The NordICC Study: rationale and design of a randomized trial on colonoscopy screening for colorectal cancer

Optimal timing of a colonoscopy screening schedule depends on adenoma detection, adenoma risk, adherence to screening and the screening objective: A microsimulation study

Colonoscopy-based screening provides protection against colorectal cancer (CRC), but the optimal starting age and time intervals of screening colonoscopies are unknown. We aimed to determine an optimal screening schedule for the US population and its dependencies on the objective of screening (life years gained or incidence, mortality, or cost reduction) and the setting in which screening is performed. We used our established open-source microsimulation model CMOST to calculate optimized colonoscopy schedules with one, two, three or four screening colonoscopies between 20 and 90 years of age. A single screening colonoscopy was most effective in reducing life years lost from CRC when performed at 55 years of age. Two, three and four screening colonoscopy schedules saved a maximum number of life years when performed between 49-64 years; 44-69 years; and 40-72 years; respectively. However, for maximum incidence and mortality reduction, screening colonoscopies needed to be scheduled 4-8 years later in life. The optimum was also influenced by adenoma detection efficiency with lower values for these parameters favoring a later starting age of screening. Low adherence to screening consistently favored a later start and an earlier end of screening. In a personalized approach, optimal screening would start earlier for high-risk patients and later for low-risk individuals. In conclusion, our microsimulation-based approach supports colonoscopy screening schedule between 45 and 75 years of age but the precise timing depends on the objective of screening, as well as assumptions regarding individual CRC risk, efficiency of adenoma detection during colonoscopy and adherence to screening.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening

INTRODUCTION

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data.

METHODS

The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial.

RESULTS

Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon.

DISCUSSION

Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

Colorectal Cancer Screening and Iron Deficiency Anemia

In the United States, colorectal cancer has the fourth highest amount of annual new cancer cases per year between 2014 and 2018. In this article, the authors review the data and guidelines supporting effective direct visualization and stool-based testing methods of colon cancer screening along with work-up and management of Iron Deficiency Anemia.

A Review of Colonoscopy in Intestinal Diseases

Since the development of the fiberoptic colonoscope in the late 1960s, colonoscopy has been a useful tool to diagnose and treat various intestinal diseases. This article reviews the clinical use of colonoscopy for various intestinal diseases based on present and future perspectives. Intestinal diseases include infectious diseases, inflammatory bowel disease (IBD), neoplasms, functional bowel disorders, and others. In cases of infectious diseases, colonoscopy is helpful in making the differential diagnosis, revealing endoscopic gross findings, and obtaining the specimens for pathology. Additionally, colonoscopy provides clues for distinguishing between infectious disease and IBD, and aids in the post-treatment monitoring of IBD. Colonoscopy is essential for the diagnosis of neoplasms that are diagnosed through only pathological confirmation. At present, malignant tumors are commonly being treated using endoscopy because of the advancement of endoscopic resection procedures. Moreover, the characteristics of tumors can be described in more detail by image-enhanced endoscopy and magnifying endoscopy. Colonoscopy can be helpful for the endoscopic decompression of colonic volvulus in large bowel obstruction, balloon dilatation as a treatment for benign stricture, and colon stenting as a treatment for malignant obstruction. In the diagnosis of functional bowel disorder, colonoscopy is used to investigate other organic causes of the symptom.

Effect of Colonoscopy Screening on Risks of Colorectal Cancer and Related Death

BACKGROUND

Although colonoscopy is widely used as a screening test to detect colorectal cancer, its effect on the risks of colorectal cancer and related death is unclear.

METHODS

We performed a pragmatic, randomized trial involving presumptively healthy men and women 55 to 64 years of age drawn from population registries in Poland, Norway, Sweden, and the Netherlands between 2009 and 2014. The participants were randomly assigned in a 1:2 ratio either to receive an invitation to undergo a single screening colonoscopy (the invited group) or to receive no invitation or screening (the usual-care group). The primary end points were the risks of colorectal cancer and related death, and the secondary end point was death from any cause.

RESULTS

Follow-up data were available for 84,585 participants in Poland, Norway, and Sweden - 28,220 in the invited group, 11,843 of whom (42.0%) underwent screening, and 56,365 in the usual-care group. A total of 15 participants had major bleeding after polyp removal. No perforations or screening-related deaths occurred within 30 days after colonoscopy. During a median follow-up of 10 years, 259 cases of colorectal cancer were diagnosed in the invited group as compared with 622 cases in the usual-care group. In intention-to-screen analyses, the risk of colorectal cancer at 10 years was 0.98% in the invited group and 1.20% in the usual-care group, a risk reduction of 18% (risk ratio, 0.82; 95% confidence interval [CI], 0.70 to 0.93). The risk of death from colorectal cancer was 0.28% in the invited group and 0.31% in the usual-care group (risk ratio, 0.90; 95% CI, 0.64 to 1.16). The number needed to invite to undergo screening to prevent one case of colorectal cancer was 455 (95% CI, 270 to 1429). The risk of death from any cause was 11.03% in the invited group and 11.04% in the usual-care group (risk ratio, 0.99; 95% CI, 0.96 to 1.04).

CONCLUSIONS

In this randomized trial, the risk of colorectal cancer at 10 years was lower among participants who were invited to undergo screening colonoscopy than among those who were assigned to no screening. (Funded by the Research Council of Norway and others; NordICC ClinicalTrials.gov number, NCT00883792.).

Clinical Effectiveness of Faecal Immunochemical Test in the Early Detection of Colorectal Cancer-An Umbrella Review

Introduction: The colorectal cancer prognosis depends on the stage of the neoplasm; therefore, its early detection plays an important role. The aim of the study is evaluation of the sensitivity, specificity, and clinical effectiveness of the faecal immunochemical test in the early colorectal cancer detection. Methods: The clinical analysis was based on the results of the studies included in a systematic review conducted in accordance with the Cochrane Collaboration guidelines. The following medical information sources were searched: Medline (via PubMed), Embase (via Ovid), The Cochrane Library. Results: From 241 citations, 13 studies were included in this review. All included studies had a low risk of bias. The faecal immunochemical test is highly specific in all analysed populations ranging from 85% to 97%. In most of the found studies, sensitivity is over 75%. The faecal immunochemical test screening also determines a reduction in death (10-59%) due to colorectal cancer. Conclusions: The faecal immunochemical test is an effective and cost-effective method of conducting population-wide colorectal cancer screening. It is an alternative or complementary to other screening tests, including colonoscopy.

Favorable Survival After Screening for Young-Onset Colorectal Cancer: Benefits of Screening in Young Adults

BACKGROUND

The increasing incidence and mortality of young-onset colorectal cancer has drawn increasing attention. However, screening for young adults is controversial given the limited evidence regarding its effectiveness.

OBJECTIVE

We aimed to clarify the characteristics of young-onset colorectal cancer and to compare long-term outcomes of screening-detected colorectal cancer and non-screening-detected colorectal cancer.

DESIGN

This was a retrospective cohort study.

SETTING

This study evaluated data from a colorectal cancer registry and medical records at a tertiary Japanese cancer center.

PATIENTS

All patients with colorectal cancer who were registered at a Japanese tertiary cancer center between January 2007 and December 2016 were included.

MAIN OUTCOME MEASURES

The colorectal cancer cases were categorized as screening-detected colorectal cancer and non-screening-detected colorectal cancer, and patients were categorized into 3 age groups: <50 years (young-onset), 50 to 75 years, and >75 years. The baseline characteristics and survival outcomes of the groups were compared using Cox regression models.

RESULTS

A total of 4345 patients were identified, with a median follow-up of 4.6 years. Relative to 50- to 75-year-old individuals, young-onset colorectal cancer was linked to a higher proportion of rectal cancer (50.4% vs 43.3%), a lower proportion of screening-detected colorectal cancer (29.4% vs 35.8%), a lower proportion of stage I colorectal cancer (15.2% vs 30.3%), and a higher proportion of stage III to IV colorectal cancer (64.0% vs 49.4%). Among patients who were <50 years old, screening-detected colorectal cancer was associated with a 50% lower risk of mortality relative to non-screening-detected colorectal cancer (HR, 0.50; 95% CI, 0.26-0.95).

LIMITATIONS

The findings were limited by the retrospective analysis from a single center.

CONCLUSIONS

Young-onset colorectal cancer was more likely to present at an advanced stage and had a lower rate of screening-detected colorectal cancer. Nevertheless, young-onset screening-detected colorectal cancer was associated with better overall survival than non-screening-detected colorectal cancer. See Video Abstract at http://links.lww.com/DCR/B829 .

SUPERVIVENCIA FAVORABLE DESPUS DEL CRIBADO DEL CNCER COLORRECTAL EN PACIENTE JOVEN BENEFICIOS DEL CRIBADO EN ADULTOS JVENES

ANTECEDENTES:La creciente incidencia y mortalidad del cáncer colorrectal en paciente joven ha atraído una atención cada vez mayor. Sin embargo, el cribado para adultos jóvenes es controvertido, dado la evidencia limitada con respecto a su efectividad.OBJETIVO:Nuestro objetivo fue identificar las características del cáncer colorrectal en paciente joven y comparar los resultados a largo plazo del cáncer colorrectal detectado por cribado y el cáncer colorrectal no detectado por cribado.DISEÑO:Este fue un estudio de cohorte retrospectivo.ESCENARIO:Este estudio evaluó datos de un registro de cáncer colorrectal y registros médicos en un centro oncológico terciario japonés.PACIENTES:Se incluyeron todos los pacientes con cáncer colorrectal registrados en un centro oncológico terciario japonés entre enero de 2007 y diciembre de 2016.PRINCIPALES MEDIDAS DE RESULTADO:Los casos de cáncer colorrectal se categorizaron como cáncer colorrectal detectado mediante cribado y cáncer colorrectal no detectado mediante cribado, y los pacientes se clasificaron en tres grupos de edad: <50 años (joven), 50-75 años y >75 años. Las características basales y los resultados de supervivencia de los grupos se compararon mediante modelos de regresión de Cox.RESULTADOS:Se identificaron un total de 4345 pacientes, con una mediana de seguimiento de 4,6 años. En relación con las personas de 50 a 75 años, el cáncer colorrectal de inicio en la juventud se relacionó con una mayor proporción de cáncer de recto (50,4% frente a 43,3%), una menor proporción de cáncer colorrectal detectado mediante exámenes de cribado (29,4% frente a 35,8%), una menor proporción de cáncer colorrectal en estadio I (15,2% frente a 30,3%) y una mayor proporción de cáncer colorrectal en estadio III-IV (64,0% frente a 49,4%). Entre los pacientes menores de 50 años, el cáncer colorrectal detectado mediante cribado se asoció con un 50% menos de riesgo de mortalidad, en comparación con el cáncer colorrectal no detectado mediante cribado (HR: 0,50; IC 95%: 0,26-0,95).LIMITACIONES:Los hallazgos fueron limitados por el análisis retrospectivo de un solo centro.CONCLUSIONES:El cáncer colorrectal en paciente joven presenta más probabilidades de presentarse en una etapa avanzada y con una tasa más baja de detección mediante cribado. No obstante, el cáncer colorrectal detectado por cribado de aparición temprana se asoció con una mejor supervivencia general que el cáncer colorrectal no detectado por cribado. Consulte Video Resumen en http://links.lww.com/DCR/B829 . (Traducción-Dr. Felipe Bellolio ).

Incidence, mortality, survival, risk factor and screening of colorectal cancer: A comparison among China, Europe, and northern America

Colorectal cancer (CRC) is one of the most common malignancies worldwide. China, Europe and northern America account for more than half of the new CRC cases and associated deaths globally. This review summarizes the current status and temporal trends of CRC in China, Europe, and northern America. The potential primary preventive strategies and latest advances in CRC screening techniques and programs are discussed. Recently, the incidence and mortality of CRC in some European and northern American countries have decreased; conversely, CRC incidence and mortality continue to increase in China. The overall 5-year relative survival rate for CRC is similar between these regions, but there is considerable heterogeneity among European countries. Implementing population-based CRC screening programs can effectively address the growing disease burden. The effectiveness of nationwide CRC screening programs in these regions has been limited by relatively low coverage and participation rate. The deployment of state-of-the-art techniques and precise risk-adapted screening strategies incorporating effective risk prediction models and screening techniques may boost screening effectiveness. Our review provides novel foundations for the development and optimization of CRC preventive strategies.

Age-Specific Rates and Time-Courses of Gastrointestinal and Nongastrointestinal Complications Associated With Screening/Surveillance Colonoscopy

INTRODUCTION

The rates of serious cardiac, neurologic, and pulmonary events attributable to colonoscopy are poorly characterized, and background event rates are usually not accounted for.

METHODS

We performed a multistate population-based study using changepoint analysis to determine the rates and timing of serious gastrointestinal and nongastrointestinal adverse events associated with screening/surveillance colonoscopy, including analyses by age (45 to <55, 55 to <65, 65 to <75, and ≥75 years). Among 4.5 million persons in the Ambulatory Surgery and Services Databases of California, Florida, and New York who underwent screening/surveillance colonoscopy in 2005-2015, we ascertained serious postcolonoscopy events in excess of background rates in Emergency Department (SEDD) and Inpatient Databases (SID).

RESULTS

Most serious nongastrointestinal postcolonoscopy events were expected based on the background rate and not associated with colonoscopy itself. However, associated nongastrointestinal events predominated over gastrointestinal events at ages ≥65 years, including more myocardial infarctions plus ischemic strokes than perforations at ages ≥75 years (361 [95% confidence intervals {CI} 312-419] plus 1,279 [95% CI 1,182-1,384] vs 912 [95% CI 831-1,002] per million). At all ages, the observed-to-expected ratios for days 0-7, 0-30, and 0-60 after colonoscopy were substantially >1 for gastrointestinal bleeding and perforation, but minimally >1 for most nongastrointestinal complications. Risk periods ranged from 1 to 125 days depending on complication type and age. No excess postcolonoscopy in-hospital deaths were observed.

DISCUSSION

Although crude counts substantially overestimate nongastrointestinal events associated with colonoscopy, nongastrointestinal complications exceed bleeding and perforation risk in older persons. The inability to ascertain modifications to antiplatelet therapy was a study limitation. Our results can inform benefit-to-risk determinations for preventive colonoscopy.

Incidence and Mortality of Proximal and Distal Colorectal Cancer in Germany

BACKGROUND

The use of colonoscopy has increased and colorectal cancer (CRC) incidence has decreased after the introduction of screening colonoscopy in Germany. However, it remains unknown to what extent progress has been achieved in the prevention of cancer in the proximal colon, distal colon, and rectum.

METHODS

We analyzed trends in CRC incidence (2000-2016) and mortality (2000-2018) in Germany by sex, age, and tumor location.

RESULTS

The age-standardized incidence of CRC declined by 22.4% (from 65.3 to 50.7 per 100 000) in men and by 25.5% (from 42.7 to 31.8 per 100 000) in women. CRC mortality declined by 35.8% (from 29.6 to 19.0 per 100 000) in men and by 40.5% (19.0 to 11.3 per 100 000) in women. Despite demographic changes, the annual numbers of CRC cases and deaths still decreased from about 60 400 to 58 300 and from around 28 700 to 24 200, respectively. The decline in incidence was greatest in groups aged ≥ 55 years. While the incidence of cancer in the distal colon and rectum decreased by 34.5% and 26.2%, respectively, in men and by 41.0% and 27.9% in women, the incidence of proximal colon cancer remained stable in men and decreased by only 7.0% in women. However, a major shift towards earlier stages was observed for the proximal cancers.

CONCLUSION

The results support the assumption that the increased use of colo - noscopy has contributed to substantial reductions in the incidence of distal CRC incidence and the mortality from cancers in the entire colon and rectum.

Determinants of colorectal cancer screening in Germany: a claims data analysis

With an incidence of 58,000 cases per year, colorectal cancer (CRC) is the third most common type of cancer in Germany. Although guaiac-based fecal occult blood tests (gFOBT) and colonoscopy are accepted strategies for CRC screening offered for individuals aged 50 or 55 onwards, utilization rates remain low.This study examines various determinants for participation in CRC screening using claims data provided by the AOK Niedersachsen and covering the years 2014 to 2016. Using multivariate logistic regression models, we analyzed sociodemographic factors (sex, age, nationality, type of employment) associated with screening behavior, including individuals who underwent colonoscopy or gFOBT. The effect of school education and professional qualification was estimated using subgroups of employees with social insurance.The analysis consisted of 620,977 insured individuals in the study population for screening colonoscopy, while the gFOBT study population contained 845,191 individuals. With increasing age, individuals were less likely to participate in CRC screening. Participation rates for screening were higher for women than men in younger age groups. However, men in higher age groups showed increased participation rates in gFOBT screening. When compared with German citizens, Turkish citizens use the colonoscopy less often and the gFOBT more often. In contrast to employees with social insurance, unemployed individuals accept the prevention services less frequently, whereas pensioners and voluntarily insured individuals exhibit increased participation rates. In terms of education and professional qualification, we estimated a significantly lower participation rate exclusively for the least educated individuals. The results help to better understand patterns of utilization and can contribute to the development of information programs for specific groups.

Population-based organized screening by faecal immunochemical testing and colorectal cancer mortality: a natural experiment

BACKGROUND

Population-based organized screening programmes for colorectal cancer (CRC) are underway worldwide, with many based on the faecal immunochemical test (FIT). No clinical trials assessing FIT compared with no screening are planned, and few studies have assessed the population impact of such programmes.

METHODS

Before 2010, 11 out of 50 Spanish provinces initiated population-based organized screening programmes with FIT for an average-risk population aged 50-69 years. We used a quasi-experimental design across Spanish provinces between 1999 and 2016 to evaluate their impact on population age-standardized mortality and incidence rates due to CRC. Difference-in-differences and synthetic control analyses were performed to test for validation of statistical assumptions and to assess the dynamics of screening-associated changes in outcomes over time.

RESULTS

No differences in outcome trends between exposed (n = 11) and control (n = 36) provinces were observed for up to 7 years preceding the implementation of screening. Relative to controls, exposed provinces experienced a mean increase in age-standardized incidence of 10.08% [95% confidence interval (CI) (5.09, 15.07)] 2 years after implementation, followed by a reduction in age-standardized mortality rates due to CRC of 8.82% [95% CI (3.77, 13.86)] after 7 years. Results were similar for both women and men. No associated changes were observed in adjacent age bands not targeted by screening, nor for 10 other major causes of death in the exposed provinces.

CONCLUSIONS

FIT-based organized screening in Spain was associated with reductions in population colorectal cancer mortality. Further research is warranted in order to assess the replicability and external validity of our findings, and on gender-specific use of FIT in organized screening.

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.

Strong Reduction of Colorectal Cancer Incidence and Mortality After Screening Colonoscopy: Prospective Cohort Study From Germany

INTRODUCTION

A claimed advantage of colonoscopy over sigmoidoscopy in colorectal cancer (CRC) screening is prevention of CRC not only in the distal colon and rectum but also in the proximal colon. We aimed to assess the association of screening colonoscopy use with overall and site-specific CRC incidence and associated mortality.

METHODS

Information on use of screening colonoscopy as well as potential confounding factors was obtained at baseline in 2000-2002, updated at 2-, 5-, 8-, and 17-year follow-up from 9,207 participants aged 50-75 years without history of CRC in a statewide cohort study in Saarland, Germany. Covariate-adjusted associations of screening colonoscopy with CRC incidence and mortality, which were obtained through record linkage with the Saarland Cancer Registry and mortality statistics up to 2018, were assessed by Cox proportional hazards models with time-varying exposure information.

RESULTS

During a median follow-up of 17.2 years, 268 participants were diagnosed with CRC and 98 died from CRC. Screening colonoscopy was associated with strongly reduced CRC incidence (adjusted hazard ratio [aHR] 0.44, 95% confidence interval [CI] 0.33-0.57) and mortality (aHR 0.34, 95% CI 0.21-0.53), with stronger reduction for distal (aHRs 0.36, 95% CI 0.25-0.51, and 0.33, 95% CI 0.19-0.59, respectively) than for proximal cancer (aHRs 0.69, 95% CI 0.42-1.13, and 0.62, 95% CI 0.26-1.45, respectively). Nevertheless, strong reduction of mortality from proximal cancer was also observed within 10 years after screening colonoscopy (aHR 0.31, 95% CI 0.10-0.96).

DISCUSSION

In this large prospective cohort study from Germany, screening colonoscopy was associated with strong reduction in CRC incidence and mortality.

Colonoscopy screening and surveillance guidelines

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

Colonoscopy Versus Fecal Immunochemical Test for Reducing Colorectal Cancer Risk: A Population-Based Case-Control Study

INTRODUCTION

Use of colonoscopy or the fecal immunochemical test (FIT) for colorectal cancer (CRC) prevention is supported by previous studies. However, there is little specific evidence regarding comparative effectiveness of colonoscopy or FIT for reducing CRC risk. In this study, we compared the association of CRC risk with colonoscopy and FIT using a nationwide database.

METHODS

This population-based case-control study used colonoscopy and FIT claims data from the Korean National Health Insurance System from 2002 to 2013. Data were analyzed from 61,221 patients with newly diagnosed CRC (case group) and 306,099 individuals without CRC (control group). Multivariable logistic regression models were used to evaluate the association between CRC and colonoscopy or FIT.

RESULTS

Colonoscopy was associated with a reduced subsequent CRC risk (adjusted odds ratio [OR] 0.29). Stronger associations were found between colonoscopy and distal CRC, compared with proximal CRC (0.24 vs 0.47). In an analysis stratified by sex, the association was weaker in female subjects compared with male subjects (0.33 vs 0.27). Any FIT exposure was associated with CRC risk with an OR of 0.74; this association was stronger for distal cancer. As the frequency of cumulative FIT assessments increased (from 1 to ≥5), the OR of FIT exposure for CRC gradually decreased from 0.81 to 0.45.

DISCUSSION

The association of colonoscopy or FIT with reduced CRC risk was stronger for distal CRC than for proximal CRC. FIT showed less CRC risk reduction than colonoscopy. However, as the frequency of cumulative FIT assessments increased, the association with CRC prevention became stronger.

Cost-effectiveness analysis of colorectal cancer screening using colonoscopy, fecal immunochemical test, and risk score

BACKGROUND AND AIM

A risk-stratification score may be useful for colorectal cancer (CRC) screening, alongside screening colonoscopy (CS) and fecal immunochemical test (FIT). This study aimed to evaluate the effectiveness and cost-effectiveness of population-based CRC screening strategies using CS, FIT, and the Japanese CRC screening score.

METHODS

The effectiveness in quality-adjusted life years (QALYs), cost-effectiveness, and required number of CS procedures were evaluated for screening strategies with primary screening CS (strategy 1), FIT (strategy 2), and the risk score (strategy 3), using a simulation model analysis with two scenarios. In scenario 1, uptake rates for all tests were 60%. In scenario 2, uptake rates for FIT and a risk score were 40%, and those for screening CS and CS following a positive FIT or high risk score were 20% and 70%, respectively.

RESULTS

In scenario 1, strategy 1 gained the highest QALYs and required the highest cost. The incremental cost-effectiveness ratios per QALY gained for strategy 1 against the others were lower than 5 000 000 JPY. Strategy 1 required more than twice as many CS procedures as the other strategies. In scenario 2, strategy 3 had the highest QALYs and lowest cost, and strategy 1 had the lowest QALYs and highest cost.

CONCLUSIONS

Screening CS has the potential to be the most effective and cost-effective form of CRC screening, although it requires a large number of CS procedures. However, if non-invasive tests are preferred by recipients, other screening strategies, particularly those using the risk score, can be more effective and cost-effective.

Colonoscopic screening is associated with reduced Colorectal Cancer incidence and mortality: a systematic review and meta-analysis

It is the great priority to detect colorectal cancer (CRC) as early as possible, finally to reduce the incidence and mortality of CRC. However, although colonoscopy is recommended in many consensuses, yet no one systematic review is conducted to figure out how colonoscopy could change the incidence and mortality. In our study, we conducted a comprehensive meta-analysis to evaluate the association between colonoscopy screening and the incidence or mortality of CRC. PubMed, EMBASE, and PMC database were systematically searched from their inception to June 2020. A total of 13 cohort and 16 case-control studies comprising 4,713,778 individuals were obtained in this review. Our results showed that colonoscopy was associated with a 52% RR reduction in incidence of CRC (RR: 0.48, 95% CI: 0.46-0.49) and 62% RR reduction in mortality of CRC (RR: 0.38, 95% CI: 0.36-0.40). Subgroup analysis of different interventions, study design, country, sample size, age or sex showed that the incidence and mortality reduction remained consistent, and colonoscopy screening had the same effect on people below and above 50. Our study indicated that colonoscopy could significantly reduce the incidence and mortality of CRC.

Comparative Evaluation of Participation and Diagnostic Yield of Colonoscopy vs Fecal Immunochemical Test vs Risk-Adapted Screening in Colorectal Cancer Screening: Interim Analysis of a Multicenter Randomized Controlled Trial (TARGET-C)

INTRODUCTION

In colorectal cancer screening, implementing risk-adapted screening might be more effective than traditional screening strategies. We aimed to compare the effectiveness of a risk-adapted screening strategy with colonoscopy and fecal immunochemical test (FIT) in colorectal cancer screening.

METHODS

A randomized controlled trial was conducted in 6 centers in China since May 2018. Nineteen thousand five hundred forty-six eligible participants aged 50-74 years were recruited and randomly allocated into 1 of the 3 screening groups in a 1:2:2 ratio: (i) one-time colonoscopy (n = 3,916), (ii) annual FIT (n = 7,854), and (iii) annual risk-adapted screening (n = 7,776). Based on the risk-stratification score, high-risk subjects were referred for colonoscopy and low-risk ones were referred for FIT. All subjects with positive FIT were referred for diagnostic colonoscopy. The detection rate of advanced neoplasm was the primary outcome. The study is registered with the China Clinical Trial Registry (www.chictr.org.cn Identifier: ChiCTR1800015506).

RESULTS

For baseline screening, the participation rates of the colonoscopy, FIT, and risk-adapted screening groups were 42.5% (1,665/3,916), 94.0% (7,386/7,854), and 85.2% (6,628/7,776), respectively. For the intention-to-screen analysis, the detection rates of advanced neoplasm were 2.40% (94/3,916), 1.13% (89/7,854), and 1.66% (129/7,776), with odds ratios (95% confidence intervals) of 2.16 (1.61-2.90; P < 0.001) for colonoscopy vs FIT, 1.45 (1.10-1.90; P < 0.001) for colonoscopy vs risk-adapted screening, and 1.49 (1.13-1.97; P < 0.001) for risk-adapted screening vs FIT, respectively. The numbers of subjects who required a colonoscopic examination to detect 1 advanced neoplasm were 18 in the colonoscopy group, 10 in the FIT group, and 11 in the risk-adapted screening group.

DISCUSSION

For baseline screening, the risk-adapted screening approach showed a high participation rate, and its diagnostic yield was superior to that of FIT at a similarly low load of colonoscopy.

Efficacy of screening using annual fecal immunochemical test alone versus combined with one-time colonoscopy in reducing colorectal cancer mortality: the Akita Japan population-based colonoscopy screening trial (Akita pop-colon trial)

PURPOSE

Screening programs using fecal occult blood testing help reduce mortality from colorectal cancer (CRC). Colonoscopy and colonoscopy combined with fecal occult blood testing are considered alternatives with higher sensitivity than fecal tests; however, to our knowledge, randomized controlled trials (RCTs) providing such evidence have not been reported. Therefore, this study aimed to compare screening using the fecal immunochemical test (FIT) combined with colonoscopy and FIT alone to evaluate the efficacy of colonoscopy screening in reducing CRC mortality.

METHODS

This multicenter, prospective, randomized, controlled study included average-risk individuals for CRC living in the study areas and aged 40-74 years. The exclusion criteria were history of CRC, hereditary non-polyposis CRC, familial adenomatous polyposis, inflammatory bowel diseases, history of cancer other than CRC within the past 5 years, and not expected to survive from comorbid illness. The intervention group underwent one-time colonoscopy and annual FIT, while the control group underwent annual FIT. The primary endpoint was mortality from CRC, while the secondary endpoints were cumulative incidence of invasive CRC, advanced CRC (invasion into the muscle layer or deeper), invasive cancer and screening sensitivities and specificities of invasive CRC, whole CRC, advanced neoplasia, and prevalence of adverse events. The intervention and control groups comprised 4876 and 4875 participants, respectively.

CONCLUSION

This explanatory RCT evaluated the efficacy of colonoscopy screening by valid statistical inference based on randomization. Data on adverse events from this kind of screening are necessary when considering implementation of future screening programs.

TRIAL REGISTRATION

UMIN Clinical Trials Registry, number UMIN000001980.

Diagnostic Yield of One-Time Colonoscopy vs One-Time Flexible Sigmoidoscopy vs Multiple Rounds of Mailed Fecal Immunohistochemical Tests in Colorectal Cancer Screening

BACKGROUND & AIMS

We compared the diagnostic yields of colonoscopy, flexible sigmoidoscopy, and fecal immunochemical tests (FITs) in colorectal cancer (CRC) screening.

METHODS

A total of 30,007 asymptomatic persons, 50-74 years old, were invited for CRC screening in the Netherlands. Participants were assigned to groups that received 4 rounds of FIT (mailed to 15,046 participants), once-only flexible sigmoidoscopy (n = 8407), or once-only colonoscopy (n = 6600). Patients with positive results from the FIT (≥10 μg Hb/g feces) were referred for colonoscopy. Patients who underwent flexible sigmoidoscopy were referred for colonoscopy if they had a polyp of ≥10 mm; adenoma with ≥25% villous histology or high-grade dysplasia; sessile serrated adenoma; ≥3 adenomas; ≥20 hyperplastic polyps; or invasive CRC. The primary outcome was number of advanced neoplasia detected (diagnostic yield) by each test. Secondary outcomes were number of colonoscopies needed to detect advanced neoplasia and number of interval CRCs found during each primary screening test. Patients with interval CRCs were found through linkage with Netherlands Cancer Registry. Advanced neoplasia were defined as CRC, adenomas ≥ 10 mm, adenomas with high-grade dysplasia, or adenomas with a villous component of at least 25%.

RESULTS

The cumulative participation rate was significantly higher for FIT screening (73%) than for flexible sigmoidoscopy (31%; P < .001) or colonoscopy (24%; P < .001). The percentage of colonoscopies among invitees was higher for colonoscopy (24%) compared to FIT (13%; P < .001) or flexible sigmoidoscopy (3%; P < .001). In the intention to screen analysis, the cumulative diagnostic yield of advanced neoplasia was higher with FIT screening (4.5%; 95% CI 4.2-4.9) than with colonoscopy (2.2%; 95% CI, 1.8-2.6) or flexible sigmoidoscopy (2.3%; 95% CI, 2.0-2.7). In the as-screened analysis, the cumulative yield of advanced neoplasia was higher for endoscopic screening with colonoscopy (9.1%; 95% CI, 7.7-10.7) or flexible sigmoidoscopy (7.4%; 95% CI, 6.5-8.5) than with the FIT (6.1%; 95% CI, 5.7-6.6). All 3 screening strategies detected a similar proportion of patients with CRC. Follow-up times differed for each test (median 8.3 years for FIT and flexible sigmoidoscopy and 5.8 years for colonoscopy). Proportions of patients that developed interval CRC were 0.13% for persons with a negative result from FIT, 0.09% for persons with a negative result from flexible sigmoidoscopy, and 0.01% for persons with a negative result from colonoscopy.

CONCLUSIONS

Mailed multiple-round FITs detect significantly more advanced neoplasia, on a population level, compared with once-only flexible sigmoidoscopy or colonoscopy screening. Significantly fewer colonoscopies are required by individuals screened by multiple FITs. Trialregister.nl numbers: first round, NTR1096; second round and additional invitees, NTR1512; fourth round, NTR5874; COCOS trial NTR1829.

Baseline Colonoscopy Findings Associated With 10-Year Outcomes in a Screening Cohort Undergoing Colonoscopy Surveillance

BACKGROUND & AIMS

Few studies have evaluated long-term outcomes of ongoing colonoscopic screening and surveillance in a screening population. We aimed to determine the 10-year risk for advanced neoplasia (defined as adenomas ≥10mm, adenomas with villous histology or high-grade dysplasia, or colorectal cancer [CRC]) and assessed whether baseline colonoscopy findings were associated with long-term outcomes.

METHODS

We collected data from the Department of Veterans Affairs Cooperative Studies Program Study on 3121 asymptomatic veterans (50-75 years old) who underwent a screening colonoscopy from 1994 through 1997 at 13 medical centers and were then followed for 10 years or until death. We included 1915 subjects with at least 1 surveillance colonoscopy and estimated cumulative incidence of advanced neoplasia by Kaplan-Meier curves. We then fit a longitudinal joint model to estimate risk of advanced neoplasia at each subsequent examination after baseline, adjusting for multiple colonoscopies within individuals.

RESULTS

Through 10 years of follow-up, there were 146 individuals among all baseline colonoscopy groups found to have at least 1 incident advanced neoplasia. The cumulative 10-year incidence of advanced neoplasia was highest among those with baseline CRC (43.7%; 95% CI 13.0%-74.4%), followed by those with baseline advanced adenoma (AA) (21.9%; 95% CI 15.7-28.1). The cumulative 10-year incidence of advanced neoplasia was 6.3% (95% CI 4.1%-8.5%) and 4.1% (95% CI 2.7%-5.4%) for baseline 1 to 2 small adenomas (<1cm, and without villous histology or high-grade dysplasia) and no neoplasia, respectively (log-rank P = .10). After adjusting for prior surveillance, the risk of advanced neoplasia at each subsequent examination was not significantly increased in veterans with 1 or 2 small adenomas at baseline (odds ratio 0.96; 95% CI 0.67-1.41) compared with veterans with no baseline neoplasia.

CONCLUSIONS

Baseline screening colonoscopy findings associate with advanced neoplasia within 10 years. Individuals with only 1 or 2 small adenomas at baseline have a low risk of advanced neoplasia over 10 years. Alternative surveillance strategies, could be considered for these individuals.

Characteristics of Advanced Colorectal Cancer Detected by Fecal Immunochemical Test Screening in Participants with a Negative Result the Previous Year

BACKGROUND

There is sufficient evidence to show the mortality reduction effect of colorectal cancer (CRC) screening programs using the fecal occult blood test (FOBT). However, we see cases that are found to be advanced CRC despite yearly FOBT screening.

METHODS

The aim of this study was to investigate the characteristics of advanced CRC detected by a fecal immunochemical test (FIT) screening program in participants with a negative screening result the previous year, which we call "Negative advanced CRC". A total of 109,639 participants (10.0% required colonoscopy, of whom 76.9% received one) underwent a CRC screening program using a FIT from fiscal 2009 to 2017. Negative advanced CRC was compared with advanced CRC (First advanced CRC) found at the first visit in a person who had not had a FIT screening history for more than 3 years. In addition, we compared the characteristics of Negative advanced CRC with those of interval cancer: cancer cases detected after a negative screening result and before the date of the next recommended screening.

RESULTS

A total of 339 cases of CRC (175 male: 164 female, 173 early stage: 166 advanced stage) were detected in the nine-year CRC screening period. The rate of right-sided CRCs was significantly higher in female (P < 0.01), advanced stage (P < 0.01), negative result previous year (P < 0.01), and symptom-negative (P < 0.01) participants than in each counterpart, respectively. The ratio of female (22/35; 62.9%) patients in Negative advanced CRCs tended to be high compared with that (40/83; 48.2%) in First advanced CRCs (P = 0.145). Overall, 22 (62.9%) of 35 Negative advanced CRCs and 28 (33.7%) of 83 First advanced CRCs were located in the right-sided colon, and the rate was significantly higher in Negative advanced CRCs (P < 0.01). In addition, the frequency of female patients was significantly higher in right-sided Negative advanced CRCs than in right-sided First advanced CRCs (P = 0.03).

CONCLUSION

The characteristics of Negative advanced CRC cases (female and right-sided colon) were similar to those of interval cancer reported so far. In the future, it will be necessary to introduce a screening program that is highly sensitive to right-sided CRC.

Colorectal cancer-screening program improves both short- and long-term outcomes: a single-center experience in Trieste

Screening programs (SC) have been proven to reduce both incidence and mortality of CRC. We retrospectively analyzed patients who underwent surgical treatment for CRC between 01/2011 and 01/2017. The current screening program in our region collects patients aged from 50 to 69. For this reason, out of a total of 600 patients, we compared 125 patients with CRC founded during the SC to 162 patients who presented with symptoms and were diagnosed between 50-69 years old (NO-SC). 45% patients in the SC group were diagnosed as AJCC stage I vs 27% patients in the NO-SC group; 14% vs 20% were stage II, 14% vs 26% were stage III, and 3% vs 14% were stage IV (p 0.002). We found a significant difference in surgical approach: 89% SC vs 56% NO-SC patients had laparoscopic surgery (p 0.002). In the NO-SC group, 16% patients underwent resection in an emergency setting. Only 5% patients in the SC group had postoperative complications vs 14% patients in the NO-SC group (p 0.03). We had a 2-year OS of 86%, being 95% in the SC group and 80% in the NO-SC group (p 0.002). Likewise, the whole 2-year DFS was 77%, whereas it was 90% in the SC group and 66% in the NO-SC group (p 0.002). Screening significantly improves early diagnosis and accelerated surgical treatment. We obtained earlier stages at diagnosis, a less invasive surgical approach, and lower rates of complications and emergency surgery, all this leading to an improvement in both OS and DFS.

Strategies for Colorectal Cancer Screening

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

Screening colonoscopy and flexible sigmoidoscopy for reduction of colorectal cancer incidence: A case-control study

BACKGROUND

Flexible sigmoidoscopy and colonoscopy are both recommended colorectal cancer screening options, but their relative effectiveness needs clarification. The aim of this study was to compare the effectiveness of colonoscopy and flexible sigmoidoscopy for reduction of colorectal cancer incidence.

METHODS

We conducted a case-control study within the linked Surveillance, Epidemiology, and End Results (SEER)-Medicare database. Cases were subjects age 70-85 years in the SEER-Medicare database diagnosed with CRC during 2004-2013. Up to 3 controls were matched to each case by birth year, sex, race, and SEER region. Receipt of screening colonoscopy or flexible sigmoidoscopy was ascertained from Medicare claims. Conditional logistic regression models were developed to estimate the odds ratios (ORs) and 95% confidence intervals (CI) for a history of screening in cases vs. controls. We conducted secondary analyses by sex, race, endoscopist characteristics, and with varying timing and duration of the look-back period.

RESULTS

Receipt of screening colonoscopy and sigmoidoscopy was associated with a 59% (OR 0.41, 95%CI 0.39, 0.43) and 22% reduction (OR 0.78, 95%CI 0.67, 0.92) in colorectal cancer incidence, respectively. Colonoscopy was associated with greater reduction in the distal colorectal cancer incidence (OR 0.22, 95%CI 0.20, 0.24) than proximal colorectal cancer incidence (OR 0.62, 95%CI 0.59, 0.66). Sigmoidoscopy was associated with a 52% reduction in distal colorectal cancer incidence (OR 0.48, 95%CI 0.37, 0.63), but with no reduction in proximal colorectal cancer incidence. These associations were stronger in men than in women. No differences by race or endoscopist characteristics were observed.

CONCLUSION

Both screening colonoscopy and sigmoidoscopy were associated with reductions in overall colorectal cancer incidence, with a greater magnitude of reduction observed with colonoscopy.

Reviewing the Evidence that Polypectomy Prevents Cancer

Colonoscopic polypectomy is fundamental to effective prevention of colorectal cancer. Polypectomy reduces colorectal cancer incidence and mortality by altering the natural history and progression of precancerous precursor polyps. Epidemiologic data from the United States, where colorectal cancer rates have been steadily declining in parallel with screening efforts, provide indisputable evidence about the effectiveness of polypectomy. Randomized controlled trials of fecal occult blood tests and flexible sigmoidoscopy, and observational colonoscopy studies, provide additional support. Longitudinal studies have shown variable levels of protection after polypectomy, highlighting the central importance of high quality and adequate surveillance of higher-risk patients.

[Current evidence and development of colorectal cancer screening in Germany]

Colon cancer is currently the third leading cause of cancer death in men and women in Germany, with a total of about 25,000 deaths per year. Established methods for early detection of colorectal cancer include lower gastrointestinal endoscopy and fecal occult blood testing. For both procedures, there is evidence of a reduction in colorectal cancer-specific mortality and for endoscopy a reduction of colorectal cancer incidence has been shown.In Germany, the guaiac test for fecal occult blood has been offered since 1977. Additionally, screening colonoscopy has been offered since 2002 and in 2016, the guaiac test was replaced by the immunological fecal occult blood test, which has an improved diagnostic performance. Overall, participation rates have been low over the past decades and differed between men, women, and age groups.Personal invitations are expected to be sent out starting in 2019 as part of the introduction of an organized colorectal cancer screening program in Germany. The program also provides for measures to systematically monitor and improve the quality of colorectal cancer screening. It remains to be seen which effects these changes will have and whether the trend towards declining colon cancer incidence and mortality that has been observed in Germany will continue in the coming years.

Colorectal Cancer in the Young: Does Screening Make Sense?

PURPOSE OF REVIEW

Colorectal cancer (CRC) screening is recommended to reduce CRC mortality. This review outlines key factors to consider when recommending screening, including disease burden, screening benefits and harms, and remaining knowledge gaps.

RECENT FINDINGS

In response to increasing rates of CRC incidence among younger (age < 50 years) adults, the American Cancer Society published guidelines in May 2018 recommending average-risk CRC screening beginning at age 45 (vs. 50) years. Rates of young-onset CRC have increased in the USA since the early 1990s. However, there is very little empirical evidence of screening effectiveness in younger adults, and few studies have reported harms of routine screening in this age group. Further, we know little about the natural history of CRC in younger adults. Uncertainty surrounding the efficacy of CRC screening in younger adults suggests the benefits may be small. Precision cancer screening-or modified screening regimens based on risk-may improve the balance of screening benefits and harms beyond conventional age-based strategies.

Comparative evaluation of novel screening strategies for colorectal cancer screening in China (TARGET-C): a study protocol for a multicentre randomised controlled trial

INTRODUCTION

Screening for colorectal cancer (CRC) is effective in reducing the disease burden. However, high-level evidence from randomised controlled trials on the effectiveness of CRC screening modalities is still lacking. We will conduct a large-scale multicentre randomised controlled trial in China to evaluate the effectiveness and cost-effectiveness of different CRC screening strategies.

METHODS AND ANALYSIS

20 000 eligible participants aged 50-74 years are enrolled in five provinces in China. After providing signed informed consent, the participants will be randomised into one of the three screening groups: (1) one-time colonoscopy (n=4000), (2) annual faecal immunochemical test (FIT) (n=8000) and (3) annual risk-adapted screening strategy (n=8000). The risk-adapted screening strategy will use an established CRC risk scoring system, the Asia-Pacific Colorectal Screening score. Participants at high risk of CRC will be referred for colonoscopy, while participants at low risk will be referred for an FIT. Information on clinical reports, epidemiological risk factors and health economic factors will be collected and stored in a web-based data management system. We will further request the participants to donate blood, faecal and saliva samples before conducting the colonoscopy. The primary outcome will be the detection rate of advanced colorectal neoplasia and the secondary outcomes will include the rates of CRC-related mortality, incidence of CRC, participation and complications. The study will last for at least 4 years and the cohort will be followed for 10 years to adequately answer the scientific questions.

ETHICS AND DISSEMINATION

This study was approved by the Ethics Committee of the National Cancer Center/Cancer Hospital, the Chinese Academy of Medical Sciences and Peking Union Medical College (18-013/1615). The results of the study will be submitted for publication in peer-reviewed journals and will be discussed by policy and decision makers.

TRIAL REGISTRATION NUMBER

ChiCTR1800015506.

Early detection and therapeutics

Early detection, including cancer screening and surveillance, is emerging as one of the most important topics in modern oncology. Because symptomatic presentation remains the predominant route to cancer diagnosis, there is a growing interest in developing techniques to detect the disease at an early, curative stage. Moreover, growing understanding of cancer biology has paved the way for prevention studies with the focus on therapeutic interventions for premalignant conditions. Where there is a recognisable precursor stage, such as a colorectal adenoma or Barrett's metaplasia, the removal of abnormal tissue prevents the development of cancer and enables stratification of the patient to a high-risk group requiring further surveillance. Here, we provide a review of the available technologies for early diagnosis and minimally-invasive treatment.

The NHS Bowel cancer screening programme achieves the anticipated survival improvement, but participation must be improved

Purpose The NHS Bowel cancer screening programme (NHSBCSP) aims to reduce colorectal cancer (CRC) cumulative mortality by up to 23 per cent; long-term outcomes at national level are not yet known. The purpose of this paper is to examine a local population of CRC patients of screening age for their characteristics and long-term survival in relation to their presentation, including through the NHSBCSP. Design/methodology/approach Retrospective analysis of a prospectively maintained CRC database for the years 2009-2014 in a single district hospital providing bowel cancer screening and tertiary rectal cancer services. Findings Of 528 CRC patients diagnosed in the screening age range, 144(27.3 per cent) presented through NHSBCSP, 308(58.3 per cent) electively with symptoms and 76(14.4 per cent) as emergency. NHSBCSP-diagnosed patients were younger (median 66 vs 68 and 69 years, respectively, p=0.001), had more often left-sided cancers (59(41.0 per cent) vs 82(26.6 per cent) and 24(31.6 per cent), respectively, p=0.001), more UICC-stage I (42(29.2 per cent) vs 49(15.9 per cent) and 2(2.6 per cent)), stage III (59(41.0 per cent) vs 106(34.4 per cent) and 20(26.3 per cent)) and less stage IV disease (8(5.6 per cent) vs 61(19.8 per cent) and 34 (44.7 per cent), respectively, p<0.001). Three-year overall survival was best for NHSBCSP and worst for emergency patients (87.5 per cent vs 69.0 per cent and 35.3 per cent, respectively, LogRank p<0.001). Originality/value Patients diagnosed within the NHSBCSP have improved outcome compared to both symptomatic elective and emergency presentations. A reduction in overall cumulative mortality in order of 25 per cent may well be achieved, but continuing high levels of emergency presentations and undetected right-sided disease emphasise need for further improvement in public participation in the NHSBCSP and research into more sensitive and acceptable alternative screening methods.

Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: long-term follow-up of the randomised US PLCO cancer screening trial

BACKGROUND

Screening flexible sigmoidoscopy reduces incidence and mortality of colorectal cancer. Previously reported results from the Prostate, Lung, Colorectal, and Ovarian Cancer (PLCO) screening trial had a median follow-up of 12 years. Whether the benefit is sustained over the long term and remains so in both sexes and all age groups is uncertain. We report long-term results after an additional 5 years of follow-up.

METHODS

Participants in the PLCO trial were recruited from the general population in the catchment areas of ten screening centres across the USA, without previous diagnosis of a prostate, lung, colorectal, or ovarian cancer or current cancer treatment. From 1993 to 2001, participants aged 55-74 years were randomly assigned to usual care or flexible sigmoidoscopy at baseline and again at 3 years or 5 years. Randomisation was done within blocks and stratified by centre, age, and sex. The primary endpoint was cause-specific mortality and secondary endpoints included incidence and tumour staging; cause of death was determined without knowledge of study arm. In this analysis, we assessed incidence and mortality rates overall, by time-period, and by combinations of sex, age at baseline (55-64 years/65-74 years), location (distal/proximal), and stage, on an intent-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT00002540.

FINDINGS

=0·01).

INTERPRETATION

Reductions in colorectal cancer incidence and mortality from flexible sigmoidoscopy screening are sustained over the long term. Differences by sex and age should be examined in other ongoing trials of colorectal cancer screening to help clarify if different screening strategies would achieve greater risk reduction.

FUNDING

Extended follow-up was funded under NIH contract HHSN261201600007I.

Polyp detection during colonoscopy using a regression-based convolutional neural network with a tracker

A computer-aided detection (CAD) tool for locating and detecting polyps can help reduce the chance of missing polyps during colonoscopy. Nevertheless, state-of-the-art algorithms were either computationally complex or suffered from low sensitivity and therefore unsuitable to be used in real clinical setting. In this paper, a novel regression-based Convolutional Neural Network (CNN) pipeline is presented for polyp detection during colonoscopy. The proposed pipeline was constructed in two parts: 1) to learn the spatial features of colorectal polyps, a fast object detection algorithm named ResYOLO was pre-trained with a large non-medical image database and further fine-tuned with colonoscopic images extracted from videos; and 2) temporal information was incorporated via a tracker named Efficient Convolution Operators (ECO) for refining the detection results given by ResYOLO. Evaluated on 17,574 frames extracted from 18 endoscopic videos of the AsuMayoDB, the proposed method was able to detect frames with polyps with a precision of 88.6%, recall of 71.6% and processing speed of 6.5 frames per second, i.e. the method can accurately locate polyps in more frames and at a faster speed compared to existing methods. In conclusion, the proposed method has great potential to be used to assist endoscopists in tracking polyps during colonoscopy.

The colorectal cancer epidemic: challenges and opportunities for primary, secondary and tertiary prevention

Colorectal cancer (CRC) is both one of the most common and one of the most preventable cancers globally, with powerful but strongly missed potential for primary, secondary and tertiary prevention. CRC incidence has traditionally been the highest in affluent Western countries, but it is now increasing rapidly with economic development in many other parts of the world. CRC shares several main risk factors, such as smoking, excessive alcohol consumption, physical inactivity and being overweight, with other common diseases; therefore, primary prevention efforts to reduce these risk factors are expected to have multiple beneficial effects that extend beyond CRC prevention, and should have high public health impact. A sizeable reduction in the incidence and mortality of CRC can also be achieved by offering effective screening tests, such as faecal immunochemical tests, flexible sigmoidoscopy and colonoscopy, in organised screening programmes which have been implemented in an increasing number of countries. Countries with early and high uptake rates of effective screening have exhibited major declines in CRC incidence and mortality, in contrast to most other countries. Finally, increasing evidence shows that the prognosis and quality of life of CRC patients can be substantially improved by tertiary prevention measures, such as the administration of low-dose aspirin and the promotion of physical activity.

How long does it take until the effects of endoscopic screening on colorectal cancer mortality are fully disclosed?: a Markov model study

A recent randomized trial has suggested persisting protection from colorectal cancer (CRC) incidence and mortality of a single flexible sigmoidoscopy for up to 17 years and possibly beyond. We performed a simulation study to explore the time course and magnitude of protection provided by screening colonoscopy against CRC death over 25 years. Using data from the German national screening colonoscopy registry, a multistate Markov model was set up based on the adenoma-carcinoma pathway to estimate cumulative CRC mortality when different proportions of the population have a single screening colonoscopy at age 55, or two screening colonoscopies at ages 55 and 65. Cumulative CRC mortality continuously increased with age and reached 2.6 and 1.7% at age 80 in the absence of screening for men and women, respectively. A single colonoscopy at age 55, even with limited uptake, would lead to much lower cumulative mortality (0.7% for men and 0.5% for women at age 80 under 100% uptake). Relative mortality reduction continued to increase over more than 10 years and reached the maximum around 12-13 years after screening. Absolute risk reduction steadily increased throughout follow-up and more than half of the total risk reduction would occur between 15-25 years. A repeat colonoscopy 10 years later further enhanced the effects and cumulative mortality remained at 0.1-0.2% under 100% uptake. Even a single (once-only) screening colonoscopy has the potential to prevent most of CRC mortalities. Protective effects are expected to be long-lasting and to become fully manifest after more than two decades from screening.

Systematic literature review of IL-6 as a biomarker or treatment target in patients with gastric, bile duct, pancreatic and colorectal cancer

Gastrointestinal cancer (GI) is a major health problem. Patients with gastric, pancreatic, colorectal, bile duct and gall bladder cancer often have advanced disease at the time of diagnosis and are generally difficult to cure, resulting in a dismal prognosis for most patients. Inflammation plays an important role in the development and growth of cancer, which has led to a growing interest in the pro-inflammatory cytokine interleukin 6 (IL-6). The aim of the present review was to evaluate the clinical use of IL-6 as a biomarker or therapeutic target in patients with GI cancer. We did a systematic review of studies (1993-2018), to assess the clinical use of IL-6 as a diagnostic, prognostic or predictive tumor biomarker or as a potential therapeutic target. This review includes 48 studies and 5316 patients. Circulating IL-6 levels appear to be an independent prognostic biomarker in patients with GI cancer, with high IL-6 levels associated with short overall survival (OS). The results for colorectal cancer were too ambiguous to give conclusive results. IL-6 seemed to be a marker for some of the clinical characteristics of GI cancer, and may have a role in the diagnostic workup in general practice. No published studies have examined the use of IL-6 as a therapeutic target in pancreatic, gastric, bile duct or colorectal cancer. In conclusion, high circulating IL-6 was associated with short OS in most studies in GI cancer patients. Whether inhibition of IL-6 would decrease GI cancer symptoms and increase quality of life is unknown.

Patients' Preferences for Primary Colorectal Cancer Screening: A Survey of the National Colorectal Cancer Screening Program in Korea

Background/Aims

The adoption of colonoscopy as a primary colorectal cancer (CRC) screening technique has been argued for in Korea, without evidence of patient preferences. This study aimed to investigate patients’ preferences for the primary CRC screening test for the National Cancer Screening Program (NCSP).

Methods

Between June and August 2016, 414 individuals aged ≥50 years who participated in the NCSP were prospectively invited to complete a questionnaire regarding their preferences for the primary CRC screening test and the reasons for their selection.

Results

Among the 396 respondents who completed the questionnaire, 124 individuals (31.3%) preferred the fecal immunochemical test (FIT), whereas 272 individuals (68.7%) preferred colonoscopy. Elderly participants preferred the FIT (p<0.001), whereas participants with a higher education level (p=0.030), a higher income level (p=0.009), or individuals with a family member (p=0.028) or acquaintance (p=0.013) with a history of CRC preferred colonoscopy. Only 12.9% of participants had a bad experience with a previous FIT; however, 39.3% of participants had a bad experience with a previous colonoscopy.

Conclusions

Colonoscopy was preferred to FIT in a 2.2:1 ratio as the primary CRC screening test for the NCSP. Patients’ preference for colonoscopy should be considered for the NCSP in Korea.

Expected long-term impact of screening endoscopy on colorectal cancer incidence: a modelling study

BACKGROUND & AIMS

Screening endoscopy reduces colorectal cancer (CRC) incidence but the time course and magnitude of effects beyond 10 years after screening are unknown. We aimed to estimate the expected time course and magnitude of long-term impact of screening endoscopy on CRC incidence.

METHODS

We used Markov models based on the natural history of the disease along with data from the German national screening colonoscopy registry to derive the expected impact of screening colonoscopy at age 55 or 60 on cumulative CRC incidence according to time of follow-up over a period of up to 25 years.

RESULTS

After a single screening colonoscopy, cumulative CRC incidence is expected to be increased for approximately 4 to 5 years. This transient increase is expected to be followed by a steadily increasing reduction in cumulative CRC incidence for at least 25 years. Less than one third of this long-term reduction is expected to be seen within 10-12 years of follow-up, the length of follow-up reported on in RCTs on flexible sigmoidoscopy screening and in most cohort studies on both sigmoidoscopy and colonoscopy screening. In relative terms, risk reduction is expected to reach its maximum approximately 15 years after a single screening colonoscopy and 20-25 years after the initial screening colonoscopy in case of repeat screening colonoscopy after 10 years.

CONCLUSIONS

The long-term impact of screening endoscopy on CRC prevention is expected to be much stronger than suggested by currently available evidence from RCTs and cohort studies with limited length of follow-up.

Quality is the Key for Emerging Issues of Population-Based Colonoscopy Screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.

Effectiveness of screening colonoscopy in reducing the risk of death from right and left colon cancer: a large community-based study

OBJECTIVE

Screening colonoscopy's effectiveness in reducing colorectal cancer mortality risk in community populations is unclear, particularly for right-colon cancers, leading to recommendations against its use for screening in some countries. This study aimed to determine whether, among average-risk people, receipt of screening colonoscopy reduces the risk of dying from both right-colon and left-colon/rectal cancers.

DESIGN

We conducted a nested case-control study with incidence-density matching in screening-eligible Kaiser Permanente members. Patients who were 55-90 years old on their colorectal cancer death date during 2006-2012 were matched on diagnosis (reference) date to controls on age, sex, health plan enrolment duration and geographical region. We excluded patients at increased colorectal cancer risk, or with prior colorectal cancer diagnosis or colectomy. The association between screening colonoscopy receipt in the 10-year period before the reference date and colorectal cancer death risk was evaluated while accounting for other screening exposures.

RESULTS

We analysed 1747 patients who died from colorectal cancer and 3460 colorectal cancer-free controls. Compared with no endoscopic screening, receipt of a screening colonoscopy was associated with a 67% reduction in the risk of death from any colorectal cancer (adjusted OR (aOR)=0.33, 95% CI 0.21 to 0.52). By cancer location, screening colonoscopy was associated with a 65% reduction in risk of death for right-colon cancers (aOR=0.35, CI 0.18 to 0.65) and a 75% reduction for left-colon/rectal cancers (aOR=0.25, CI 0.12 to 0.53).

CONCLUSIONS

Screening colonoscopy was associated with a substantial and comparably decreased mortality risk for both right-sided and left-sided cancers within a large community-based population.

[Quality is the Key for Emerging Issues of Population-based Colonoscopy Screening]

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rate in population-based screening program. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis and socioeconomic burden. In addition, harmful effect of colonoscopy may increase with age and comorbidity. As the adverse event risk in population-based colonoscopy screening may offset benefit of the screening colonoscopy, the adverse events associated with screening colonoscopy should be well managed and monitored. To adopt population-based colonoscopy screening, consensus for the risk and benefits of screening colonoscopy should be formed for its potential harms, patient preference, socioeconomic considerations, quality improvement of colonoscopy as well as its efficacy for CRC prevention. As the suboptimal colonoscopy quality is a major pitfall of population-based colonoscopy screening, adequate training and provider regulation for screening colonoscopists should be the first step to minimize the variation of quality between colonoscopists. Gastroenterologists should lead quality improvement, auditing, and training associated with colonoscopy in a population-based colonoscopy screening program.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Colorectal Cancer Screening-Who, How, and When?

Colorectal cancer (CRC) is the third most common cancer worldwide. It is amenable to screening as it occurs in premalignant, latent, early, and curable stages. PubMed, Cochrane Database of Systematic Reviews, and national and international CRC screening guidelines were searched for CRC screening methods, populations, and timing. CRC screening can use direct or indirect tests, delivered opportunistically or via organized programs. Most CRCs are diagnosed after 60 years of age; most screening programs apply to individuals 50-75 years of age. Screening may reduce disease-specific mortality by detecting CRC in earlier stages, and CRC incidence by detecting premalignant polyps, which can subsequently be removed. In randomized controlled trials (RCTs) guaiac fecal occult blood testing (gFOBt) was found to reduce CRC mortality by 13%-33%. Fecal immunochemical testing (FIT) has no RCT data comparing it to no screening, but is superior to gFOBt. Flexible sigmoidoscopy (FS) trials demonstrated an 18% reduction in CRC incidence and a 28% reduction in CRC mortality. Currently, RCT evidence for colonoscopy screening is scarce. Although not yet corroborated by RCTs, it is likely that colonoscopy is the best screening modality for an individual. From a population perspective, organized programs are superior to opportunistic screening. However, no nation can offer organized population-wide colonoscopy screening. Thus, organized programs using cheaper modalities, such as FS/FIT, can be tailored to budget and capacity.

Quality is the key for emerging issues of population-based colonoscopy screening

Colonoscopy is currently regarded as the gold standard and preferred method of screening for colorectal cancer (CRC). However, the benefit of colonoscopy screening may be blunted by low participation rates in population-based screening programs. Harmful effects of population-based colonoscopy screening may include complications induced by colonoscopy itself and by sedation, psychosocial distress, potential over-diagnosis, and socioeconomic burden. In addition, harmful effects of colonoscopy may increase with age and comorbidities. As the risk of adverse events in population-based colonoscopy screening may offset the benefit, the adverse events should be managed and monitored. To adopt population-based colonoscopy screening, consensus on the risks and benefits should be developed, focusing on potential harm, patient preference, socioeconomic considerations, and quality improvement of colonoscopy, as well as efficacy for CRC prevention. As suboptimal colonoscopy quality is a major pitfall of population-based screening, adequate training and regulation of screening colonoscopists should be the first step in minimizing variations in quality. Gastroenterologists should promote quality improvement, auditing, and training for colonoscopy in a population-based screening program.