Colorectal cancer screening: clinical guidelines and rationale

Cost-effectiveness Analysis of Colorectal Cancer Screening Strategies Using Active Learning and Monte Carlo Simulation

INTRODUCTION

Detection of colorectal cancer (CRC) in the early stages through available screening tests increases the patient's survival chances. Multimodal screening policies can benefit patients by providing more diverse screening options and balancing the risks and benefits of screening tests. We investigate the cost-effectiveness of a wide variety of multimodal CRC screening policies.

METHODS

We developed a Monte Carlo simulation framework to model CRC dynamics. We proposed an innovative calibration process using machine learning models to estimate age- and size-specific adenomatous polyps' progression and regression rates. The proposed approach significantly expedites the model parameter space search.

RESULTS

Two multimodal proposed policies (i.e., 1] colonoscopy at 50 y and fecal occult blood test annually between 60 and 75 y and 2] colonoscopy at 50 and 60 y and fecal immunochemical test annually between 70 and 75 y) are identified as efficient frontier policies. Both policies are cost-effective at a willingness to pay of $50,000. Sensitivity analyses were performed to assess the sensitivity of results to a change in screening test costs as well as adherence behavior. The sensitivity analysis results suggest that the proposed policies are mostly robust to the considered changes in screening test costs, as there is a significant overlap between the efficient frontier policies of the baseline and the sensitivity analysis cases. However, the efficient frontier policies were more sensitive to changes in adherence behavior.

CONCLUSION

Generally, combining stool-based tests with visual tests will benefit patients with higher life expectancy and a lower expected cost compared with unimodal screening policies. Colonoscopy at younger ages (when the colonoscopy complication risk is lower) and stool-based tests at older ages are shown to be more effective.

HIGHLIGHTS

We propose a detailed Markov model to capture the colorectal cancer (CRC) dynamics. The proposed Markov model presents the detailed dynamics of adenomas progression to CRC.We use more than 44,000 colonoscopy reports and available data in the literature to calibrate the proposed Markov model using an innovative approach that leverages machine learning models to expedite the calibration process.We investigate the cost-effectiveness of a wide variety of multimodal CRC screening policies and compare their performances with the current in-practice policies.

Colorectal cancer screening at age 45 years in Israel: Cost-effectiveness and global implications

BACKGROUND

Colorectal cancer (CRC) incidence at ages <50 years is increasing worldwide. Screening initiation was lowered to 45 years in the United States. The cost-effectiveness of initiating CRC screening at 45 years in Israel was assessed with the aim of informing national policy and addressing internationally relevant questions.

METHODS

A validated CRC screening model was calibrated to Israeli data and examined annual fecal immunochemical testing (FIT) or colonoscopy every 10 years from 45 to 74 years (FIT45-74 or Colo45-74) versus from 50 to 74 years (FIT50-74 or Colo50-74). The addition of a fourth colonoscopy at 75 years was explored, subanalyses were performed by sex/ethnicity, and resource demands were estimated.

RESULTS

FIT50-74 and Colo50-74 reduced CRC incidence by 57% and 70% and mortality by 70% and 77%, respectively, versus no screening, with greater absolute impact in Jews/Other versus Arabs but comparable relative impact. FIT45-74 further reduced CRC incidence and mortality by an absolute 3% and 2%, respectively. With Colo45-74 versus Colo50-74, CRC cases and deaths increased slightly as three colonoscopies per lifetime shifted to 5 years earlier but mean quality-adjusted life-years gained (QALYGs) per person increased. FIT45-74 and Colo45-74 cost 23,800-53,900 new Israeli shekels (NIS)/QALYG and 110,600-162,700 NIS/QALYG, with the lowest and highest values among Jewish/Other men and Arab women, respectively. A fourth lifetime colonoscopy cost 48,700 NIS/QALYG. Lowering FIT initiation to 45 years with modest participation required 19,300 additional colonoscopies in the first 3 years.

CONCLUSIONS

Beginning CRC screening at 45 years in Israel is projected to yield modest clinical benefits at acceptable costs per QALYG. Despite different estimates by sex/ethnicity, a uniform national policy is favored. These findings can inform Israeli guidelines and serve as a case study internationally.

The Efficacy of Real-time Computer-aided Detection of Colonic Neoplasia in Community Practice: A Pragmatic Randomized Controlled Trial

BACKGROUND & AIMS

The use of computer-aided detection (CADe) has increased the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance in randomized controlled trials (RCTs) but has not shown benefit in real-world implementation studies. We performed a single-center pragmatic RCT to evaluate the impact of real-time CADe on ADRs in colonoscopy performed by community gastroenterologists.

METHODS

We enrolled 1100 patients undergoing colonoscopy for CRC screening, surveillance, positive fecal-immunohistochemical tests, and diagnostic indications at one community-based center from September 2022 to March 2023. Patients were randomly assigned (1:1) to traditional colonoscopy or real-time CADe. Blinded pathologists analyzed histopathologic findings. The primary outcome was ADR (the percentage of patients with at least 1 histologically proven adenoma or carcinoma). Secondary outcomes were adenomas detected per colonoscopy (APC), sessile-serrated lesion detection rate, and non-neoplastic resection rate.

RESULTS

The median age was 55.5 years (interquartile range, 50-62 years), 61% were female, 72.7% were of Hispanic ethnicity, and 9.1% had inadequate bowel preparation. The ADR for the CADe group was significantly higher than the traditional colonoscopy group (42.5% vs 34.4%; P = .005). The mean APC was significantly higher in the CADe group compared with the traditional colonoscopy group (0.89 ± 1.46 vs 0.60 ± 1.12; P < .001). The improvement in adenoma detection was driven by increased detection of <5 mm adenomas. CADe had a higher sessile-serrated lesion detection rate than traditional colonoscopy (4.7% vs 2.0%; P = .01). The improvement in ADR with CADe was significantly higher in the first half of the study (47.2% vs 33.7%; P = .002) compared with the second half (38.7% vs 34.9%; P = .33).

CONCLUSIONS

In a single-center pragmatic RCT, real-time CADe modestly improved ADR and APC in average-detector community endoscopists. (ClinicalTrials.gov number, NCT05963724).

Health State Utilities Associated with False-Positive Cancer Screening Results

INTRODUCTION

Early cancer detection can significantly improve patient outcomes and reduce mortality rates. Novel cancer screening approaches, including multi-cancer early detection tests, have been developed. Cost-utility analyses will be needed to examine their value, and these models require health state utilities. The purpose of this study was to estimate the disutility (i.e., decrease in health state utility) associated with false-positive cancer screening results.

METHODS

In composite time trade-off interviews using a 1-year time horizon, UK general population participants valued 10 health state vignettes describing cancer screening with true-negative or false-positive results. Each false-positive vignette described a common diagnostic pathway following a false-positive result suggesting lung, colorectal, breast, or pancreatic cancer. Every pathway ended with a negative result (no cancer detected). The disutility of each false positive was calculated as the difference between the true-negative and each false-positive health state, and because of the 1-year time horizon, each disutility can be interpreted as a quality-adjusted life-year decrement associated with each type of false-positive experience.

RESULTS

A total of 203 participants completed interviews (49.8% male; mean age = 42.0 years). The mean (SD) utility for the health state describing a true-negative result was 0.958 (0.065). Utilities for false-positive health states ranged from 0.847 (0.145) to 0.932 (0.059). Disutilities for false positives ranged from - 0.031 to - 0.111 (- 0.041 to - 0.111 for lung cancer; - 0.079 for colorectal cancer; - 0.031 to - 0.067 for breast cancer; - 0.048 to - 0.088 for pancreatic cancer).

CONCLUSION

All false-positive results were associated with a disutility. Greater disutility was associated with more invasive follow-up diagnostic procedures, longer duration of uncertainty regarding the eventual diagnosis, and perceived severity of the suspected cancer type. Utility values estimated in this study would be useful for economic modeling examining the value of cancer screening procedures.

The Role of the Gut Microbiome in Cancer: A Review, With Special Focus on Colorectal Neoplasia and Clostridioides difficile

The gut microbiome has coevolved with humans to aid in physiologic functions and prevent disease. An increasing prevalence of gut dysbiosis in modern society exists and has strong linkages to multiple disease processes common in the developed world. Mechanisms for microbiome-human interactions that impact host homeostasis include bacterial metabolite/toxin production, biofilm formation with mucous layer infiltration, and host immune system modulation. Most of this crosstalk occurs at the epithelial layer of the gut, and as such the role of these interactions in the induction of colorectal cancer-a highly prevalent disease globally and one undergoing significant epidemiologic shifts-is under increasing scrutiny. Although multiple individual gut bacteria have been hypothesized as possible driver organisms in the oncogenic process, no bacterium has been definitively identified as a causal agent of colorectal cancer, suggesting that host lifestyle factors, microbiome community interactions, and the mucosal and/or systemic immune response may play a critical role in the process. Recent evidence has emerged implicating the ubiquitous human pathogen Clostridioides difficile as a possible promoter of colorectal cancer through chronic toxin-mediated cellular changes. Although much remains to be defined regarding the natural history of infections caused by this pathogen and its potential for oncogenesis, it provides a strong model for the role of both individual bacteria and of the gut microbial community as a whole in the development of colorectal cancer.

Skin Cancers in Medicare Beneficiaries With Actinic Keratoses

Importance

Actinic keratoses (AK) are common premalignant skin lesions with a small risk of progressing to cutaneous squamous cell carcinoma (SCC). There is some evidence that patients with AKs also have increased risks of other skin cancers beyond SCC. However, the absolute risks of skin cancer in patients with AKs are unknown.

Objective

To calculate the absolute and relative risks of future skin cancer in Medicare beneficiaries with AKs.

Design, Setting, and Participants

This retrospective cohort study was performed using a deidentified, random sample of 4 999 999 fee-for-service Medicare beneficiaries from 2009 through 2018. Patients with treated AKs were included, and patients with seborrheic keratoses (SKs) were included as a comparator group. All patients were required to have at least 1 year between data set entry and first AK or SK. Patients with a history of skin cancer were excluded. Data were analyzed from September 2022 to March 2023.

Main Outcomes and Measures

Outcomes were first surgically treated skin cancer, including keratinocyte carcinoma (including SCC and basal cell carcinoma [BCC]) and melanoma. The absolute risks of skin cancer in patients with AKs were evaluated. Skin cancer risks in patients with AKs were compared with patients with SKs using adjusted competing risks regression.

Results

A total of 555 945 patients with AKs (mean [SD] age, 74.0 [7.4] years; 55.4% female) and 481 024 patients with SKs (mean [SD] age, 73.3 [7.3] years; 72.4% female) were included. The absolute risk of skin cancer after a first AK was 6.3% (95% CI, 6.3%-6.4%) at 1 year, 18.4% (95% CI, 18.3%-18.5%) at 3 years, and 28.5% (95% CI, 28.4%-28.7%) at 5 years. Patients with AKs had increased risk of skin cancer compared with patients with SKs (any skin cancer: adjusted hazard ratio [aHR], 2.17; 95% CI, 2.15-2.19; keratinocyte carcinoma: aHR, 2.20; 95% CI, 2.18-2.22; SCC: aHR, 2.63; 95% CI, 2.59-2.66; BCC: aHR, 1.85; 95% CI, 1.82-1.87; and melanoma: aHR, 1.67; 95% CI, 1.60-1.73).

Conclusions and Relevance

In this cohort study, older patients with AKs had substantial absolute risks, as well as elevated relative risks, of skin cancer. AKs may be clinical markers of UV exposure and increased skin cancer risk, including SCC, BCC, and melanoma. However, guidelines are lacking for follow-up skin cancer surveillance in patients with AKs. Efforts to develop evidence-based recommendations for skin cancer surveillance in patients with AKs are paramount.

Age-Based Comparative Analysis of Colorectal Cancer Colonoscopy Screening Findings

Background and Objectives: Colorectal cancer (CRC) incidence is rapidly emerging among individuals <50 years, termed as early-onset colorectal cancer (EOCRC). This study aimed to probe variations in tumorigenic pathology and relevant manifestations (polyp and adenoma incidence) between suspected cases of EOCRC and late-onset CRC (LOCRC; ≥50 years of age). Materials and Methods: Between September 2022 and February 2023, colonoscopy-based screening data from 1653 patients were included in this study. All eligible participants were divided into two groups, depending upon patient age, where Group 1 consisted of 1021 patients aged <50 years while Group 2 consisted of 632 patients aged ≥ 50 years. Polyp samples were collected when identified peri-procedurally and characterized according to World Health Organization criteria. Results: Polyp detection rate was 42% for the <50-year age group, while this was 76% for the ≥50-year age group. Additionally, the <50-year age group predominated in hyperplastic polyp manifestation, particularly within the rectum and sigmoid colon. In addition, the ≥50-year age group had increased prevalence of serrated polyps and differing adenoma manifestations. Conclusions: This investigation served to highlight the importance of age stratification for CRC colonoscopy-based screening effectiveness, with particular reference to evaluations that are based on polyp localization within differing colon regions.

Patient Preferences in Diagnostic Imaging: A Scoping Review

BACKGROUND

As new diagnostic imaging technologies are adopted, decisions surrounding diagnostic imaging become increasingly complex. As such, understanding patient preferences in imaging decision making is imperative.

OBJECTIVES

We aimed to review quantitative patient preference studies in imaging-related decision making, including characteristics of the literature and the quality of the evidence.

METHODS

The Pubmed, Embase, EconLit, and CINAHL databases were searched to identify studies involving diagnostic imaging and quantitative patient preference measures from January 2000 to June 2022. Study characteristics that were extracted included the preference elicitation method, disease focus, and sample size. We employed the PREFS (Purpose, Respondents, Explanation, Findings, Significance) checklist as our quality assessment tool.

RESULTS

A total of 54 articles were included. The following methods were used to elicit preferences: conjoint analysis/discrete choice experiment methods (n = 27), contingent valuation (n = 16), time trade-off (n = 4), best-worst scaling (n = 3), multicriteria decision analysis (n = 3), and a standard gamble approach (n = 1). Half of the studies were published after 2016 (52%, 28/54). The most common scenario (n = 39) for eliciting patient preferences was cancer screening. Computed tomography, the most frequently studied imaging modality, was included in 20 studies, and sample sizes ranged from 30 to 3469 participants (mean 552). The mean PREFS score was 3.5 (standard deviation 0.8) for the included studies.

CONCLUSIONS

This review highlights that a variety of quantitative preference methods are being used, as diagnostic imaging technologies continue to evolve. While the number of preference studies in diagnostic imaging has increased with time, most examine preventative care/screening, leaving a gap in knowledge regarding imaging for disease characterization and management.

Impact of the COVID-19 pandemic on the mortality among patients with colorectal cancer in Hiroshima, Japan: A large cancer registry study

BACKGROUND

This retrospective cohort study aimed to evaluate the impact of the COVID-19 pandemic on colorectal cancer care and mortality using a large cancer registry in Hiroshima Prefecture, Japan. The study aimed to estimate the all-cause mortality rates within 1 year of diagnosis among colorectal cancer patients diagnosed during the pandemic period (2020 and 2021) compared to those diagnosed during the pre-pandemic period (2018 and 2019).

METHODS

The day of diagnosis was set as Day 0 and Cox regression models were utilized to estimate crude hazard ratios (HRs) and adjusted HRs, accounting for age, sex, cancer stage, and treatment status. Two sensitivity analyses of overall survival were performed with different cutoffs of the pre-pandemic/pandemic periods and year-to-year comparisons. Subgroup analyses were performed using likelihood ratio tests.

RESULTS

A total of 15,085 colorectal cancer patients were included, with 6499 eligible for follow-up. A median age of included patients was 72 years old, of which 59% were male. The distribution of cancer stages showed little variation between the pre-pandemic and pandemic periods. With a median follow-up of 177 days, the number of events was 316/3111 (173 events per 1000 person-years [E/1000PY], 95% confidence interval [CI]: 154-192 E/1000PY) in the pre-pandemic period, and 326/2746 (245 E/1000PY, 95% CI: 220-274 E/1000PY) in the pandemic period (crude HR: 1.42, 95% CI: 1.22-1.66; adjusted HR: 1.25, 95% CI: 1.07-1.46). The two sensitivity analyses and subgroup analyses consistently supported these findings.

CONCLUSIONS

The study revealed an increased colorectal cancer mortality during the pandemic period, suggesting a continuous impact of the COVID-19 pandemic on the known and unknown risk factors for colorectal cancer for several years. Further studies are necessary to mitigate the adverse effects on patient outcomes.

Clinical utility of colon capsule endoscopy: a moving target?

The purpose of this article is to provide an overview of white light colon capsule endoscopy's current clinical application, concentrating on its most recent developments. Second-generation colon capsule endoscopy (CCE2) is approved by the FDA for use as an adjunctive test in patients with incomplete colonoscopy and within Europe in patients at average risk, those with incomplete colonoscopies or those unwilling to undergo conventional colonoscopies. Since the publication of European Society of GI Endoscopy guidelines on the use of CCE, there has been a significant increase in comparative studies on the diagnostic yield of CCE. This paper discusses CCE2 in further detail. It explains newly developed colon capsule system and the current status on the use of CCE, it also provides a comprehensive summary of systematic reviews on the implementation of CCE in colorectal cancer screening from a methodological perspective. Patients with ulcerative colitis can benefit from CCE2 in terms of assessing mucosal inflammation. As part of this review, performance of CCE2 for assessing disease severity in ulcerative colitis is compared with colonoscopy. Finally, an assessment if CCE can become a cost-effective clinical service overall.

Noninvasive Colorectal Cancer Prevention Options in Older Adults

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide and its incidence increases with age. The proportion of older adults in the United States continues to rise, making CRC prevention a key health priority for our aging population. CRC is a largely preventable disease through screening and polyp surveillance, and noninvasive modalities represent an important option for older adults in whom the burdens and risks of invasive testing are higher compared with younger adults. This review highlights the evidence, risks, and benefits of noninvasive CRC screening and surveillance options in older adults and discusses the challenges of CRC prevention in this cohort.

Comprehensive Cost Implications of Commercially Available Noninvasive Colorectal Cancer Screening Modalities

BACKGROUND

There is an increasing usage of noninvasive screening modalities for colorectal cancer (CRC), primarily the fecal immunochemical test (FIT) and multi-target stool DNA test (Cologuard [CG]). The aim of this study was to determine the comprehensive, long-term cost implications of these noninvasive screening modalities.

STUDY DESIGN

Using a national insurer-based administrative dataset, patients screened for CRC from January 1, 2019 to December 31, 2019 were analyzed. A hierarchical logic system was used to determine the primary screening modality for each patient. The total annual costs in US dollars ($) were extrapolated using number of patients screened, costs per test, screening intervals, and costs incurred from false results. Patients within our tumor registry diagnosed with CRC were matched to their claims data, and cancer stage distribution was compared.

RESULTS

Of 119,334 members who underwent noninvasive screening, 38.1% underwent screening with FIT and 40.0% with CG. The combined annual cost for these 2 screening modalities was $13.7 million. By transitioning to FIT alone for all noninvasive screening, the total annual cost would decrease to $7.9 million, resulting in a savings of approximately $5.8 million per year. Additionally, by combining data from the network cancer registry and insurer-based claims dataset, we were able to match 533 individuals who underwent screening and were later diagnosed with CRC. The rate of early-stage (stage 0 to II) disease was found to be similar between those screened with FIT and CG (59.5% FIT vs 63.2% CG; p = 0.77).

CONCLUSIONS

The adoption of FIT as the primary noninvasive CRC screening method has the potential to generate significant cost savings, and therefore, carries significant value implications for a large population health system.

Utility of FDG PET/CT in Patient with Synchronous Breast and Colon Cancer

The most common malignancy in women is breast cancer, and the second one is colon cancer. Synchronous breast and colon cancers are rare. Here, we reported a 60-year-old woman with a left breast mass for six months. Biopsy revealed an invasive ductal carcinoma. She underwent 2-[Fluorine-18]fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET)/computed tomography (CT) scan for evaluation of the extent of the disease. FDG PET/CT revealed an advanced left breast cancer with multiple metastases in both regional and distant lymph nodes (in left axilla level I/II, lower paratracheal region, and right lung hilum), bilateral lungs, and axial and proximal appendicular skeletons. An early staged synchronous colon cancer was detected incidentally on FDG PET/CT images. After endoscopic mucosal resection of colon cancer, she received palliative chemotherapy for breast cancer with a marked therapeutic response. The disease status of post-treated breast cancer remained relatively stationary for more than one year. Brain metastasis was noted afterward. Nevertheless, there was no evidence of colon cancer recurrence throughout her breast cancer disease course.

Natural Compounds Targeting the Autophagy Pathway in the Treatment of Colorectal Cancer

Autophagy is a highly conserved intracellular degradation pathway by which misfolded proteins or damaged organelles are delivered in a double-membrane vacuolar vesicle and finally degraded by lysosomes. The risk of colorectal cancer (CRC) is high, and there is growing evidence that autophagy plays a critical role in regulating the initiation and metastasis of CRC; however, whether autophagy promotes or suppresses tumor progression is still controversial. Many natural compounds have been reported to exert anticancer effects or enhance current clinical therapies by modulating autophagy. Here, we discuss recent advancements in the molecular mechanisms of autophagy in regulating CRC. We also highlight the research on natural compounds that are particularly promising autophagy modulators for CRC treatment with clinical evidence. Overall, this review illustrates the importance of autophagy in CRC and provides perspectives for these natural autophagy regulators as new therapeutic candidates for CRC drug development.

An Evaluation of Critical Factors for the Cost-Effectiveness of Real-Time Computer-Aided Detection: Sensitivity and Threshold Analyses Using a Microsimulation Model

BACKGROUND

The use of computer-aided detection (CAD) increases the adenoma detection rates (ADRs) during colorectal cancer (CRC) screening/surveillance. This study aimed to evaluate the requirements for CAD to be cost-effective and the impact of CAD on adenoma detection by endoscopists with different ADRs.

METHODS

We developed a semi-Markov microsimulation model to compare the effectiveness of traditional colonoscopy (mean ADR, 26%) to colonoscopy with CAD (mean ADR, 37%). CAD was modeled as having a $75 per-procedure cost. Extensive 1-way sensitivity and threshold analysis were performed to vary cost and ADR of CAD. Multiple scenarios evaluated the potential effect of CAD on endoscopists' ADRs. Outcome measures were reported in incremental cost-effectiveness ratios, with a willingness-to-pay threshold of $100,000/quality-adjusted life year.

RESULTS

When modeling CAD improved ADR for all endoscopists, the CAD cohort had 79 and 34 fewer lifetime CRC cases and deaths, respectively, per 10,000 persons. This scenario was dominant with a cost savings of $143 and incremental effectiveness of 0.01 quality-adjusted life years. Threshold analysis demonstrated that CAD would be cost-effective up to an additional cost of $579 per colonoscopy, or if it increases ADR from 26% to at least 30%. CAD reduced CRC incidence and mortality when limited to improving ADRs for low-ADR endoscopists (ADR <25%), with 67 fewer CRC cases and 28 CRC deaths per 10,000 persons compared with traditional colonoscopy.

CONCLUSIONS

As CAD is implemented clinically, it needs to improve mean ADR from 26% to at least 30% or cost less than $579 per colonoscopy to be cost-effective when compared with traditional colonoscopy. Further studies are needed to understand the impact of CAD on community practice.

[20 years of screening colonoscopy in Germany: current status, critical review and outlook]

20 years of colonoscopy for early cancer detection and screening in Germany. A success story - there is no longer any doubt about that, but a critical look should not be missing either.

Comparison of Quality Measures for Detection of Neoplasia at Screening Colonoscopy

BACKGROUND & AIMS

The proportion of colonoscopies with at least one adenoma (adenoma detection rate [ADR]) is inversely associated with colorectal cancer (CRC) risk and death. The aim of this study was to examine whether such associations exist for colonoscopy quality measures other than ADR.

METHODS

We used data from the Polish Colorectal Cancer Screening Program collected in 2000-2011. For all endoscopists who performed ≥100 colonoscopies we calculated detection rates of adenomas (ADR), polyps (PDR), and advanced adenomas (≥10 mm/villous component/high-grade dysplasia [AADR]); and number of adenomas per colonoscopy (APC) and per colonoscopy with ≥1 adenoma (APPC). We followed patients until CRC diagnosed before recommended surveillance, death, or December 31, 2019. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional-hazard models. We used Harrell's C statistic to compare the predictive power of the quality measures.

RESULTS

Data on 173,287 patients (median age, 56 years; 37.8% male) and 262 endoscopists were used. During a median follow-up of 10 years and 1,490,683 person-years, we identified 395 CRCs. All quality measures were significantly associated with CRC risk and death. The relative reductions in CRC risk were as follows: for ADR ≥24.9% (reference <12.1%; HR, 0.41; 95% CI, 0.25-0.66), PDR ≥42.7% (reference <19.9%; HR, 0.35; 95% CI, 0.24-0.51), AADR ≥9.1% (reference <4.1%; HR, 0.69; 95% CI, 0.49-0.96), APC ≥0.37 (reference <0.15; HR, 0.35; 95% CI, 0.21-0.58), and APPC ≥1.54 (reference <1.19; HR, 0.54; 95% CI, 0.35-0.83). AADR was the only quality measure with significantly lower predictive power than ADR (Harrell's C, 59.7 vs 63.4; P = .001). Similar relative reductions were observed for CRC death.

CONCLUSIONS

This large observational study confirmed the inverse association between ADR and CRC risk and death. The PDR and APC quality measures appear to be comparable with ADR.

Strong Hereditary Predispositions to Colorectal Cancer

Cancer is one of the most common causes of death worldwide. A strong predisposition to cancer is generally only observed in colorectal cancer (5% of cases) and breast cancer (2% of cases). Colorectal cancer is the most common cancer with a strong genetic predisposition, but it includes dozens of various syndromes. This group includes familial adenomatous polyposis, attenuated familial adenomatous polyposis, MUTYH-associated polyposis, NTHL1-associated polyposis, Peutz-Jeghers syndrome, juvenile polyposis syndrome, Cowden syndrome, Lynch syndrome, and Muir-Torre syndrome. The common symptom of all these diseases is a very high risk of colorectal cancer, but depending on the condition, their course is different in terms of age and range of cancer occurrence. The rate of cancer development is determined by its conditioning genes, too. Hereditary predispositions to cancer of the intestine are a group of symptoms of heterogeneous diseases, and their proper diagnosis is crucial for the appropriate management of patients and their successful treatment. Mutations of specific genes cause strong colorectal cancer predispositions. Identifying mutations of predisposing genes will support proper diagnosis and application of appropriate screening programs to avoid malignant neoplasm.

Single CT Appointment for Double Lung and Colorectal Cancer Screening: Is the Time Ripe?

Annual screening of lung cancer (LC) with chest low-dose computed tomography (CT) and screening of colorectal cancer (CRC) with CT colonography every 5 years are recommended by the United States Prevention Service Task Force. We review epidemiological and pathological data on LC and CRC, and the features of screening chest low-dose CT and CT colonography comprising execution, reading, radiation exposure and harm, and the cost effectiveness of the two CT screening interventions. The possibility of combining chest low-dose CT and CT colonography examinations for double LC and CRC screening in a single CT appointment is then addressed. We demonstrate how this approach appears feasible and is already reasonable as an opportunistic screening intervention in 50–75-year-old subjects with smoking history and average CRC risk. In addition to the crucial role Computer Assisted Diagnosis systems play in decreasing the test reading times and the need to educate radiologists in screening chest LDCT and CT colonography, in view of a single CT appointment for double screening, the following uncertainties need to be solved: (1) the schedule of the screening CT; (2) the effectiveness of iterative reconstruction and deep learning algorithms affording an ultra-low-dose CT acquisition technique and (3) management of incidental findings. Resolving these issues will imply new cost-effectiveness analyses for LC screening with chest low dose CT and for CRC screening with CT colonography and, especially, for the double LC and CRC screening with a single-appointment CT.

Commencing colorectal cancer screening at age 45 years in U.S. racial groups

Screening for colorectal cancer (CRC) is cost-effective for reducing its mortality among the average-risk population. In the US, CRC incidence and mortality differ among racial/ethnic groups, with non-Hispanic Blacks (NHB) and American Indian/Alaska Natives showing highest incidence and mortality and earlier presentation. Since 2005, some professional societies have recommended CRC screening for NHB to commence at 45 years or earlier; this was not implemented due to lack of recommendation from key groups that influence insurance payment coverage. In 2017 the highly influential U.S. Multi-Society Task Force for Colorectal Cancer recommended screening to commence at 45 years for NHB; this recommendation was supplanted by data showing an increase in early-onset CRCs in non-Hispanic Whites approaching the under-50-year rates observed for NHB. Subsequently the American Cancer Society and the USPSTF recommended that the entire average-risk population move to commence CRC screening at 45 years. Implementing screening in 45–49-year-olds has its challenges as younger groups compared with older groups participate less in preventive care. The US had made extensive progress pre-COVID-19 in closing the disparity gap for CRC screening in NHB above age 50 years; implementing screening at younger ages will take ingenuity, foresight, and creative strategy to reach a broader-aged population while preventing widening the screening disparity gap. Approaches such as navigation for non-invasive and minimally invasive CRC screening tests, removal of financial barriers such as co-pays, and complete follow up to abnormal non-invasive screening tests will need to become the norm for broad implementation and success across all racial/ethnic groups.

Evaluating the Potential of Polygenic Risk Score to Improve Colorectal Cancer Screening

BACKGROUND

Colorectal cancer has high incidence and associated mortality worldwide. Screening programs are recommended for men and women over 50. Intermediate screens such as fecal immunochemical testing (FIT) select patients for colonoscopy with suboptimal sensitivity. Additional biomarkers could improve the current scenario.

METHODS

We included 2,893 individuals with a positive FIT test. They were classified as cases when a high-risk lesion for colorectal cancer was detected after colonoscopy, whereas the control group comprised individuals with low-risk or no lesions. 65 colorectal cancer risk genetic variants were genotyped. Polygenic risk score (PRS) and additive models for risk prediction incorporating sex, age, FIT value, and PRS were generated.

RESULTS

Risk score was higher in cases compared with controls [per allele OR = 1.04; 95% confidence interval (CI), 1.02-1.06; P < 0.0001]. A 2-fold increase in colorectal cancer risk was observed for subjects in the highest decile of risk alleles (≥65), compared with those in the first decile (≤54; OR = 2.22; 95% CI, 1.59-3.12; P < 0.0001). The model combining sex, age, FIT value, and PRS reached the highest accuracy for identifying patients with a high-risk lesion [cross-validated area under the ROC curve (AUROC): 0.64; 95% CI, 0.62-0.66].

CONCLUSIONS

This is the first investigation analyzing PRS in a two-step colorectal cancer screening program. PRS could improve current colorectal cancer screening, most likely for higher at-risk subgroups. However, its capacity is limited to predict colorectal cancer risk status and should be complemented by additional biomarkers.

IMPACT

PRS has capacity for risk stratification of colorectal cancer suggesting its potential for optimizing screening strategies alongside with other biomarkers.

Coupé VM. A progressive three-state model to estimate time to cancer: a likelihood-based approach

Background

To optimize colorectal cancer (CRC) screening and surveillance, information regarding the time-dependent risk of advanced adenomas (AA) to develop into CRC is crucial. However, since AA are removed after diagnosis, the time from AA to CRC cannot be observed in an ethically acceptable manner. We propose a statistical method to indirectly infer this time in a progressive three-state disease model using surveillance data.

Methods

Sixteen models were specified, with and without covariates. Parameters of the parametric time-to-event distributions from the adenoma-free state (AF) to AA and from AA to CRC were estimated simultaneously, by maximizing the likelihood function. Model performance was assessed via simulation. The methodology was applied to a random sample of 878 individuals from a Norwegian adenoma cohort.

Results

Estimates of the parameters of the time distributions are consistent and the 95% confidence intervals (CIs) have good coverage. For the Norwegian sample (AF: 78%, AA: 20%, CRC: 2%), a Weibull model for both transition times was selected as the final model based on information criteria. The mean time among those who have made the transition to CRC since AA onset within 50 years was estimated to be 4.80 years (95% CI: 0; 7.61). The 5-year and 10-year cumulative incidence of CRC from AA was 13.8% (95% CI: 7.8%;23.8%) and 15.4% (95% CI: 8.2%;34.0%), respectively.

Conclusions

The time-dependent risk from AA to CRC is crucial to explain differences in the outcomes of microsimulation models used for the optimization of CRC prevention. Our method allows for improving models by the inclusion of data-driven time distributions.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-022-01645-2).

Guaiac-based faecal occult blood tests versus faecal immunochemical tests for colorectal cancer screening in average-risk individuals

BACKGROUND

Worldwide, many countries have adopted colorectal cancer (CRC) screening programmes, often based on faecal occult blood tests (FOBTs). CRC screening aims to detect advanced neoplasia (AN), which is defined as CRC or advanced adenomas. FOBTs fall into two categories based on detection technique and the detected blood component: qualitative guaiac-based FOBTs (gFOBTs) and faecal immunochemical tests (FITs), which can be qualitative and quantitative. Screening with gFOBTs reduces CRC-related mortality.

OBJECTIVES

To compare the diagnostic test accuracy of gFOBT and FIT screening for detecting advanced colorectal neoplasia in average-risk individuals.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, BIOSIS Citation Index, Science Citation Index Expanded, and Google Scholar. We searched the reference lists and PubMed-related articles of included studies to identify additional studies.

SELECTION CRITERIA

We included prospective and retrospective studies that provided the number of true positives, false positives, false negatives, and true negatives for gFOBTs, FITs, or both, with colonoscopy as reference standard. We excluded case-control studies. We included studies in which all participants underwent both index test and reference standard ("reference standard: all"), and studies in which only participants with a positive index test underwent the reference standard while participants with a negative test were followed for at least one year for development of interval carcinomas ("reference standard: positive"). The target population consisted of asymptomatic, average-risk individuals undergoing CRC screening. The target conditions were CRC and advanced neoplasia (advanced adenomas and CRC combined).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened and selected studies for inclusion. In case of disagreement, a third review author made the final decision. We used the Rutter and Gatsonis hierarchical summary receiver operating characteristic model to explore differences between tests and identify potential sources of heterogeneity, and the bivariate hierarchical model to estimate sensitivity and specificity at common thresholds: 10 µg haemoglobin (Hb)/g faeces and 20 µg Hb/g faeces. We performed indirect comparisons of the accuracy of the two tests and direct comparisons when both index tests were evaluated in the same population.

MAIN RESULTS

We ran the initial search on 25 June 2019, which yielded 63 studies for inclusion. We ran a top-up search on 14 September 2021, which yielded one potentially eligible study, currently awaiting classification. We included a total of 33 "reference standard: all" published articles involving 104,640 participants. Six studies evaluated only gFOBTs, 23 studies evaluated only FITs, and four studies included both gFOBTs and FITs. The cut-off for positivity of FITs varied between 2.4 μg and 50 µg Hb/g faeces. For each Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 domain, we assessed risk of bias as high in less than 20% of studies. The summary curve showed that FITs had a higher discriminative ability than gFOBTs for AN (P < 0.001) and CRC (P = 0.004). For the detection of AN, the summary sensitivity of gFOBTs was 15% (95% confidence interval (CI) 12% to 20%), which was significantly lower than FITs at both 10 μg and 20 μg Hb/g cut-offs with summary sensitivities of 33% (95% CI 27% to 40%; P < 0.001) and 26% (95% CI 21% to 31%, P = 0.002), respectively. Results were simulated in a hypothetical cohort of 10,000 screening participants with 1% CRC prevalence and 10% AN prevalence. Out of 1000 participants with AN, gFOBTs missed 850, while FITs missed 670 (10 μg Hb/g cut-off) and 740 (20 μg Hb/g cut-off). No significant differences in summary specificity for AN detection were found between gFOBTs (94%; 95% CI 92% to 96%), and FITs at 10 μg Hb/g cut-off (93%; 95% CI 90% to 95%) and at 20 μg Hb/g cut-off (97%; 95% CI 95% to 98%). So, among 9000 participants without AN, 540 were offered (unnecessary) colonoscopy with gFOBTs compared to 630 (10 μg Hb/g) and 270 (20 μg Hb/g) with FITs. Similarly, for the detection of CRC, the summary sensitivity of gFOBTs, 39% (95% CI 25% to 55%), was significantly lower than FITs at 10 μg and 20 μg Hb/g cut-offs: 76% (95% CI 57% to 88%: P = 0.001) and 65% (95% CI 46% to 80%; P = 0.035), respectively. So, out of 100 participants with CRC, gFOBTs missed 61, and FITs missed 24 (10 μg Hb/g) and 35 (20 μg Hb/g). No significant differences in summary specificity for CRC were found between gFOBTs (94%; 95% CI 91% to 96%), and FITs at the 10 μg Hb/g cut-off (94%; 95% CI 87% to 97%) and 20 μg Hb/g cut-off (96%; 95% CI 91% to 98%). So, out of 9900 participants without CRC, 594 were offered (unnecessary) colonoscopy with gFOBTs versus 594 (10 μg Hb/g) and 396 (20 μg Hb/g) with FITs. In five studies that compared FITs and gFOBTs in the same population, FITs showed a higher discriminative ability for AN than gFOBTs (P = 0.003). We included a total of 30 "reference standard: positive" studies involving 3,664,934 participants. Of these, eight were gFOBT-only studies, 18 were FIT-only studies, and four studies combined both gFOBTs and FITs. The cut-off for positivity of FITs varied between 5 µg to 250 µg Hb/g faeces. For each QUADAS-2 domain, we assessed risk of bias as high in less than 20% of studies. The summary curve showed that FITs had a higher discriminative ability for detecting CRC than gFOBTs (P < 0.001). The summary sensitivity for CRC of gFOBTs, 59% (95% CI 55% to 64%), was significantly lower than FITs at the 10 μg Hb/g cut-off, 89% (95% CI 80% to 95%; P < 0.001) and the 20 μg Hb/g cut-off, 89% (95% CI 85% to 92%; P < 0.001). So, in the hypothetical cohort with 100 participants with CRC, gFOBTs missed 41, while FITs missed 11 (10 μg Hb/g) and 11 (20 μg Hb/g). The summary specificity of gFOBTs was 98% (95% CI 98% to 99%), which was higher than FITs at both 10 μg and 20 μg Hb/g cut-offs: 94% (95% CI 92% to 95%; P < 0.001) and 95% (95% CI 94% to 96%; P < 0.001), respectively. So, out of 9900 participants without CRC, 198 were offered (unnecessary) colonoscopy with gFOBTs compared to 594 (10 μg Hb/g) and 495 (20 μg Hb/g) with FITs. At a specificity of 90% and 95%, FITs had a higher sensitivity than gFOBTs.

AUTHORS' CONCLUSIONS

FITs are superior to gFOBTs in detecting AN and CRC in average-risk individuals. Specificity of both tests was similar in "reference standard: all" studies, whereas specificity was significantly higher for gFOBTs than FITs in "reference standard: positive" studies. However, at pre-specified specificities, the sensitivity of FITs was significantly higher than gFOBTs.

Colorectal Cancer: A Review of Carcinogenesis, Global Epidemiology, Current Challenges, Risk Factors, Preventive and Treatment Strategies

Colorectal cancer (CRC) is the second most deadly cancer. Global incidence and mortality are likely to be increased in the coming decades. Although the deaths associated with CRC are very high in high-income countries, the incidence and fatalities related to CRC are growing in developing countries too. CRC detected early is entirely curable by surgery and subsequent medications. However, the recurrence rate is high, and cancer drug resistance increases the treatment failure rate. Access to early diagnosis and treatment of CRC for survival is somewhat possible in developed countries. However, these facilities are rarely available in developing countries. Highlighting the current status of CRC, its development, risk factors, and management is crucial in creating public awareness. Therefore, in this review, we have comprehensively discussed the current global epidemiology, drug resistance, challenges, risk factors, and preventive and treatment strategies of CRC. Additionally, there is a brief discussion on the CRC development pathways and recommendations for preventing and treating CRC.

Epidemiology and biology of early onset colorectal cancer

Colorectal cancer (CRC) is the third leading cause of cancer-related mortality in men or women in the United States. Average-risk screening that begins at age 50 years has reduced incidence and mortality of CRC in those over 50 years of age, whereas CRC incidence in those under age 50 years (early onset colorectal cancer (eoCRC)) has recently and dramatically increased. In this review, we summarize the recent literature including risk factors for eoCRC, differences in clinicopathologic presentation and outcomes in eoCRC, and emerging evidence regarding the molecular pathways that are altered in eoCRC compared to later onset CRC (loCRC). Epidemiologic studies of eoCRC show predominance in distal colon and rectum, and association with several modifiable risk factors, including diabetes, obesity, diet, sedentary time, alcohol consumption and smoking. Data regarding potential risk factors of prior antibiotic exposure and microbiome alterations or direct carcinogen exposure are still emerging. Aggressive clinicopathologic features of eoCRC at presentation may be due to delay in diagnosis or more aggressive tumor biology. EoCRC outcomes are similar to loCRC when matched for stage, but overall mortality is greater due to higher frequency of advanced disease at a younger presentation, with more life-years lost. There are only few molecular evaluations of eoCRC to date, with findings of potential increase in TP53 and CTNNB1 somatic mutation and decrease in APC, KRAS and BRAF somatic mutation, compared to loCRC. Other findings include LINE-1 hypomethylation, absence of microsatellite instability (MSI-H), presence of chromosomal instability (CIN) or microsatellite and chromosomal stability (MACS). These studies are only now emerging and have not yet identified a specific molecular signature defining eoCRC. Further research evaluating genetic and molecular differences as well as environmental triggers for eoCRCs should provide a clearer understanding to inform targeted screening for pre-symptomatic at-risk younger individuals.

Causes of gastrointestinal bleeding in oral anticoagulant users compared to non-users in a population-based study

BACKGROUND/AIMS

Causes of gastrointestinal bleeding (GIB) in patients on oral anticoagulants (OACs) are not well established. The aims of the study were to compare the causes of GIB in patients on OACs and those not on OAC therapy.

METHODS

A nationwide study of all GIB events in patients on OACs in Iceland from 2014-2019 was conducted. Bleeding events were obtained through ICD-10 codes and review of endoscopy databases, confirmed by review of medical records. For comparison, patients not on OACs from previous Icelandic population-based studies were used.

RESULTS

Among 752 GIB events in 12,005 patients on OACs, 273 (1.9%) had verified upper and 391 (2.7%) had verified lower GIB. For lower GIB, multivariate analysis showed that OAC users were more likely to have colonic polyps (OR 6.6, 95% CI: 2.4 - 17.8, p < .001) or colorectal cancer (OR 3.7, 95% CI: 2.0 - 7.0, p < .001) but less likely to have ischemic colitis (OR 0.11, 95% CI: 0.04 - 0.26, p < .001). For upper GIB, bleeding from mucosal erosions (OR 4.0 95% CI: 2.5 - 7.9, p < .001) and angiodysplasia (OR 3.6, 95%CI: 1.5 - 8.6, p = .003) were more common in OAC users.

CONCLUSIONS

A high proportion of GIB caused by colonic polyps and colorectal cancer among OAC patients indicates that OACs treatment may facilitate cancer diagnosis. The low proportion of ischemic colitis among those on OACs suggests that OACs provide a protective effect against ischemic colitis. OACs seem to increase the bleeding from angiodysplasia and mucosal erosive disease.

Efficacy and safety of berberine in preventing recurrence of colorectal adenomas: A systematic review and meta-analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Berberine(BBR) is a kind of isoquinoline alkaloids extracted from the rhizomes of Coptis chinensis Franch., which was the main active ingredient. Accumulating evidence has shown that it has potential pharmacological effects in preventing the recurrence of colorectal adenomas.

AIM OF THE STUDY

The roles of BBR in the overall recurrence of colorectal adenoma have still not been assessed because of the limitations of the available data and the restriction of a single study. Therefore, we evaluated the effectiveness and safety of BBR in preventing the recurrence of colorectal adenomas through a systematic review and meta-analysis of available data.

MATERIALS AND METHODS

We searched four English databases (PubMed (MEDLINE), the Cochrane Central Register of Controlled Trials (CENTRAL), Embase and Web of Science) and four Chinese language databases (Chinese Biomedicine (CBM), China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals Database (VIP) and the WanFang Database) from their inception through October 2020. Meta-analysis was performed with RevMan5.3 software after data extraction and the quality of studies assessment.

RESULTS

Three randomized controlled clinical trials were included with 1076 patients. Our results illustrated that 1-year and 2-year supplementation with BBR was associated with lower recurrence rate of colorectal adenoma (RR 0.69, 95% CI 0.57 to 0.84, p=0.0001; RR 0.75, 95% CI 0.64 to 0.88, p=0.0004). The relative risk of oral BBR for 1 year and 2 years is not comparable, for 2-year efficacy outcomes were assessed in all participants who had at least one colonoscopy with pathological evaluation after baseline (lots of participants completed the first colonoscopy but discontinued during the second follow-up interval.). Moreover, the results also suggest that BBR had more adverse events than placebo (RR 2.91, 95% CI 1.24 to 6.85, p=0.01). Through the full-text reading, no serious adverse events were observed, and constipation was the most common event which disappears once the drug is discontinued.

CONCLUSION

Generally, the present study indicated that BBR has a comparable therapeutic effect on the prevention of colorectal adenomas recurrence. Adverse reactions are worthy of attention which requires additional studies to obtain a precise conclusion.

PROSPERO REGISTRATION NO

CRD42020209135.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Updates on Age to Start and Stop Colorectal Cancer Screening: Recommendations From the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Three-decade quantitative evaluation of cancer-related research in Nigeria from 1990-2019

Introduction: There exists a knowledge gap in the quality and quantity of cancer-related research in Nigeria. This review gives a report on cancer research literature indexed in the Web of Science (WoS) in Nigeria from 1990 -2019. Materials and methods: The data used in the present study were published research papers retrieved from the Web of Science. Results: A total of 629 research articles were published within this period across 276 journals. The highest number of articles was published in 2019 (n = 62), while the least was in 1992 (n = 2). However, the last ten years witnessed explosive growth, and it accounted for 63% of the total number of articles. The most relevant authors are Olapade HI (33 articles), Huo D (28 articles), and Ogundiran TO (21 articles). The most relevant sources in the area of cancer research in Nigeria are Nigerian Journal of Clinical Practice (52 articles), East African Medical Journal (23 articles), and African Health Sciences (21 articles). The most relevant author's affiliations are University of Ibadan (n=206), University of Nigeria, Nsukka (n = 115), and Obafemi Awolowo University (n = 105). Conclusion: The results from this study show that Nigerian institutions need to collaborate extensively with foreign institutions and partner with industries in order to improve the quality of their research output.

Updates on age to start and stop colorectal cancer screening: recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer

This document is a focused update to the 2017 colorectal cancer (CRC) screening recommendations from the U.S. Multi-Society Task Force on Colorectal Cancer, which represents the American College of Gastroenterology, the American Gastroenterological Association, and the American Society for Gastrointestinal Endoscopy. This update is restricted to addressing the age to start and stop CRC screening in average-risk individuals and the recommended screening modalities. Although there is no literature demonstrating that CRC screening in individuals under age 50 improves health outcomes such as CRC incidence or CRC-related mortality, sufficient data support the U.S. Multi-Society Task Force to suggest average-risk CRC screening begin at age 45. This recommendation is based on the increasing disease burden among individuals under age 50, emerging data that the prevalence of advanced colorectal neoplasia in individuals ages 45 to 49 approaches rates in individuals 50 to 59, and modeling studies that demonstrate the benefits of screening outweigh the potential harms and costs. For individuals ages 76 to 85, the decision to start or continue screening should be individualized and based on prior screening history, life expectancy, CRC risk, and personal preference. Screening is not recommended after age 85.

Dietary Risk Factors and Odds of Colorectal Adenoma in Malaysia: A Case Control Study

Current evidence suggests that dietary and lifestyle factors may play an important role in colorectal cancer risk but there are only a few studies that investigated their relationship with colorectal adenomas (CRA), the precursors for colorectal cancer. A case-control study was conducted to determine the relationship between dietary and lifestyle factors associated with CRA risk among 125 subjects with CRA and 150 subjects without CRA at Hospital Canselor Tuanku Muhriz UKM (HCTM), Malaysia. We used dietary history questionnaire (DHQ) and International Physical Activity Questionnaire-Short Form (IPAQ) to estimate the diet and physical activity. The findings of this study showed that male gender [OR = 2.71 (95% CI= 1.01-7.27)], smoking [OR = 6.39 (95% CI= 1.04-39.30)], family history of cancer [OR = 6.39 (95% CI= 1.04-39.30)], high body fat percentage [OR = 1.25 (95% CI= 1.04-1.51)], high calorie and fat intake [OR = 1.03 (95% CI= 1.01-1.06)], [OR = 1.01 (95% CI= 0.95-1.09)] and red meat intake more than 100 g per day [OR = 1.02 (95% CI= 1.01-1.04)] increased CRA risk. High fiber [OR = 0.78 (95% CI= 0.64-0.95)] and calcium intake [OR = 0.78 (95% CI= 0.98-1.00)] was found to decrease CRA risk. Some of these modifiable risk factors could be advocated as lifestyle interventions to reduce risk of CRA.

Superiority of fecal carcinoembryonic antigen as diagnosis marker for adenomatous polyposis coli and asymptomatic colorectal cancer

BACKGROUND

Non-invasive diagnostic tools of adenomatous polyposis coli (APC) and asymptomatic colorectal cancer (CRC) are urgently needed. Although fecal carcinoembryonic antigen (FCEA) has been documented in some studies, the diagnostic potential for the detection of APC and asymptomatic CRC has not been described yet.

METHODS

This is a retrospective study. The pre-diagnostic serum carcinoembryonic antigen (SCEA) and fecal occult blood test (FOBT) levels were retrospectively analyzed in 212 patients with intestinal diseases group (IDG) and 224 controls. The levels of FCEA across all the studied groups were measured using electronic chemiluminescence immunoassay (ECLIA), and their sensitivity and specificity were used to evaluate their diagnostic potential. The individual diagnostic accuracy of the three indices, as well as their combined diagnostic potential, was compared using the receiver operating characteristic (ROC) curve and chi-square test.

RESULTS

The FCEA had low sensitivity (50%) and high specificity (93.91%) for the diagnosis of IDG, with the area under the curve (AUC) value of 0.781. The AUC of FCEA was higher than that of SCEA for the diagnosis of APC and CRC in the APC, asymptomatic CRC, and APC + CRC-stage I patients. The AUCs of FCEA were 0.708 and 0.691 for the 'double-negative patients' and 'triple-negative patients', respectively. In addition, FCEA could diagnose 45.5% of the 'double-negative' patients, 43.3% of the asymptomatic patients, and 42.9% of the 'triple-negative' patients. The combination of FCEA and FOBT improved the diagnostic value (AUC = 0.916).

CONCLUSION

FCEA has been demonstrated to be a favorable diagnostic marker in intestinal diseases, especially in the APC, asymptomatic CRC, and 'double-negative' or 'triple-negative' CRC patients.

A realist review protocol of the role and contribution of the advanced nurse practitioner (ANP) in gastroenterology nursing

Background: The role and contribution of advanced nurse practitioners (ANP) has been well researched and found to be of great value for improving quality patient care and enhancing patient outcomes through education and health promotion. However, the role and the contribution of the ANP to gastroenterology nursing have not been evaluated either nationally or internationally. A review to determine the role and contribution of the ANP in gastroenterology nursing will inform on the contribution of the role and whether the role makes a difference to patient outcomes and cost effectiveness of patient care. Objective: This review aims to investigate the nursing role and contribution of the advanced nurse practitioner in gastroenterology. Furthermore, improved understanding of the underlying causal mechanisms explaining how the ANP role in gastroenterology nursing works, will provide a deeper understanding of how, why, for whom and in what contexts the role and contribution of the ANP to gastroenterology nursing are most successful. Methods: A realist review will consolidate evidence on how, when why and where the ANP role in gastroenterology works or fails through identifying programme theories underlying to the role’s introduction. The following steps will be operationalised; locating existing theories, searching the literature, documenting literature selection, engaging in data extraction and synthesis and refining programme theory. As an iterative approach, review cycles will uncover explanatory and contingent theories through context-mechanism-outcome configurations (CMOCc). Due to the variation in context and mechanisms, different outcomes will be likely across different clinical settings although similar patterns may be identified. Conclusions: Due to the theory-oriented approach of realist reviews, the pragmatic consequences of the review, will lend itself to deeper understanding of how the role and contribution of the ANP in gastroenterology nursing works in practice.

A Comprehensive Comparison of Early-Onset and Average-Onset Colorectal Cancers

BACKGROUND

The causative factors for the recent increase in early-onset colorectal cancer (EO-CRC) incidence are unknown. We sought to determine if early-onset disease is clinically or genomically distinct from average-onset colorectal cancer (AO-CRC).

METHODS

Clinical, histopathologic, and genomic characteristics of EO-CRC patients (2014-2019), divided into age 35 years and younger and 36-49 years at diagnosis, were compared with AO-CRC (50 years and older). Patients with mismatch repair deficient tumors, CRC-related hereditary syndromes, and inflammatory bowel disease were excluded from all but the germline analysis. All statistical tests were 2-sided.

RESULTS

In total, 759 patients with EO-CRC (35 years, n = 151; 36-49 years, n = 608) and AO-CRC (n = 687) were included. Left-sided tumors (35 years and younger = 80.8%; 36-49 years = 83.7%; AO = 63.9%; P < .001 for both comparisons), rectal bleeding (35 years and younger = 41.1%; 36-49 years = 41.0%; AO = 25.9%; P = .001 and P < .001, respectively), and abdominal pain (35 years and younger = 37.1%; 36-49 years = 34.0%; AO = 26.8%; P = .01 and P = .005, respectively) were more common in EO-CRC. Among microsatellite stable tumors, we found no differences in histopathologic tumor characteristics. Initially, differences in TP53 and Receptor Tyrosine Kinase signaling pathway (RTK-RAS)alterations were noted by age. However, on multivariate analysis including somatic gene analysis and tumor sidedness, no statistically significant differences at the gene or pathway level were demonstrated. Among advanced microsatellite stable CRCs, chemotherapy response and survival were equivalent by age cohorts. Pathogenic germline variants were identified in 23.3% of patients 35 years and younger vs 14.1% of AO-CRC (P = .01).

CONCLUSIONS

EO-CRCs are more commonly left-sided and present with rectal bleeding and abdominal pain but are otherwise clinically and genomically indistinguishable from AO-CRCs. Aggressive treatment regimens based solely on the age at CRC diagnosis are not warranted.

Targeting the Tumor Extracellular Matrix by the Natural Molecule 4-Methylumbelliferone: A Complementary and Alternative Cancer Therapeutic Strategy

In antineoplastic therapy, one of the challenges is to adjust the treatment to the needs of each patient and reduce the toxicity caused by conventional antitumor strategies. It has been demonstrated that natural products with antitumoral properties are less toxic than chemotherapy and radiotherapy. Also, using already developed drugs allows developing substantially less costly methods for the discovery of new treatments than traditional drug development. Candidate molecules proposed for drug repositioning include 4-methylumbelliferone (4-MU), an orally available dietetic product, derivative of coumarin and mainly found in the plant family Umbelliferae or Apiaceae. 4-MU specifically inhibits the synthesis of glycosaminoglycan hyaluronan (HA), which is its main mechanism of action. This agent reduces the availability of HA substrates and inhibits the activity of different HA synthases. However, an effect independent of HA synthesis has also been observed. 4-MU acts as an inhibitor of tumor growth in different types of cancer. Particularly, 4-MU acts on the proliferation, migration and invasion abilities of tumor cells and inhibits the progression of cancer stem cells and the development of drug resistance. In addition, the effect of 4-MU impacts not only on tumor cells, but also on other components of the tumor microenvironment. Specifically, 4-MU can potentially act on immune, fibroblast and endothelial cells, and pro-tumor processes such as angiogenesis. Most of these effects are consistent with the altered functions of HA during tumor progression and can be interrupted by the action of 4-MU. While the potential advantage of 4-MU as an adjunct in cancer therapy could improve therapeutic efficacy and reduce toxicities of other antitumoral agents, the greatest challenge is the lack of scientific evidence to support its approval. Therefore, crucial human clinical studies have yet to be done to respond to this need. Here, we discuss and review the possible applications of 4-MU as an adjunct in conventional antineoplastic therapies, to achieve greater therapeutic success. We also describe the main proposed mechanisms of action that promote an increase in the efficacy of conventional antineoplastic strategies in different types of cancer and prospects that promote 4-MU repositioning and application in cancer therapy.

Patient-Reported Outcomes and Preferences for Colon Capsule Endoscopy and Colonoscopy: A Systematic Review with Meta-Analysis

Colon capsule endoscopy as an alternative to colonoscopy for the diagnosis of colonic disease may serve as a less invasive and more tolerable investigation for patients. Our aim was to examine patient-reported outcomes for colon capsule endoscopy compared to conventional optical colonoscopy including preference of investigation modality, tolerability and adverse events. A systematic literature search was conducted in Web of Science, PubMed and Embase. Search results were thoroughly screened for in- and exclusion criteria. Included studies underwent assessment of transparency and completeness, after which, data for meta-analysis were extracted. Pooled estimates of patient preference were calculated and heterogeneity was examined including univariate meta-regressions. Patient-reported tolerability and adverse events were reviewed. Out of fourteen included studies, twelve had investigated patient-reported outcomes in patients who had undergone both investigations, whereas in two the patients were randomized between investigations. Pooled patient preferences were estimated to be 52% (CI 95%: 41-63%) for colon capsule endoscopy and 45% (CI 95%: 33-57%) for conventional colonoscopy: not indicating a significant difference. Procedural adverse events were rarely reported by patients for either investigation. The tolerability was high for both colon capsule endoscopy and conventional colonoscopy. Patient preferences for conventional colonoscopy and colon capsule endoscopy were not significantly different. Procedural adverse events were rare and the tolerability for colon capsule endoscopy was consistently reported higher or equal to that of conventional colonoscopy.

Factors Associated With Advanced Colorectal Neoplasia in Patients With CKD

RATIONALE & OBJECTIVE

The risk of developing colorectal cancer in patients with chronic kidney disease (CKD) is twice that of the general population, but the factors associated with colorectal cancer are poorly understood. The aim of this study was to identify factors associated with advanced colorectal neoplasia in patients with CKD.

STUDY DESIGN

Prospective cohort study.

SETTING & PARTICIPANTS

Patients with CKD stages 3-5, including those treated with maintenance dialysis or transplantation across 11 sites in Australia, New Zealand, Canada, and Spain, were screened for colorectal neoplasia using a fecal immunochemical test (FIT) as part of the Detecting Bowel Cancer in CKD (DETECT) Study.

EXPOSURE

Baseline characteristics for patients at the time of study enrollment were ascertained, including duration of CKD, comorbidities, and medications.

OUTCOME

Advanced colorectal neoplasia was identified through a 2-step verification process with colonoscopy following positive FIT and 2-year clinical follow-up for all patients.

ANALYTICAL APPROACH

Potential factors associated with advanced colorectal neoplasia were explored using multivariable logistic regression. Sensitivity analyses were performed using grouped LASSO (least absolute shrinkage and selection operator) logistic regression.

RESULTS

Among 1,706 patients who received FIT-based screening-791 with CKD stages 3-5 not receiving kidney replacement therapy (KRT), 418 receiving dialysis, and 497 patients with a functioning kidney transplant-117 patients (6.9%) were detected to have advanced colorectal neoplasia (54 with CKD stages 3-5 without KRT, 34 receiving dialysis, and 29 transplant recipients), including 9 colorectal cancers. The factors found to be associated with advanced colorectal neoplasia included older age (OR per year older, 1.05 [95% CI, 1.03-1.07], P<0.001), male sex (OR, 2.27 [95% CI, 1.45-3.54], P<0.001), azathioprine use (OR, 2.99 [95% CI, 1.40-6.37], P=0.005), and erythropoiesis-stimulating agent use (OR, 1.92 [95% CI, 1.22-3.03], P=0.005). Grouped LASSO logistic regression revealed similar associations between these factors and advanced colorectal neoplasia.

LIMITATIONS

Unmeasured confounding factors.

CONCLUSIONS

Older age, male sex, erythropoiesis-stimulating agents, and azathioprine were found to be significantly associated with advanced colorectal neoplasia in patients with CKD.

A Pilot Study Investigating the Expression Levels of Pluripotency-Associated Genes in Rectal Swab Samples for Colorectal Polyp and Cancer Diagnosis and Prognosis

Change in gene expression is inevitable in cancer development. With more studies demonstrating the contributions of cancer stem cells (CSCs) in colorectal cancer (CRC) development, this study is aimed at investigating whether rectal swab specimen serves as a tool for detection of dysregulation of CSC or stem cell (SC) markers and at evaluating its potential as a new promising screening method for high-risk patients. Expression levels of 15 pluripotency-associated genes were assessed by quantitative PCR in 53 rectal swab specimens referred for endoscopic screening. Dysregulated genes and joint panels based on such genes were examined for their diagnostic potentials for both polyp and CRC. Out of 15 genes, Oct4, CD26, c-MYC, and CXCR4 showed significantly differential expression among normal, polyp, and CRC patients. A panel of Oct4 and CD26 showed an AUC value of 0.80 (p = 0.003) in identifying CRC patients from polyp/normal subjects, with sensitivity and specificity of 84.6% and 69.2%. A panel of c-MYC and CXCR4 achieved CRC/polyp identification with an AUC value of 0.79 (p = 0.002), with a sensitivity of 82.8% and specificity of 80.0%. The sensitivity for polyp and CRC was 80.0% and 85.7%, respectively. Further analysis showed that higher c-MYC and CXCR4 level was detected in normal subjects who developed polyps after 5-6 years, in comparison with subjects with no lesion developed, and the AUC of the c-MYC and CXCR4 panel increased to 0.88 (p < 0.001), with sensitivity and specificity of 84.4% and 92.3%, respectively, when these patients were included in the polyp group. This study suggests that the Oct4 and CD26 panel is a promising biomarker for distinguishing CRC from normal and polyp patients, whereas the c-MYC and CXCR4 panel may identify polyp and CRC from normal individuals.

Colorectal cancer incidence and mortality: the current status, temporal trends and their attributable risk factors in 60 countries in 2000-2019

BACKGROUND

Globally, colorectal cancer (CRC) imposes a substantial burden on healthcare systems and confers considerable medical expenditures. We aimed to evaluate the global and regional burden in epidemiological trends and factors associated with the incidence and mortality of CRC.

METHODS

We used data from the GLOBOCAN database to estimate CRC incidence and mortality worldwide in 2020 and their association with the human development index (HDI). Trends of age-standardized rates of incidence and mortality in 60 countries (2000-2019) were evaluated by Joinpoint regression analysis using data of Global Burden of Disease 2019. The association between exposure to country-level lifestyle, metabolic and socioeconomic factors obtained from the World Health Organization Global Health Observatory and World Bank DataBank data and CRC incidence and mortality was determined by multivariable linear regression.

RESULTS

CRC incidence and mortality varied greatly in the 60 selected countries, and much higher incidence and mortality were observed in countries with higher HDIs, and vice versa. From 2000 to 2019, significant increases of incidence and mortality were observed for 33 countries (average annual percent changes [AAPCs], 0.24-3.82) and 18 countries (AAPCs, 0.41-2.22), respectively. A stronger increase in incidence was observed among males (AAPCs, 0.36-4.54) and individuals <50 years (AAPCs, 0.56-3.86). Notably, 15 countries showed significant decreases in both incidence (AAPCs, -0.24 to -2.19) and mortality (AAPCs, -0.84 to -2.74). A significant increase of incidence among individuals <50 years was observed in 30 countries (AAPCs, 0.28-3.62). Countries with higher incidence were more likely to have a higher prevalence of alcohol drinking, higher level of cholesterol level, higher level of unemployment, and a poorer healthcare system.

CONCLUSIONS

Some high-HDI countries showed decreasing trends in CRC incidence and mortality, whereas developing countries that previously had low disease burden showed significantly increased incidence and mortality trends, especially in males and populations ≥50 years, which require targeted preventive health programs.

Racial and ethnic disparities in colorectal cancer incidence and mortality

The occurrence of colorectal cancer (CRC) shows a large disparity among recognized races and ethnicities in the U.S., with Black Americans demonstrating the highest incidence and mortality from this disease. Contributors for the observed CRC disparity appear to be multifactorial and consequential that may be initiated by structured societal issues (e.g., low socioeconomic status and lack of adequate health insurance) that facilitate abnormal environmental factors (through use of tobacco and alcohol, and poor diet composition that modifies one's metabolism, microbiome and local immune microenvironment) and trigger cancer-specific immune and genetic changes (e.g., localized inflammation and somatic driver gene mutations). Mitigating the disparity by prevention through CRC screening has been demonstrated; this has not been adequately shown once CRC has developed. Acquiring additional knowledge into the science behind the observed disparity will inform approaches towards abating both the incidence and mortality of CRC between U.S. racial and ethnic groups.

Multidisciplinary prevention and management strategies for colorectal cancer and cardiovascular disease

Colorectal cancer (CRC) and cardiovascular disease (CVD) are leading causes of morbidity and mortality worldwide. Their numerous shared and modifiable risk factors underscore the importance of effective prevention strategies for these largely preventable diseases. Conventionally regarded as separate disease entities, clear pathophysiological links and overlapping risk factors represent an opportunity for synergistic collaborative efforts of oncologists and cardiologists. In addition, current CRC treatment approaches can exert cardiotoxicity and thus increase CVD risk. Given the complex interplay of both diseases and increasing numbers of CRC survivors who are at increased risk for CVD, multidisciplinary cardio-oncological approaches are warranted for optimal patient care from primary prevention to acute disease treatment and long-term surveillance.

Early colorectal cancer detection-Current and evolving challenges in evidence, guidelines, policy, and practices

The understanding at the beginning of the last century that colorectal cancer began as a localized disease that progressed and became systemic, and that most colorectal cancer arose from adenomatous polyps gave rise to aggressive attempts at curative treatment and eventually attempts to detect advanced lesions before they progressed to invasive disease. In the last four decades, steadily greater uptake of screening has led to reductions in colorectal cancer incidence and mortality. However, the fullest potential of screening is not being met due to the lack of organized screening, where a systems approach could lead to higher rates of screening of average and high risk groups, higher quality screening, and prompt followup of adults with positive screening tests. ABSTRACT: Since the beginning of the 20th century, there has been a general understanding that colorectal cancer is a clonal disease that progresses from a localized stage with a favorable prognosis through progressively more advanced stages which have progressively worse prognosis. That understanding led first to determined efforts to detect and treat early stage symptomatic disease, and then to detect pre-symptomatic colorectal cancer and precursor lesions, where there was hope that the natural history of the disease could be arrested and the incidence and premature mortality of colorectal cancer averted. Toward the end of the last century, guidelines for colorectal cancer screening, growth in the number of technical options for screening, and a steady increase in the proportion of the adult population who attended screening contributed to the beginning of a significant decline in colorectal cancer incidence and mortality. Despite this progress, colorectal cancer remains the third leading cause of death among men and women in the United States. Screening for early detection of precursor lesions and localized cancer offers the single most productive opportunity to further reduce the burden of disease, and yet nearly four in five deaths from colorectal cancer are associated with having never been screened, not recently screened, or not followed up for an abnormal screening test. This simple observation is a call to action in all communities to apply existing knowledge to fulfill the potential to prevent avertable incidence and mortality.

Dehydrodiisoeugenol inhibits colorectal cancer growth by endoplasmic reticulum stress-induced autophagic pathways

Background

Dehydrodiisoeugenol (DEH), a novel lignan component extracted from nutmeg, which is the seed of Myristica fragrans Houtt, displays noticeable anti-inflammatory and anti-allergic effects in digestive system diseases. However, the mechanism of its anticancer activity in gastrointestinal cancer remains to be investigated.

Methods

In this study, the anticancer effect of DEH on human colorectal cancer and its underlying mechanism were evaluated. Assays including MTT, EdU, Plate clone formation, Soft agar, Flow cytometry, Electron microscopy, Immunofluorescence and Western blotting were used in vitro. The CDX and PDX tumor xenograft models were used in vivo.

Results

Our findings indicated that treatment with DEH arrested the cell cycle of colorectal cancer cells at the G1/S phase, leading to significant inhibition in cell growth. Moreover, DEH induced strong cellular autophagy, which could be inhibited through autophagic inhibitors, with a rction in the DEH-induced inhibition of cell growth in colorectal cancer cells. Further analysis indicated that DEH also induced endoplasmic reticulum (ER) stress and subsequently stimulated autophagy through the activation of PERK/eIF2α and IRE1α/XBP-1 s/CHOP pathways. Knockdown of PERK or IRE1α significantly decreased DEH-induced autophagy and retrieved cell viability in cells treated with DEH. Furthermore, DEH also exhibited significant anticancer activities in the CDX- and PDX-models.

Conclusions

Collectively, our studies strongly suggest that DEH might be a potential anticancer agent against colorectal cancer by activating ER stress-induced inhibition of autophagy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01915-9.

EndoCuff-Assisted Colonoscopy Versus Standard Colonoscopy in Colonic Polyp Detection-Experience from a Single Tertiary Centre

Background. Standard colonoscopy fails to visualize the entire colon mucosa and consequently a significant amount of polyps are still being missed. New device, such as EndoCuff, have been developed to improve mucosal visualisation, hence the quality in colonoscopy. The aim of this study was to assess the diagnostic yield of EndoCuff-assisted colonoscopy in comparison with standard colonoscopy by taking into consideration several quality indicators. Methods. In this study, 965 adults ≥ 18 years referred for colonoscopy were randomly divided into two groups. The main statistical investigation compared the difference between EndoCuff-assisted colonoscopy (EC) vs. standard colonoscopy (SC) in the detection of colonic polyps and adenoma detection rate (ADR). The second inquiry sought to compare experienced vs. recently trained and female vs. male operators. Results. The ADR was higher for EC than for SC (37.50% vs. 26.64%). Regarding the mean number of detected polyps per procedure (MPP), the result was statistically significant when generally comparing the EC vs. SC (p=0.0009). There were no differences in MPP between EC and SC for recently trained endoscopists (p=0.7446), while a significant difference for experienced doctors (p=0,0020) was noted. A significant difference was observed between female doctors and male doctors only when using SC. EC was more helpful for female doctors when assessing MPP (p=0.0118). No serious adverse events related to EndoCuff-assisted colonoscopy was noted. Conclusions. EndoCuff-assisted colonoscopy seems to be safe and may bring benefits for improving the polyp/adenoma detection rates in regard to missed lesions, usually located in blind areas.

Hypermethylation of SHISA3 DNA as a blood-based biomarker for colorectal cancer

In Taiwan, colorectal cancer (CRC) is the second most common cancer and the cancer with the third highest mortality rate. This may be because of the difficulty of detecting the disease in the early stages, as well as the fact that colonoscopy, a typical method used in screening for CRC, causes discomfort to the recipient and is prone to technical interference. For the earlier detection of CRC, finding an easier screening method with a simpler collection procedure is essential. Thus, in the present study, plasma samples from patients with CRC were analyzed to determine the extent of methylation in SHISA3 DNA. Studies have suggested that SHISA3, a newly identified tumor suppressor, can regulate tumor growth, and that the inactivation of its DNA can be traced to epigenomic alterations in CRC. Another study reported the presence of hypermethylated SHISA3 DNA in CRC biopsy specimens. In the present study, the plasma of 30 patients with CRC and nine healthy controls was collected and analyzed for the concentration of cell-free DNA through bisulfite sequencing. The methylation rates were determined. Our results have shown that an increasing amount of cell-free DNA in the group of CRC patient's plasma compared to the healthy group. Moreover, patients with later stages of CRC had higher concentrations of cell-free DNA. Notably, the methylation rate of SHISA3 was higher in the plasma of the CRC group than in that of the healthy group. The results indicated that the presence of tumor cells does not reduce the degree of SHISA3 DNA in the peripheral blood of patients with CRC. In other words, the hypermethylation of SHISA3, which inactivates the gene, is a potential cause of tumorigenesis. Furthermore, the methylation rate of SHISA3 DNA was higher in the plasma of patients with stage II CRC than in that of those with stage I CRC. In conclusion, the combination of conventional testing and screening for SHISA3 hypermethylation in plasma could improve the rate at which CRC is detected.

Development of a decision aid to support colorectal cancer screening: perspectives of Asians in an endemic urban community-a qualitative research study

BACKGROUND

Colorectal cancer (CRC) is a common malignancy worldwide. Despite being the most common cancer in Singapore, CRC screening rate remains low due to knowledge deficits, social reasons such as inconvenience and a lack of reminder or recommendation. A decision aid (DA) may facilitate an individual's decision-making to undertake CRC screening by addressing misconceptions and barriers. We postulate that a more person-centred and culturally adapted DA will better serve the local population. The views of the target users are thus needed to develop such a DA. A CRC screening DA prototype has been adapted from an American DA to cater to the Asian users. This study aimed to explore user perspectives on an adapted CRC screening DA-prototype in terms of the design, content and perceived utility.

METHODS

The study used in-depth interviews (IDIs) and focus group discussions (FGDs) to gather qualitative data from English-literate multi-ethnic Asian adults aged 50 years old and above. They had yet to screen for CRC before they were recruited from a public primary care clinic in Singapore. The interviews were audio-recorded, transcribed and analysed to identify emergent themes via thematic analysis.

RESULTS

This study included 27 participants involved in 5 IDI and 5 FGDs. Participants found the DA easily comprehensible and of appropriate length. They appreciated information about the options and proposed having multi-lingual DAs. The design, in terms of the layout, size and font, was well-accepted but there were suggestions to digitalize the DA. Participants felt that the visuals were useful but there were concerns about modesty due to the realism of the illustration. They would use the DA for information-sharing with their family and for discussion with their doctor for decision making. They preferred the doctor's recommendation for CRC screening and initiating the use of the DA.

CONCLUSIONS

Participants generally had favourable perceptions of the DA-prototype. A revised DA will be developed based on their feedback. Further input from doctors on the revised DA will be obtained before assessing its effectiveness to increase CRC screening rate in a randomized controlled trial.