Colorectal cancer screening: Systematic review of screen-related morbidity and mortality

A novel dual-target Septin9 methylation assay for improved detection of early-stage colorectal cancer and high-grade intraepithelial neoplasia

BACKGROUND

Colorectal cancer (CRC) ranks as the third most common malignancies in the world, and periodic examination of the patient is advantageous in reducing the mortality of CRC. The first blood-based Septin9 gene methylation assay which recognized by the US FDA for CRC examination was Epi proColon. However, this assay was not broadly applied in the current clinical guideline because of its relatively lower sensitivity in the detection of early-stage CRC.

METHODS

This study aimed at developing a new multiplex Septin9 methylation assay (ColonUSK) which simultaneously evaluates two CpG-rich subregions in the promoter of the Septin9 gene and an internal control in a single reaction. ColonUSK proved increased sensitivity, with a detection limit as low as 12pg of the positive DNA compared with the Septin9 assay targeting one CpG-rich subregion. 1366 subjects were prospectively recruited from four comprehensive hospitals in China in an opportunistic screening study for assessing its value in CRC detection. Blind testing was developed to evaluate ColonUSK in comparison with clinical examination using clinical gold standard such as colonoscopy.

RESULTS

The assay demonstrates clinical sensitivity for diagnosing colorectal cancer (CRC) and advanced adenoma at rates of 77.34% and 25.26%, respectively. Furthermore, ColonUSK exhibits a high degree of specificity for non-CRC cases (95.95%) clinically. Significantly, the detection rate of cases in high-grade intraepithelial neoplasia increased to 54.29%. The value for the assay in the Kappa test was 0.76, showing a high degree of consistency between ColonUSK and clinical gold standard.

CONCLUSIONS

ColonUSK indicated moderate diagnostic value and could become a non-invasive detection way for CRC. The implementation of the ColonUSK assay has the capacity to markedly enhance CRC screening practices.

National screening for colorectal cancer is associated with stage shift to earlier diagnosis

BACKGROUND

Australia's National Bowel Cancer Screening Program consists of an immunohistochemical faecal occult blood test, targeting adults aged 50-74. Existing literature supports the principle of early detection of colorectal cancer (CRC) via national screening, but little is known about the association between colonoscopy or polypectomy rates and CRC stage over time. The aim of this study is to identify the longitudinal change to colonoscopy and polypectomy rates, and any stage shift associated with this screening program.

METHODS

A retrospective data-linkage study was performed using the Australian national health database (Medicare) to obtain colonoscopy and polypectomy rates between 1998 and 2017. A second prospective database of CRC resection specimens was analysed for this period. The cohort was divided based on time intervals related to the National Bowel Cancer Screening Program: pre-commencement 1998-2006 (Period A), immediately post-commencement 2007-2011 (Period B), and subsequent years 2012-2017 (Period C). Linear regression was used to test relation between annualized predictor and response variables.

RESULTS

Annual colonoscopy rates doubled, and polypectomy rates tripled during the study (P < 0.001). Annual colonoscopy rate correlated to a lower T-stage (P = 0.038) and lower N-stage (P = 0.026), and there was a 7% increase in early CRC (stage I-II) in Period C (P < 0.001). Across the study period there was also a significant increase in right-sided tumours, and concurrent MMR deficiency and BRAF mutation.

CONCLUSION

Polypectomy and colonoscopy rates increased after the introduction of the National Bowel Cancer screening program. There was a clinically significant shift to earlier CRC stage which manifested 5 years after its implementation.

The impact on clinical outcomes and healthcare resources from discontinuing colonoscopy surveillance subsequent to low-risk adenoma removal: A simulation study using the OncoSim-Colorectal model

OBJECTIVE

To estimate the impact on clinical outcomes and healthcare resource use from recommending that patients with 1-2 low-risk adenomas (LRAs) return to routine fecal immunochemical test (FIT) screening instead of surveillance colonoscopy, from a Canadian provincial healthcare system perspective.

METHODS

The OncoSim-Colorectal microsimulation model simulated average-risk individuals eligible for FIT-based colorectal cancer (CRC) screening in Alberta, Canada. We simulated two surveillance strategies that applied to individuals with 1-2 LRAs (<10 mm) removed as part of the average risk CRC screening program: (a) Surveillance colonoscopy (status quo) and (b) return to FIT screening (new strategy); both at 5 years after polypectomy. A 75 ng/mL FIT positivity threshold was used in the base case. The simulations projected average annual CRC outcomes and healthcare resource use from 2023 to 2042. We conducted alternative scenarios and sensitivity analyses on key variables.

RESULTS

Returning to FIT screening (versus surveillance colonoscopy) after polypectomy was projected to have minimal impact on long-term CRC incidence and deaths (not statistically significant). There was a projected decrease of one (4%) major bleeding event and seven (5%) perforation events per year. There was a projected increase of 4800 (1.5%) FIT screens, decrease of 3900 (5.1%) colonoscopies, and a decrease of $3.4 million (1.2%) in total healthcare costs per year, on average. The annual colonoscopies averted and healthcare cost savings increased over time. Results were similar in the alternative scenarios and sensitivity analyses.

CONCLUSIONS

Returning to FIT screening would have similar clinical outcomes as surveillance colonoscopy but could reduce colonoscopy demand and healthcare costs.

Deaths and cardiopulmonary events following colorectal cancer screening-A systematic review with meta-analyses

BACKGROUND

Colorectal cancer screening programmes (CRCSPs) are implemented worldwide despite recent evidence indicating more physical harm occurring during CRCSPs than previously thought. Therefore, we aimed to review the evidence on physical harms associated with endoscopic diagnostic procedures during CRCSPs and, when possible, to quantify the risk of the most serious types of physical harm during CRCSPs, i.e. deaths and cardiopulmonary events (CPEs).

METHODS

Systematic review with descriptive statistics and random-effects meta-analyses of studies investigating physical harms following CRCSPs. We conducted a systematic search in the literature and assessed the risk of bias and the certainty of the evidence.

RESULTS

We included 134 studies for review, reporting findings from 151 unique populations when accounting for multiple screening interventions per study. Physical harm can be categorized into 17 types of harm. The evidence was very heterogeneous with inadequate measurement and reporting of harms. The risk of bias was serious or critical in 95% of assessments of deaths and CPEs, and the certainty of the evidence was very low in all analyses. The risk of death was assessed for 57 populations with large variation across studies. Meta-analyses indicated that 3 to 23 deaths occur during CRCSPs per 100,000 people screened. Cardiopulmonary events were assessed for 55 populations. Despite our efforts to subcategorize CPEs into 17 distinct subtypes, 41% of CPE assessments were too poorly measured or reported to allow quantification. We found a tendency towards lower estimates of deaths and CPEs in studies with a critical risk of bias.

DISCUSSION

Deaths and CPEs during CRCSPs are rare, yet they do occur during CRCSPs. We believe that our findings are conservative due to the heterogeneity and low quality of the evidence. A standardized system for the measurement and reporting of the harms of screening is warranted.

TRIAL REGISTRATION

PROSPERO Registration number CRD42017058844.

Attitudes and health behaviors of middle-aged and older adults with elevated tumor markers in China

Objectives

To understand the attitudes and health behaviors of middle-aged and older adults in China after receiving elevated results of tumor markers (TMs) test in the annual health examinations (AHEs) and explore the influencing factors.

Methods

A three-section online questionnaire survey was conducted from March 1 to April 30, 2020 in Hangzhou, China, to people who were aged 45 and older and had at least one elevated result of TMs test. Clinical information was collected from the online survey and medical records. Descriptive statistics were carried out followed by regression analyses.

Results

Of 380 participants, 76.1% were unwilling to quit the TMs test in AHEs, whereas 75.3% would take the doctor's advice and quit unnecessary TMs test; 67.4% felt stressed about their TMs. Among participants with elevated TMs, 76.8% changed lifestyle to keep healthy, 74.2% sought health information, 58.9% requested a TMs retest, and 50.3% did further tests to confirm a diagnosis. Family history of cancer was associated with lifestyle changing; education level, area of residence and health insurance were associated with health information seeking; comorbidity were associated with retests and sequential confirming tests.

Conclusion

The application of the TMs test in AHEs among Chinese people may lead to positive and negative behavioral consequences and psychological distress. Doctors have a significant impact on patients' health behaviors. Accurate indications and adequate communication with patients before and after the TMs test are in great need.

The Effectiveness of Screening Total Colonoscopy for Preoperative Patients with Gastric Cancer

BACKGROUND

Colorectal cancer (CRC) is the most common cancer that coincides with gastric cancer (GC). Although the usefulness of total colonoscopy (TCS) as a CRC screening tool has been reported in preoperative patients with GC, the long-term outcome of patients with synchronous CRC (SCRC) remains unclear. This study aims to clarify the significance of preoperative screening TCS for GC in terms of survival outcomes.

PATIENTS AND METHODS

We included 796 patients who underwent preoperative screening TCS for GC. The risk factors, clinicopathological features, and survival outcome of SCRC were examined. Furthermore, the cost-effectiveness was evaluated from the perspective of improving the rates of mortality caused by CRC.

RESULTS

SCRC was observed in 43 patients (5.4%). Endoscopic treatment for SCRC was performed on 30 patients. In total, 15 patients underwent surgical resection, including 2 patients requiring additional surgery after endoscopic treatment. Regarding pathological stages, 25 patients had stage 0, 12 patients had stage I, 5 patients had stage II, and 1 patient had stage IIIB disease. The cumulative mortality rates were as follows: GC-related deaths, 12.6%; deaths from cancers other than CRC, 1%; deaths from other causes, 5.5%. No deaths were attributed to SCRC. Comparing the patients who did not undergo TCS, an incremental cost-effectiveness ratio analysis suggested that a screening cost of 5.86 million yen was required to prevent one CRC death.

CONCLUSIONS

Curative treatment was possible in all patients with SCRC. No deaths were attributed to SCRC, suggesting that screening TCS for GC is effective.

The risk of bleeding and perforation from sigmoidoscopy or colonoscopy in colorectal cancer screening: A systematic review and meta-analyses

INTRODUCTION

Physical harm from Colorectal Cancer Screening tends to be inadequately measured and reported in clinical trials. Also, studies of ongoing Colorectal Cancer Screening programs have found more frequent and severe physical harm from screening procedures, e.g., bleeding and perforation, than reported in previous trials. Therefore, the objectives of the study were to systematically review the evidence on the risk of bleeding and perforation in Colorectal Cancer Screening.

DESIGN

Systematic review with descriptive statistics and random-effects meta-analyses.

METHODS

We systematically searched five databases for studies investigating physical harms related to Colorectal Cancer Screening. We assessed the internal and the external validity using the ROBINS-I tool and the GRADE approach. Harm estimates was calculated using mixed Poisson regression models in random-effect meta-analyses.

RESULTS

We included 89 studies. Reporting and measurement of harms was inadequate in most studies. In effect, the risk of bias was critical in 97.3% and serious in 98.3% of studies. All GRADE ratings were very low. Based on severe findings with not-critical risk of bias and 30 days follow-up, the risk of bleedings per 100,000 people screened were 8 [2;24] for sigmoidoscopy, 229 [129;408] for colonoscopy following fecal immunochemical test, 68 [39;118] for once-only colonoscopy, and 698 [443;1045] for colonoscopy following any screening tests. The risk of perforations was 88 [56;138] for colonoscopy following fecal immunochemical test and 53 [25;112] for once-only colonoscopy. There were no findings within the subcategory severe perforation with long-term follow-up for colonoscopy following any screening tests and sigmoidoscopy.

DISCUSSION

Harm estimates varied widely across studies, reporting and measurement of harms was mostly inadequate, and the risk of bias and GRADE ratings were very poor, collectively leading to underestimation of harm. In effect, we consider our estimates of perforation and bleeding as conservative, highlighting the need for better reporting and measurement in future studies.

TRIAL REGISTRATION

PROSPERO registration number: CRD42017058844.

Fibroblast Activation Protein-α (FAP) Identifies Stromal Invasion in Colorectal Neoplasia

The increasing detection of colorectal adenomas and early adenocarcinomas (ADCs) in the context of nationwide screening programs has led to a significant increase in the incidence of inconclusive diagnoses in which histopathologic analysis of endoscopic biopsies does not allow pathologists to provide a reliable diagnosis of stromal invasion. The objective of this study was to analyze the discriminative capacity of the immunohistochemical expression of fibroblast activation protein-α (FAP) in distinguishing colorectal adenomas with low-grade dysplasia (LGD) and high-grade dysplasia (HGD) from invasive intestinal-type ADCs. The study analyzed the first endoscopic biopsies from a series of patients classified as inconclusive or conclusive for stromal invasion based on the pathologic report. In total, 30 ADCs, 52 HGDs, and 15 LGDs were included in the study. FAP expression was detected in 23/30 ADCs and was negative in all adenomas with either LGD or HGD features (100% specificity and 76.7% sensitivity, area under the curve=0.883, CI=0.79-0.98). Considering these findings, we conclude that FAP is a potentially useful tool for helping pathologists identify invasive lesions in colorectal endoscopic biopsies, avoiding unnecessary biopsy repetitions.

Hepatocellular Carcinoma Risk Scores Predict Patients Under Surveillance at Low Risk of Benefit and High Risk of Harm

AIMS

Surveillance for hepatocellular carcinoma (HCC) is recommended for patients with cirrhosis. Multiple risk scores aim to stratify HCC risk, potentially allowing individualized surveillance strategies. We sought to validate four risk scores and quantify the consequences of surveillance via the calculation of numbers needed to benefit (NNB) and harm (NNH) according to classification by risk score strata.

METHODS

Data were collected on 482 patients with cirrhosis during 2013-2014, with follow-up until 31/12/2019. Risk scores (aMAP, Toronto risk index, ADRESS HCC, HCC risk score) were derived from index clinic results. The area under the receiving operating characteristic curve (AUC) was calculated for each. Additionally, per-risk strata, NNB was calculated as total surveillance ultrasounds per surveillance diagnosed early HCC (stage 0/A) and NNH as total ultrasounds performed per false positive (abnormal surveillance with normal follow-up imaging).

RESULTS

22 (4.6%) patients developed HCC. 77% (17/22) were diagnosed through surveillance, of which 13/17 (76%) were early stage. There were 88 false positives and no false negatives (normal surveillance result however subsequent HCC detection). Overall NNB and NNH were 241 and 36, respectively. No score was significantly superior using AUC. Patients classified as low risk demonstrated no surveillance benefit (AMAP, THRI) or had a high NNB of > 300/900 (ADRESS HCC, HCC risk score), with low NNH (24-38).

CONCLUSION

Given the lack of benefit and increased harm through false positives in low-risk groups, a risk-based surveillance strategy may have the potential to reduce patient harm and increase benefit from HCC surveillance.

CLINICAL TRIALS REGISTRATION

This was not a clinical trial and the study was not pre-registered.

Primary Tumor Resection for Metastatic Colorectal, Gastric and Pancreatic Cancer Patients: In Search of Scientific Evidence to Inform Clinical Practice

The management of the primary tumor in metastatic colorectal, gastric and pancreatic cancer patients may be challenging. Indeed, primary tumor progression could be associated with severe symptoms, compromising the quality of life and the feasibility of effective systemic therapy, and might result in life-threatening complications. While retrospective series have suggested that surgery on the primary tumor may confer a survival advantage even in asymptomatic patients, randomized trials seem not to definitively support this hypothesis. We discuss the evidence for and against primary tumor resection for patients with metastatic gastrointestinal (colorectal, gastric and pancreatic) cancers treated with systemic therapies and put in context the pros and cons of the onco-surgical approach in the time of precision oncology. We also evaluate current ongoing trials on this topic, anticipating how these will influence both research and everyday practice.

Quality indicators for colonoscopy in Egypt: A prospective multicenter study

BACKGROUND AND STUDY AIMS

Despite its wide availability, we do not have sufficient data aboutthe quality of colonoscopy in Egypt. In this study, we proposed 13 indicators to assess the quality of colonoscopy procedures in the included study centers aiming to attain a representative image of the quality of CS in Egypt.

PATIENTS AND METHODS

A multicenter prospective study was conducted between July and December 2020, which included all patients who underwent colonoscopy in the participating centers. The following were the proposed quality indicators: indications for colonoscopy, preprocedure clinical assessment, obtaining written informed consent, adequate colon preparation, sedation, cecal intubation rate (CIR), withdrawal time, adenoma detection rate (ADR), complication rate, photographic documentation, automated sterilization, regular infection control check, and well-equipped postprocedure recovery room.

RESULT

A total of 1,006 colonoscopy procedures were performed during the study duration in the included centers. Our analysis showed the following four indicators that were fulfilled in all centers: appropriate indications for colonoscopy, preprocedure assessment, written informed consent, and automated sterilization. However, photographic documentation and postprocedure follow-up room were fulfilled only in 57 %. Furthermore, 71 % of the centers performed regular infection control checks. Adequate colon preparation was achieved in 61 % of the procedures, 81 % of the procedures were performed under sedation, 95.4 % CIR, 11-min mean withdrawal time, 15 % ADR, and 0.1 % overall complication rate. Statistically significant factors affecting CIR were age > 40 years, high-definition endoscope, previous colon intervention, and rectal bleeding, whereas those affecting ADR were age > 40 years, the use of image enhancement, previous colon intervention, rectal bleeding, the use of water pump, and a withdrawal time of > 9 min.

CONCLUSION

Our study revealed the bright aspects of colonoscopy practice in Egypt, including high CIRs and low complication rates; conversely, ADR, bowel cleansing quality, and infection control measures should be improved.

A meta-analysis of the value of circulating tumor cells in monitoring postoperative recurrence and metastasis of colorectal cancer

Objective

Circulating tumor cells (CTCs) as novel biomarkers are widely investigated in various cancers, although most of the literature shows that CTCs have predictive value for recurrence, metastasis, and prognosis after CRC surgery, results remain controversial. We aimed to systematically evaluate the value of CTCs in monitoring of colorectal cancer (CRC) recurrence and metastasis after surgery.

Method

The PubMed, Cochrane Library, Embase, and other databases were searched from the establishment of the database to May 27, 2021. Relevant literature searches and data extraction were performed independently by two reviewers. The quality assessment was performed using the QUADAS2 scale developed by the Cochrane collaboration. The heterogeneity was checked using the Spearman correlation coefficient and the Cochran-Q test in the Meta-Disc1.4 software. Subgroup analysis was used to explore the source of heterogeneity. Considering that all the included papers were clinical studies with clinical heterogeneity, random effect model was adopted for analysis. And the sensitivity (Sen), specificity (Spe), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and summary receiver operating characteristic (SROC) curves of CTCs, in monitoring recurrence and metastasis after CRC, were calculated. The publication bias of the included studies was assessed using Deek’s funnel figure.

Result

The literature included a total of 13 articles, comprising 1788 cases, and the overall quality of the literature was high. After summing up the indicators, the sensitivity pooled-value of the peripheral blood CTCs to monitor the recurrence and metastasis value of CRC after CRC was 0.67 [95%CI (0.62, 0.71)], specificity pooled-value was 0.71 [95%CI (0.67, 0.72)], PLR pooled-value was 2.37 [95%CI [1.52, 3.71]), NLR pooled into 0.53 [95%CI (0.36, 0.78)], DOR pooled into 4.97 [95%CI (2.11, 11.72)], AUC was 0.7395.

Conclusion

Peripheral blood CTCs have a moderate monitoring value for recurrence and metastasis after CRC; CTCs detected one week after surgery may be more correlated with recurrence and metastasis.

Setting up a regional expert panel for complex colorectal polyps

BACKGROUND AND AIMS

Advanced endoscopic resection techniques for complex colorectal polyps have evolved significantly over the past decade, leading to a management shift from surgical to endoscopic resection as the preferred treatment. However, in practice, interhospital consultation and appropriate referral management remain challenging, leading to unnecessary surgical resections. To support regional care for patients with complex colorectal polyps, facilitate peer consultations, and lower thresholds for referrals, an expert panel consultation platform was initiated in the northwestern region of the Netherlands.

METHODS

We initiated a regional expert panel in the northwestern region of the Netherlands for patients with complex colorectal polyps and studied the implementation, adaption, and clinical impact. All panel consultations between June 2019 and May 2021 were retrospectively analyzed, and user satisfaction among panel members was evaluated.

RESULTS

Eighty-eight patients with complex colorectal polyps from 11 of 15 participating centers (73.3%) were discussed in our panel. The most common reason for panel consultation was suspicion of invasive cancer in 36.4% (n = 32). After panel consultation, 43.2% of the consulting endoscopists (n = 38) changed their initial treatment strategy, and in 63.6% (n = 56) patients were referred to another endoscopy center. Of 26 cases submitted with a primary proposal for surgical treatment, surgery was avoided in 7 (26.9%). User satisfaction was rated high in most participating centers (91.7%).

CONCLUSIONS

Our study shows that implementation of and consultation with a regional expert panel can be a valuable tool for endoscopists to guide and optimize treatment of complex colorectal polyps and facilitate interhospital referrals in a regional network.

MicroRNA-766-3p-mediated downregulation of HNF4G inhibits proliferation in colorectal cancer cells through the PI3K/AKT pathway

Nuclear receptors (NRs) are a class of transcription factors that play a pivotal role in carcinogenesis, but their function in colorectal cancer (CRC) remains unclear. Here, we investigate the role NRs play in CRC pathogenesis. We found that hepatocyte nuclear factor 4 gamma (HNF4G; NR2A2), hepatocyte nuclear factor 4α (HNF4A; NR2A1), and retinoid-related orphan receptor γ (RORC; NR1F3) were significantly upregulated in CRC tissues analyzed by GEPIA bioinformatics tool. The expression of HNF4G was examined in CRC samples and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Increased expression of HNF4G was strongly associated with high tumor-node-metastasis stage and poor prognosis. Moreover, overexpression of HNF4G significantly promoted the proliferation of CRC cells in vitro. Next, we found that HNF4G promoted CRC proliferation via the PI3K/AKT pathway through targeting of GNG12 and PTK2. In addition, HNF4G was verified as a direct target of microRNA-766-3p (miR-766-3p). miR-766-3p inhibited the proliferation of CRC cells by targeting HNF4G in vitro and in vivo. Collectively, our study indicates that miR-766-3p reduces the proliferation of CRC cells by targeting HNF4G expression and thus inhibits the PI3K/AKT pathway. Therefore, development of therapies which target the miR-766-3p/HNF4G axis may aid in the treatment of CRC.

Prognosis prediction of stage IV colorectal cancer patients by mRNA transcriptional profile

BACKGROUND

Stage IV colorectal cancer patients with liver metastasis represent a special group of CRC patients with poor prognosis. The prognostic factors have not been investigated for stage IV CRC patients undergoing primary cancer resection but not candidates for metastasis resection.

METHODS

Ninety-nine stage IV CRC patients who underwent primary cancer resection without metastasis resection were retrospectively recruited. Both whole-exome sequencing (WES) and RNA-seq were performed with frozen primary cancer tissues, using para-cancerous normal tissues as the control. Valid data were obtained from 78 patients for WES and 84 patients for RNA-seq. Univariate, multivariate Cox analyses were performed and Nomogram model was established to predict patient prognosis.

RESULTS

The correlation between patient prognosis and clinicopathological factors, mutational status, or mRNA level changes was examined. Univariate (p = 0.0007) and subsequent multivariate analyses on clinicopathological factors showed that location (left or right) was the only independent risk factor for patient prognosis (HR = 3.63; 95% CI: 1.56-8.40, p = 0.003), while T, N, M staging, gender, race, location (rectum or colon), and pathological types were not stratifying factors. The mutational status of APC, TP53, KRAS, TTN, SYNE1, SMAD4, PIK3CA, RYR2, and BRAF did not show significant stratification in patient prognosis. RNA-seq showed that genes related to membrane function, ion channels, transporters, or receptors were among those with significant mRNA level alterations. Univariate analysis identified 97 genes with significantly altered mRNA levels, while NEUROD1, FGF18, SFTA2, PLAC1, SAA2, DSCAML1, and OTOP3 were significant in multivariate analysis. A risk model was established to stratify the prognosis of stage IV CRC patients. A Nomogram model was established with these genes to predict individual patient prognosis.

CONCLUSIONS

A panel of eight genes with significant mRNA level alterations was capable of predicting the prognosis and risk of the specific patient group. Future prospective study is needed to validate the model.

An overview of artificial intelligence in oncology

Cancer is associated with significant morbimortality globally. Advances in screening, diagnosis, management and survivorship were substantial in the last decades, however, challenges in providing personalized and data-oriented care remain. Artificial intelligence (AI), a branch of computer science used for predictions and automation, has emerged as potential solution to improve the healthcare journey and to promote precision in healthcare. AI applications in oncology include, but are not limited to, optimization of cancer research, improvement of clinical practice (eg., prediction of the association of multiple parameters and outcomes - prognosis and response) and better understanding of tumor molecular biology. In this review, we examine the current state of AI in oncology, including fundamentals, current applications, limitations and future perspectives.

Varying fecal immunochemical test screening cutoffs by age and gender: a way to increase detection rates and reduce the number of colonoscopies

BACKGROUND AND AIMS

Most colorectal cancer (CRC) screening programs based on the fecal immunochemical test (FIT) use the same cutoff value for all participants. This study aimed at finding age- and gender-specific cutoff values that can improve population-based CRC screening.

METHODS

This observational study used data from the first 2 years of the Danish FIT-based CRC screening program to estimate sensitivity, specificity, number of positive tests, number of screen-detected cancers and adenomas, and number of interval cancers for various cutoff values for different male and female age groups.

RESULTS

Data from 531,828 participants showed that lower cutoff values for older residents and higher cutoff values for younger residents increased the overall sensitivity and specificity, decreased the number of needed colonoscopies by 7%, increased the number of screen-detected cancer by 1.1%, increased the number of screen-detected adenomas by 5%, and decreased the number of interval cancers by approximately 1.5%. However, these cutoff values also increased an inequality in sensitivity and specificity. Choosing cutoff values that ensured equal sensitivity between the groups, however, did increase inequality in, for example, the interval cancer rate.

CONCLUSIONS

In a FIT-based CRC program it is possible to decrease the number of needed colonoscopies while at the same time to increase overall sensitivity and specificity and detect more cancers and adenomas by using different cutoff values for different male and female age groups. However, this increases inequality in sensitivity and specificity, whereas other strategies like ensuring equal sensitivity could be considered.

Lifestyle predictors for inconsistent participation to fecal based colorectal cancer screening

BACKGROUND

Consistent participation in colorectal cancer (CRC) screening with repeated fecal immunochemical test (FIT) is important for the success of the screening program. We investigated whether lifestyle risk factors for CRC were related to inconsistent participation in up to four rounds of FIT-screening.

METHOD

We included data from 3,051 individuals who participated in up to four FIT-screening rounds and returned a lifestyle questionnaire. Using logistic regression analyses, we estimated associations between smoking habits, body mass index (BMI), physical activity, alcohol consumption, diet and a healthy lifestyle score (from least favorable 0 to most favorable 5), and inconsistent participation (i.e. not participating in all rounds of eligible FIT screening invitations).

RESULTS

Altogether 721 (24%) individuals were categorized as inconsistent participants Current smoking and BMI ≥30 kg/m2 were associated with inconsistent participation; odds ratios (ORs) and 95% confidence intervals (CIs) were 1.54 (1.21-2.95) and 1.54 (1.20-1.97), respectively. A significant trend towards inconsistent participation by a lower healthy lifestyle score was observed (p < 0.05).

CONCLUSIONS

Lifestyle behaviors were associated with inconsistent participation in FIT-screening. Initiatives aimed at increasing participation rates among those with the unhealthiest lifestyle have a potential to improve the efficiency of screening.

In silico identification of the specific pathways in each stage of colorectal cancer and the association of their top genes with drug resistance and sensitivity

Investigating the specific pathways and their relation with survival, mutation, sensitivity, and resistance to various drugs in different stages of colorectal cancer (CRC) could be effective in cancer treatment. In this study, identifying the specific pathways in each stage of CRC compared to other stages was considered via meta-analytic methodology. The Cancer Genome Atlas (TCGA) data with gene set enrichment analysis (GSEA) software, and CRC RNA-Seq data were used to enrich and determine specific pathways as well as to evaluate the expression level of TOP RANK genes. In addition, The Cancer Cell Line Encyclopedia (CCLE) data were used to correlate candidate genes with drug resistance. Finally, using Gene Expression Omnibus (GEO) data, drugs that could affect the expression level of these genes were identified. Three specific molecular pathways, including oxidative phosphorylation (OXPHOS), regulation of transporter activity (RTA), and negative regulation of transmembrane receptor protein serine threonine kinase (NRSTK) have been identified as hub pathways for stages II, III, and IV, respectively (P < 0.01). The expression level of TOP RANK genes in each stage increased on average twice compared to other stages (P < 0.01), and CCNB1, DKK1, NOG genes were associated with survival in stages II and IV, respectively (P < 0.01). The expression of some selected genes had a correlation with drug resistance and sensitivity (P < 0.05). GEO data revealed that gamma-tocotrienol (g-T3), NSC319726, and Casiopeina Cas-II-gly may reduce the expression of, NDUFAF1, CCNB1, DKK1 genes, respectively (P < 0.01). Specific pathways and TOP RANK genes could lead to cancer progression and malignancy, resistance to chemotherapy drugs, poor survival in patients, and metastasis. Therefore, identification and targeting these pathways at each stage could be crucial in inhibiting progression at different stages of CRC.

Two sides of every coin: individuals' experiences of undergoing colorectal cancer screening by faecal immunochemical test and colonoscopy

BACKGROUND

Acceptability of the recommended screening procedure represents a crucial determinant of the impact of colorectal cancer (CRC) screening programmes. This study aims to explore how individuals in CRC screening experience the screening procedure.

METHODS

Study participants (n = 44), aged 60-62 years, screened by faecal immunochemical test (FIT) and/or colonoscopy, were recruited from the Screening of Swedish Colons (SCREESCO) study. Data were collected through six focus group discussions and 20 individual telephone interviews and analyzed using qualitative content analysis.

RESULTS

The analysis resulted in 30 subcategories together forming four categories describing individuals' experiences of the CRC screening procedure: From no worries to bothering emotions; Varying logistical concerns; Being well treated, but inconsistently informed and involved and Expectations not matching reality. Some subcategories only applied to either FIT or colonoscopy screening, while others applied to both screening procedures.

CONCLUSIONS

Undergoing CRC screening by FIT or colonoscopy is an individual experience. Strategies to improve patient experiences may include using one-sample FITs and optimizing bowel preparation and scheduling of colonoscopies according to individual preferences. Ensuring that needs for emotional support are acknowledged, together with clear and adequate information delivered at right time are further important aspects to consider.

Detection of Circulating Tumor DNA Methylation in Diagnosis of Colorectal Cancer

INTRODUCTION

Emerging evidence has demonstrated the potential of the circulating tumor DNA (ctDNA) methylation in the application of cancer diagnosis.

METHODS

Three genes including Septin9, Syndecan-2 (SDC2), and branched-chain amino acid transaminase 1 (BCAT1), which have been well demonstrated to have aberrant expression in colorectal cancer (CRC) as tumor suppressors, were selected for detection. A total of 234 peripheral plasma samples from 104 patients with CRC and 130 patients with colorectal polyps, and 60 plasma samples from healthy controls, were collected before any treatment. A real-time polymerase chain reaction-based gene panel was used to detect the methylation of Septin9, SDC2, and BCAT1. The composite score (P) was calculated according to the cycle threshold values of the 3 methylated genes using the logistic regression equation.

RESULTS

The ctDNA methylation of the 3 genes had a significantly higher level in patients with CRC, compared with patients with colorectal polyps and healthy controls. The composite score (P) showed association with tumor stages in CRC but not with the tumor location (colon or rectum). In addition, BCAT1 and Septin9 showed better performance for CRC diagnosis, by which CRC was able to distinguish from polyps with sensitivity of 83.7%, specificity of 93.9%, and area under the curve of 0.908. The diagnostic efficiency was significantly improved by combining composite score (P), carcinoembryonic antigen, and fecal immunochemical test for hemoglobin (area under the curve = 0.962).

DISCUSSION

The composite score (P) derived from the ctDNA methylation levels of Septin9, SDC2, and BCAT1 can be used for CRC diagnosis with high sensitivity and high specificity. A combination of ctDNA methylation, carcinoembryonic antigen, and fecal immunochemical test for hemoglobin was proved to be the most effective approach to diagnose CRC.

Overtreatment in nonmalignant lesions detected in a colorectal cancer screening program: a retrospective cohort study

Background

Although colorectal cancer (CRC) screening programs reduce CRC incidence and mortality, they are associated with risks in healthy subjects. However, the risk of overtreatment and overdiagnosis has not been determined yet. The aim of this study was to report the surgery rates in patients with nonmalignant lesions detected within the first round of a fecal immunochemical test (FIT) based CRC screening program and the factors associated with it.

Methods

We included in this analysis all patients with nonmalignant lesions detected between May 2013 and June 2019 in the Galician (Spain) CRC screening program. We calculated surgery rate according to demographic variables, the risk classification according to the colonoscopy findings (European guidelines for quality assurance), the endoscopist’s adenoma detection rate (ADR) classified into quartiles and the hospital’s complexity level. We determined which variables were independently associated with surgery rate and expressed the association as Odds Ratio and its 95% confidence interval (CI).

Results

We included 15,707 patients in the analysis with high (19.9%), intermediate (26.9%) low risk (23.3%) adenomas and normal colonoscopy (29.9%) detected in the analyzed period. Colorectal surgery was performed in 162 patients (1.03, 95% CI 0.87–1.19), due to colonoscopy complications (0.02, 95% CI 0.00–0.05) and resection of colorectal benign lesions (1.00, 95% CI 0.85–1.16). Median hospital stay was 6 days with 17.3% patients developing minor complications, 7.4% major complications and one death. After discharge, complications developed in 18.4% patients. In benign lesions, an endoscopic resection was performed in 25.4% and a residual premalignant lesion was detected in 89.9%. The variables independently associated with surgery in the multivariable analysis were age (≥60 years = 1.57, 95% CI 1.11–2.23), sex (female = 2.10, 95% CI 1.52–2.91), the European guidelines classification (high risk = 67.94, 95% CI 24.87–185.59; intermediate risk = 5.63, 95% CI 1.89–16.80; low risk = 1.43; 95% CI 0.36–5.75), the endoscopist’s ADR (Q4 = 0.44, 95% CI 0.28–0.68; Q3 = 0.44, 95% CI 0.27–0.71; Q2 = 0.71, 95% CI 0.44–1.14) and the hospital (tertiary = 0.54, 95% CI 0.38–0.79).

Conclusions

In a CRC screening program, the surgery rate and the associated complications in patients with nonmalignant lesions are low, and related to age, sex, endoscopic findings, endoscopist’s ADR and the hospital’s complexity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08606-w.

The impact of 6 years of the National Colorectal Cancer Screening Program on colorectal cancer incidence and 5-year survival

We aimed to assess the impact of the first three rounds of the National Colorectal Cancer Screening Program (NCCSP) on CRC incidence and mortality in Slovenia. In NCCSP, we use two fecal immune tests (FITs) and if test is positive patient is referred to colonoscopy. From 2009, we invite Slovenian residents aged 50-69 years, one screening round takes 2 years. The response rate was from 56.9 to 59.9%. FIT was positive in 6.0-6.2% (more in older patients and in men; P < 0.05). The adenoma detection rate was >51.3% (more in men; P < 0.01). In NCCSP, 70.3% of all cancers diagnosed were in stages I and II, while 20.7% of all CRC were found in polyps resected during colonoscopies. Patients with positive first FIT have odds ratio 2.19 [95% confidence interval (CI), 2.06-2.32] for advanced neoplasia and cancer compared to patients with two negative FITs. The incidence rate for CRC has dropped significantly after 6 years in population and in men (P < 0.01) but not in women. Five-year CRC survival was 31.3% higher if cancer was diagnosed in NCCSP (P < 0.05). After 6 years of NCCSP, the incidence rate for CRC has dropped significantly (P < 0.01). Hazard ratio for death from CRC was 3.84 higher (95% CI, 3.36-4.40; P < 0.001) in patients with cancer detected outside the program.

IMPACT OF SCREENING ON SHORT-TERM MORTALITY AND MORBIDITY FOLLOWING TREATMENT FOR COLORECTAL CANCER

BACKGROUND AND AIMS

The aim of this study was to describe short-term changes in morbidity and mortality associated with the implementation of screening for colorectal cancer in Denmark.

MATERIALS AND METHODS

Prospective cohort study with inclusion of all patients aged 50-75 years treated for colorectal cancer between 1 March 2014 and 31 December 2015 in Denmark. Adjusted hazard ratios were calculated for 30 and 90 days mortality using Cox Regression. We made two adjusted models-a "basic" adjusted for screening status, sex, age, smoking, alcohol consumption, and cancer type and an "advanced" that also included body mass index and American society of Anesthesiologists score in analyses. Relative risks were calculated for postoperative surgical and medical complications.

RESULTS

In total, 5348 patients were included. In the "basic model," adjusted risk of 30 and 90 days total mortality was reduced in the screen-detected group (p < 0.01, HR = 0.43, CI = 0.24-0.76) and (p < 0.01, HR = 0.45, CI = 0.30-0.69). In the "advanced model," only 90 days total mortality was significantly reduced in the screen-detected group (p = 0.01, HR 0.59, CI = 0.39-0.90). No significant changes were found with regard to surgical and medical complications, respectively, (p = 0.05 (CI = 0.76-1.00) and p = 0.47(CI = 0.74-1.15)).

CONCLUSION

This nationwide study showed that screening for colorectal cancer was associated with a lower 90 days total mortality although no significant improvements were seen with regard to morbidity.

Colonoscopy screening and surveillance guidelines

The Colonoscopy Screening and Surveillance Guidelines were developed by the Japan Gastroenterological Endoscopy Society as basic guidelines based on the scientific methods. The importance of endoscopic screening and surveillance for both detection and post-treatment follow-up of colorectal cancer has been recognized as essential to reduce disease mortality. There is limited high-level evidence in this field; therefore, we had to focus on the consensus of experts. These clinical practice guidelines consist of 20 clinical questions and eight background knowledge topics that have been determined as the current guiding principles.

Perforation and post-polypectomy bleeding complicating colonoscopy in a population-based screening program

Background and study aims We aimed to estimate the rate of hospital admissions for perforation and for post-polypectomy bleeding, after outpatient colonoscopy following a first positive fecal occult blood test screen through the population-based ColonCancerCheck program in Ontario, Canada. Patients and methods We identified all individuals aged 50 to 74 years with a first positive CCC gFOBT screening result from 2008 to 2017 who underwent outpatient colonoscopy ≤ 6 months later and who did not receive a diagnosis of CRC ≤ 24 months later. We identified inpatient hospital admissions for colonic perforation ≤ 7 days after and for post-polypectomy bleeding ≤ 14 days following colonoscopy. Results Among 121,626 individuals who underwent colonoscopy, the rate of perforation was 0.6 per 1000 from 2008 to 2012 and 0.4 per 1000 from 2013 to 2017. The rate was elevated among those aged 70 to 74 years; those with comorbidities; when colonoscopy was performed by endoscopists other than gastroenterologists or endoscopists with low prior year volume; and when polypectomy was performed during colonoscopy. The rate of bleeding was 4.3 per 1000 and was elevated among those aged 70 to 74 years, those with comorbidity, and with complex polypectomy. Both outcomes were more common among those aged 70 to 74 years, those with a 5-year cumulative Charlson score ≥ 1, those with prior hospitalization for ischemic heart disease, and those with endoscopists whose prior year colonoscopy volume was in the three lower quartiles. Conclusions Colonic perforation and post-polypectomy bleeding, among participants of population-based colorectal screening programs who test positive in the absence of colorectal cancer, are infrequent but serious complications, which increase with participant age and comorbidity, and with endoscopist characteristics.

Association between lifestyle and site-specific advanced colorectal lesions in screening with faecal immunochemical test and sigmoidoscopy

BACKGROUND

Lifestyle factors may help to identify individuals at high-risk for colorectal cancer (CRC).

AIMS

To examine the association between lifestyle, referral for follow-up colonoscopy and proximal neoplasia detection in CRC screening.

METHODS

In this observational study, 14,832 individuals aged 50-74 years were invited to faecal immunochemical test (FIT) or sigmoidoscopy screening. Advanced lesions (AL), including advanced adenomas, advanced serrated lesions and CRC were divided according to location: distal-only, or proximal with or without distal AL. We collected information on smoking habit, body mass index and alcohol intake through a questionnaire.

RESULTS

Out of 3,318 FIT and 2,988 sigmoidoscopy participants, 516 (16%) and 338 (11%), respectively, were referred for follow-up colonoscopy after a positive screening test. Two-hundred-and-fifty-six (4%) had distal-only and 119 (2%) proximal AL. In FIT participants, obesity and high alcohol intake were associated with proximal AL; odds ratio (95% confidence interval) 2.68 (1.36-5.26) and 2.16 (1.08-4.30), respectively. In sigmoidoscopy participants, current smoking was associated with proximal AL; 4.58 (2.24-9.38), and current smoking and obesity were associated with referral for colonoscopy; 2.80 (2.02-3.89) and 1.42 (1.01-2.00), respectively.

CONCLUSION

Current smoking, obesity and high alcohol intake were associated with screen-detected proximal colorectal AL. Current smoking and obesity were associated with referral for follow-up colonoscopy in sigmoidoscopy screening.

Assessment of Antioxidant Effect of Beta-Glucan on the Whole Blood Oxidative DNA Damage with the Comet Assay in Colorectal Cancer

OBJECTIVE

The present study aims to evaluate the antioxidant effect of beta glucan on oxidative DNA damage by comet assay.

METHODS

A total of 19 adult females and males diagnosed with stage 3-4 colorectal cancer and a control group of 20 age-matched healthy subjects were enrolled in the study. Blood samples of the participants were analyzed using Comet Assay for the parameters of DNA damage.

RESULTS

Significantly increased DNA damage was observed in patients versus control group as indicated by greater values of tail moment, tail percent DNA and tail length. Following incubation with β-glucan, a substantial reduction was found in the aforementioned parameters of DNA damage. Comet assay revealed significant levels of endogenous DNA damage in patients as shown by remarkable increases in the tail moment, the percentage of DNA in the tail and the tail length values, in comparison with the control group. Following treatment of fresh whole blood with β-glucan incubation, DNA damages were significantly reduced but lower values were observed after β-glucan incubation in the patient group versus control group.

CONCLUSION

β-Glucan was found to reduce DNA damage substantially in colorectal cancer patients and show antimutagenic effects. Our results suggested that dietary β-glucan intake might be important in the genesis of colorectal cancer tumors.

Detection of colorectal cancer in urine using DNA methylation analysis

Colorectal cancer (CRC) is the second leading cause for cancer-related death globally. Clinically, there is an urgent need for non-invasive CRC detection. This study assessed the feasibility of CRC detection by analysis of tumor-derived methylated DNA fragments in urine. Urine samples, including both unfractioned and supernatant urine fractions, of 92 CRC patients and 63 healthy volunteers were analyzed for DNA methylation levels of 6 CRC-associated markers (SEPT9, TMEFF2, SDC2, NDRG4, VIM and ALX4). Optimal marker panels were determined by two statistical approaches. Methylation levels of SEPT9 were significantly increased in urine supernatant of CRC patients compared to controls (p < 0.0001). Methylation analysis in unfractioned urine appeared inaccurate. Following multivariate logistic regression and classification and regression tree analysis, a marker panel consisting of SEPT9 and SDC2 was able to detect up to 70% of CRC cases in urine supernatant at 86% specificity. First evidence is provided for CRC detection in urine by SEPT9 methylation analysis, which combined with SDC2 allows for an optimal differentiation between CRC patients and controls. Urine therefore provides a promising liquid biopsy for non-invasive CRC detection.

Korean colonoscopy screening pilot study (K-cospi) for screening colorectal cancer: study protocol for the multicenter, community-based clinical trial

BACKGROUND

The Korean National Cancer Screening Program has been providing annual fecal immunochemical test for colorectal cancer (CRC) to adults aged 50 years and older since 2004. The Korean Colonoscopy Screening Pilot Study was developed to evaluate the effectiveness of colonoscopy screening for CRC incidence and mortality, screening-related complications, and acceptability of colonoscopy as a primary modality for the national CRC screening program.

METHODS

This study and its protocols have been approved by the Korean Public Institutional Review Board and the National Cancer Center Institutional Review Board. We obtain written informed consent from all participants. The target population is males and females aged 50-74 years living within the pilot sites. A total of 26,640 participants will be recruited for colonoscopy screening. Subjects who have been diagnosed with CRC, who are currently undergoing treatment for CRC, or who have undergone colonoscopy screening within the past 5 years are not allowed to participate. All participants need to complete baseline questionnaires. This pilot study is currently conducted by 104 endoscopists from 57 national cancer screening institutions (42 primary, 10 secondary, and 5 tertiary institutions) located in Goyang-si, Gimpo-si, and Paju-si. The number of endoscopists, medical institutions, and districts participating in the pilot study will be expanded, if necessary. Participating endoscopists at each medical institution perform colonoscopy and report the colonoscopy results to a centralized electronic case report system. We conduct a telephone survey after 7 days and 4 weeks post-colonoscopy to assess for procedure-related complications and satisfaction of the participants. In case of abnormal findings from colonoscopy screening, we track the results from follow-up diagnostic tests. Data from this pilot study will be linked to the diagnostic workup results, the Korean Cancer Registry, and death certificate data for analysis of the performance, long-term effects, and cost-effectiveness of colonoscopy.

DISCUSSION

The results will provide critical information to determine whether the introduction of colonoscopy as the primary modality of the Korean National Cancer Screening Program would be acceptable and feasible. Trial registration Korean Clinical Research Information Service registry, KCT0004142. Registered on 15 July 2019, http://cris.nih.go.kr/cris/en/search/search_result_st01.jsp?seq=16227.

Proton-pump inhibitors are associated with a high false-positivity rate in faecal immunochemical testing

BACKGROUND

False-positivity rates in faecal immunochemical test (FIT) can be affected by drug exposure. We aimed to assess the association between proton pump inhibitors (PPI) consumption and false positive (FP) results in a colorectal cancer (CRC) screening programme using electronic prescription records.

METHODS

A retrospective cohort study within a population-based screening program for CRC from 2010 to 2016 was performed. Participants with a conclusive FIT result and with prescription electronic data were included. An FP result was defined as having a positive FIT (≥ 20 µg haemoglobin/g faeces) and a follow-up colonoscopy without intermediate or high-risk lesions or CRC. Screening data were anonymously linked to the public data analysis program for health research and innovation (PADRIS) database that recorded patient diseases history and reimbursed medication. PPI exposure was defined as having retrieved at least one dispensation of PPI three months prior to the FIT.

RESULTS

A total of 89,199 tests (of 46,783 participants) were analysed, 4824 (5.4%) tested positive and the proportion of FP was 53.5%. Overall, 17,544 participants (19.7%) were PPI users prior to FIT performance. PPI exposure increased the probability of obtaining an FP FIT result from 50.4 to 63.3% (adjusted OR 1.39; 95% CI 1.18-1.65). Nonsteroidal anti-inflammatory drugs, acetylsalicylic acid, antibiotics, and laxatives were also associated with an FP result. The effect of PPI was independent and showed a synergistic interaction with nonsteroidal anti-inflammatory drugs.

CONCLUSION

PPIs increase FIT positivity at the expense of FP results. The recommendation to avoid their use before FIT performance could reduce up to 3% of colonoscopies and 9% of FP results.

Psychological Stress Up-Regulates CD147 Expression Through Beta-Arrestin1/ERK to Promote Proliferation and Invasiveness of Glioma Cells

Psychological stress is closely related to the occurrence and prognosis of various malignant tumors, but the underlying mechanisms are not well studied. CD147 has been reported to be expressed in glioma and other malignant tumors. CD147 not only participates in lactic acid transport, but it also plays an important role in the invasion and metastasis of malignant tumor cells by stimulating the production of numerous matrix metalloproteinases (MMPs) and vascular endothelial growth factor by fibroblasts, and could also act as an autocrine factor stimulating MMPs production in metastatic tumor cells. Here, we found that silencing CD147 in chronically stressed nude mice not only inhibited the proliferation of xenografts but also decreased matrix metalloproteinase-2, 9 expression and lactic acid content in tumor tissues. Furthermore, norepinephrine (NE) was significantly increased in the serum of nude mice in glioma stress model. To determine the underlying cellular mechanism, we added exogenous NE into LN229 and U87 cells to simulate the stress environment in vitro. The invasiveness of the glioma cells was subsequently examined using a Matrigel invasion assay. We demonstrated that knockdown of CD147 inhibited glioma invasiveness and metastasis with norepinephrine stimulation. Luciferase reporter gene experiments further demonstrated that the expression of CD147 is up-regulated primarily by norepinephrine via the β-Adrenalin receptor (βAR)-β-arrestin1-ERK1/2-Sp1 pathway. High expression of CD147 promoted the secretion of MMP-2 and the increment of lactic acid, which accelerated the augmented invasion and metastasis of glioma induced by psychological stress. Taken together, these results suggest that psychological stress promotes glioma proliferation and invasiveness by up-regulating CD147 expression. Thus, CD147 might be a potential target site in the treatment of glioma progression induced by chronic psychological stress.

EXPERIMENTAL ASSESSMENT OF INTACT COLON DEFORMATION UNDER LOCAL FORCES APPLIED BY MAGNETIC CAPSULE ENDOSCOPES

Magnetically guided capsule endoscopy is a promising technology for clinical application. A platform that simulates the magnetic capsule endoscope system is built to study the deformation process of the colon when its lumen suffers local forces. Force-displacement curves of the porcine large intestine under various experiment conditions, including different loading positions (haustra or taeniae coli), loading directions, colon inner pressures and specimen lengths, were measured to analyze the mechanical behavior of the intact large intestine during interactions with magnetic capsule endoscopes. In the practical application of the magnetic capsule endoscope, these data are imperative to optimize the control scheme and reduce operation risks. Based on our experiments, the taeniae coli of the intact large intestine show higher linear stiffness than the haustra, and inflation reduces the linear stiffness of the colon. Magnetic capsule with small edge radii can more easily damage or even perforate the colon. Based on our test results, we suggest that the force applied to the colon should be limited to below 17[Formula: see text]N when the capsule is actuated forward along the colon and limited to below 10[Formula: see text]N when the capsule is vertical to the colon during lesion screening.

Psychological distress and quality of life following positive fecal occult blood testing in colorectal cancer screening

OBJECTIVE

This study aimed to assess psychological functioning, quality of life, and regret about screening after a positive fecal immunochemical test (FIT) and subsequent colonoscopy, and to evaluate changes over time.

METHODS

This is a prospective cohort study. Individuals aged 55 to 75 with a positive FIT that were referred for colonoscopy between July 2017 and November 2018, were invited to complete questionnaires related to psychological distress and health-related quality of life at three predefined time points: before colonoscopy, after histopathology result notification, and after 6 months. Four questionnaires were used: the Psychological Consequences Questionnaire (PCQ), the six-item Cancer Worry Scale (CWS), the Decision Regret Scale (DRS), and the 36-item Short-Form (SF-36).

RESULTS

A total of 1066 participants out of 2151 eligible individuals were included. Patients with cancer showed a significant increase in psychological dysfunction (P = .01) and cancer worry (P = .008) after colonoscopy result notification, and a decline to pre-colonoscopy measurements after 6 months. In the no-cancer groups, psychological dysfunction and cancer worry significantly decreased over time (P < .05) but there was no ongoing decline. After 6 months, 17% of participants with no cancer experienced high level of cancer worry (CWS ≥ 10). Yet, only 5% reported high level of regret about screening participation (DRS > 25). A good global quality of life was reported in participants with no cancer.

CONCLUSION

Some psychological distress remains up to 6 months after colonoscopy in participants who tested false-positive in the Dutch bowel cancer screening program.

Incidence of and Risk Factors for Systemic Adverse Events After Screening or Primary Diagnostic Colonoscopy: A Nationwide Cohort Study

OBJECTIVES

To estimate the systemic serious adverse event (SAE) rates after colonoscopy and to identify their risk factors.

METHODS

A nationwide cohort study was conducted using the comprehensive French claims databases SNDS (National Health Data System). Patients aged 30 years and over who underwent a first screening or diagnostic colonoscopy in 2010-2015 were included. The rates of cardiovascular and renal SAEs were estimated within 5 days after colonoscopy. The standardized incidence ratios were calculated to compare these incidence rates with those of the same events in the general population, and the associated risk factors were assessed by multilevel logistic regression.

RESULTS

Among the 4,088,799 included patients (median age, 59 years [interquartile range = 50-67]; 55.2% women; 30.1% with a Charlson index score ≤1), the 5-day SAE incidence rate was 2.8/10,000 procedures for shock, 0.87/10,000 for myocardial infarction, 1.9/10,000 for stroke, 2.9/10,000 for pulmonary embolism, 5.5/10,000 for acute renal failure, and 3.3/10,000 for urolithiasis. These SAEs occurred 3.3 to 15.8 times more often during the first 5 days after colonoscopy than expected in the general population. Thirty-day mortality rates ranged from 2.2/1,000 cases of urolithiasis to 268.1/1,000 cases of shock. Increasing age was associated with an increasing incidence of SAEs. Risks of shock and acute renal failure were associated with a greater number of comorbidities than the other SAEs. Colonoscopies in university hospitals were associated with higher risks, reflecting patient selection processes.

DISCUSSION

The systemic SAEs can be associated with a substantial mortality. They should be taken into account when deciding colonoscopy, in addition to perforation and bleeding, particularly in elderly patients with multiple comorbidities.

Comparison of the participation rate between CT colonography and colonoscopy in screening population: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVE

To compare the participation rate between CT colonography (CTC) and colonoscopy in screening population in randomized controlled trials (RCTs).

METHODS

A search was performed using the PubMed, Web of Science, and Cochrane databases. RCTs that included screening populations and reported participation number were assessed. Cochrane risk of bias tool was used to assess the bias and quality. Risk ratio (RR) was used to present the results. The non-participation rate was analyzed to verify the results of participation rate.

RESULTS

Five of 760 studies, with a total of 15,974 invitees, were included. The participation rate was higher at CTC (28.8%) than colonoscopy (20.8%), although the difference did not reach statistical significance (RR = 1.26; p = 0.070; I² = 90.3%). The non-participation rate at CTC was significantly lower than colonoscopy (RR = 0.92; p = 0.012; I² = 86.7%). Subgroup analysis suggested both the participation and non-participation rate were with significant difference between reduced/no cathartic preparation CTC and colonoscopy. Cumulative meta-analysis showed both the participation rate and non-participation rate exhibited a trend over time and sample size.

CONCLUSION

The participation rate was higher at CTC than colonoscopy, although the difference did not reach statistical significance. But the non-participation rate was with statistical difference. Screening population seemed more likely to participate the reduced/no cathartic preparation CTC. Statistical evidence was provided for more large RCTs are needed in the future.

ADVANCES IN KNOWLEDGE

The screening populations seem more likely to participate in the CTC, especially the reduced/no cathartic preparation CTC. The statistical evidence was provided for more large RCTs are needed in the future.

False-Positive Results in a Population-Based Colorectal Screening Program: Cumulative Risk from 2000 to 2017 with Biennial Screening

BACKGROUND

The aim of this study was to estimate the cumulative risk of a false-positive (FP) result in a fecal occult blood test (FOBT) through 7 screening rounds and to identify its associated factors in a population-based colorectal cancer screening program.

METHODS

Retrospective cohort study, which included participants ages 50 to 69 years of a colorectal cancer screening program in Catalonia, Spain. During this period, 2 FOBTs were used (guaiac and immunochemical). A discrete-time survival model was performed to identify risk factors of receiving a positive FOBT with no high-risk adenoma or colorectal cancer in the follow-up colonoscopy. We estimated the probability of having at least 1 FP over 7 screening rounds.

RESULTS

During the period of 2000 to 2017, the cumulative FP risk was 16.3% (IC_95%: 14.6%-18.3%), adjusted by age, sex, and type of test. The median number of screens was 2. Participants who began screening at age 50 years had a 7.3% [95% confidence interval (CI), 6.35-8.51] and a 12.4% (95% CI, 11.00-13.94) probability of an FP with 4 screening rounds of guaiac-based test and immunochemical test, respectively. Age, the fecal immunochemical test, first screening, and number of personal screens were factors associated with an FP result among screenees.

CONCLUSIONS

The cumulative risk of an FP in colorectal screening using FOBT seems acceptable as the colonoscopy, with its high accuracy, lengthens the time until additional colorectal screening is required, while complication rates remain low.

IMPACT

It is useful to determine the cumulative FP risk in cancer screening for both advising individuals and for health resources planning.

Integrated analyses of microRNA-29 family and the related combination biomarkers demonstrate their widespread influence on risk, recurrence, metastasis and survival outcome in colorectal cancer

Background

Emerging evidence has revealed miR-29 family as promising biomarkers for colorectal cancer (CRC), but their biomarker potential and molecular mechanisms remain poorly understood.

Methods

We performed a comprehensive meta-analysis to evaluate the biomarker performance of individual miR-29 and the related miRNA combination biomarkers. Meanwhile, we conducted an integrative bioinformatics analysis to unfold the underlying biological function of miR-29 and their relationship with CRC.

Results

Using miR-29 expression to diagnose CRC produced 0.82 area under the curve, 70% sensitivity and 81% specificity while the combination biomarkers based on miR-29 enhanced the diagnostic power with an AUC of 0.86, a sensitivity of 78% and a specificity of 91%. For the prognosis evaluation, patients with higher expression of miR-29 had better survival outcome (pooled HR 0.78; 95% CI 0.56–1.07). In addition, miR-29 has also been identified as potential biomarker for predicting recurrence and metastasis in CRC. Then the genes regulated by the miR-29 family were retrieved and found closely associated with the molecular pathogenesis of CRC according to the gene ontology and pathway analysis. Furthermore, hub nodes and significant modules were identified from the protein–protein interaction network constructed with miR-29 family targets, which were also confirmed highly involved in the establishment and development of CRC.

Conclusions

Current evidences suggest miR-29 family may become promising biomarkers for risk, recurrence, metastasis and survival outcome of CRC. Meanwhile our data highlight the potential clinical use of miRNA combination biomarkers. Nevertheless, further prospective studies are warranted before the application of the useful biomarkers in the clinical.

Screening for new primary cancers in patients with metastatic breast cancer: a provincial analysis of the Choosing Wisely Canada recommendations

Introduction

Patients with metastatic cancer have a decreased life expectancy, and with screening and surveillance for new primary cancers, they run the risk of immediate harm with little chance of any benefit. Choosing Wisely Canada therefore recommends that such investigations be avoided in patients with metastatic disease.

Methods

We examined cancer screening practices in a subset of patients with metastatic cancer in Newfoundland and Labrador. Patients with metastatic breast cancer seen at the provincial cancer clinic during 2014-2016 were identified from the Newfoundland and Labrador Cancer Registry. For each patient, we assessed whether any one or a combination of screening mammography, Pap (Papanicolaou) test, flexible sigmoidoscopy or colonoscopy, or fecal immunohistochemical test were performed at any point after the diagnosis of metastatic disease.

Results

Of 305 patients with metastatic breast cancer, 114 (37.4%) underwent at least 1 screening investigation (mean: 2.92 investigations per screened patient). The most common screening investigations were mammography (n = 197) and Pap test (n = 107). Primary care providers ordered most of the screening investigations (70%); oncology specialists ordered 14%, and other specialists, 12%. Median overall survival for patients with breast cancer after a diagnosis of metastatic disease was 42 months, with a 5-year overall survival of 35.9%.

Conclusions

A significant proportion of patients with metastatic breast cancer in Newfoundland and Labrador are still undergoing screening for new primary malignancies, which is discordant with oncology guidelines from Choosing Wisely Canada. Increased education strategies are needed if the Choosing Wisely Canada recommendations are to be implemented into routine clinical practice.

Patient, Procedure, and Endoscopist Risk Factors for Perforation, Bleeding, and Splenic Injury After Colonoscopies

BACKGROUND & AIMS

We investigated perforations, bleeding, and splenic injuries after screening or diagnostic colonoscopies to identify patient-, procedure-, endoscopist-, and facility-associated risk factors.

METHODS

We analyzed data from the SNIIRAM-PMSI national claims databases in France. A total of 4,088,799 patients, 30 years or older, undergoing a first screening or diagnostic colonoscopy from 2010 through 2015 were identified. Rates of severe adverse events (SAEs) were estimated using stringent and broad definitions. Risk factors associated with perforations and major bleeding were estimated using multilevel logistic regression models, adjusted for patient, colonoscopy, and endoscopist characteristics.

RESULTS

Perforation rates ranged from 3.5 (stringent definition) to 7.3 (broad definition) per 10,000 procedures, bleeding rates ranged from 6.5 to 23.1 per 10,000 procedures, and splenic injury rates ranged from 0.20 to 0.34 per 10,000 procedures. Rates of 30-day mortality were 13.2 per 1000 bleeds, 29.2 per 1000 perforations, and 36.1 per 1000 splenic injuries (stringent definitions). Patient characteristics associated with SAEs were increasing age (especially for perforation), cancer, and cardiovascular comorbidities. Procedure characteristics associated with SAEs included polypectomy-especially of polyps larger than 1 cm with an increased risk of perforation (odds ratio, 4.1; 95% CI, 3.4-5.0) and bleeding (odds ratio, 13.3; 95% CI, 11.7-15.1). Less-experienced endoscopists and endoscopists who performed a smaller number of colonoscopies were independently associated with a risk of SAEs.

CONCLUSION

In an analysis of national claims databases in France, we found SAEs related to screening and diagnostic colonoscopies to be more frequent in older patients, in patients with comorbidities, and with less-experienced endoscopists. Patients at risk of SAE should be identified and colonoscopies should be performed or supervised by experienced endoscopists.

Overexpression of microRNA‑101 causes anti‑tumor effects by targeting CREB1 in colon cancer

Accumulating evidence has demonstrated that aberrantly expressed microRNAs (miRNAs) are involved in the initiation and progression of numerous types of human cancer. Although a number of miRNAs have been demonstrated to be associated with the diagnosis, progression and prognosis of colon cancer, the function of miRNA‑101 (miR‑101) in colon cancer remains unclear, and the molecular mechanisms underlying the effects of miR‑101 in colon cancer require further investigation. The present study investigated the role of miR‑101 in colon cancer, and the results suggested that miR‑101 expression levels were significantly decreased in colorectal carcinoma tissues and in three types of colorectal cancer cell lines. Furthermore, overexpression of miR‑101 inhibited cell proliferation and migration in HT29 cells. The transcription factor cAMP responsive element binding protein 1 (CREB1) was identified to be a direct target of miR‑101 using a luciferase reporter assay, reverse transcription‑quantitative polymerase chain reaction analysis and western blot assay. miR‑101 overexpression in tumor xenografts in vivo decreased the expression levels of proliferating cell nuclear antigen and CREB1, and suppressed tumor growth. The present results suggested that miR‑101 may serve a role in colon cancer by directly targeting CREB1. Collectively, the present study may contribute to the development of improved diagnosis and prognostics for colon cancer.

Adverse events related to colonoscopy: Global trends and future challenges

Colonoscopy is a widely used method for diagnosing and treating colonic disease. The number of colonoscopies is increasing worldwide, and concerns about associated adverse events are growing. Large-scale studies using big data for post-colonoscopy complications have been reported. A colon perforation is a severe complication with a relatively high mortality rate. The perforation rate, as reported in large studies (≥ 50,000 colonoscopies) published since 2000, ranges from 0.005-0.085%. The trend in the overall perforation rate in the past 15 years has not changed significantly. Bleeding is a more common adverse event than perforation. Recent large studies (≥ 50,000 colonoscopies) have reported post-colonoscopy bleeding occurring in 0.001-0.687% of cases. Most studies about adverse events related to colonoscopy were performed in the West, and relatively few studies have been conducted in the East. The incidence of post-colonoscopy complications increases in elderly patients or patients with inflammatory bowel diseases. It is important to use a unified definition and refined data to overcome the limitations of previous studies. In addition, a structured training program for endoscopists and a systematic national management program are needed to reduce post-colonoscopy complications. In this review, we discuss the current trends in colonoscopy related to adverse events, as well as the challenges to be addressed through future research.

Quality assurance of colonoscopy within the Dutch national colorectal cancer screening program

Colorectal cancer (CRC) screening is capable of reducing CRC-related morbidity and mortality. Colonoscopy is the reference standard to detect CRC, also providing the opportunity to detect and resect its precursor lesions: colorectal polyps. Therefore, colonoscopy is either used as a primary screening tool or as a subsequent procedure after a positive triage test in screening programs based on non-invasive stool testing or sigmoidoscopy. However, in both settings, colonoscopy is not fully protective for the occurrence of post-colonoscopy CRCs (PCCRCs). Because most PCCRCs are the result of colonoscopy-related factors, a high-quality procedure is of paramount importance to assure optimal effectiveness of CRC screening programs. For this reason, at the start of the Dutch fecal immunochemical test (FIT)-based screening program, quality criteria for endoscopists performing colonoscopies in FIT-positive screenees, as well as for endoscopy centers, were defined. In conjunction, an accreditation and auditing system was designed and implemented. In this report, we describe the quality assurance process for endoscopists participating in the Dutch national CRC screening program, including a detailed description of the evidence-based quality criteria. We believe that our experience might serve as an example for colonoscopy quality assurance programs in other CRC screening programs.

Are anxiety levels associated with the decision to participate in a Swedish colorectal cancer screening programme? A nationwide cross-sectional study

OBJECTIVES

Colorectal cancer (CRC) screening programmes are commonly challenged by low uptake, limiting their potential to reduce CRC burden. We aimed to investigate anxiety levels related to the decision to participate or not in CRC screening among screening participants and non-participants. Further to explore associations between higher anxiety levels related to the decision and individuals' characteristics.

DESIGN

A nationwide cross-sectional study conducted with individuals included in a national randomised controlled CRC screening trial, the Screening of Swedish Colons (SCREESCO).

PARTICIPANTS

A total of 1409 individuals, 60-62 years, recruited from SCREESCO during 2015-2016 participated in the study; 1256 had participated in CRC screening (faecal immunochemical test: n=958; colonoscopy: n=298) and 153 had declined screening participation.

MEASURES

Anxiety levels were assessed with the State-Trait Anxiety Inventory (STAI) S-Anxiety Scale. Health literacy (HL) was assessed with the Swedish Functional and Communicative and Critical Health Literacy Scales.

RESULTS

Altogether, 79% of survey participants reported lower anxiety levels regarding their CRC screening decision (STAI S-Anxiety <40). Anxiety levels did not differ between screening participants and non-participants (mean STAI S-Anxiety score=34.1 vs 33.9, p=0.859). The odds of reporting higher anxiety levels increased by female sex (OR=1.37; CI 1.04 to 1.80; p=0.025) and previous faecal sampling (OR=1.53; CI 1.14 to 2.05; p=0.004), and decreased if living with partner (OR=0.65; CI 0.48 to 0.88; p=0.005), working (OR=0.72; CI 0.53 to 0.96; p=0.027) or having sufficient HL (functional: OR=0.49; CI 0.33 to 0.73, p≤0.001; communicative and critical: OR=0.55; CI 0.38 to 0.82; p=0.003).

CONCLUSIONS

Anxiety levels did not differ between screening participants and non-participants. Higher anxiety scores were associated with certain characteristics. Interventions accounting for these characteristics can be applied to reduce anxiety and facilitate programme acceptance.

TRIAL REGISTRATION NUMBER

NCT02078804; Results.