Flexible sigmoidoscopy versus faecal occult blood testing for colorectal cancer screening in asymptomatic individuals

Non-participation of asymptomatic candidates in screening protocols reduces early diagnosis and worsens prognosis of colorectal cancer

The Agatsuma et al's study shows that despite the evidence of the benefits of an early colorectal cancer (CRC) diagnosis, through screening in asymptomatic subjects, up to 50% of candidates reject this option and many of those affected are diagnosed later, in advanced stages. The efficacy of screening programs has been well-established for several years, which reduces the risk of CRC morbidity and mortality, without taking into account the test used for screening, or other tools. Nevertheless, a significant proportion of patients remain unscreened, so understanding the factors involved, as well as the barriers of the population to adherence is the first step to possibly modify the participation rate. These barriers could include a full range of social and political aspects, especially the type of financial provision of each health service. In Japan, health services are universal, and this advantageous situation makes it easier for citizens to access to these services, contributing to the detection of various diseases, including CRC. Interestingly, the symptomatic CRC group had a lower early-stage diagnosis rate than the patients detected during follow-up for other comorbidities, and symptomatic and cancer screening groups showed similar early-stage diagnosis.

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.

Is flexible sigmoidoscopy screening associated with reducing colorectal cancer incidence and mortality? a meta-analysis and systematic review

Background

The question of whether flexible sigmoidoscopy (FS) for colorectal cancer (CRC) affects incidence or mortality remains unclear. In this study, we conducted a meta-analysis and systematic review to explore this issue.

Methods

A systematic search of PubMed, EMBASE, and ClinicalTrials.gov was performed for cohort studies (CS), case-control studies, and randomized controlled trials (RCTs) of people who underwent FS and reported mortality or incidence of CRC until 11 December 2022. Relative risk (RR) was applied as an estimate of the effect of interest. To combine the RRs and 95% confidence intervals, a random-effects model was used. The quality of the included studies and evidence was assessed by the Newcastle-Ottawa quality assessment scale, the Jadad scale, and the "Grading of Recommendations Assessment, Development and Evaluation System."

Results

There were a total of six RCTs and one CS, comprising 702,275 individuals. FS was found to be associated with a 26% RR reduction in CRC incidence (RR, 0.74; 95% CI, 0.66-0.84) and a 30% RR reduction in CRC mortality (RR, 0.70; 95% CI, 0.58-0.85). In the incidence subgroup analysis, FS significantly reduced the incidence of CRC compared with non-screening, usual care, and fecal immunochemical testing. Significance was also shown in men, women, distal site, stages III-IV, ages 55-59, and age over 60. In terms of the mortality subgroup analysis, the results were roughly the same as those of incidence.

Conclusion

According to this study, FS might reduce the incidence and mortality of CRC. To confirm this finding, further prospective clinical studies should be conducted based on a larger-scale population.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42023388925.

Colon Cancer Screening Methods: 2023 Update

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. National screening guidelines have been implemented to identify and remove precancerous polyps before they become cancer. Routine CRC screening is advised for people with average risk starting at age 45 because it is a common and preventable malignancy. Various screening modalities are currently in use, ranging from stool-based tests (fecal occult blood test (FOBT), fecal immunochemical test (FIT), and FIT-DNA test), radiologic tests (computed tomographic colonography (CTC), double contrast barium enema), and visual endoscopic examinations (flexible sigmoidoscopy (FS), colonoscopy, and colon capsule endoscopy (CCE)) with their varying sensitivity and specificity. Biomarkers also play a vital role in assessing the recurrence of CRC. This review offers a summary of the current screening options, including biomarkers available to detect CRC, highlighting the benefits and challenges encompassing each screening modality.

A Liquid Biopsy Signature for the Detection of Patients With Early-Onset Colorectal Cancer

BACKGROUND & AIMS

Early-onset colorectal cancer (EOCRC) is a distinct clinical and molecular entity with poor survival outcomes compared with late-onset CRC. Although the incidence of EOCRC is rising, current CRC screening strategies have several limitations in diagnostic performance for EOCRC. In view of this clinical challenge, novel and robust biomarkers for detection of EOCRC are necessary. The aim of this study was to develop a circulating micro RNA (miRNA) signature for the diagnosis of patients with EOCRC.

METHODS

A systematic discovery approach by analyzing a large, publicly available, noncoding RNA expression profiling dataset (GSE115513) was used. A panel of miRNAs was identified, which was subsequently validated in blood samples from patients with EOCRC in 2 independent cohorts (n = 149) compared with controls (n = 110) and pre/postoperative plasma specimens (n = 22) using quantitative reverse-transcription polymerase chain reaction assays.

RESULTS

In the discovery phase, 4 miRNAs were found to be expressed in blood samples. A combination signature of these 4 miRNAs (miR-193a-5p, miR-210, miR-513a-5p, and miR-628-3p) yielded an area under the curve of 0.92 (95% confidence interval, 0.85-0.96) for identification of EOCRC in the training cohort. The miRNA panel performance was then confirmed in an independent validation cohort (area under the curve, 0.88; 95% confidence interval, 0.82-0.93). Moreover, the miRNA panel robustly identified patients with early-stage EOCRC (P < .001). The decreased expression of miRNAs in postsurgery plasma specimens indicated their tumor specificity.

CONCLUSIONS

Our novel miRNA signature for the diagnosis of EOCRC has the potential to identify patients with EOCRC with high accuracy for clinical application in the noninvasive diagnosis of EOCRC.

Brazilian Survey on Preventive Actions for the Population With Access to Primary Healthcare: Inefficient Spending in a Country in Economic Crisis

BACKGROUND

Cancer ranks second as a cause of death in Brazil. Although preventive practices are part of the daily routine of primary healthcare (PHC) teams, organized screening programs are lacking. This study aimed to evaluate the adequacy of preventive interventions in the main cancer types, as defined by the Brazilian government.

METHODS

We analyzed cross-sectional data from a larger project conducted in 2016 with PHC service users and physicians from all over Brazil, interviewed by trained research staff. The sample was stratified by the number of PHC physicians per geographic region, who were eligible for inclusion if they had been working in the same PHC unit for at least one year. Twelve adult patients with at least two encounters were included per participating physician. Only the data from service users were analyzed in this study. We evaluated the questions about preventive practices and calculated the following indicators: coverage, focus, screening errors, and screening ratio. National guidelines and international evidence were used as a comparison parameter.

RESULTS

The study population consisted of 6160 service users. The data indicate that the recommendations for cervical, breast, and prostate cancer screening and for treatment of tobacco dependence are not adequately followed. Coverage for breast and cervical cancer screening presented an overutilization bias, with rates 50% and 9% above the expected, respectively. The screening focus was also inadequate: 24%, 47%, and 54% of the screening tests for the three cancer types were performed in individuals outside the recommended age range. 31% of smokers were not approached for treatment.

CONCLUSION

These findings indicate that the Brazilian population has been subjected to inadequate and potentially iatrogenic interventions in PHC. New policies based on stricter criteria of adequacy and increased use of the concept of quaternary prevention may improve the effectiveness and equity of the health system.

How the COVID-19 pandemic has affected the colorectal cancer screening in Italy: A minireview

The coronavirus disease 2019 (COVID-19) pandemic has caused detrimental effects on many aspects of healthcare practice. Screening programs for the commonest malignancies, namely colorectal cancer (CRC), breast cancer and cervical cancer have been discontinued or interrupted since the beginning of restriction measures aimed to limit transmission of the new coronavirus infection. Robust evidence exists in favour of the role of screening campaigns in reducing mortality from CRC. In fact, the majority of pre-malignant lesions of the colon and rectum can be diagnosed with colonoscopy and treated by endoscopic or surgical resection. Besides, colonoscopy screening allows the diagnosis of CRCs in their pre-clinical stage. Italy was one of the first European countries where a high level of COVID-19 infections and deaths was observed, and one of the first where lockdowns and strict measures were adopted to reduce the risk of COVID-19 diffusion among the population. A systematic review of the literature was performed, including the PubMed, Scopus, Web of Sciences, and Reference Citation Analysis databases, with the aim of critically evaluating the impact of the COVID-19 pandemic on CRC screening in Italy. We found that reduction of CRC screening activity surpassed 50% in most endoscopic units, with almost 600000 fewer CRC screening exams conducted in the first 5 mo of 2020 vs the same period of 2019. While the consequences of the discontinuation of endoscopy screening for the prognosis and mortality of CRC will be evident in the next few years, recent data confirm that CRC is currently treated at a more advanced stage than in the pre-COVID-19 era. Since delays in CRC prevention and early diagnosis may translate to increased CRC-specific mortality, world healthcare systems should adopt strategies to maintain the regularity of CRC screening during subsequent peaks of the COVID-19 pandemic, or future events that might hamper screening programs.

High levels of triglycerides, apolipoprotein B, and the number of colorectal polyps are risk factors for colorectal polyp recurrence after endoscopic resection: a retrospective study

Background

The recurrence of polyps after endoscopic treatment is a difficult problem and there may be an association between blood lipid levels and colorectal polyps, but this is controversial and the aim of this study is to explore the risk factors for colorectal polyp recurrence.

Methods

A total of 357 patients who underwent intestinal polypectomy from January 1, 2019 to June 1, 2020 in Sichuan Provincial People's Hospital were included in this retrospective study to analyze the potential association between blood indices and recurrence risk. Polyp recurrence was defined as the detection of 1 or more polyps at any time after polypectomy, regardless of site. Follow-up was performed through the electronic medical record system. Patients' age, gender, tobacco and alcohol liking, duration of follow-up, body mass index (BMI), polyp size, number, type of pathology, and lipid profiles (triglycerides, cholesterol, apolipoprotein B, and apolipoprotein A) were collected.

Results

Triglycerides (1.54±0.95 vs. 1.25±1.01, P=0.036) and apolipoprotein B (0.87±0.26 vs. 0.79±0.16 mL, P=0.001) were significantly different in both the recurrence and non-recurrence groups. Binary logistic regression identified 3 independent risk factors for recurrence: triglycerides [odds ratio (OR): 1.763, 95% confidence interval (CI): 1.003 to 3.098, P=0.049], apolipoprotein B (OR: 5.438, 95% CI: 1.411 to 20.961, P=0.014), and the number of polyps (OR: 2.540, 95% CI: 1.649 to 3.911, P<0.001).

Conclusions

High levels of triglycerides, apolipoprotein B, and the number of colorectal polyps are risk factors for colorectal polyp recurrence after endoscopic resection. Therefore, for patients at high risk of polyp recurrence, we recommend aggressive control of triglyceride and apolipoprotein B levels.

Findings from the first colorectal cancer screening among 103 542 individuals in Vietnam with systematic review of colorectal cancer screening programs in Asia-Pacific region

BACKGROUND

Colorectal cancer is a leading cancer incidence and cause of death worldwide and in Vietnam. Although screening is considered an effective measure to prevent and control colorectal cancer, there is no such effort in Vietnam.

METHODS

Between 01 January 2018 and 31 October 2019, a population-based colorectal cancer screening program was conducted in Hanoi, Vietnam. A health advocacy campaign and follow-up phone calls were used to enroll residents aged ≥40 years old to complete an immunochemical-fecal occult blood testing. Positive immunochemical-fecal occult blood testing was followed by a colonoscopy. We also conducted a systematic review of the colorectal cancer screening programs in the Asia-Pacific region that used similar approach by searching Ovid Medline and PubMed databases.

RESULTS

During study period, 103 542 individuals among 672 742 eligible residents attended the screening of whom 81.5% participants finished immunochemical-fecal occult blood testing test and the positive rate was 6.1%. The coverage rate for immunochemical-fecal occult blood testing test was 11.9%. Among 2278 individuals who underwent colonoscopy, 3.5% were histologically diagnosed with cancer, 17.8% with advanced adenomas, and 23.1% with non-advanced adenomas. Males had significantly higher detection rate of advanced adenomas, cancer or ≥ two polyps/tumor than females (P < 0.0001). The systematic review showed that in two-step modality (i.e. immunochemical-fecal occult blood testing/fecal immunochemical test and colonoscopy), the test positive was from 4.1 to 10.6%. Once colonoscopy was performed subsequently, the rate of cancer among positive participants was from 1.7 to 16.4% and that of advanced adenomas was from 7.1 to 23.1%.

CONCLUSION

We showed that the two-step modality is a promising strategy for colorectal cancer screening in Vietnam that might apply to similar settings with limited resources.

Trends of Cancer Screenings, Diagnoses, and Mortalities During the COVID-19 Pandemic: Implications and Future Recommendations

Introduction

The impact of the COVID-19 pandemic on cancer screenings and care has yet to be determined. This study aims to investigate the screening, diagnosis, and mortality rates of the top five leading causes of cancer mortality in the United States from 2019 to 2021 to determine the potential impact of the COVID-19 pandemic on cancer care.

Methods

A retrospective cohort study investigating the impact of the COVID-19 pandemic on screening, diagnoses, and mortality rates of the top five leading causes of cancer death (lung/bronchus, colon/rectum, pancreas, breast, and prostate), as determined by the National Institute of Health (NIH) utilizing The United States Healthcare Cost Institute and American Cancer Society databases from 2019 to 2021.

Results

Screenings decreased by 24.98% for colorectal cancer and 16.01% for breast cancer from 2019 to 2020. Compared to 2019, there was a .29% increase in lung/bronchus, 19.72% increase in colorectal, 1.46% increase in pancreatic, 2.89% increase in breast, and 144.50% increase in prostate cancer diagnoses in 2020 (all P < .01). There was an increase in the total number of deaths from colorectal, pancreatic, breast, and prostate cancers from 2019 to 2021.

Conclusion

There was a decrease in the screening rates for breast and colorectal cancer, along with an increase in the estimated incidence and mortality rate among the five leading causes of cancer deaths from 2019 to 2021. The findings suggest that the COVID-19 pandemic is associated with impaired cancer screening, diagnosis, and care, and further emphasizes the need for proactive screening and follow-up to prevent subsequent cancer morbidity and mortality.

The Black Panther, Masculinity Barriers to Medical Care, and Colorectal Cancer Screening Intention Among Unscreened American Indian/Alaska Native, Black, and White Men

Objective

To determine if masculinity barriers to medical care and the death from colorectal cancer (CRC) of actor Chadwick Boseman (The Black Panther) influenced CRC early-detection screening intent among unscreened American Indian/Alaska Native (AIAN) and Non-Hispanic-Black (Black) men compared with Non-Hispanic-White (White) men.

Methods

Using a consumer-panel, we surveyed U.S. men aged 18-75 years (N = 895) using the 24-item Masculinity Barriers to Medical Care (MBMC) scale. We calculated the median score to create binary exposures to evaluate associations with CRC screening intent and conducted multivariable logistic regression to evaluate independent associations stratified by race/ethnicity.

Results

Overall, Black respondents were most likely to have a high MBMC score (55%) compared to White (44%) and AIAN (51%) men (p = 0.043). AIAN men were least likely to report CRC screening intent (51.1%) compared with Black (68%) and White men (64%) (p < 0.001). Black men who reported the recent death of Chadwick Boseman increased their awareness of CRC were more likely (78%) to report intention to screen for CRC compared to those who did not (56%) (p < 0.001). Black men who exhibited more masculinity-related barriers to care were more likely to intend to screen for CRC (OR: 1.76, 95% CI: 0.98-3.16) than their counterparts, as were Black men who reported no impact of Boseman's death on their CRC awareness (aOR: 2.96, 95% CI: 1.13-7.67). Conversely, among AIAN men, those who exhibited more masculinity-related barriers to care were less likely to have CRC screening intent (aOR: 0.47, 95% CI: 0.27-0.82) compared with their counterparts.

Conclusions

Masculinity barriers to medical care play a significant role in intention to screen for CRC. While Black men were most likely to state that The Black Panther's death increased their awareness of CRC, it did not appear to modify the role of masculine barriers in CRC screening intention as expected. Further research is warranted to better understand how masculine barriers combined with celebrity-driven health-promotion interventions influence the uptake of early-detection screening for CRC.

Impact

Our study provides formative data to develop behavioral interventions focused on improving CRC screening completion among diverse men.

Engaging the Community on Colorectal Cancer Screening Education: Focus Group Discussions Among African Americans

Colorectal cancer (CRC) is the third most diagnosed cancer in the USA, and African Americans experience disproportionate CRC diagnosis and mortality. Early detection could reduce CRC incidence and mortality, and reduce CRC health disparities, which may be due in part to lower screening adherence and later stage diagnosis among African Americans compared to whites. Culturally tailored interventions to increase access to and uptake of CRC stool-based tests are one effective strategy to increase benefits of screening among African Americans. The objectives of this study were to obtain feedback from African Americans on CRC educational materials being developed for a subsequent behavioral clinical trial and explore participants' knowledge, attitudes, and beliefs about CRC and CRC screening. Seven focus groups were conducted between February and November 2020. Participants were African Americans recruited through community contacts. Four focus groups were held in-person and three were conducted virtually due to Covid-19 restrictions. Participants ranked CRC educational text messages and provided feedback on a culturally tailored educational brochure. A focus group guide with scripted probes was used to elicit discussion and transcripts were analyzed using traditional content analysis. Forty-two African Americans participated. Four themes were identified from focus group discussions: (1) knowledge, attitudes, and beliefs on CRC and CRC screening; (2) reliable sources of cancer education information; (3) cultural factors affecting perspectives on health; and (4) community insights into cancer education. Participant input on the brochure was incorporated in content creation. Engaging African American community members to qualitatively examine cancer prevention has value in improving implementation strategy and planning for behavioral clinical trials.

Screening for Colorectal Cancer Leading into a New Decade: The "Roaring '20s" for Epigenetic Biomarkers?

Colorectal cancer (CRC) has an important bearing (top five) on cancer incidence and mortality in the world. The etiology of sporadic CRC is related to the accumulation of genetic and epigenetic alterations that result in the appearance of cancer hallmarks such as abnormal proliferation, evasion of immune destruction, resistance to apoptosis, replicative immortality, and others, contributing to cancer promotion, invasion, and metastasis. It is estimated that, each year, at least four million people are diagnosed with CRC in the world. Depending on CRC staging at diagnosis, many of these patients die, as CRC is in the top four causes of cancer death in the world. New and improved screening tests for CRC are needed to detect the disease at an early stage and adopt patient management strategies to decrease the death toll. The three pillars of CRC screening are endoscopy, radiological imaging, and molecular assays. Endoscopic procedures comprise traditional colonoscopy, and more recently, capsule-based endoscopy. The main imaging modality remains Computed Tomography (CT) of the colon. Molecular approaches continue to grow in the diversity of biomarkers and the sophistication of the technologies deployed to detect them. What started with simple fecal occult blood tests has expanded to an armamentarium, including mutation detection and identification of aberrant epigenetic signatures known to be oncogenic. Biomarker-based screening methods have critical advantages and are likely to eclipse the classical modalities of imaging and endoscopy in the future. For example, imaging methods are costly and require highly specialized medical personnel. In the case of endoscopy, their invasiveness limits compliance from large swaths of the population, especially those with average CRC risk. Beyond mere discomfort and fear, there are legitimate iatrogenic concerns associated with endoscopy. The risks of perforation and infection make endoscopy best suited for a confirmatory role in cases where there are positive results from other diagnostic tests. Biomarker-based screening methods are largely non-invasive and are growing in scope. Epigenetic biomarkers, in particular, can be detected in feces and blood, are less invasive to the average-risk patient, detect early-stage CRC, and have a demonstrably superior patient follow-up. Given the heterogeneity of CRC as it evolves, optimal screening may require a battery of blood and stool tests, where each can leverage different pathways perturbed during carcinogenesis. What follows is a comprehensive, systematic review of the literature pertaining to the screening and diagnostic protocols used in CRC. Relevant articles were retrieved from the PubMed database using keywords including: "Screening", "Diagnosis", and "Biomarkers for CRC". American and European clinical trials in progress were included as well.

Socioeconomic Determinants of Participation in Cancer Screening in Argentina: A Cross-Sectional Study

Low socioeconomic status is associated with late cancer diagnosis and mortality in Argentina. It is important that cancer screening services are accessible to the whole population so that cancer can be detected early. Our aim in this study was to investigate socioeconomic determinants for the disparities in the use of breast, cervical, and colorectal cancer screening services in Argentina, and to measure the country progress in reducing differences in cancer screening participation across socioeconomic levels. We performed a secondary analysis of cross-sectional data from the 2018 National Survey of Risk Factors of Argentina. The sample included data from 49,170 households. We also compared the results with data from the 2013 wave of the same survey in order to assess progress on cancer screening participation across income and education categories. Income, education, health insurance, disability, and marital status were associated with cancer screening underuse in Argentina. Comparison between 2013 and 2018 demonstrated that there has been some progress toward increasing cancer screening uptake, but this increase is not equitably distributed across the population. To further reduce disparities in cancer participation across socioeconomic levels, cancer screening programs in Argentina should reinforce strategies to become more accessible. It is important to proactively reach those populations that are underusers of cancer screening and ensure that barriers that stop people from accessing cancer screening are explored and adequately addressed.

Detection of cancers and advanced adenomas in asymptomatic participants in colorectal cancer screening: a cross-sectional study

OBJECTIVES

To assess detection rates for colorectal cancer (CRC) and advanced adenomas in asymptomatic CRC screening participants and bowel symptoms in association with CRC and advanced adenoma.

DESIGN

Cross-sectional study.

SETTING

Two screening centres.

PARTICIPANTS

42 554 men and women, aged 50-74 years, participating in a randomised CRC screening trial. 36 059 participants underwent a sigmoidoscopy (and follow-up colonoscopy if positive sigmoidoscopy) and 6495 underwent a colonoscopy after a positive faecal immunochemical test (FIT).

PRIMARY AND SECONDARY OUTCOME MEASURES

Proportion of asymptomatic participants diagnosed with CRC or advanced adenomas. Prevalence of bowel symptoms (rectal bleeding, change in bowel habits, diarrhoea, constipation, bloating, alternating bowel habits, general symptoms, other bowel symptoms) recorded by the endoscopist and their association with CRC and advanced adenomas.

RESULTS

Among sigmoidoscopy participants, 7336 (20.3%) reported at least one symptom. 120 (60%) out of 200 individuals with screen-detected CRC and 1301 (76.5%) out of 1700 with advanced adenoma were asymptomatic. Rectal bleeding was associated with detection of CRC and advanced adenoma (OR 4.3, 95% CI 3.1 to 6.1 and 1.8, 95% CI 1.5 to 2.1, respectively), while change in bowel habits only with CRC detection (OR 3.8, 95% CI 2.4 to 6.1). Among the FIT positives, 2173 (33.5%) reported at least one symptom. Out of 299 individuals with screen-detected CRC and 1639 with advanced adenoma, 167 (55.9%) and 1 175 (71.7%) were asymptomatic, respectively. Detection of CRC was associated with rectal bleeding (OR 1.8, 95% CI 1.4 to 2.3), change in bowel habits (OR 2.2, 95% CI 1.4 to 3.5) and abdominal pain (OR 1.8, 95% CI 1.2 to 2.7).

CONCLUSIONS

Some bowel symptoms increased the likelihood of being diagnosed with CRC or advanced adenoma. However, the majority of individuals with these findings were asymptomatic. Asymptomatic individuals should be encouraged to participate in CRC screening.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov Identifier: NCT01538550.

Screening Status as a Determinant of Choice of Colorectal Cancer Screening Method: A Population-Based Informed Survey

Objectives

Fecal blood testing is a noninvasive alternative to colonoscopy for colorectal cancer (CRC) screening and is preferred by a substantial proportion of individuals. However, participant-related determinants of the choice of screening method, particularly up-to-date screening status, remain less studied. We aimed to determine if up-to-date screening status was related to choosing a fecal blood test over colonoscopy.

Setting

Participants in the population-based cross-sectional survey study Bus Santé in Geneva, Switzerland - aged 50-69 years.

Design

Cross-sectional survey study using mailed questionnaires inquiring about CRC screening method of choice after providing information on advantages and disadvantages of both screening methods. We used multivariable logistic regression models to determine the association between up-to-date CRC screening status and choosing fecal blood testing.

Key results

We included 1,227 participants. Thirty-eight percent of participants did not have up-to-date CRC screening. Overall, colonoscopy (54.9%) was preferred to fecal blood testing (45.1%) (p < 0.001) as screening method of choice. However, screening method choices differed between those with (65.6% colonoscopy and 34.4% fecal blood testing) and without up-to-date CRC screening (36.5% colonoscopy and 63.5% fecal blood testing). Not having up-to-date CRC screening was associated with a higher probability of choosing fecal blood testing as screening method (odds ratio = 2.6 [1.9; 3.7], p < 0.001) after adjustment for the aforementioned confounders.

Conclusions

Not having up-to-date screening was independently associated with fecal blood testing as the preferred method for CRC screening. Proposing this method to this subpopulation, in a context of shared decision, could potentially increase screening uptake in settings where it is already high.

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.

Incidence and risk factors for preneoplastic and neoplastic lesions of the colon and rectum in patients under 50 referred for colonoscopy

Colorectal cancer (CRC) diagnosed before the age of 50, known as early-onset CRC (eoCRC), is considered uncommon. We aimed at analysing the incidence of preneoplastic and neoplastic lesions of the colon and rectum in patients under 50 years old and to identify possible predictors Methods: We retrospectively collected data from 1778 patients under 50 years old (mean age 39.9±7.8) referred for colonoscopy between 2015-2018. Cumulative incidence of adenomas and eoCRC was assessed. Multivariable regression models were fitted Results: The cumulative incidence for adenomas was 11.0% (95% CI 9-12), while it was 1.5% (95% CI 1-2) for eoCRC (metastatic disease in 13/27 patients). Age as a continuous variable was associated with the presence of adenomas (incidence rate ratio 1.06; 95% CI 1.03-1.09; p<0.001). EoCRC arose in most cases in the rectum (13/27, 48.1%). Age ≥40 was the main risk factor (OR 2.25; 95% CI 1.35-3.73; p=0.002) for both adenomas (160/196 patients, 81.6%) and eoCRC (20/27 patients, 74.1%), while smoking seemed to have no role (p=0.772). The presence of alarm symptoms was statistically significant at bivariable analysis for eoCRC only (OR 3.70; 95% CI 1.49-9.22; p=0.005), as well as having multiple gastrointestinal symptoms (OR 19.85; 95% CI 2.64-149.42; p=0.004). Only 3/27 (11.1%) patients with eoCRC had a family history for CRC Conclusions: A high cumulative incidence rate of both adenomas and eoCRC was found, this latter occurring more common in patients aged 40-49, without apparent risk factors. The presence of alarm symptoms or multiple gastrointestinal symptoms led to a late diagnosis.

Real-Time Polyp Detection, Localization and Segmentation in Colonoscopy Using Deep Learning

Computer-aided detection, localisation, and segmentation methods can help improve colonoscopy procedures. Even though many methods have been built to tackle automatic detection and segmentation of polyps, benchmarking of state-of-the-art methods still remains an open problem. This is due to the increasing number of researched computer vision methods that can be applied to polyp datasets. Benchmarking of novel methods can provide a direction to the development of automated polyp detection and segmentation tasks. Furthermore, it ensures that the produced results in the community are reproducible and provide a fair comparison of developed methods. In this paper, we benchmark several recent state-of-the-art methods using Kvasir-SEG, an open-access dataset of colonoscopy images for polyp detection, localisation, and segmentation evaluating both method accuracy and speed. Whilst, most methods in literature have competitive performance over accuracy, we show that the proposed ColonSegNet achieved a better trade-off between an average precision of 0.8000 and mean IoU of 0.8100, and the fastest speed of 180 frames per second for the detection and localisation task. Likewise, the proposed ColonSegNet achieved a competitive dice coefficient of 0.8206 and the best average speed of 182.38 frames per second for the segmentation task. Our comprehensive comparison with various state-of-the-art methods reveals the importance of benchmarking the deep learning methods for automated real-time polyp identification and delineations that can potentially transform current clinical practices and minimise miss-detection rates.

Melanoma Prevention: Comparison of Different Screening Methods for the Selection of a High Risk Population

Background: Guidelines recommend limiting melanoma screening in a population with known risk factors, but none indicates methods for efficient recruitment. The purpose of this study is to compare three different methods of recruiting subjects to be screened for melanoma to detect which, if any, is the most efficient. Methods: From 2010 to 2019, subjects were recruited as follows: (1) regular skin examinations (RS), mainly conducted through the Associazione Contro il Melanoma network; (2) occasional melanoma screening (OS), during annual public campaigns; (3) and selective screening (SS), where people were invited to undergo a skin check after filling in a risk evaluation questionnaire, in cases where the assigned outcome was intermediate/high risk. Melanoma risk factors were compared across different screening methods. Generalized Linear Mixed Models were used for multivariable analysis. Results: A total of 2238 subjects (62.7% women) were recruited, median age 44 years (2–85), and 1094 (48.9 %) records were collected through RS, 826 (36.9 %) through OS, and 318 (14.2 %) through SS. A total of 131 suspicious non-melanoma skin cancers were clinically diagnosed, 20 pathologically confirmed, and 2 melanomas detected. SS performed significantly better at selecting subjects with a family history of melanoma and I-II phototypes compared to OS. Conclusions: Prior evaluation of melanoma known risk factors allowed for effective selection of a population to screen at higher risk of developing a melanoma.

Adverse events of colonoscopy in a colorectal cancer screening program with fecal immunochemical testing: a population-based observational study

Background and study aims  The aim of this study was to assess adverse events (AEs) associated with colonoscopy in the French colorectal cancer screening program with fecal occult blood test (FOBT). Patients and methods  A retrospective cohort study was performed of all colonoscopies performed from 2015 to 2018 for a positive fecal immunochemical test (FIT) in patients aged 50 to 74 years within the screening program in progress in Alsace, part of the French program. AEs were recorded through prospective voluntary reporting by community gastroenterologists and retrospective postal surveys addressed to individuals screened. They were compared with those recorded in the previous program following colonoscopies performed from 2003 to 2014 for a positive guaiac-based FOBT (gFOBT). Results  Of 9576 colonoscopies performed for a positive FIT, 6194 (64.7 %) were therapeutic. Overall, 180 AEs were recorded (18.8 ‰, 95 % CI 16.1-21.5), 114 of them (11.9 ‰, 95 % CI 9.7-14.1) requiring hospitalization, 55 (5.7‰, 95 % CI 4.2-7.3) hospitalization > 24 hours, and eight (0.8 ‰, 95 % CI 0.3-1.4) surgery. The main complications requiring hospitalization were perforation (n = 18, 1.9 ‰, 95 % CI 1.0-2.7) and bleeding (n = 31, 3.2 ‰, 95 % CI 2.1-4.4). Despite a significant increase in several risk factors for complication, the rate of AEs remained stable between gFOBT and FIT programs. Overall, we observed one death (1/27,000 colonoscopies) and three splenic injuries. Conclusions  The harms of colonoscopy in a colorectal cancer screening program with FIT are more frequent than usually estimated. This study revealed six AEs requiring hospitalization > 24 hours (three bleeds, two perforations), one necessitating surgery, and 50 minor complications per 1000 colonoscopies.

Consequences of screening in colorectal cancer (COS-CRC): development and dimensionality of a questionnaire

BACKGROUND

Harms of colorectal cancer (CRC) screening include psychosocial consequences. We have not identified studies using a participant-relevant questionnaire with adequate measurement properties to investigate these harms. However, Brodersen et al. have previously developed a core questionnaire consequences of screening (COS) for use in screening for life-threatening diseases. Therefore, the objectives were: (1) To investigate content validity of COS in a CRC screening setting and in case of gaps in content coverage (2) generate new items and themes and (3) test the possibly extended version of COS for dimensionality and differential item functioning (DIF) using Rasch Models.

METHODS

We performed two-part-focus-groups with CRC screenees. Screenees were recruited by strategic sampling. In the first part 16 screenees with false-positive results (n = 7) and low-risk polyps (n = 9) were interviewed about their CRC screening experiences and in the second part COS was examined for content validity. When new information was developed in the focus groups, new items covering this topic were generated. Subsequently, new items were, together with COS, tested in the subsequent interviews. A random subsample (n = 410) from a longitudinal questionnaire study, not yet published, was used to form the data for this paper. We analysed multidimensionality and uniform DIF with Andersen's conditional likelihood ratio test. We assessed individual item fit to the model. We also analysed Local Dependence (LD) and DIF by partial gamma coefficients using Rasch Models.

RESULTS

COS was found relevant in a CRC screening setting. However, new information was discovered in the focus groups, covered by 18 new CRC screening-specific items. The Rasch analyses only revealed minor problems in the COS-scales. The 18 new items were distributed on four new CRC screening-specific dimensions and one single item.

CONCLUSION

An extended version of COS specifically for use in a CRC screening setting has been developed. The extended part encompasses four new scales and one new single item. The original COS with the CRC-screening specific extension is called consequences of screening in colorectal cancer (COS-CRC). COS-CRC possessed reliability, unidimensionality and invariant measurement.

[PAPPS Cancer Expert Group. Cancer Prevention Recommendations. 2020 PAPPS update]

El cáncer es una de las principales causas de morbilidad y mortalidad. El consumo de tabaco, la dieta poco saludable, la inactividad física son algunos de los factores de riesgo que forman parte del estilo de vida y que han provocado un aumento del cáncer. En este artículo se actualizan las evidencias y recomendaciones de las estrategias de prevención para cada uno de los cánceres con mayor incidencia, con base en la disminución de los factores de riesgo (prevención primaria) y en el diagnóstico precoz del cáncer, a través del cribado y la detección temprana de los signos y síntomas, en población de riesgo medio y de riesgo elevado.

The Case for High-Quality Colonoscopy Remaining a Premier Colorectal Cancer Screening Strategy in the United States

Most colorectal cancer screening in the United States occurs in the opportunistic setting, where screening is initiated by a patient-provider interaction. Colonoscopy provides the longest-interval protection, and high-quality colonoscopy is ideally suited to the opportunistic setting. Both detection and colonoscopic resection have improved as a result of intense scientific investigation. Further improvements in detection are expected with the introduction of artificial intelligence programs into colonoscopy platforms. We may expect recommended intervals or colonoscopy after negative examinations performed by high-quality detectors to expand beyond 10 years. Thus, high-quality colonoscopy remains an excellent approach to colorectal cancer screening in the opportunistic setting.

Colon Capsule Endoscopy: Indications, Findings, and Complications - Data from a Prospective German Colon Capsule Registry Trial (DEKOR)

Background/Aims

Reliable and especially widely accepted preventive measures are crucial to further reduce the incidence of colorectal cancer (CRC). Colon capsule endoscopy (CCE) might increase the screening numbers among patients unable or unwilling to undergo conventional colonoscopy. This registry trial aimed to document and determine the CCE indications, findings, complications, and adverse events in outpatient practices and clinics throughout Germany.

Methods

Patients undergoing CCE between 2010 and 2015 were enrolled in this prospective multicenter registry trial at six German centers. Patient demographics, outcomes, and complications were evaluated.

Results

A total of 161 patients were included. Of the CCE evaluations, 111 (68.9%) were considered successful. Pathological findings in the colon (n=92, 60.1%) and in the remaining gastrointestinal tract (n=38, 24.8%) were recorded. The main finding was the presence of polyps (n=52, 32.3%). Furthermore, five carcinomas (3.1%) were detected and histologically confirmed later. Adequate bowel cleanliness was more likely to be achieved in the outpatient setting (p<0.0001). Interestingly, 85 patients (55.6%) chose to undergo CCE based on personal motivation.

Conclusions

CCE seems to be a reliable and safe endoscopic tool for screening for CRC and detecting other diseases. Its patient acceptance and feasibility seems to be high, especially in the outpatient setting.

Promoting colorectal cancer screening: a systematic review and meta-analysis of randomised controlled trials of interventions to increase uptake

Colorectal cancer (CRC) represents a global public health concern. CRC screening is associated with significant reductions in CRC incidence and mortality, however, uptake is suboptimal. This systematic review and meta-analysis of randomised controlled trials explored the effectiveness of interventions designed to increase screening uptake, plus the impact of various moderators. Data from 102 studies including 1.94 million participants were analysed. Results showed significant benefit of all interventions combined (OR, 1.49, 95% CI: 1.43, 1.56, p < 0.001). The effects were similar in studies using objective versus self-reported uptake measures and lower in studies judged to be at high risk of bias. Moderator analyses indicated significant effects for aspects of behaviour (effects lower for studies on non-endoscopic procedures), and intervention (effects higher for studies conducted in community settings, in healthcare systems that are not free, and that use reminders, health-professional providers, paper materials supplemented with in-person or phone contact, but avoid remote contact). Interventions that included behaviour change techniques targeting social support (unspecified or practical), instructions or demonstration of the behaviour, and that added objects to the environment produced stronger effects. The way in which findings can inform interventions to improve CRC screening uptake is discussed.

An examination of colorectal cancer burden by socioeconomic status: evidence from GLOBOCAN 2018

AIM AND BACKGROUND

Colon and rectum (colorectal) cancer cause substantial mortality and morbidity worldwide. The management and control of a complex disease such as cancer cannot rely on the old strategy of "one disease one medicine" and must make a transition into new-age practices involving predictive, preventive, and personalized medicine (PPPM) at its core. Adoption of PPPM approach to cancer management at the policy level requires quantification of cancer burden at the country level. For this purpose, we examine the burden of colorectal cancer in 185 countries in 2018. Based on results, we discuss the opportunities presented by PPPM and challenges to be encountered while adopting PPPM for the treatment and prevention of colorectal cancer.

DATA AND METHODS

Age- and sex-wise estimates of colorectal cancer were procured from the GLOBOCAN 2018. The country- and region-wise burden of colorectal cancer in 185 countries was examined using all-age and age-standardized incidence and mortality estimates. Human development index (HDI) was employed as the indicator of socioeconomic status of a country. Mortality-to-incidence ratio (MIR) was employed as the proxy of 5-year survival rate.

RESULTS

Globally, colorectal cancer claimed an estimated 880,792 lives (males 484,224; females 396,568) with 1.85 million new cases (males 1.03 million; females 823,303) were estimated to be diagnosed in 2018. Globally, the age-standardized incidence rate (ASIR) was 19.7/100,000, whereas age-standardized mortality rate (ASMR) recorded to be 16.3/100,000 in 2018. Age-standardized rates were the highest in developed countries led by Hungary with ASIR of 51.2/100,000 followed by South Korea with ASIR of 44.5/100,000. ASMR followed the patterns of ASIR with the highest ASMR recorded by Hungary (21.5 per 100,000) and Slovakia (20.4 per 100,000). Globally, MIR stood at 0.48, and among the countries recording more than 1000 cases, Nepal registered the highest MIR of 0.83 and the lowest was recorded by South Korea (0.27). The age-standardized rates exhibited nonlinear association with HDI, whereas MIR was negatively associated with HDI.

CONCLUSION

Colorectal cancer causes a substantial burden worldwide and exhibit a positive association with the socioeconomic status. With the aid of improving screening modalities, preventable nature of the disease (due to dietary and lifestyle risk factors) and improving treatment procedures, the burden of CRC can largely be curtailed. The high burden of CRC in developing countries, therefore, calls for effective prevention strategies, cost-effective screening, and early-stage detection, cost-effective predictive, and personalized treatment regime.

Comparison of Systematic Video Documentation With Narrative Operative Report in Colorectal Cancer Surgery

Importance

Despite ongoing advances in the field of colorectal surgery, the quality of surgical treatment is still variable. As an intrinsic part of surgical quality, the technical information regarding the surgical procedure is reflected only by the narrative operative report (NR), which has been found to be subjective and regularly omits important information.

Objective

To investigate systematic video recording (SVR) as a potential improvement in quality and safety with regard to important information in colorectal cancer surgery.

Design, Setting, and Participants

The Imaging for Quality Control Trial was a prospective, observational cohort study conducted between January 12, 2016, and October 30, 2017, at 3 centers in the Netherlands. The study group consisted of 113 patients 18 years or older undergoing elective laparoscopic surgery for colorectal cancer. These patients were case matched and compared with cases from a historical cohort that received only an NR.

Interventions

Among study cases, participating surgeons were requested to systematically capture predefined key steps of the surgical procedure intraoperatively on video in short clips.

Main Outcomes and Measures

The SVRs and NRs were analyzed for adequacy with respect to the availability of important information regarding the predefined key steps. Adequacy of the reported information was defined as the proportion of key steps with available and sufficient information in the report. Adequacy of the SVR and NR was compared between the study and control groups, with the SVR alone and as an adjunct to the NR in the study group vs NR alone in the control group.

Results

Of the 113 study patients, 69 women (61.1%) were included; mean (SD) age was 66.3 (9.8) years. In the control group, a mean (SD) of 52.5% (18.3%) of 631 steps were adequately described in the NR. In the study group, the adequacy of both the SVR (78.5% [16.5%], P < .001) and a combination of the SVR with NR (85.1% [14.6%], P < .001) was significantly superior to NR alone. The only significant difference between the study and historical control groups regarding postoperative and pathologic outcomes was a shorter postoperative mean (SD) length of stay in favor of the study group (8.0 [7.7] vs 8.6 [6.8] days; P = .03).

Conclusions and Relevance

Use of SVR in laparoscopic colorectal cancer surgery as an adjunct to the NR might be superior in documenting important steps of the operation compared with NR alone, adding to the overall availability of necessary intraoperative information and contributing to quality control and objectivity.

Consensus statement of the Italian society of colorectal surgery (SICCR): management and treatment of hemorrhoidal disease

Hemorrhoidal disease (HD) is the most common proctological disease in the Western countries. However, its real prevalence is underestimated due to the frequent self-medication.The aim of this consensus statement is to provide evidence-based data to allow an individualized and appropriate management and treatment of HD. The strategy used to search for evidence was based on application of electronic sources such as MEDLINE, PubMed, Cochrane Review Library, CINAHL, and EMBASE.These guidelines are inclusive and not prescriptive.The recommendations were defined and graded based on the current levels of evidence and in accordance with the criteria adopted by American College of Chest Physicians. The recommendations were graded A, B, and C.

Socioeconomic determinants of cancer screening utilisation in Latin America: A systematic review

INTRODUCTION

Cancer incidence and mortality in Latin America are rising. While effective cancer screening services, accessible to the whole population and enabling early cancer detection are needed, existing research shows the existence of disparities in screening uptake in the region.

OBJECTIVE

We conducted a systematic review to investigate the socioeconomic determinants for the disparities in the use of breast, cervical and colorectal cancer screening services in Latin America.

METHODS

We searched for studies reporting on socioeconomic determinants impacting on access to breast, cervical and colorectal cancer screening, published from 2009 through 2018. The studies that qualified for inclusion contained original analyses on utilisation of breast, cervical and colorectal cancer screening across socioeconomic levels in Latin America. For each study, paired reviewers performed a quality analysis followed by detailed review and data extraction.

RESULTS

Twenty-four articles that met the eligibility criteria and were of sufficient quality were included in this review. Thirteen of the included articles were written in English, eight in Portuguese and three in Spanish, and they reported on the use of breast or cervical cancer screening. No studies were found on the socioeconomic determinants regarding the utilisation of colorectal cancer screening in Latin America. Low income, low education level, lack of health insurance and single marital status were all found to be determinants of underuse of breast and cervical cancer screening services.

CONCLUSIONS

Cancer screening programs in the region must prioritize reaching those populations that underuse cancer screening services to ensure equitable access to preventive services. It is important to develop national screening programmes that are accessible to all (including uninsured people) through, for example, the use of mobile units for mammography and self-screening methods.

How confident are medical students about making clinical decisions relying on the evidence? A cross-sectional questionnaire study

Objective: Giving information and providing advice on diagnostic tests is one of the tasks physicians must carry out personally. To do so, they must evaluate the evidence and integrate their findings into everyday practice. Clinical decisions should be based on evidence. How well current medical education prepares for such evidence-based clinical decision-making is largely unclear. Therefore, it was examined how confident medical students are in clinical decision-making based on evidence using epidemiological data. It was examined whether the decision-making confidence increases the higher the semester. Further questions were whether scientifically active medical students show higher decision-making confidence and whether the representation of figures as pictograms rather than tables positively influences the decision-making confidence. Methods: An online survey of the medical students of the Friedrich-Alexander-University Erlangen-Nürnberg was carried out. Respondents were presented with three clinical decision-making situations in random order for evaluation in the form of screening scenarios. In each case, the decision-making confidence also had to be specified. The scenarios contained only epidemiological data on existing screening tests. For each scenario, the numbers were presented as a table or a pictogram in a random fashion. In order to avoid false confidence resulting from preconceived opinions neither the illnesses nor the screening tests were mentioned by name. Results: Answers from 171 students were evaluated. Decision-making confidence in dealing with the numbers does not increase in higher semesters (r_Pearson =0.018, p=0.41). Scientific work is not associated with a higher decision-making confidence (t(169)=-1.26, p=0.11, d=-0.19). Presentation as a pictogram leads to a higher decision-making confidence compared to tables (Pictogram: M=2.33, SD=1.07, Table with numbers: M=2.64, SD=1.11, t(511)=3.21, p<0.01, d=0.28). Conclusions: Medical students from higher semesters show no higher decision-making confidence compared to medical students from lower semesters. Curricular events and scientific work, such as a doctoral thesis, do not seem to strengthen the required skills sufficiently. If evidence is presented in the form of pictograms, this seems to improve student confidence in decision-making.

High-Intensity Versus Low-Intensity Surveillance for Patients With Colorectal Adenomas: A Cost-Effectiveness Analysis

BACKGROUND

Surveillance of patients with colorectal adenomas has limited long-term evidence to support current practice.

OBJECTIVE

To compare the lifetime benefits and costs of high- versus low-intensity surveillance.

DESIGN

Microsimulation model.

DATA SOURCES

U.S. cancer registry, cost data, and published literature.

TARGET POPULATION

U.S. patients aged 50, 60, or 70 years with low-risk adenomas (LRAs) (1 to 2 small adenomas) or high-risk adenomas (HRAs) (3 to 10 small adenomas or ≥1 large adenoma) removed after screening with colonoscopy or fecal immunochemical testing (FIT).

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

No further screening or surveillance, routine screening after 10 years, low-intensity surveillance (10 years after LRA removal and 5 years after HRA removal), and high-intensity surveillance (5 years after LRA removal and 3 years after HRA removal).

OUTCOME MEASURES

Colorectal cancer (CRC) incidence and incremental cost-effectiveness.

RESULTS OF BASE-CASE ANALYSIS

Without surveillance or screening, lifetime CRC incidence for patients aged 50 years was 10.9% after LRA removal and 17.2% after HRA removal at screening colonoscopy. Subsequent colonoscopic screening, low-intensity surveillance, or high-intensity surveillance decreased incidence by 39%, 46% to 48%, and 55% to 56%, respectively. Incidence of CRC and surveillance benefits were higher for adenomas detected at FIT screening and lower for older patients. High-intensity surveillance cost less than $30 000 per quality-adjusted life-year (QALY) gained compared with low-intensity surveillance.

RESULTS OF SENSITIVITY ANALYSIS

High-intensity surveillance cost less than $100 000 per QALY gained in most alternative scenarios for adenoma recurrence, CRC incidence, longevity, quality of life, screening ages, surveillance ages, test performance, disutilities, and cost.

LIMITATION

Few surveillance outcome data exist.

CONCLUSION

The model suggests that high-intensity surveillance as recommended in the United States provides modest but clinically relevant benefits over low-intensity surveillance at acceptable cost.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Colorectal cancer screening with faecal testing, sigmoidoscopy or colonoscopy: a systematic review and network meta-analysis

OBJECTIVE

Evaluate effectiveness, harms and burdens of faecal blood testing, sigmoidoscopy and colonoscopy screening for colorectal cancer over 15 years.

DESIGN

We performed an update of a Cochrane systematic review, and performed network meta-analysis comparing randomised trials evaluating colorectal cancer screening with guaiac faecal occult blood test (gFOBT) (annual, biennial), faecal immunochemical test (FIT) (annual, biennial), sigmoidoscopy (once-only) or colonoscopy (once-only) in a healthy population, aged 50-79 years. We conducted subgroup analysis on sex. Follow-up >5 years was required for analysis of colorectal cancer incidence and mortality.

RESULTS

12 randomised trials proved eligible. Compared with no-screening, we found high certainty evidence for sigmoidoscopy screening slightly reducing colorectal cancer incidence (relative risk (RR) 0.76; 95% confidence interval (CI 0.70 to 0.83) and mortality (RR 0.74; 95% CI 0.69 to 0.80), while gFOBT screening had little or no difference on colorectal cancer incidence, but slightly reduced colorectal cancer mortality (annual: RR 0.69; 95% CI 0.56 to 0.86, biennial: RR 0.88; 95% CI 0.82 to 0.93). No screening test reduced mortality nor incidence by more than six per 1000 screened over 15 years. Sigmoidoscopy had a greater effect in men, for both colorectal cancer incidence (women: RR 0.86; 95% CI 0.81 to 0.92, men: RR 0.75, 95% CI 0.71 to 0.79), and mortality (women: RR 0.85; 95% CI 0.71 to 0.96, men: RR 0.67; 95% CI 0.61 to 0.75) (moderate certainty).

CONCLUSIONS

In a 15-year perspective, sigmoidoscopy reduces colorectal cancer incidence, while sigmoidoscopy, annual and biennial gFOBT all reduce colorectal cancer mortality. Sigmoidoscopy may reduce colorectal cancer incidence and mortality more in men than in women.

PROSPERO REGISTRATION NUMBER

CRD42018093401.

Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: a microsimulation modelling study

OBJECTIVE

To estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk.

DESIGN

Microsimulation modelling study using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon).

SETTING

A parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures.

POPULATION

Norwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%).

COMPARISONS

Four screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence.

MAIN OUTCOME MEASURES

Colorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach.

RESULTS

Over 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates.

CONCLUSIONS

Over a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.

Risk Prediction Models for Colorectal Cancer Incorporating Common Genetic Variants: A Systematic Review

Colorectal cancer screening reduces colorectal cancer incidence and mortality. Risk models based on phenotypic variables have relatively good discrimination in external validation and may improve efficiency of screening. Models incorporating genetic variables may perform better. In this review, we updated our previous review by searching Medline and EMBASE from the end date of that review (January 2014) to February 2019 to identify models incorporating at least one SNP and applicable to asymptomatic individuals in the general population. We identified 23 new models, giving a total of 29. Of those in which the SNP selection was on the basis of published genome-wide association studies, in external or split-sample validation the AUROC was 0.56 to 0.57 for models that included SNPs alone, 0.61 to 0.63 for SNPs in combination with other risk factors, and 0.56 to 0.70 when age was included. Calibration was only reported for four. The addition of SNPs to other risk factors increases discrimination by 0.01 to 0.06. Public health modeling studies suggest that, if determined by risk models, the range of starting ages for screening would be several years greater than using family history alone. Further validation and calibration studies are needed alongside modeling studies to assess the population-level impact of introducing genetic risk-based screening programs.

Colorectal cancer screening from 45 years of age: Thesis, antithesis and synthesis

Colorectal cancer incidence and mortality in patients younger than 50 years are increasing, but screening before the age of 50 is not offered in Europe. Advanced-stage diagnosis and mortality from colorectal cancer before 50 years of age are increasing. This is not a detection-bias effect; it is a real issue affecting the entire population. Three independent computational models indicate that screening from 45 years of age would yield a better balance of benefits and risks than the current start at 50 years of age. Experimental data support these predictions in a sex- and race-independent manner. Earlier screening is seemingly affordable, with minimal impediments to providing younger adults with colonoscopy. Indeed, the American Cancer Society has already started to recommend screening from 45 years of age in the United States. Implementing early screening is a societal and public health problem. The three independent computational models that suggested earlier screening were criticized for assuming perfect compliance. Guidelines and recommendations should be derived from well-collected and reproducible data, and not from mathematical predictions. In the era of personalized medicine, screening decisions might not be based solely on age, and sophisticated prediction software may better guide screening. Moreover, early screening might divert resources away from older individuals with greater biological risks. Finally, it is still unknown whether early colorectal cancer is part of a continuum of disease or a biologically distinct disease and, as such, it might not benefit from screening at all. The increase in early-onset colorectal cancer incidence and mortality demonstrates an obligation to take actions. Earlier screening would save lives, and starting at the age of 45 years may be a robust screening option.

Psychosocial consequences of receiving false-positive colorectal cancer screening results: a qualitative study

Objective: The objective of this study was to investigate the psychosocial consequences of receiving false-positive colorectal cancer (CRC) screening results, following a positive immunochemical faecal occult blood test. Design, setting, and subjects: We conducted a qualitative study with four semi-structured focus group interviews with 16 participants aged 50-74, all of whom had received a false-positive result in the national Danish CRC screening programme. We selected, recruited, and grouped participants to ensure maximum variation, and to enable a level of confidence to speak openly about experiences of screening. We subjected interview data, audio-recordings, and transcripts to a strategy of qualitative analysis called systematic text condensation. Results: We identified four main themes which described the psychosocial consequences of false-positive CRC screening results: anxiety; discomfort; changed self-perception and behaviour; and considerations on participation in screening. Each of these themes covered a wide range of experiences which were relevant to the informants and broadly shared by them in many aspects. Conclusions: Receiving false-positive results from CRC screening can lead to negative psychosocial consequences such as changes in self-perception and anxiety: some participants may experience subsequent relief, others not. These negative psychosocial consequences might persist over time. Implications: Negative psychosocial consequences from false-positive CRC screening results may result in a greater use of general practitioner services by healthy people who need reassurance or further tests. More research using condition-specific measures is required to further understand the degree and potential persistence of psychosocial consequences of false-positive results from CRC screening. Key Points Participants who receive false-positive colorectal cancer (CRC) screening results may experience negative psychosocial consequences e.g. anxiety and subsequent relief. Participants who receive false-positive CRC screening results may experience discomfort during the screening process. Participants who receive false-positive CRC screening results may experience longer term changes of self-perception. Participants who receive false-positive CRC screening results may experience ambivalence about the offered diagnostic down-stream procedures including colonoscopy.

Comparison of prognostic models to predict the occurrence of colorectal cancer in asymptomatic individuals: a systematic literature review and external validation in the EPIC and UK Biobank prospective cohort studies

OBJECTIVE

To systematically identify and validate published colorectal cancer risk prediction models that do not require invasive testing in two large population-based prospective cohorts.

DESIGN

Models were identified through an update of a published systematic review and validated in the European Prospective Investigation into Cancer and Nutrition (EPIC) and the UK Biobank. The performance of the models to predict the occurrence of colorectal cancer within 5 or 10 years after study enrolment was assessed by discrimination (C-statistic) and calibration (plots of observed vs predicted probability).

RESULTS

The systematic review and its update identified 16 models from 8 publications (8 colorectal, 5 colon and 3 rectal). The number of participants included in each model validation ranged from 41 587 to 396 515, and the number of cases ranged from 115 to 1781. Eligible and ineligible participants across the models were largely comparable. Calibration of the models, where assessable, was very good and further improved by recalibration. The C-statistics of the models were largely similar between validation cohorts with the highest values achieved being 0.70 (95% CI 0.68 to 0.72) in the UK Biobank and 0.71 (95% CI 0.67 to 0.74) in EPIC.

CONCLUSION

Several of these non-invasive models exhibited good calibration and discrimination within both external validation populations and are therefore potentially suitable candidates for the facilitation of risk stratification in population-based colorectal screening programmes. Future work should both evaluate this potential, through modelling and impact studies, and ascertain if further enhancement in their performance can be obtained.

Colorectal cancer screening by colonoscopy and trends in disease-specific mortality: a population-based ecological study of 358 German districts

PURPOSE

Screening for colorectal cancer (CRC) by colonoscopy was implemented in Germany in 2002. Although the procedure has proven to be effective in reducing disease-specific mortality in numerous clinical studies, its effect at the population level is unclear. We performed an ecological study at the level of 358 German districts, testing the hypothesis that a higher participation rate in screening colonoscopy is associated with a stronger decline in CRC mortality from 2001 to 2012.

METHODS

Information on the use of colonoscopy in each district was extracted from settlement data, used for the remuneration of physicians of the ambulant sector from 2008 to 2011. Yearly mortality rates for each district from 2001 to 2012 were derived from the official mortality statistics. A spatial model was fitted, considering other factors which might influence early detection of CRC (fecal occult blood test (FOBT), diagnostic colonoscopy, material and social area deprivation, and rural-urban disparities).

RESULTS

The population-weighted mean annual participation rate during 2008-2011 in screening colonoscopy was 2.0% (range 0.6 to 3.9%). The weighted mean annual percentage change (APC) of CRC mortality was - 2.9% (range - 7.8 to 1.2%). According to the fully adjusted model, a 1% higher annual participation rate in colonoscopy screening was associated with an additional annual change in CRC mortality rate of - 0.34% (p = 0.015). Given an annual 2.0% participation rate, colonoscopy screening attributed 23% to the observed decline.

CONCLUSIONS

Our real-world data from Germany provide first evidence that colonoscopy screening for CRC is effective in reducing disease-specific mortality at the population level.

Fecal immunochemical test in cancer screening - colonoscopy outcome in FIT positives and negatives

Objectives: Fecal immunochemical test (FIT) is used in colorectal cancer (CRC) screening, but evaluations of multiple sample strategies in colonoscopy screening cohorts are rare. The aim of this study was to assess accuracy of FIT for advanced neoplasia (AN) with two fecal samples in a colonoscopy screening cohort. Materials and methods: The study comprised 1155 participants of the colonoscopy arm in SCREESCO (Screening of Swedish Colons, NCT02078804), a randomized controlled study on CRC screening of 60-year-olds from the Swedish average-risk population. Participants provided two FIT samples prior to colonoscopy. First sample, mean of two, and any of the two samples above cut off level were assessed. Colonoscopy findings (CRC, advanced adenoma (AA), AN (CRC + AA) and adenoma characteristics) were evaluated in uni- and multivariable analysis in relation to FIT positivity (at ≥10 µg hemoglobin (Hb)/g). Results: Of 1155 invited, 806 (416 women, 390 men) participated. CRC, AA and non-AA were found in one (0.1%), 80 (9.9%) and 145 (18%), respectively. Sensitivity and specificity for AN were 20%/93%, 25%/92% and 26%/89% for first, mean of two and any of the two samples respectively at cut off level 10 µg/g, corresponding to 60 (74%)-65 (80%) participants with missed AN. The difference in sensitivity between screening strategies was non-significant. The specificity for first sample was significantly higher than for any of the two samples at cut off 10 µg/g (p = .02) and 20 µg/g (p = .04). FIT positivity in participants with adenoma was associated with pedunculated shape (p = .007) and high-risk dysplasia (p = .009). Conclusions: In an average-risk colonoscopy screening cohort of 60-year-olds, sensitivity for AN was modest and did not increase when using two samples instead of one. FIT predominantly detected adenomas with pedunculated shape and high-risk dysplasia, and participants with flat or broad based adenomas may thus be missed in screening.

Effect of once-only flexible sigmoidoscopy screening on the outcomes of subsequent faecal occult blood test screening

OBJECTIVE

To investigate the outcomes of biennial guaiac faecal occult blood test (gFOBT) screening after once-only flexible sigmoidoscopy (FS) screening.

METHODS

Between 1994 and 1999, as part of the UK FS Screening Trial (UKFSST), adults aged 55-64 were randomly allocated to an intervention group (offered FS screening) or a control group (not contacted). From 2006, a subset of UKFSST participants (20,895/44,041 intervention group; 41,497/87,149 control group) were invited to biennial gFOBT screening by the English Bowel Cancer Screening Programme. We analysed gFOBT uptake, test positivity, yield of colorectal cancer (CRC), and positive predictive value (PPV) for CRC, advanced adenomas (AAs), and advanced colorectal neoplasia (ACN: AA/CRC).

RESULTS

Uptake of gFOBT at first invitation was 1.9% lower (65.7% vs. 67.6%, p < 0.01) among intervention versus control group participants. Positivity was 0.4% lower (2.0% vs. 2.4%, p < 0.01) and CRC yield was 0.08% lower (0.19% vs. 0.27%, p = 0.14). PPVs were also lower in the intervention versus control group, at 10.3% vs. 12.3% ( p = 0.44) for CRC, 22.7% vs. 31.4% ( p < 0.01) for AA, and 33.0% vs. 43.7% ( p < 0.01) for ACN. Among those who refused FS ( n = 5532), gFOBT uptake at first invitation was 47.7%, CRC yield was 0.25%, and PPV for ACN was 46.2%. Among FS attenders ( n = 15,363), uptake was 72.2%, CRC yield was 0.18%, and PPV for ACN was 27.9%.

CONCLUSIONS

Uptake, positivity and PPV of gFOBT screening were reduced following prior offer of FS screening. However, a quarter of FS screened participants receiving a diagnostic examination after positive gFOBT were diagnosed with ACN.

General health checks in adults for reducing morbidity and mortality from disease

BACKGROUND

General health checks are common elements of health care in some countries. They aim to detect disease and risk factors for disease with the purpose of reducing morbidity and mortality. Most of the commonly used individual screening tests offered in general health checks have been incompletely studied. Also, screening leads to increased use of diagnostic and therapeutic interventions, which can be harmful as well as beneficial. It is therefore important to assess whether general health checks do more good than harm. This is the first update of the review published in 2012.

OBJECTIVES

To quantify the benefits and harms of general health checks.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, two other databases and two trials registers on 31 January 2018. Two review authors independently screened titles and abstracts, assessed papers for eligibility and read reference lists. One review author used citation tracking (Web of Knowledge) and asked trial authors about additional studies.

SELECTION CRITERIA

We included randomised trials comparing health checks with no health checks in adults unselected for disease or risk factors. We did not include geriatric trials. We defined health checks as screening for more than one disease or risk factor in more than one organ system.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data and assessed the risk of bias in the trials. We contacted trial authors for additional outcomes or trial details when necessary. When possible, we analysed the results with a random-effects model meta-analysis; otherwise, we did a narrative synthesis.

MAIN RESULTS

We included 17 trials, 15 of which reported outcome data (251,891 participants). Risk of bias was generally low for our primary outcomes. Health checks have little or no effect on total mortality (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.97 to 1.03; 11 trials; 233,298 participants and 21,535 deaths; high-certainty evidence, I² = 0%), or cancer mortality (RR 1.01, 95% CI 0.92 to 1.12; 8 trials; 139,290 participants and 3663 deaths; high-certainty evidence, I² = 33%), and probably have little or no effect on cardiovascular mortality (RR 1.05, 95% CI 0.94 to 1.16; 9 trials; 170,227 participants and 6237 deaths; moderate-certainty evidence; I² = 65%). Health checks have little or no effect on fatal and non-fatal ischaemic heart disease (RR 0.98, 95% CI 0.94 to 1.03; 4 trials; 164,881 persons, 10,325 events; high-certainty evidence; I² = 11%), and probably have little or no effect on fatal and non-fatal stroke (RR 1.05 95% CI 0.95 to 1.17; 3 trials; 107,421 persons, 4543 events; moderate-certainty evidence, I² = 53%).

AUTHORS' CONCLUSIONS

General health checks are unlikely to be beneficial.

Early-onset colorectal cancer in young individuals

Treatment of young adults with colorectal cancer (CRC) represents an unmet clinical need, especially as diagnosis in this population might lead to the greatest loss of years of life. Since 1994, CRC incidence in individuals younger than 50 years has been increasing by 2% per year. The surge in CRC incidence in young adults is particularly alarming as the overall CRC frequency has been decreasing. Early-onset CRC are characterized by a more advanced stage at diagnosis, poorer cell differentiation, higher prevalence of signet ring cell histology, and left colon-sided location of the primary tumor. Among EO-CRC, approximately 30% of patients are affected by tumors harboring mutations causing hereditary cancer predisposing syndromes, and 20% have familial CRC. Most notably, the remaining 50% of EO-CRC patients have neither hereditary syndromes nor familial CRC, thus representing a formidable challenge for research. In this review article we summarize epidemiology, clinical and molecular features, heredity and outcome of treatments of EO-CRC, and provide considerations for future perspectives.

Sex differences in faecal occult blood test screening for colorectal cancer

Background

This analysis of patients in a randomized population‐based health services study was done to determine the effects of faecal occult blood test (FOBT) screening of colorectal cancer (CRC) in outcomes beyond mortality, and to obtain explanations for potential sex differences in screening effectiveness.

Methods

In the Finnish FOBT screening programme (2004–2011), people aged 60–69 years were randomized into the screening and control arms. Differences in incidence, symptoms, tumour location, TNM categories, non‐vital outcomes and survival in the screening and control arms were analysed.

Results

From 321 311 individuals randomized, 743 patients with screening‐detected tumours and 617 control patients with CRC were analysed. CRC was less common in women than in men (0·34 versus 0·50 per cent; risk ratio (RR) 0·82, 95 per cent c.i. 0·74 to 0·91) and women were less often asymptomatic (16·7 versus 22·0 per cent; RR 0·76, 0·61 to 0·93). Women more often had right‐sided tumours (32·0 versus 21·3 per cent; RR 1·51, 1·26 to 1·80). Among men with left‐sided tumours, those in the screening arm had lower N (RR 1·23, 1·02 to 1·48) and M (RR 1·57, 1·14 to 2·17) categories, as well as a higher overall survival rate than those in the control arm. Furthermore among men with left‐sided tumours, non‐radical resections (26·2 versus 15·7 per cent; RR 1·67, 1·22 to 2·30) and postoperative chemotherapy sessions (61·6 versus 48·2 per cent; RR 1·28, 1·10 to 1·48) were more frequent in the control arm. Similar benefits of screening were not detected in men with right‐sided tumours or in women.

Conclusion

Biennial FOBT screening seems to be effective in terms of improving several different outcomes in men, but not in women. Differences in incidence, symptoms and tumour location may explain the differences in screening efficacy between sexes.

Only of benefit in men

Modeling in Colorectal Cancer Screening: Assessing External and Predictive Validity of MISCAN-Colon Microsimulation Model Using NORCCAP Trial Results

BACKGROUND

Microsimulation models are increasingly being used to inform colorectal cancer (CRC) screening recommendations. MISCAN-Colon is an example of such a model, used to inform the Dutch CRC screening program and US Preventive Services Task Force guidelines. Assessing the validity of these models is essential to provide transparency regarding their performance. In this study, we tested the external and predictive validity of MISCAN-Colon.

METHODS

We validated MISCAN-Colon using the Norwegian Colorectal Cancer Prevention (NORCCAP) trial, a randomized controlled trial that examined the effectiveness of once-only flexible sigmoidoscopy (FS) screening. We simulated the study population and design of the NORCCAP trial in MISCAN-Colon and compared 10- to 12-year model-predicted hazard ratios (HRs) for overall and distal CRC incidence and mortality to those observed. In addition, we compared the numbers of screen-detected neoplasia. Finally, we predicted the trial's future results to allow for the assessment of predictive validity.

RESULTS

MISCAN-Colon predicted an HR for overall CRC incidence (0.85), distal CRC incidence (0.82), overall CRC mortality (0.68), and distal CRC mortality (0.62). These were within the limits of the 95% confidence intervals of the NORCCAP trial results. Similar results were observed for the number of screen-detected cancers. The model significantly underestimated the number of screen-detected adenomas. Model-predicted HRs for CRC incidence and mortality up to 15- to 17-year follow-up were 0.84 and 0.72, respectively.

CONCLUSION

Although the underestimation of screen-detected adenomas requires further investigation, MISCAN-Colon is able to make a valid replication of the CRC incidence and mortality reduction of an FS screening trial, which suggests that it can be considered a useful tool to support decision making on CRC screening.

Valuing Healthcare Improvement: Implicit Norms, Explicit Normativity, and Human Agency

I argue that greater attention to human agency and normativity in both researching and practicing service improvement may be one strategy for enhancing improvement science, illustrating with examples from cancer screening. Improvement science tends to deliberately avoid explicit normativity, for paradigmatically coherent reasons. But there are good reasons to consider including explicit normativity in thinking about improvement. Values and moral judgements are central to social life, so an adequate account of social life must include these elements. And improvement itself is unavoidably normative: it assumes that things could and should be better than they are. I seek to show that normativity will always be implicated in the creation of evidence, the design of programs, the practice of healthcare, and in citizens' judgements about that care, and to make a case that engaging with this normativity is worthwhile.

Why do some participants in colorectal cancer screening choose not to undergo colonoscopy following a positive test result? A qualitative study

OBJECTIVE

Our aim was to investigate why participants opted out of colonoscopy following a positive screening result for colorectal cancer.

DESIGN

Semi-structured, qualitative, single interviews. We audio-recorded and transcribed all interviews verbatim and used Strauss and Corbin's concept of open, axial, and selective coding to identify the main categories shared across all interviews. These formed the basis of our findings.

SETTING

A Danish national colorectal cancer screening programme.

SUBJECTS

Single interviews with 13 participants who declined to have a colonoscopy.

MAIN OUTCOME MEASURES

Reasons to decline colonoscopy after positive screening test.

RESULTS

Participants gave 42 different reasons for deciding not to have a colonoscopy and we coded them into nine main categories; Practical barriers, Discomfort of the examination, Personal integrity, Multimorbidity, Feeling healthy, Not having the energy, Belief that cancer is not present, Risk of complications, and Distrust in the accuracy of the iFOBT.

CONCLUSIONS

Our findings suggest that some practical barriers could be quite easily addressed, by offering the participants alternative management and procdures.

IMPLICATIONS

Further research is needed to examine how widely our findings are represented in the general population, and how general practitioners should consult with patients who have opted out of colonoscopy, despite a positive screening result. Key points   Some screening participants are reluctant to proceed with further diagnostic tests for colorectal cancer following a positive screening result.   • Interviews with people, who had refused a follow-up colonoscopy, discovered nine categories (42 reasons) of reasons for refusal.   • Reluctance can be addressed by offering support with pre-procedure preparations and alternatives to colonoscopy.   • General practitioners face ethical dilemmas and challenges, when patients at risk of colorectal cancer decline to proceed with screening.

Colon cancer screening with CT colonography: logistics, cost-effectiveness, efficiency and progress

Colorectal cancer (CRC) incidence and mortality can be significantly reduced by population screening. Several different screening methods are currently in use, and this review focuses specifically on the imaging technique computed tomographic colonography (CTC). The challenges and logistics of CTC screening, as well as the importance of test accuracy, uptake, quality assurance and cost-effectiveness will be discussed. With comparable advanced adenoma detection rates to colonoscopy (the most commonly used whole-colon investigation), CTC is a less-invasive alternative, requiring less laxative, and with the potential benefit that it permits assessment of extra colonic structures. Three large-scale European trials have contributed valuable evidence supporting the use of CTC in population screening, and highlight the importance of selecting appropriate clinical management pathways based on initial CTC findings. Future research into CTC-screening will likely focus on radiologist training and CTC quality assurance, with identification of evidence-based key performance indicators that are associated with clinically-relevant outcomes such as the incidence of post-test interval cancers (CRC occurring after a presumed negative CTC). In comparison to other CRC screening techniques, CTC offers a safe and accurate option that is particularly useful when colonoscopy is contraindicated. Forthcoming cost-effectiveness analyses which evaluate referral thresholds, the impact of extra-colonic findings and real-world uptake will provide useful information regarding the feasibility of future CTC population screening.