An updated Asia Pacific Consensus Recommendations on colorectal cancer screening

Euxanthone suppresses tumor growth and metastasis in colorectal cancer via targeting CIP2A/PP2A pathway

AIM

Colorectal cancer (CRC) accounts for over 600,000 deaths annually worldwide. Euxanthone is a flavonoid compound extracted from Polygala caudata, with documented anti-neoplastic actions. The current study aimed to determine the therapeutic potential of euxanthone in CRC.

METHODS AND MATERIALS

Cell Counting Kit-8 (CCK-8) assay was used to analyze the effect of euxanthone on the cell viability, and apoptosis was detected by the TUNEL assay. The in vitro migratory capacity was determined by wound healing and the invasiveness was assessed by Transwell assay. Western blotting was used to determine the level of relevant proteins. Furthermore, a CRC xenograft murine model was used to analyze the therapeutic efficacy of euxanthone in vivo. Isobaric tags for relative and absolute quantification (iTRAQ) was then performed to identify the potential targets of euxanthone. To validate the role of cancerous inhibitor of PP2A (CIP2A) in the anti-cancer effects of euxanthone, plasmid overexpressing CIP2A and shRNA targeting CIP2A were used in in vitro assays.

KEY FINDINGS

Euxanthone decreased cell viability and increased apoptosis in CRC cells, in addition to restraining migration, invasion and EMT. Similarly, euxanthone also effectively suppressed tumor growth and pulmonary metastasis in vivo. iTRAQ analysis identified CIP2A as the primary target responsible for the anticancer effects of euxanthone. The mediatory role of CIP2A was validated when the anticancer activity of euxanthone was significantly blocked by CIP2A overexpression, while CIP2A knockdown sensitized the CRC cells to euxanthone.

SIGNIFICANCE

Euxanthone exerts anti-cancer effects in vitro and in vivo in CRC by targeting CIP2A/PP2A signaling.

Fecal markers in the management of inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by periods of symptomatic remission and relapse. Diagnosis and assessment of IBD are based on clinical evaluation, serum parameters, radiology, and endoscopy. Fecal markers have emerged as new diagnostic tools to detect and monitor intestinal inflammation. Fecal calprotectin (FC) and lactoferrin (FL) were identified decades ago as potentially revolutionary markers for IBD. Following these discoveries numerous additional markers, including S100A12, M2-PK, metalloproteinases, hemoglobin, myeloperoxidase, lysozyme, polymorphonuclear elastase, neopterin, and nitric oxide, have also been suggested as novel markers of IBD. But only FC and FL are used for the management of clinical IBD patients. The objective of this review is to introduce the clinical applications of fecal markers in the diagnosis, monitoring and prediction of outcomes of inflammatory bowel disease.

MicroRNA-202-5p functions as a tumor suppressor in colorectal carcinoma by directly targeting SMARCC1

Recently, microRNAs (miRNAs) have been emerged as critical regulators for human diseases and as prognostic markers in several tumors, including colorectal carcinoma (CRC). Herein, we identified a tumor-suppressive miRNA, miR-202-5p, which may suppress CRC tumorigenesis. SWI/SNF related, matrix associated, actin dependent regulator of chromatin subfamily c member 1 (SMARCC1) is a susceptibility gene in CRC. However, the role of SMARCC1 in CRC tumorigenesis has not been elucidated. In our present study, we demonstrated that miR-202-5p was a tumor-suppressive miRNA in CRC progression. We found that expression of miR-202-5p was obviously decreased in CRC tissues. Down-regulation of miR-202-5p was associated with postoperative survival. Overexpression of miR-202-5p inhibited the growth and metastasis of CRC cells. The SMARCC1 was a direct target of miR-202-5p and promoted the growth and metastasis of CRC cells. Further study showed that SMARCC1 could reverse the inhibitory effect of miR-202-5p on growth and metastasis of CRC cells. In conclusion, our data highlight the key role of miR-202-5p in the progression of CRC. Thus, miR-202-5p may be a potential prognostic marker and of treatment relevance for CRC progression intervention.

Effectiveness of reminder strategies on cancer screening adherence: a randomised controlled trial

BACKGROUND

Few randomised controlled trials (RCTs) have evaluated the different recalling approaches for enhancing adherence to faecal immunochemical test (FIT)-based screening.

AIM

The authors evaluated the effectiveness of two telecommunication strategies on improving adherence to yearly FIT screening.

DESIGN AND SETTING

A randomised, parallel group trial was performed in a primary care screening practice.

METHOD

The authors recruited 629 asymptomatic individuals aged 40-70 years with a negative FIT in 2015 to a population-based screening programme. On participation, they were invited to repeat their second round of FIT in 2016, 12 months after the first test. Each participant was randomly assigned to either interactive telephone reminder (n = 207), short message service reminder (SMS, n = 212), or control, where no additional interventions were delivered after the findings of their first FIT was communicated to the participants (n = 210). Reminders in the intervention groups were delivered 1 month before subjects' expected return. Additional telephone reminders were delivered 2 months after the expected return date to all subjects who defaulted specimen return. The outcomes included rates of FIT collection and specimen return up to 6 months after their expected return.

RESULTS

At 6 months, the cumulative FIT collection rate was 95.1%, 90.4%, and 86.5%, respectively, for the telephone, SMS, and control groups (P = 0.010). The corresponding specimen return rate was 94.1%, 90.0%, and 86.0% (P = 0.022). When compared with the control, only subjects in the telephone group were significantly more likely to collect FIT tubes (adjusted odds ratio [AOR] 3.18, 95% confidence interval [CI] = 1.50 to 6.75, P = 0.003) and return completed specimens (AOR = 2.73, 95% CI = 1.35 to 5.53, P = 0.005).

CONCLUSION

Interactive telephone reminders are effective at securing previously screened subjects to repeat screening 1 year after a negative finding.

Value of combined detection of serum carcino-embryonic antigen, carbohydrate antigen 19-9 and cyclooxygenase-2 in the diagnosis of colorectal cancer

The aim of the present study was to investigate the value of combined detection of serum carcino-embryonic antigen (CEA), carbohydrate antigen (CA) 19-9 and cyclooxygenase-2 (COX-2) in the diagnosis of colorectal cancer. A total of 50 patients with colorectal cancer were selected as Group A and 50 healthy subjects as the control group. A sample of 2 ml fasting venous blood was drawn from patients in each group, and serum CEA, CA19-9 and COX-2 were detected using electrochemiluminescence analyzer and ELISA. Receiver operating characteristic curve analysis was performed on analyze the sensitivity and specificity of diagnostic methods for colorectal cancer patients at different stages. The expression levels of CEA, CA199 and COX-2 in the cancer patients group were significantly higher than those in the healthy group (P<0.05). The coincidence rates of CEA, CA199, COX-2 and combined detection were 56.0, 64.0, 62.0 and 88.0%, respectively. The coincidence rate of combined detection was significantly higher than that of diagnosis using a single factor (P<0.05). Sensitivity of combined detection of colorectal cancer patients with stage I, II, III and IV were 82.9, 85.3, 86.4 and 88.7%, respectively. The specificities were 65.3, 68.7, 57.8 and 58.6%, respectively. Thus, CEA, CA199 and COX-2 in serum are highly expressed in colorectal cancer patients, and may useful as effective indicators for the early diagnosis of colorectal cancer.

Is water exchange superior to water immersion in detecting adenomas during colonoscopies? Results from a Bayesian network meta-analysis

AIM

Water-assisted colonoscopy (water exchange [WE] and water immersion [WI]) has been shown to improve the adenoma detection rate. However, few studies have compared these two methods head-to-head. Thus, we conducted a network meta-analysis to integrate both direct and indirect evidence comparing the effectiveness of these two procedures.

METHOD

We searched PubMed, Web of Science, and the Cochrane Central Register of Controlled Trials for original papers and abstracts published up to March 2018. Randomized controlled trials (RCTs) reporting data in accordance with the eligibility criteria were included in this study. We performed a Bayesian random effects network meta-analysis with mixed comparisons.

RESULTS

Twenty-nine studies (n = 11464 patients) including 6 direct and 23 indirect comparisons were included in this network meta-analysis. There was a statistically significant difference in the efficacy of adenoma detection when WE was compared with WI (risk ratio [RR]: 1.2, 95% credible interval [CrI]: 1.1-1.3), air insufflation (AI; RR: 1.3, 95% CrI: 1.1-1.4), and carbon dioxide (CO2) insufflation (RR: 1.2, 95% CrI: 1.1-1.5). The different methods were ranked in order from the most to least effective in adenoma detection as follows: WE, WI, AI, and CO2. Moreover, although there were no significant differences in pain scores, willingness to repeat, caecal intubation rate, or total procedure time between WI and WE colonoscopy, WE required a longer caecal intubation time than WI.

CONCLUSION

This network meta-analysis supposes that WE may be superior to WI in detecting adenomas during colonoscopies without affecting other technical features or patient acceptance.

Identification of risk factors for neoplastic colonic polyps in young adults with bloody stool in comparison with those without symptom

BACKGROUND AND AIMS

The incidence and disease burden of colorectal cancer (CRC) in young adults were increasing. However, there was a dearth of advice on how to identify young population at risk for neoplastic colonic polyps (NCPs) and CRC. We aimed to identify risk factors for NCPs and CRC in young adults presenting with bloody stool.

METHODS

A total of 1496 subjects younger than 40 years old who underwent colonoscopy due to bloody stool from 2005 to 2014 were enrolled in this retrospective study as the study group, and 1481 age-matched and gender-matched asymptomatic subjects who underwent colonoscopy for health checkup from 2011 to 2016 were enrolled as the control group at a tertiary center hospital.

RESULTS

Multivariate analysis results showed that increasing age (odds ratio [OR] = 1.11, 95% confidence interval [CI]: 1.07-1.15, P < 0.001), higher body mass index (BMI) (OR = 1.07, 95%CI: 1.03-1.12, P = 0.001), diabetes mellitus (OR = 2.80, 95%CI: 1.06-7.42, P = 0.038), and positive family history of CRC (OR = 13.28, 95%CI: 5.70-30.97, P < 0.001) were identified as independent risk factors for NCPs in study group. The best cut-off values by receiver operating characteristic curve for age and BMI were 32 years old and 24.8 kg/m² , respectively. More risk factors were associated with the higher risk for NCPs (OR = 2.17 every increasing one risk factor, P < 0.001). In the control group, no independent risk factors were identified.

CONCLUSIONS

Adults aged ≤ 40 years with bloody stool who had increasing age (> 32 years old), higher BMI (> 24.8 kg/m² ), diabetes mellitus, and positive family history of CRC had a higher detection rate of NCPs and CRC.

Individualized colorectal cancer screening based on the clinical risk factors: beyond family history of colorectal cancer

BACKGROUND AND AIMS

Individuals without a family history of colorectal cancer (CRC) are screened uniformly despite interpersonal risk. To assess individual risk, we examined the age-specific prevalence of advanced colorectal neoplasia (ACRN) according to clinical risk factors and fecal immunochemical test (FIT) results.

METHODS

Participants without a family history of CRC who underwent screening colonoscopies and FITs were included. Clinical risk factors for ACRN were identified by using a logistic regression model. Point scores were assigned to each associated factor based on a regression coefficient.

RESULTS

A total of 34,658 participants were included. Age, male sex, smoking, and obesity were identified as risk factors. One-, 2-, and 1-point scores were assigned to male sex, smoking, and obesity, respectively. The prevalence of ACRN in individuals with 0, 1, and ≥2 risk score points was 1.4%, 1.6%, and 2.9% among those aged 50 to 51 years and 3.1%, 5.5%, and 7.5% among those aged ≥66 years, respectively. Among FIT-positive individuals, the prevalence of ACRN was 11.0% and 21.2% in those aged between 50 and 51 years and those aged ≥66 years, respectively. Among FIT-negative individuals with ≥2 risk score points, the prevalence of ACRN was 2.5% and 6.0% among those aged 50 to 51 years and those aged ≥66 years, respectively.

CONCLUSION

If the clinical risk score is ≥2 points (persons with smoking history or obese men), early colonoscopy may be recommended, even with no family history of CRC. Additionally, FIT may be an appropriate initial screening modality for average-risk individuals if the clinical risk score is 0 to 1.

Research progress on patient comfort during bowel preparation

Bowel preparation is one of the key and necessary steps for preoperative preparations of multiple operations such as electronic colonoscopy, capsule endoscopy, barium X-ray, colorectal surgery, gynecology surgery, and urology surgery. Although better methods for bowel preparation have been explored continuously, patient intolerance still exists during the current bowel preparation process. Adverse reactions such as nausea and vomiting often occur, leading to poor comfort experience and affecting the patient's compliance and bowel preparation results. This article reviews the factors influencing patient comfort during bowel preparation and the corresponding interventions.

Diagnostic Performance of Intestinal Fusobacterium nucleatum in Colorectal Cancer: A Meta-Analysis

BACKGROUND

Increasing evidence has supported the link of intestinal Fusobacterium nucleatum infection to colorectal cancer (CRC). However, the value of F. nucleatum as a biomarker in CRC detection has not been fully defined. In order to reduce the random error and bias of individual research, this meta-analysis aimed to evaluate the diagnostic performance of intestinal F. nucleatum in CRC patients and provide evidence-based data to clinical practice.

METHODS

An article search was performed from PubMed, Embase, Cochrane Library, and Web of Science databases up to December 2017, using the following key words: "Fusobacterium nucleatum", "Fusobacterium spp.", "Fn", "colorectal cancer(s)", "colorectal carcinoma(s)", "colorectal neoplasm(s)", and "colorectal tumor(s)". Articles on relationships between F. nucleatum and CRC were selected according to the preestablished inclusion and exclusion criteria. This meta-analysis was performed using STATA 12.0 software, which included mapping of forest plots, heterogeneity tests, meta-regression, subgroup analysis, sensitivity analysis, and publication bias. The sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and their corresponding 95% confidence interval (CI) of each eligible study were summarized.

RESULTS

Finally, data for 1198 participants (629 CRC and 569 healthy controls) in 10 controlled studies from seven articles were included. The summary receiver operator characteristic curve was mapped. The diagnostic performance of intestinal F. nucleatum infection on CRC was as follows: the area under the curve: 0.86 (95% CI: 0.83-0.89), the pooled sensitivity: 0.81 (95% CI: 0.64-0.91), specificity: 0.77 (95% CI: 0.59-0.89), and DOR: 14.00 (95% CI: 9.00-22.00).

CONCLUSION

Intestinal F. nucleatum is a valuable marker for CRC diagnosis.

Advanced Colonic Neoplasia at Follow-up Colonoscopy According to Risk Components and Adenoma Location at Index Colonoscopy: A Retrospective Study of 1,974 Asymptomatic Koreans

Background/Aims

We aimed to estimate the cumulative incidence of advanced colonic neoplasia and analyze the risk factors for advanced colonic neoplasia according to risk components and adenoma location at index colonoscopy.

Methods

We reviewed 1,974 subjects who underwent a follow-up colonoscopy after a complete screening colonoscopy and the removal of all polyps. We estimated the cumulative incidence of a subsequent advanced neoplasia according to risk groups (normal, low-risk, and high-risk). Risk factors were analyzed by risk components (≥3 adenomas, adenoma ≥1 cm, and villous-type adenoma) and adenoma location.

Results

Overall, 111 advanced neoplasias (5.6%) were newly diagnosed at the follow-up colonoscopy. The 3-year cumulative incidences of advanced neoplasia were 0.8%, 3.1%, and 10.2% in the normal, low-risk, and high-risk groups, respectively (p<0.0001), and the 5-year cumulative incidences were 2.2%, 8.6%, and 20.2%, respectively (p<0.0001). Age ≥60 years (hazard ratio [HR], 1.78; 95% confidence interval [CI], 1.21 to 2.63), right-sided colonic adenoma (HR, 1.74; 95% CI, 1.13 to 2.66), ≥3 adenomas (HR, 2.00; 95% CI, 1.22 to 3.28), and adenomas ≥1 cm in size (HR, 2.03; 95% CI, 1.20 to 3.44) in the index colonoscopy were independent risk factors for subsequent development of advanced neoplasia.

Conclusions

Right-sided colonic adenoma, ≥3 adenomas, adenomas ≥1 cm, and age ≥60 years at the index colonoscopy were significant risk factors for advanced neoplasia following a complete screening colonoscopy and removal of all polyps.

The protective role of all-transretinoic acid (ATRA) against colorectal cancer development is achieved via increasing miR-3666 expression and decreasing E2F7 expression

OBJECTIVE

Colorectal cancer (CRC) is one of the most common malignancies with high morbidity and mortality rates worldwide. This study aimed to investigate whether miR-3666 was involved in inhibitory effects of all-transretinoic acid (ATRA) on the development of colorectal cancer (CRC).

MATERIAL AND METHODS

Surgical specimens of CRC tissues and adjacent non-tumor mucosa were collected for determining miR-3666 expression. Human CRC HCT116 cells were treated with different doses of ATRA (10, 20, 40, and 60 μM, respectively) and/or transfected with miR-3666 mimic, miR-3666 inhibitor, E2F7 siRNAs or their controls, respectively. After different treatments, cell viability, apoptosis, migration and invasion were detected. The regulatory relationship between miR-3666 and E2F7 was investigated. Furthermore, the association between MAPK/ERK pathway and ATRA or miR-3666/E2F7 was explored.

RESULTS

The miR-3666 was lowly expressed in CRC tissues, while E2F7 was highly expressed. ATRA decreased HCT116 cell viability, migration, and invasion, and induced apoptosis, indicating that ATRA inhibited the malignant behaviors of HCT116 cells. Moreover, ATRA increased miR-3666 expression, and effects of ATRA on the malignant behaviors of HCT116 cells were achieved by positive regulating miR-3666 expression. Furthermore, E2F7 was a target gene of miR-3666, and knockdown of E2F7 reversed the combined effects of ATRA and miR-3666 inhibitor on the malignant behaviors of HCT116 cells. Besides, ATRA inhibited the activation of MAPK/ERK signaling pathway, which was reversed by inhibition of miR-3666.

CONCLUSIONS

Our results reveal that ATRA protects against CRC development possible via increasing miR-3666 expression and decreasing E2F7 expression. MiR-3666/E2F7 may play a key role in regulating the inhibitory effects of ATRA on HCT116 cells via suppressing the activation of MAPK/ERK signaling pathway.

Estimation of age effect with change-points on survival of cancer patients

There is a global trend that the average onset age of many human complex diseases is decreasing, and the age of cancer patients becomes more spread out. The age effect on survival is nonlinear in practice and may have one or more important change-points at which the trend of the effect can be very different before and after these threshold ages. Identification of these change-points allows clinical researchers to understand the biologic basis for the complex relation between age and prognosis for optimal prognostic decision. This paper considers estimation of the potentially nonlinear age effect for general partly linear survival models to ensure a valid statistical inference on the treatment effect. A simple and efficient sieve maximum likelihood estimation method that can be implemented easily using standard statistical software is proposed. A data-driven adaptive algorithm to determine the optimal location and the number of knots for the identification of the change-points is suggested. Simulation studies are performed to study the performance of the proposed method. For illustration purpose, the method is applied to a breast cancer data set from the public domain to investigate the effect of onset age on the disease-free survival of the patients. The results revealed that the risk is highest among young patients and young postmenopausal patients, probably because of a change in hormonal environment during a certain phase of menopause.

Use of a GP-endorsed 12 months' reminder letter to promote uptake of bowel scope screening: protocol for a randomised controlled trial in a hard-to-reach population

INTRODUCTION

Flexible sigmoidoscopy (FS) screening is associated with reduced colorectal cancer incidence and mortality when offered as a one-off test to men and women aged 55-64. The test, also referred to as the 'bowel scope screening' (BSS) test, was added to England's national Bowel Cancer Screening Programme in March 2013, where it is offered to men and women aged 55. Since its implementation, uptake of the BSS test has been low, with only 43% of the eligible population attending an appointment. Sending non-participants a reminder at age 56 has been shown to improve uptake by up to nine percentage points at a single centre in London; we hypothesise that adding a general practitioners (GPs) endorsement to the reminder could improve uptake even further.

METHODS AND ANALYSIS

This paper describes the protocol for a randomised controlled trial which will examine the effectiveness of adding a GPs endorsement to a reminder for BSS non-participants aged 56. All screening-eligible adults who have not responded to a BSS appointment at London North West Healthcare NHS Trust within 12 months of their initial invitation will be randomised to receive either a GP-endorsed reminder letter or reminder letter without GP endorsement. The primary outcome will be the proportion of individuals screened within each group 8 weeks after the reminder. Statistical comparisons will be made using univariate and multivariate logistic regression, with 'uptake' as the outcome variable, GP reminder group as the exposure and sociodemographic variables as covariates.

ETHICS AND DISSEMINATION

The study was approved by the Yorkshire & Humber-Bradford Leeds Research Ethics Committee (16/YH/0298) and the Confidentiality Advisory Group (17/CAG/0162). The results will be disseminated in a peer-reviewed journal in accordance with the Consort statement and will be made available to the public.

TRIAL REGISTRATION NUMBER

ISRCTN82867861.

Fecal immunochemical test for predicting mucosal healing in ulcerative colitis patients: A systematic review and meta-analysis

BACKGROUND AND AIM

Fecal immunochemical test (FIT) is a promising marker for assessment of inflammatory bowel disease activity. However, the utility of FIT for predicting mucosal healing (MH) of ulcerative colitis (UC) patients has yet to be clearly demonstrated. The objective of our study was to perform a diagnostic test accuracy test meta-analysis evaluating the diagnostic accuracy of FIT in predicting MH of UC patients.

METHODS

We systematically searched the databases from inception to November 2017 that evaluated MH in UC. The methodological quality of each study was assessed according to the Quality Assessment of Diagnostic Accuracy Studies checklist. The extracted data were pooled using a summary receiver operating characteristic curve model. Random-effects model was used to summarize the diagnostic odds ratio, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio.

RESULTS

Six studies comprising 625 UC patients were included in the meta-analysis. The pooled sensitivity and specificity values for predicting MH in UC were 0.77 (95% confidence interval [CI], 0.72-0.81) and 0.81 (95% CI, 0.76-0.85), respectively. The FIT level had a high rule-in value (positive likelihood ratio, 3.79; 95% CI, 2.85-5.03) and a moderate rule-out value (negative likelihood ratio, 0.26; 95% CI, 0.16-0.43) for predicting MH in UC. The results of the receiver operating characteristic curve analysis (area under the curve, 0.88; standard error of the mean, 0.02) and diagnostic odds ratio (18.08; 95% CI, 9.57-34.13) also revealed improved discrimination for identifying MH in UC with FIT concentration.

CONCLUSION

Our meta-analysis has found that FIT is a simple, reliable non-invasive marker for predicting MH in UC patients.

Association between Fusobacterium nucleatum and colorectal cancer: Progress and future directions

The initiation and progression of colorectal cancer (CRC) involves genetic and epigenetic alterations influenced by dietary and environmental factors. Increasing evidence has linked the intestinal microbiota and colorectal cancer. More recently, Fusobacterium nucleatum (Fn), an opportunistic commensal anaerobe in the oral cavity, has been associated with CRC. Several research teams have reported an overabundance of Fn in human CRC and have elucidated the possible mechanisms by which Fn is involved in colorectal carcinogenesis in vitro and in mouse models. However, the mechanisms by which Fn promotes colorectal carcinogenesis remain unclear. To provide new perspectives for early diagnosis, the identification of high risk populations and treatment for colorectal cancer, this review will summarize the relative research progresses regarding the relationship between Fn and colorectal cancer.

Hispidulin suppresses cell growth and metastasis by targeting PIM1 through JAK2/STAT3 signaling in colorectal cancer

Colorectal cancer (CRC) accounts for over 600 000 deaths annually worldwide. The current study aims to evaluate the value of proto‐oncogene PIM1 as a therapeutic target in CRC and investigate the anticancer activity of hispidulin, a naturally occurring phenolic flavonoid compound, against CRC. Immunohistochemistry analysis showed that PIM1 was upregulated in CRC tissue. The role of PIM1 as an oncogene was evidenced by the fact that PIM1 knockdown inhibits cell growth, induces apoptosis, and suppresses invasion. Our results showed that hispidulin exerts antitumor activity in CRC through inhibiting the expression of PIM1. Moreover, our findings revealed that hispidulin downregulated the expression of PIM1 by inhibiting JAK2/STAT3 signaling by generating reactive oxygen species. Furthermore, our in vivo studies showed that hispidulin can significantly inhibit tumor growth and metastasis in CRC. Collectively, our results provide an experimental basis for trialing hispidulin in CRC treatment. PIM1 can be considered a potential therapeutic target in CRC.

RNF6 Promotes Colorectal Cancer by Activating the Wnt/β-Catenin Pathway via Ubiquitination of TLE3

Gene amplification is a hallmark of cancer and is frequently observed in colorectal cancer. Previous whole-genome sequencing of colorectal cancer clinical specimens identified amplification of Ring finger protein 6 (RNF6), a RING-domain E3 ubiquitin ligase. In this study, we showed that RNF6 is upregulated in 73.5% (147/200) of patients with colorectal cancer and was positively associated with RNF6 gene amplification. Furthermore, RNF6 expression and its gene amplification were independent prognostic factors for poor outcome of patients with colorectal cancer. RNF6 promoted cell growth, cell-cycle progression, and epithelial-to-mesenchymal transition in colorectal cancer cells; RNF6 also promoted colorectal tumor growth and lung metastasis in mouse models. Mechanistic investigations revealed that RNF6 bound and ubiquitylated transducin-like enhancer of split 3 (TLE3), a transcriptional repressor of the β-catenin/TCF4 complex. RNF6-mediated degradation of TLE3 significantly suppressed the association of TLE3 with TCF4/LEF, which in turn led to recruitment of β-catenin to TCF4/LEF, triggering Wnt/β-catenin activation. Restoration of TLE3 expression abolished the oncogenic effects of RNF6. Taken together, these results demonstrate that RNF6 plays a pivotal oncogenic role in colorectal tumorigenesis.Significance: RNF6-mediated ubiquitination and degradation of TLE3 activates the Wnt/β-catenin pathway in colorectal carcinogenesis. Cancer Res; 78(8); 1958-71. ©2018 AACR.

Socioeconomic and ethnic inequities within organised colorectal cancer screening programmes worldwide

OBJECTIVE

Colorectal cancer (CRC) screening programmes can reduce CRC mortality. However, the implementation of a screening programme may create or exacerbate socioeconomic and ethnic health inequities if participation varies by subgroup. We determined which organised programmes characterise participation inequities by socioeconomic and ethnic subgroups, and assessed the variation in subgroup participation among programmes collecting group-specific data.

DESIGN

Employing a literature review and survey among leaders of national or regional screening programmes, this study identified published and unpublished data on participation by socioeconomic status and ethnicity. We assessed programmes offering faecal occult blood tests (FOBT) for screening. Primary outcome was screening participation rate.

RESULTS

Across 24 organised FOBT-screening programmes meeting the inclusion criteria, participation rates ranged from 21% to 73%. Most programmes (13/24, 54%) did not collect data on participation by socioeconomic status and ethnicity. Among the 11 programmes with data on participation by socioeconomic status, 90% (28/31 publications) reported lower participation among lower socioeconomic groups. Differences across socioeconomic gradients were moderate (66% vs 71%) to severe (35% vs 61%). Only six programmes reported participation results by ethnicity. Ethnic differences were moderate, though only limited data were available for evaluation.

CONCLUSIONS

Across organised CRC screening programmes worldwide, variation in participation by socioeconomic status and ethnicity is often not assessed. However, when measured, marked disparities in participation by socioeconomic status have been observed. Limited data were available to assess inequities by ethnicity. To avoid exacerbating health inequities, screening programmes should systematically monitor participation by socioeconomic status and ethnicity, and investigate and address determinants of low participation.

Review of Blood-Based Colorectal Cancer Screening: How Far Are Circulating Cell-Free DNA Methylation Markers From Clinical Implementation?

Colorectal cancer (CRC) is a leading cause of cancer related deaths worldwide, and late stages (III-IV) in particular have low 5-year survival rates. Stage shifting by CRC screening programs has proven effective by decreasing morbidity and mortality and in many countries national CRC screening programs have been implemented. Currently, European, Asian, and American authorities recommend screening for CRC using fecal occult blood testing, sigmoidoscopy, or colonoscopy. Because these approaches all have weaknesses (eg, poor compliance, high costs, test invasiveness), much effort has been put into the development of alternative screening approaches, many of which are blood-based. Blood-based strategies especially present the advantages of minimally invasiveness compared to endoscopies and an expectantly higher compliance rate compared to stool-based tests. The last decades have seen many discovery studies identifying promising blood-based biomarkers of CRC; however, common to all of these markers is that their clinical usefulness remains evasive. At present only one blood-based CRC screening marker has been approved in the United States. The aim of this review is to discuss the development of blood-based cell-free DNA methylation marker candidates for CRC screening. On the basis of a methodical literature search, the past, present, and future of cell-free DNA screening markers for CRC are revised and discussed. Resource limitations and technical challenges related to sensitivity and specificity measurements keep many markers at bay. Possible solutions to these problems are offered to enable markers to benefit future screening participants.

Risk factors for intraepithelial neoplasia in patients with colorectal adenoma

AIM

To identify risk factors for intraepithelial neoplasia in colorectal adenoma by analyzing the clinical, endoscopic, and histopathological features of patients with colorectal adenoma.

METHODS

The clinical, endoscopic, and histopathological features of 657 patients with colorectal adenomatous polyps diagnosed by colonoscopy from January 2014 to April 2016 at Wuhan Union Hospital were retrospectively analyzed. The patients were divided into an intraepithelial neoplasia group and a non-intraepithelial neoplasia group according to the pathological diagnosis. χ² test was applied for univariate analysis between the two groups. Multivariate Logistic regression analysis was used to identify the risk factors for intraepithelial neoplasia and its malignancy degree in adenoma.

RESULTS

Most of colorectal adenomas were located in the left colon. The total incidence of intraepithelial neoplasia in colorectal adenoma was 22.68%. Age, polyp diameter, length of pedicle, and pathologic type were identified to be risk factors for intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -4.384 + 0.796X2 (age) + 0.324X3 (polyp diameter) + 1.296X4 (pedicle condition) + 0.944X7 (pathology type). Gender, age, and polyp size were identified to be risk factors for high-grade intraepithelial neoplasia in adenoma, which could be incorporated in Logistic regression equation: logit P = -2.939 + 1.036X1 (gender) + 0.853X2 (age) + 1.023X3 (polyp diameter). Total cholesterol (TC) and triglyceride (TG) in the low-grade and high-grade intraepithelial neoplasia groups were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). Low-density lipoprotein cholesterol (LDL-C) and uric acid (URIC) in the high-grade intraepithelial neoplasia group were both significantly higher than those in the non-intraepithelial neoplasia group (P < 0.05). There was no significant difference in the high-density lipoprotein cholesterol (HDL-C) or CEA among the three groups.

CONCLUSION

There is a greater risk of intraepithelial neoplasia among patients older than 40, having villous adenoma with diameter > 1 cm and pedicle. Male, polyp diameter, and age are risk factors for high-grade intraepithelial neoplasia in colorectal adenoma. The occurrence of intraepithelial neoplasia in adenoma may be related to blood lipids and uric acid levels.

RNF216 contributes to proliferation and migration of colorectal cancer via suppressing BECN1-dependent autophagy

Originally identified as an E3 ligase regulating toll-like receptor (TLR) signaling, ring finger protein 216 (RNF216) also plays an essential role in autophagy, which is fundamental to cellular homeostasis. Autophagy dysfunction leads to an array of pathological events, including tumor formation. In this study, we found that RNF216 was upregulated in human colorectal cancer (CRC) tissues and cell lines, and was associated with progression of CRC. RNF216 promoted CRC cell proliferation and migration in vitro and in vivo, largely by enhancing proteasomal degradation of BECN1, a key autophagy regulator and tumor suppressor. RNF216 restricted CRC cell autophagy through BECN1 inhibition under nutritional starvation conditions. RNF216 knockdown increased the autophagy, limiting CRC cell proliferation and migration. Moreover, BECN1 knockdown or autophagy inhibition restored proliferation and migration of RNF216-knockdown CRC cells. Collectively, our results suggested that RNF216 promoted CRC cell proliferation and migration by negatively regulating BECN1-dependent autophagy. This makes RNF216 as a potential biomarker and novel therapeutic target for inhibiting CRC development and progression.

Lack of Association between Red Meat Consumption and a Positive Fecal Immunochemical Colorectal Cancer Screening Test in Khon Kaen, Thailand: a Population- Based Randomized Controlled Trial

Background:

There is convincing evidence from epidemiological studies that meat consumption increases colorectal cancer (CRC) risk. However, assessment of any association with a positive fecal immunochemical test (FIT) in CRC screening has been limited. If a link could be shown this might be helpful for establishing a risk group for colonoscopy.

Objective:

This study aimed to assess any association between meat consumption and other lifestyle factors and a positive FIT result in a Thai population.

Methods:

A cross-sectional analytical study was conducted with 1,167 participants in a population-based randomized controlled trial. CRC was screened from May 2016 - February 2017. Subjects aged 45-74 years who met the eligibility criteria were randomly allocated to the study arm. A positive FIT was determined with cut-off 100 ng/mL. Multiple logistic regression was used to analyze any relationship between lifestyle factors and a positive FIT.

Result:

The total number of subjects was 1,060 (90.8% return rate of FIT). With FIT100, FIT150, and FIT200, positive tests were found in 92 (8.68%), 74 (6.98%), and 60 (5.66%), respectively. No significant associations were noted with any of the variables, except for being aged 60-74 years (ORadj = 1.62, 95%CI: 1.03-2.54) Borderline significance was observed for high consumption of vegetables (ORadj = 0.62, 95%CI: 0.36-1.07) and being male (ORadj = 1.39, 95%CI:0.87-2.22).

Conclusion:

Despite the evidence from the literature, no association was here found between a positive FIT result and meat consumption or other well-established lifestyle parameters. Being aged 60-74 years was a risk factor which should be taken into account in CRC screening strategy in countries like Thailand with limited access to endoscopy.

Three-year colonoscopy surveillance after polypectomy in Korea: a Korean Association for the Study of Intestinal Diseases (KASID) multicenter prospective study

Background/Aims

Colonoscopic surveillance is currently recommended after polypectomy owing to the risk of newly developed colonic neoplasia. However, few studies have investigated colonoscopy surveillance in Asia. This multicenter and prospective study was undertaken to assess the incidence of advanced adenoma based on baseline adenoma findings at 3 years after colonoscopic polypectomy.

Methods

A total of 1,323 patients undergoing colonoscopic polypectomy were prospectively assigned to 3-year colonoscopy surveillance at 11 tertiary endoscopic centers. Relative risks for advanced adenoma after 3 years were calculated according to baseline adenoma characteristics.

Results

Among 1,323 patients enrolled, 387 patients (29.3%) were followed up, and the mean follow-up interval was 31.0±9.8 months. The percentage of patients with advanced adenoma on baseline colonoscopy was higher in the surveillance group compared to the non-surveillance group (34.4% vs. 25.7%). Advanced adenoma recurrence was observed in 17 patients (4.4%) at follow-up. The risk of advanced adenoma recurrence was 2 times greater in patients with baseline advanced adenoma than in those with baseline non-advanced adenoma, though the difference was not statistically significant (6.8% [9/133] vs. 3.1% [8/254], P=0.09). Advanced adenoma recurrence was observed only in males and in subjects aged ≥50 years. In contrast, adenoma recurrence was observed in 187 patients (48.3%) at follow-up. Male sex, older age (≥50 years), and multiple adenomas (≥3) at baseline were independent risk factors for adenoma recurrence.

Conclusions

A colonoscopy surveillance interval of 3 years in patients with baseline advanced adenoma can be considered appropriate.

Hsa-miR-875-5p exerts tumor suppressor function through down-regulation of EGFR in colorectal carcinoma (CRC)

Hsa-miRNA-875-5p (miR-875-5p) has recently been discovered to have anticancer efficacy in different organs. However, the role of miR-875-5p on colorectal carcinoma (CRC) is still ambiguous. In this study, we investigated the role of miR-875-5p on the development of CRC. The results indicated that miR-875-5p was significantly down-regulated in primary tumor tissues and very low levels were found in CRC cell lines. Ectopic expression of miR-875-5p in CRC cell lines significantly suppressed cell growth as evidenced by cell viability assay, colony formation assay and BrdU staining, through inhibition of cyclin D1, cyclin D2, CDK4 and up-regulation of p57(Kip2) and p21(Waf1/Cip1). In addition, miR-875-5p induced apoptosis, as indicated by concomitantly with up-regulation of key apoptosis protein cleaved caspase-3, and down-regulation of anti-apoptosis protein Bcl2. Moreover, miR-875-5p inhibited cellular migration and invasiveness through inhibition of matrix metalloproteinases (MMP)-7 and MMP-9. Further, oncogene EGFR was revealed to be a putative target of miR-875-5p, which was inversely correlated with miR-875-5p expression in CRC. Taken together, our results demonstrated that miR-875-5p played a pivotal role on CRC through inhibiting cell proliferation, migration, invasion, and promoting apoptosis by targeting oncogenic EGFR.

Systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations

AIM

To summarize and compare worldwide colorectal cancer (CRC) screening recommendations in order to identify similarities and disparities.

METHODS

A systematic literature search was performed using MEDLINE, EMBASE, Scopus, CENTRAL and ISI Web of knowledge identifying all average-risk CRC screening guideline publications within the last ten years and/or position statements published in the last 2 years. In addition, a hand-search of the webpages of National Gastroenterology Society websites, the National Guideline Clearinghouse, the BMJ Clinical Evidence website, Google and Google Scholar was performed.

RESULTS

Fifteen guidelines were identified. Six guidelines were published in North America, four in Europe, four in Asia and one from the World Gastroenterology Organization. The majority of guidelines recommend screening average-risk individuals between ages 50 and 75 using colonoscopy (every 10 years), or flexible sigmoidoscopy (FS, every 5 years) or fecal occult blood test (FOBT, mainly the Fecal Immunochemical Test, annually or biennially). Disparities throughout the different guidelines are found relating to the use of colonoscopy, rank order between test, screening intervals and optimal age ranges for screening.

CONCLUSION

Average risk individuals between 50 and 75 years should undergo CRC screening. Recommendations for optimal surveillance intervals, preferred tests/test cascade as well as the optimal timing when to start and stop screening differ regionally and should be considered for clinical decision making. Furthermore, local resource availability and patient preferences are important to increase CRC screening uptake, as any screening is better than none.

A modified colorectal screening score for prediction of advanced neoplasia: A prospective study of 5744 subjects

BACKGROUND AND AIM

We validated a modified risk algorithm based on the Asia-Pacific Colorectal Screening (APCS) score that included body mass index (BMI) for prediction of advanced neoplasia.

METHODS

Among 5744 Chinese asymptomatic screening participants undergoing a colonoscopy in Hong Kong from 2008 to 2012, a random sample of 3829 participants acted as the derivation cohort. The odds ratios for significant risk factors identified by binary logistic regression analysis were used to build a scoring system ranging from 0 to 6, divided into "average risk" (AR): 0; "moderate risk" (MR): 1-2; and "high risk" (HR): 3-6. The other 1915 subjects formed a validation cohort, and the performance of the score was assessed.

RESULTS

The prevalence of advanced neoplasia in the derivation and validation cohorts was 5.4% and 6.0%, respectively (P = 0.395). Old age, male gender, family history of colorectal cancer, smoking, and BMI were significant predictors in multivariate regression analysis. A BMI cut-off at > 23 kg/m² had better predictive capability and lower number needed to screen than that of > 25 kg/m² . Utilizing the score developed, 8.4%, 57.4%, and 34.2% in the validation cohort were categorized as AR, MR, and HR, respectively. The corresponding prevalence of advanced neoplasia was 3.8%, 4.3%, and 9.3%. Subjects in the HR group had 2.48-fold increased prevalence of advanced neoplasia than the AR group. The c-statistics of the modified score had better discriminatory capability than that using predictors of APCS alone (c-statistics = 0.65 vs 0.60).

CONCLUSIONS

Incorporating BMI into the predictors of APCS score was found to improve risk prediction of advanced neoplasia and reduce colonoscopy resources.

Epigenetic biomarkers: Current strategies and future challenges for their use in the clinical laboratory

Epigenetic modifications and regulators represent potential molecular elements which control relevant physiological and pathological features, thereby contributing to the natural history of human disease. These epigenetic modulators can be employed as disease biomarkers, since they show several advantages and provide information about gene function, thus explaining differences among patient endophenotypes. In addition, epigenetic biomarkers can incorporate information regarding the effects of the environment and lifestyle on health and disease, and monitor the effect of applied therapies. Technologies used to analyze these epigenetic biomarkers are constantly improving, becoming much easier to use. Laboratory professionals can easily acquire experience and techniques are becoming more affordable. A high number of epigenetic biomarker candidates are being continuously proposed, making now the moment to adopt epigenetics in the clinical laboratory and convert epigenetic marks into reliable biomarkers. In this review, we describe some current promising epigenetic biomarkers and technologies being applied in clinical practice. Furthermore, we will discuss some laboratory strategies and kits to accelerate the adoption of epigenetic biomarkers into clinical routine. The likelihood is that over time, better markers will be identified and will likely be incorporated into future multi-target assays that might help to optimize its application in a clinical laboratory. This will improve cost-effectiveness, and consequently encourage the development of theragnosis and the application of precision medicine.

Screening of colorectal cancer: present and future

Colorectal cancer (CRC) is the third most common cancer in males and second in females, and the fourth most common cause of cancer death worldwide. Currently, about 60-70% of diagnosed cases in symptomatic patients are detected at an advanced stage of disease. Earlier stage detection through the use of screening strategies would allow for better outcomes in terms of reducing the disease burden. Areas covered: The aim of this paper is to review the current published evidence from literature which assesses the performance and effectiveness of different screening tests for the early detection of CRC. Expert commentary: Adequate screening strategies can reduce CRC incidence and mortality. In the last few decades, several tests have been proposed for CRC screening. To date, there is still insufficient evidence to identify which approach is definitively superior, and no screening strategy for CRC can therefore be defined as universally ideal. The best strategy would be the one that can be economically viable and to which the patient can adhere best to over time. The latest guidelines suggest colonoscopy every 10 years or annual fecal immuno-chemical test (FIT) for people with normal risk, while for individuals with high risk or hereditary syndromes specific recommendations are provided.

Fecal Clostridium symbiosum for Noninvasive Detection of Early and Advanced Colorectal Cancer: Test and Validation Studies

Objective

Current non-invasive early detection of colorectal cancer (CRC) requires improvement. We aimed to identified a fecal Clostridium symbiosum-based biomarker for early and advanced colorectal cancer detection.

Design

In the test stage, the relative abundance of Clostridium symbiosum (C. symbiosum) was measured by qPCR in 781 cases including 242 controls, 212 colorectal adenoma (CRA) patients, 109 early CRC (tumor restricted to the submucosa) patients, 218 advanced CRC patients. The prediction accuracy was compared to Fusobacterium nucleatum (F. nucleatum), fecal immunochemical test (FIT) and CEA (carcinoembryonic antigen) and validated in an independent cohort of 256 subjects. Current status of the trial:ongoing/still enrolling. Primary endpoint:June, 2017 (Clinicaltrials.gov Identifier NCT02845973).

Results

Significant stepwise increase of C. symbiosum abundance was found in CRA, early CRC and advanced CRC (P < 0.01). C. symbiosum outperformed all the other markers in early CRC prediction performance. The combination of C. symbiosum and FIT achieved better performance (0.803 for test cohort and 0.707 for validation cohort). For overall discrimination of CRCs, the combination of all above markers achieved the performance of 0.876.

Conclusions

Fecal C. symbiosum is a promising biomarker for early and noninvasive detection of colorectal cancer, being more effective than F. nucleatum, FIT and CEA. Combining C. symbiosum and FIT or CEA may improve the diagnosis power.

•

The fecal abundance of Clostridium symbiosum was found increased in patients with colorectal neoplasia and it may serve as a potiential biomarker in non-invasive early differentiation of colorectal cancer from healthy controls.

•

The fecal abundance of Clostridium symbiosum was even more sensitive and efficient in diagnosis of both early and advanced colorectal cancer than reported markers like fecal immunochemical test, carcinoembryonic antigen and the abundance of Fusobacterium nucleatum.

•

Combining the abundance of Clostridium symbiosum and the other markers above may further enhance its predictive performance.

Community-based survey of knowledge of, attitudes to and practice of colorectal cancer screening in Hong Kong

OBJECTIVE

We aimed to investigate the knowledge, attitudes and practice of colorectal cancer (CRC) and screening in the community to complement the introduction of population-based CRC screening in Hong Kong SAR, China.

METHODS

Clients attending the Family Planning Association of Hong Kong clinics from March to June 2016 were randomly invited to participate in this questionnaire survey.

RESULTS

Knowledge of CRC and screening for it was still deficient in the community. Respondents scored less than half on their knowledge of the symptoms and screening methods of CRC as well as on the local screening policy. Fewer than 30% knew that CRC can be asymptomatic and they had insufficient knowledge of primary lifestyle prevention of CRC. However, most (86.0%) would like to participate in CRC screening. The cost and trouble involved were the two main reasons given for not wanting to do so. Only 14.0% of the whole sample and 27.0% of those aged 50 years or above had undergone CRC screening irrespective of screening method. One-fifth of those who had been screened had some abnormality, with a cancer detection rate of 2.2%. Employment, income, knowledge and perception of risk were major determinants of their decision to undergo screening.

CONCLUSIONS

To reduce the morbidity and mortality of CRC significantly, average risk and high-risk groups should be encouraged to come forward for screening even if they are asymptomatic. Educating the population, simplifying the screening procedure and offering financial support by the government are keys to success.

Colonoscopy and sigmoidoscopy use among older adults in different countries: A systematic review

Screening for colorectal cancer (CRC) by colonoscopy and sigmoidoscopy has been demonstrated to be effective in reducing CRC incidence and mortality, and they are increasingly employed as screening tests and for diagnostic purposes in many countries. We conducted a systematic review to provide up-to-date estimates on the utilization of lower gastrointestinal endoscopy (colonoscopy and sigmoidoscopy) in the general average-risk population in different countries. PubMed and Web of Science were searched for relevant articles published between 1 September 2008 and 31 October 2016. A total of 23 studies from the US and 20 studies from other countries were included in this review. Estimates from the US were highest, continued to increase over the past decade and reached 62% for colonoscopy use within 10years in people aged 50-75years in 2012. Endoscopy use in other countries was substantially lower (12-44% for lifetime colonoscopy use and 13-30% for recent colonoscopy use), except for Germany, where 55% of the screening-eligible population reported colonoscopy utilization within the previous 10years in 2008-2011. Both lifetime and recent endoscopy use increased with age and peaked at approximately 70-75years. Although several European and Asian countries have started to collect endoscopy utilization data through periodic national health surveys, more data are still much needed from non-US countries. With the implementation of CRC screening programs in an increasing number of countries, especially European countries, an increase in endoscopy use and subsequent reduction in CRC incidence and mortality in the years to come might be expected in those countries.

Ginkgolic acid inhibits the invasiveness of colon cancer cells through AMPK activation

Tumor cell invasion and metastasis are important processes in colorectal cancer that exert negative effects on patient outcomes; consequently, a prominent topic in the field of colorectal cancer study is the identification of safe and affordable anticancer drugs against cell invasion and metastasis, with limited side effects. Ginkgolic acid is a phenolic acid extracted from ginkgo fruit, ginkgo exotesta and ginkgo leaves. Previous studies have indicated that ginkgolic acid inhibits tumor growth and invasion in a number of types of cancer; however, limited studies have considered the effects of ginkgolic acid on colon cancer. In the present study, SW480 colon cancer cells were treated with a range of concentrations of ginkgolic acid; tetrazolium dye-based MTT, wound-scratch and transwell migration assays were performed to investigate the effects on the proliferation, migration and invasion of colon cancer cells, and potential mechanisms for the effects were explored. The results indicated that ginkgolic acid reduced the proliferation and significantly inhibited the migration and invasion of SW480 cells in a concentration-dependent manner. Additional experiments indicated that ginkgolic acid significantly decreased the expression of invasion-associated proteins, including matrix metalloproteinase (MMP)-2, MMP-9, urinary-type plasminogen activator and C-X-C chemokine receptor type 4, and activated adenosine monophosphate activated protein kinase (AMPK) in SW480 cells. Small interfering RNA silencing of AMPK expression reversed the effect of ginkgolic acid on the expression of invasion-associated proteins. This result suggested that ginkgolic acid inhibited the proliferation, migration and invasion of SW480 colon cancer cells by inducing AMPK activation and inhibiting the expression of invasion-associated proteins.

Impact of socioeconomic status on survival of colorectal cancer patients

Socioeconomic status (SES) has an impact on the survival of various cancers, but it has not been fully understood in colorectal cancer (CRC). The Surveillance, Epidemiology and End Results database was adopted to detect the role of SES in the survival outcomes of CRC. A total of 184,322 eligible patients were included and SES status was analyzed. The multivariable analysis showed that Non-Hispanic Black (HR, 1.20; 95% CI, 1.15-1.24), being widowed (HR, 1.04; 95% CI, 1.01-1.07), any Medicaid (HR, 1.36; 95% CI, 1.33-1.39) and the lowest education level group patients had relative poorer prognosis. Besides, sex, tumor location, age, differentiation level and American Joint Committee on Cancer stage also had significant effects on overall survival of CRC. The individuals were further divided into five groups according to the number of survival-adverse factors. All of the four groups containing adverse factors showed impaired survival outcomes compared with the group containing no adverse factor.

Accuracy of Faecal Immunochemical Test to Predict Endoscopic and Histological Healing in Ulcerative Colitis: A Prospective Study Based on Validated Histological Scores

BACKGROUND AND AIMS

Endoscopic and histological healing are associated with improved clinical outcomes in ulcerative colitis [UC]. We aimed to investigate the predictive value of faecal immunochemical test [FIT] for endoscopic and histological healing in UC.

METHODS

We measured quantitative FIT and faecal calprotectin [FC] in 140 consecutive UC patients who underwent colonoscopy. We assessed the diagnostic accuracy of FIT for predicting endoscopic healing using the Mayo endoscopic subscore [MES 0/1] and for histological healing using the Geboes score [< 2.0] and Nancy index [grade ≤ 1]. The predictive abilities of FIT were compared with those of FC.

RESULTS

FIT had an area under the curve [AUC] of 0.77 (95% confidence interval [CI] 0.67-0.86, p < 0.001) for endoscopic healing, an AUC of 0.77 [95% CI 0.67-0.86, p < 0.001] using the Geboes score, and 0.77 [95% CI 0.66-0.85, p < 0.001] using the Nancy Index for histological healing. The AUC of FIT was comparable to that of FC for endoscopic healing [p = 0.773] and histological healing [p = 0.767-0.960], and was comparable to colonoscopy for histological healing [p = 0.384-0.673]. FIT < 50 ng/ml predicted endoscopic healing with a sensitivity, specificity, and positive predictive value [PPV] of 72%, 68%, and 82%, respectively, and for histological healing with a sensitivity, specificity, and PPV of 73-75%, 67%, and 78-80%, respectively. Combining FIT with FC led to a higher specificity [90%] for histological healing. Over 85% of patients with FIT < 50 ng/ml and FC < 50 μg/g achieved histological healing.

CONCLUSIONS

FIT is highly sensitive and accurate to predict endoscopic and histological healing in UC. It represents a promising non-invasive tool for monitoring mucosal healing in UC.

Comparative Evaluation of Preliminary Screening Methods for Colorectal Cancer in a Mass Program

BACKGROUND

The fecal immunochemical test (FIT) has been widely used in preliminary screening for colorectal cancer (CRC). The high-risk factor questionnaire (HRFQ) and quantitative risk-assessment method (QRAM) are recommended for estimating the risk of CRC qualitatively and quantitatively in China.

AIM

We aimed to prospectively compare the diagnostic values of CRC preliminary screening methods to identify which method is preferable as a screening strategy.

METHODS

Individuals aged 40-74 years old were enrolled in a mass CRC screening program from January 1, 2007 to December 31, 2014, in Jiashan County, Zhejiang Province, China. FIT of two stool specimens at 1-week intervals was performed by laboratory personnel and face-to-face interviews were conducted by trained investigators. Screening data in the program were linked to a CRC surveillance and registry system, and CRC cases reported in the system were regarded as true patients.

RESULTS

A total of 96,043 subjects were included. The sensitivity and specificity of FIT for detecting CRC cases were 75.49% (95% CI 69.84-80.39) and 90.36% (95% CI 90.17-90.54), respectively. QRAM was more sensitive (p < 0.001) and less specific (p < 0.001) than HRFQ. The sensitivity and specificity of FIT along with HRFQ were 86.56% (95% CI 81.81-90.22) and 81.37% (95% CI 81.12-81.62), and those of FIT along with QRAM were 88.93% (95% CI 84.47-92.23) and 73.95% (95% CI 73.67-74.23).

CONCLUSIONS

Our findings suggest that CRC preliminary screening with FIT and QRAM in parallel has high sensitivity and satisfactory specificity, and is a useful strategy in mass screening programs.

Impact of Fecal Hb Levels on Advanced Neoplasia Detection and the Diagnostic Miss Rate For Colorectal Cancer Screening in High-Risk vs. Average-Risk Subjects: a Multi-Center Study

Objectives:

The Asia-Pacific Colorectal Screening (APCS) scoring system was developed to identify high-risk subjects for advanced neoplasia. However, the appropriate fecal immunochemical test (FIT) cutoff for high-risk population may be different from that of average-risk population. We aimed to evaluate the FIT performance at different cutoffs in high-risk subjects undergoing colorectal cancer (CRC) screening.

Methods:

We prospectively enrolled asymptomatic subjects aged 50–75 years. Using the APCS score, subjects were stratified into either the average-risk or high-risk groups. All subjects were tested with one-time quantitative FIT and underwent colonoscopy. We compared the FIT performance for advanced neoplasia between two groups using different cutoffs (5 (FIT5), 10 (FIT10), 20 (FIT20), 30 (FIT30), and 40 (FIT40) μg Hb/g feces).

Results:

Overall, 1,713 subjects were recruited, and 1,222 (71.3%) and 491 (28.7%) were classified as average-risk and high-risk, respectively. Advanced neoplasia was detected in 90 (7.4%) of the average-risk subjects and 65 (13.2%) of the high-risk subjects. In the high-risk group, by decreasing the cutoff from FIT40 to FIT5, the sensitivity increased by 33.8 percentage points with decreased specificity by 11 percentage points. In the average-risk group, the sensitivity increased by 20 percentage points with decreased specificity by 9.6 percentage points. At the lowest cutoff (FIT5), the number of needed colonoscopies to find one advanced neoplasia was 2.8 and 6.1 for the high-risk and average-risk groups, respectively.

Conclusions:

Using an appropriate FIT cutoff for CRC screening in high-risk subjects could improve CRC screening performance and reduce the unnecessary colonoscopies. To maintain high sensitivity and specificity for advanced neoplasia, the optimal cutoff FIT in the high-risk subjects should be lower than that in the average-risk subjects.

Selecting a Cut-off for Colorectal Cancer Screening With a Fecal Immunochemical Test

OBJECTIVES

Fecal immunochemical tests (FITs) for hemoglobin (Hb) are increasingly used for colorectal cancer (CRC) screening. However, cut-offs for defining test positivity are varying widely. We aimed to evaluate the impact of cut-off selection on key indicators of diagnostic performance in a true screening setting.

METHODS

We evaluated diagnostic performance of FOB Gold, a widely used quantitative FIT, for detecting advanced neoplasms (AN) across a wide range of possible cut-offs among 1822 participants of screening colonoscopy aged 50-79 years in Germany.

RESULTS

The positive predictive value (PPV) for detecting AN showed a very steep increase with increasing cut-off up to 35.2% (95% CI 29.9-40.9%) at a cut-off of 9 μg Hb/g feces at which sensitivity and specificity were 48.8% (95% CI 42.1-55.6%) and 88.5% (95% CI 86.8-89.9%), respectively. A further moderate increase of PPV up to 56.9% (95% CI 47.8-65.5%), along with a major decrease in sensitivity was observed when gradually increasing the cut-off to 25 μg Hb/g feces at which sensitivity and specificity were 31.9% (95% CI 25.9-38.5%) and 96.9% (95% CI 95.9-97.6%), respectively. Further increases of the cut-off hardly affected PPV and specificity, but went along with further relevant decline in sensitivity.

CONCLUSIONS

Our study illustrates delineation of a range of meaningful cut-offs (here: 9-25 μg Hb/g feces) according to expected diagnostic yield in a true screening setting. Selecting a cut-off within or beyond this range should consider characteristics of the specific target population, such as AN prevalence or available colonoscopy capacity.

The Association between Distal Findings and Proximal Colorectal Neoplasia: A Systematic Review and Meta-Analysis

OBJECTIVES

Whether screening participants with distal hyperplastic polyps (HPs) detected by flexible sigmoidoscopy (FS) should be followed by subsequent colonoscopy is controversial. We evaluated the association between distal HPs and proximal neoplasia (PN)/advanced proximal neoplasia (APN) in asymptomatic, average-risk patients.

METHODS

We searched Ovid Medline, EMBASE, and the Cochrane Library from inception to 30 June 2016 and included all screening studies that examined the relationship between different distal findings and PN/APN. Data were independently extracted by two reviewers with disagreements resolved by a third reviewer. We pooled absolute risks and odds ratios (ORs) with a random effects meta-analysis. Seven subgroup analyses were performed according to study characteristics. Heterogeneity was characterized with the I² statistics.

RESULTS

We analyzed 28 studies (104,961 subjects). When compared with normal distal findings, distal HP was not associated with PN (OR=1.16, 95% confidence interval (CI)=0.89-1.51, P=0.14, I²=40%) or APN (OR=1.09, 95% CI=0.87-1.36, P=0.39, I²=5%), while subjects with distal non-advanced or advanced adenoma had higher odds of PN/APN. Higher odds of PN/APN were observed for more severe distal lesions. Weaker association between distal and proximal findings was noticed in studies with higher quality, larger sample size, population-based design, and more stringent endoscopy quality-control measures. The Egger's regression tests showed all P>0.05.

CONCLUSIONS

Distal HP is not associated with PN/APN in asymptomatic screening population when compared with normal distal findings. Hence, the presence of distal HP alone detected by FS does not automatically indicate colonoscopy referral for all screening participants, as other risk factors of PN/APN should be considered.

Quantitation of faecal Fusobacterium improves faecal immunochemical test in detecting advanced colorectal neoplasia

OBJECTIVE

There is a need for an improved biomarker for colorectal cancer (CRC) and advanced adenoma. We evaluated faecal microbial markers for clinical use in detecting CRC and advanced adenoma.

DESIGN

We measured relative abundance of Fusobacterium nucleatum (Fn), Peptostreptococcus anaerobius (Pa) and Parvimonas micra (Pm) by quantitative PCR in 309 subjects, including 104 patients with CRC, 103 patients with advanced adenoma and 102 controls. We evaluated the diagnostic performance of these biomarkers with respect to faecal immunochemical test (FIT), and validated the results in an independent cohort of 181 subjects.

RESULTS

The abundance was higher for all three individual markers in patients with CRC than controls (p<0.001), and for marker Fn in patients with advanced adenoma than controls (p=0.022). The marker Fn, when combined with FIT, showed superior sensitivity (92.3% vs 73.1%, p<0.001) and area under the receiver-operating characteristic curve (AUC) (0.95 vs 0.86, p<0.001) than stand-alone FIT in detecting CRC in the same patient cohort. This combined test also increased the sensitivity (38.6% vs 15.5%, p<0.001) and AUC (0.65 vs 0.57, p=0.007) for detecting advanced adenoma. The performance gain for both CRC and advanced adenoma was confirmed in the validation cohort (p=0.0014 and p=0.031, respectively).

CONCLUSIONS

This study identified marker Fn as a valuable marker to improve diagnostic performance of FIT, providing a complementary role to detect lesions missed by FIT alone. This simple approach may improve the clinical utility of the current FIT, and takes one step further towards a non-invasive, potentially more accurate and affordable diagnosis of advanced colorectal neoplasia.

Exendin-4 does not modify growth or apoptosis of human colon cancer cells

AIM

Glucagon-like peptide-1 (GLP-1) receptor agonists are a kind of very popular antidiabetes drugs. They promote cell proliferation and survival through activation of signaling pathways in human islet cells involving phosphate idylinositol 3 kinase (PI3K) and extracellular regulated kinases 1 and 2 (ERK1/2), which are frequently activated in human colon cancer cells. Then, it is possible that taking GLP-1 receptor (GLP-1R) agonists persistently would induce proliferation of β cells as well as colon cancer cells. So, clarifying the effects and mechanisms of GLP-1R agonists on colon cancer cells has important clinical implications.

MATERIALS AND METHODS

We investigated GLP-1R expression in human colon cancer tissue samples with immunohistochemisty analysis and explored the effects of exendin-4, a GLP-1 receptor agonist, on colon cancer cells in vitro and in vivo.

RESULTS

The results showed lack of GLP-1R expression in both human colon cancer tissues and colon cancer cell lines. Exendin-4 did not enhance the proliferation and migration of colon cancer cell lines in vitro, and nor did it inhibit apoptosis induced by cytotoxic agents such as 5-fluorouracil (5-FU) or irinotecan. In addition, exendin-4 did not promote the propagation of colon cancer cells in vivo.

CONCLUSION

Our study suggests that GLP-1R agonists do not modify the growth or survival of human colon cancer cells and may be safe for diabetic patients with colon cancer.

Association between CYP24A1 polymorphisms and the risk of colonic polyps and colon cancer in a Chinese population

AIM

To determine the pathogenesis and potential single nucleotide polymorphisms (SNPs) as screening sites for colonic polyps, colon cancer and ulcerative colitis, and to analyze the possible association between these genetic polymorphisms and the three diseases.

METHODS

We evaluated genetic polymorphisms in 144 newly diagnosed colonic polyp patients, 96 colon cancer patients and 44 ulcerative colitis patients. The four SNPs genotyped were rs4809957, rs6068816, rs6091822 and rs8124792. The control group consisted of 504 East Asians enrolled in the 1000 Genomes Project. Correlations between CYP24A1 SNPs and the diseases were analyzed by Fisher’s exact probability test.

RESULTS

CYP24A1 polymorphisms rs4809957 A/G and rs6068816 C/T showed a statistically significant association with risk of the three diseases, when both the genotypes and allele frequencies were considered. With regard to rs6091822 G/T, all three diseases were related to risk allele carriers (GT + TT) vs wild-type (GG), but the associations between the allele frequencies and the diseases were not significant. The risk of colonic polyps and colon cancer was related to the allele frequencies of rs8124792 G/A, and this association remained for genotype frequencies of this SNP.

CONCLUSION

Four SNPs are related to the risk of colonic polyps and colon cancer. G allele in rs6091822 G/T may play an anti-cancer role only if it is homozygous. The A allele, which is a minor component of rs8124792, may be indicated in the diagnosis of colonic polyps or colon cancer rather than ulcerative colitis.

Epi proColon® 2.0 CE: A Blood-Based Screening Test for Colorectal Cancer

Epi proColon^® 2.0 CE is a blood-based test designed to aid in the early detection of colorectal cancer. The test comprises a qualitative assay for the polymerase chain reaction (PCR) detection of methylated Septin9 DNA, the presence of which is associated with colorectal cancer: however, positive results should be verified by colonoscopy or sigmoidoscopy. Epi proColon^® 2.0 CE discriminated between patients with colorectal cancer and healthy controls with high clinical sensitivity and specificity in pivotal case-control studies. The sensitivity of the test did not appear to be affected by the tumour location or by patient age or gender. In addition, limited data suggest that Epi proColon^® 2.0 CE discriminated between patients with colorectal cancer and healthy controls with higher sensitivity and generally similar specificity to that of the faecal immunochemical test, and with higher sensitivity and specificity to that of the guaiac-based faecal occult blood test (statistical data not available). In an observational study, most patients who refused colonoscopy for screening accepted a non-invasive test option as an alternative, and preferred Epi proColon^® 2.0 CE over a stool-based test. Large prospective trials of Epi proColon^® 2.0 CE in a screening setting will be required to further elucidate the cost-effectiveness of the test. Nevertheless, currently available data suggests that Epi proColon^® 2.0 CE has the potential to be a sensitive and convenient screening option for patients refusing screening by colonoscopy.

Emerging Gastrointestinal and Liver Diseases in Asia Pacific: Implications to Health Care in the Region (World Gastroenterology Organization: Asian Pacific Association of Gastroenterology Distinguished Global Lecture 2015)

Colorectal cancer (CRC), gastroesophageal reflux disease (GERD), inflammatory bowel disease (IBD), and nonalcoholic fatty liver disease are considered important emerging diseases in the Asia Pacific (AP) region. The incidence rate of CRC is the highest among gastrointestinal cancers in the region surpassing that of gastric cancer. However, population CRC screening is limited by availability of adequate health resources and financing. GERD is a highly prevalent disease in AP with the prevalence of GERD symptoms and reflux esophagitis reported to be increasing. The usage of proton pump inhibitors has also been reported to be high. The incidence and prevalence of IBD is not as high as in the west but is now an increasingly recognizable disease in the AP region. Being a complicated disease, IBD will pose a huge financial burden with the increasing use of expensive biological drugs. In tandem with the exponential increase in obesity and diabetes mellitus in AP, nonalcoholic fatty liver disease will become the most important liver disease in the region in the coming years. These emerging diseases reflect the continued fast-paced socioeconomic development in the region with marked lifestyle changes and increasing affluence.

Colorectal cancer screening

Colorectal cancer, which is the leading cancer in Singapore, can be prevented by increased use of screening and polypectomy. A range of screening strategies such as stool-based tests, flexible sigmoidoscopy, colonoscopy and computed tomography colonography are available, each with different strengths and limitations. Primary care physicians should discuss appropriate screening modalities with their patients, tailored to their individual needs. Physicians, patients and the government should work in partnership to improve uptake of colorectal cancer screening to reduce the morbidity and mortality from colorectal cancer.

Colorectal cancer population screening programs worldwide in 2016: An update

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The incidence and mortality show wide geographical variations. Screening is recommended to reduce both incidence and mortality. However, there are significant differences among studies in implementation strategies and detection. This review aimed to present the results and strategies of different screening programs worldwide. We reviewed the literature on national and international screening programs published in PubMed, on web pages, and in clinical guidelines. CRC Screening programs are currently underway in most European countries, Canada, specific regions in North and South America, Asia, and Oceania. The most extensive screening strategies were based on fecal occult blood testing, and more recently, the fecal immunochemical test (FIT). Participation in screening has varied greatly among different programs. The Netherlands showed the highest participation rate (68.2%) and some areas of Canada showed the lowest (16%). Participation rates were highest among women and in programs that used the FIT test. Men exhibited the greatest number of positive results. The FIT test has been the most widely used screening program worldwide. The advent of this test has increased participation rates and the detection of positive results.

Text-message Reminders in Colorectal Cancer Screening (TRICCS): a randomised controlled trial

BACKGROUND

We investigated the effectiveness of a text-message reminder to improve uptake of the English Bowel Cancer Screening programme in London.

METHODS

We performed a randomised controlled trial across 141 general practices in London. Eight thousand two hundred sixty-nine screening-eligible adults (aged 60-74 years) were randomised in a 1 : 1 ratio to receive either a text-message reminder (n=4134) or no text-message reminder (n=4135) if they had not returned their faecal occult blood test kit within 8 weeks of initial invitation. The primary outcome was the proportion of adults returning a test kit at the end of an 18-week screening episode (intention-to-treat analysis). A subgroup analysis was conducted for individuals receiving an invitation for the first time.

RESULTS

Uptake was 39.9% in the control group and 40.5% in the intervention group. Uptake did not differ significantly between groups for the whole study population of older adults (adjusted odds ratio (OR) 1.03, 95% confidence interval (CI) 0.94-1.12; P=0.56) but did vary between the groups for first-time invitees (uptake was 34.9% in the control and 40.5% in the intervention; adjusted OR 1.29, 95% CI 1.04-1.58; P=0.02).

CONCLUSIONS

Although text-message reminders did not significantly increase uptake of the overall population, the improvement among first-time invitees is encouraging.