps and adenomas. Elevated conversion of ω-6 PUFAs to longer-chain ω-6s such as DTA may indicate altered PUFA metabolism at the tissue level.

Gallbladder stones and gallbladder polyps associated with increased risk of colorectal adenoma in men

BACKGROUND AND AIMS

Most cases of colorectal cancer develop via an adenoma to carcinoma sequence. Gallbladder polyps share some risk factors with colorectal polyps. Little is known about the relationship between gallbladder diseases and different status of colorectal polyps by gender. This study was to investigate the association of gallbladder stones and polyps with colorectal adenomas by gender in a Taiwanese population.

METHODS

A total of 7066 eligible subjects who underwent a total colonoscopy as a part of health check-up between January 2001 and August 2009 were recruited. Colonoscopic findings were classified into polyp-free, non-neoplastic polyps and colorectal adenomas. Gallbladder stones and gallbladder polyps were diagnosed based on ultrasonographic findings.

RESULTS

There was a significant difference in the status of colon polyps between subjects with and without gallbladder polyps. However, the status of colon polyps was not significantly different between subjects with or without gallbladder stones. After adjusting obesity, fasting plasma glucose, and other variables, there was a positive relationship between gallbladder polyps and colorectal adenomas (odds ratio [OR]: 1.396, 95% confidence interval [CI]: 1.115-1.747) but not non-neoplastic polyps in all subjects. In men, gallbladder polyps (OR: 1.560, 95% CI: 1.204-2.019) and gallbladder stones (OR: 1.465, 95% CI 1.081-1.984) were positively associated with colorectal adenomas. In women, neither gallbladder polyps nor gallbladder stones were significantly related to colon polyps.

CONCLUSIONS

Both gallbladder polyps and gallbladder stones were associated with an increased risk of colorectal adenomas in men but not in women. Gender difference was significant for the association between gallbladder lesions and colorectal polyps.

Young Adult Cancer: Influence of the Obesity Pandemic

OBJECTIVE

The purpose of this article is to review the association of the obesity pandemic with appearance of cancers in young adults under age 50 and to define potential mechanisms by which obesity may accelerate the development of malignancy.

METHODS

A comprehensive narrative review was performed to integrate preclinical, clinical, and epidemiologic evidence describing the association of obesity with cancer in young adults based on a search of PubMed and Google databases.

RESULTS

Results from more than 100 publications are summarized. Although they differ in age groups analyzed and incidence of obesity, sufficient data exists to suggest an influence of the obesity pandemic on the increase of cancer among young adults.

CONCLUSIONS

Cancer in young adults is occurring with increasing frequency. Overweight and obesity have become major public health issues reaching pandemic proportions. Excess weight is associated with increased cancer risk, morbidity, and mortality. Multiple murine models indicate that obesity not only increases cancer incidence but also accelerates its development. Thus, the possibility exists that overweight and obesity may be contributing to the appearance of specific malignancies at younger ages. This prospect, in association with the worldwide expansion of obesity, suggests an impending explosive increase in obesity-associated cancers in young adults.

Detecting dysplasia using white light endoscopy or chromoendoscopy in ulcerative colitis patients without primary sclerosing cholangitis: A systematic review and meta-analysis

BACKGROUND

Endoscopic examinations are a vital diagnostic tool for dysplasia. Establishing the precision of different modes of examination is essential due to the disparate pick-up rates of dysplasia.

OBJECTIVE

The aim of this article was to establish the pick-up rates of dysplastic or cancerous lesions using white light endoscopy (WLE) and random/targeted biopsies, or chromoendoscopy (CE), in patients with ulcerative colitis (UC) without primary sclerosing (PSC) or Crohn's disease (CD).

DATA SOURCES

A systematic review to identify all studies up to November 2017, without language restriction, was conducted from PubMed, the Cochrane Controlled Trials Register (1960-2017), MEDLINE, CINAHL and EMBASE (1981-2017). MeSH and text word terms used included "ulcerative colitis", "dysplasia", "random biopsy", "targeted biopsy", "colonoscopy", "white light", and "chromoendoscopy". Further searches were performed using the bibliographies of these articles.

STUDY SELECTION

All studies reporting on colonoscopy detection rates of dysplasia and cancers in UC without involvement of PSC or CD were included. There was no age restriction to include patients.

DATA EXTRACTION

Outcome data were extracted by 2 authors independently using outcome measures defined a priori. Quality assessment was performed using the Newcastle-Ottawa scales.

DATA SYNTHESIS

Data were extracted and analysed according to meta-analytical techniques using comprehensive meta-analysis. The pooled overall pick-up rate of dysplastic/cancerous lesions on WLE random biopsies was 5.6% [Event rate 0.06 (0.01, 0.23), df = 4, I2 = 94%]. Using a combined random and targeted approach with WLE the incidence was 5.1% [Event rate 0.05 (0.03, 0.09), df = 4, I2 = 96%]. One study reported on CE and found a 7% pick-up rate for dysplastic lesions.

CONCLUSIONS

Endoscopic examination of UC patients without PSC identifies dysplastic or cancerous lesions in 5-7% of cases. WLE and random biopsies may pick-up a similar number of lesions to targeted biopsies, however the number of biopsies may need to be greater to achieve this equivalence. CE has a slightly higher pick-up rate. Further comparative studies are required to strengthen the body of evidence.

Giant tubular adenoma with malignancy clinical characteristics in a female teenager: Case report and a review of the literature

BACKGROUND

Adenomas of the colon are usually benign tumors which carry a tendency for malignancy. These tumors can be villous, tubular, tubulovillous, or sessile serrated. Those with adenomatous structure can develop malignant characteristics in 1.5% to 9.4% of cases.

METHODS

We present a case report of a 16-year-old female adolescent with an adenoma of the descending colon. History revealed prolonged diarrheic syndrome for the past 6 months, repeated headache, and a weight loss of ∼5 kg in the past month. One week before the admission, the patient presented an episode of inferior digestive hemorrhage.

RESULTS

On admission laboratory tests revealed iron deficiency anemia, and a mildly increased erythrocyte sedimentation rate. The abdominal ultrasound revealed an inhomogeneous mass of the descending colon and 2 hyperechoic lesions in the liver. The colonoscopy showed a tumor of the descending colon, a tubular adenoma according to the pathological examination. Additionally, we noted an atypical presentation of the tumor and the signs of mild dysplasia identified at the pathological examination.

CONCLUSION

Weight loss, bowel transit alterations, loss of appetite, and inferior hemorrhage in an adolescent can be symptoms of a benign or malignant tumor of the colon.

Diagnostic value of high-resolution micro-endoscopy for the classification of colon polyps

AIM: To study a new imaging equipment, high-resolution micro-endoscopy (HRME), in the diagnosis and pathological classification of colon polyps.

METHODS: We selected 114 specimens of colon polyps, 30 of which were colon polyps with known pathological types and 84 that were prospective polyp specimens; 10 normal colon mucosa specimens served as controls. We obtained images of 30 colon polyp specimens with known pathological types using HRME and analyzed the characteristics of these images to develop HRME diagnostic criteria for different pathological types of colon polyps. Based on these criteria, we performed a prospective study of 84 colon polyp specimens using HRME and compared the results with those of the pathological examination to evaluate the diagnostic value of HRME in the pathological classification of different types of colon polyps.

RESULTS: In the 30 cases of known pathological type of colon polyp samples, there were 21 cases of adenomatous polyps, which comprised nine cases of tubular adenoma, seven cases of villous adenoma and five cases of mixed adenomas. The nine cases of non-adenomatous polyps included four cases of inflammatory polyps and five cases of hyperplastic polyps five. Ten cases of normal colonic mucosa were confirmed pathologically. In a prospective study of 84 cases using HRME, 23 cases were diagnosed as inflammatory polyps, 11 cases as hyperplastic polyps, 18 cases as tubular adenoma, eight cases as villous adenoma and 24 cases as mixed adenomas. After pathological examination, 24 cases were diagnosed as inflammatory polyps, 11 cases as hyperplastic polyps, 19 cases as tubular adenoma, eight cases as villous adenoma and 22 cases as mixed adenomas. Compared with the pathological examinations, the sensitivities, specificities, accuracies, and positive and negative predictive values of HRME in diagnosing inflammatory polyps (87.5%, 96.7%, 94.0%, 91.3% and 95.1%), hyperplastic polyps (72.7%, 95.9%, 92.9%, 72.7% and 95.9%), tubular adenomas (73.7%, 93.8%, 89.3%, 77.8% and 92.4%), villous adenomas (75.0%, 97.4%, 95.2%, 75.0% and 97.4%), and mixed adenomas (75.0%, 93.3%, 88.1%, 81.8% and 90.3%) were relatively high.

CONCLUSION: HRME has a relatively high diagnostic value in the pathological classification of colon polyps. Thus, it may be an alternative to confocal microendoscopy in lower-resource or community-based settings.

Types and patterns of colonic polyps encountered at a tertiary care center in a developing country in South Asia

PURPOSE

To identify the prevalence, types, and patterns of colonic polyps in a cohort of patients presenting to a tertiary care referral center in Sri Lanka.

METHODS

Endoscopy and pathology reports of a single unit from 2006 to 2013 were analyzed retrospectively. Spearman's correlation coefficient and chi-square test were used to identify correlations.

RESULTS

There were a total of 158 patients (M : F, 10 : 57) who had polyps encountered on colonoscopy (n = 1408) and flexible sigmoidoscopy (n = 2402) with an incidence of 4.1%. Mean age was 56.5 years (SD 16.4) and the incidence of polyps increased with age. The majority (81.6%) had one polyp. A total of 188 polyps were assessed and most were seen in the rectum (33.5%) followed by sigmoid colon (22.9%). The commonest histological type was tubulovillous adenoma (33.5%) followed by tubular adenoma (24.5%). Most polyps were benign (91.5%). There was no statistically significant correlation with age or gender with malignancy, site, or histology.

DISCUSSION AND CONCLUSION

The incidence of colorectal polyps was lower than the values reported in the west. More polyps were identified in males. There was no statistically significant association between age, gender, or multiplicity and malignant change in the polyps.

Long-term use of metformin and colorectal cancer risk in type II diabetics: a population-based case-control study

In vitro and animal studies indicate that metformin prevents colorectal cancer (CRC). Epidemiological studies, however, have been equivocal. We undertook this study to assess whether metformin prevents CRC in individuals with type II diabetes. We performed a nested case–control study restricted to Danish citizens with type II diabetes. Data were collected from four Danish nationwide registries. Cases were type II diabetics with a primary CRC between 2000 and 2009, and controls were sampled among subjects with type II diabetes. Long-term exposure to metformin was defined by the redeeming of prescriptions for a cumulative dose of 2000 g within 5 years prior to the index date. To control for potential confounders, we used unconditional logistic regression. We generated adjusted odds ratios (OR) for the association between metformin and CRC and performed subanalyses for selected subgroups and for the dose–response relation. We identified 2088 cases and 9060 controls during the study period. The association between long-term metformin use and CRC gave an adjusted OR at 0.83 (95% CI 0.68–1.00). A protective effect on CRC with long-term use of metformin was only evident for women (OR 0.66 vs. 0.99 for men). There was a significant dose–response association of metformin use >250 defined daily dose (DDD) and for the duration of metformin use >1 year. We found an indication of a protective effect of long-term metformin use against CRC in type II diabetics, although this effect was only seen in women.

Adiposity and the risk of colorectal adenomatous polyps: a meta-analysis

OBJECTIVE

The findings from epidemiological studies addressing the association between adiposity and the risk of colorectal adenomatous polyps are inconsistent. We performed a meta-analysis of epidemiological studies including cross-sectional, case-control, and cohort studies.

METHODS

We searched PubMed and EMBASE in June, 2010. All searched articles were reviewed and selected independently by two evaluators according to pre-determined selection criteria.

RESULTS

We included 25 studies (nine cross-sectional studies, eleven case-control studies, and five prospective cohort studies) that comprised a total of 300,671 participants and 20,903 cases in the final analysis. When all studies were pooled, the odds ratio (OR) or relative risk (RR) of adiposity and abdominal adiposity for colorectal adenomatous polyp risk was 1.43 (95% confidence interval (CI) 1.23-1.67; n = 22) and 1.42 (95% CI 1.30-1.56; n = 12), respectively. Similarly, an increased risk of colorectal adenomatous polyps was observed in most of the subgroup meta-analyses.

CONCLUSIONS

Overall, we found that adiposity and abdominal adiposity significantly increased the risk of colorectal adenomatous polyps in a meta-analysis of epidemiological studies.