Colorectal Screening is Associated with Reduced Colorectal Cancer Risk: A Case–Control Study within the Population-Based Ontario Familial Colorectal Cancer Registry

Akita Japan population-based colonoscopy screening trial: report of initial colonoscopy

OBJECTIVE

To assess the safety and quality of baseline screening colonoscopy in a randomised controlled trial (RCT).

METHODS

A population-based RCT with an explanatory design is ongoing to evaluate the efficacy of colonoscopy screening in 9751 men and women aged 40-74 years at average risk of colorectal cancer (CRC) in Japan. Screening colonoscopies for the intervention group were performed from June 2009 to June 2017.

RESULTS

Of the 4861 participants in the intervention group, 4495 (92.5%) underwent screening colonoscopy. The quality of bowel preparation was excellent (34.8%) or good (45.6%) in 80.4% of cases. The caecal intubation rate was 99.7% (4483/4495), and the mean (±SD) withdrawal time was 9.7 (±5.3) min. The adenoma detection rate (ADR) was 39.4% (1770/4495). A total of 27 participants (0.6%) were diagnosed with CRC, and 266 (5.9%) were diagnosed with advanced neoplasia (AN). In women, adenomas were more frequently detected in the proximal colon than in the distal colon (proximal: 18.9% vs distal: 16.4%, p=0.024), and a similar trend was observed for AN (proximal: 2.4% vs distal: 1.5%, p=0.045). No serious adverse events related to screening colonoscopy were reported, and minor adverse events were observed in two participants (0.04%).

CONCLUSIONS

Adequate performance in compliance, ADR, and safety was confirmed in the intervention arm of the RCT evaluating the efficacy of screening colonoscopy. The high quality of screening colonoscopy observed in the trial suggests its feasibility as a population-based screening approach.

TRIAL REGISTRATION NUMBER

UMIN000001980.

Screening for Colorectal Cancer

Colorectal cancer remains the third leading cause of cancer death in the United States. Colorectal cancer screening allows for prevention and early detection of precancerous and cancerous lesions, and screening has been shown to be effective in preventing colorectal cancer deaths. Screening recommendations vary by patient risk profile. A variety of screening modalities exist.

Uptake and Short-term Outcomes of High-risk Screening Colonoscopy Billing Codes: A Population-based Study Among Young Adults

Background

Persons suspected or confirmed with familial colorectal cancer syndrome are recommended to have biennial colonoscopy from late adolescence or early adulthood. Persons without a syndrome but with one or more affected first-degree relatives are recommended to begin colonoscopy 10 years before the age at diagnosis of the youngest affected relative, and every 5 to 10 years. Ontario introduced colonoscopy billing codes for these two indications in 2011.

Methods

We identified persons in Ontario under 50 years of age, without a prior history of colorectal cancer or inflammatory bowel disease, with one or more of these billing claims between 2013 and 2017. We described the index colonoscopy, and subsequent colonoscopy up-to-date status. We computed average annual rates of colorectal and other cancer diagnoses, and displayed mean cumulative function plots, stratified by billing code, age and sex.

Results

Billing claims for ‘familial syndrome’ high-risk screening colonoscopy were identified among 14,846 persons; the average annual rate of CRC diagnoses was 38.6 per 100,000 among males and 22.2 among females. Colonoscopy up-to-date status fell to 50% within 7 years. Billing claims for ‘first-degree relative’ screening colonoscopy was identified among 49,505 persons; average annual rates of CRC diagnoses were 16.3 among males and 13.5 per 100,000 among females, respectively.

Conclusion

Colorectal cancer was more frequent following billing claims for high-risk screening colonoscopy for familial syndromes, as were noncolorectal malignancies potentially associated with these syndromes. This billing claim for familial colorectal cancer syndrome colonoscopy appears to identify a group at elevated short-term risk for cancer.

Association of Family History and Life Habits in the Development of Colorectal Cancer: A Matched Case-Control Study in Mexico

Colorectal cancer (CRC) is one of the most frequently diagnosed cancers and, as such, is important for public health. The increased incidence of this neoplasm is attributed to non-modifiable controls such as family history and modifiable variable behavioral risk factors involved in lifestyle like diets in Mexico. The presence of these factors is unknown. Therefore, the aim of this study was to evaluate family history and lifestyle factors associated with developing colorectal cancer in a Mexican population. Descriptive statistics and multivariate logistic regression were used to estimate the adjusted odds ratios (OR), as well as the 95% confidence intervals (CI). In this paper, significant differences were demonstrated between cases and controls. A family history of cancer (FHC) increased the probability of CRC [OR = 3.19 (95% CI: 1.81-5.60)]. The area of urban residence was found to be a protective factor compared to the rural area. This was also the case for frequent consumption of fruits [OR = 0.49 (95% CI: 0.28-0.88)], the frequent consumption of beef [OR = 2.95 (95% CI: 1.05-8.26)], pork [OR = 3.26 (95% CI: 1.34-7.90)], and region-typical fried food [OR = 2.79 (95% CI (1.32-5.89)]. These results provide additional evidence supporting the association of some CRC risk factors with family history of cancer, low fruit consumption, high consumption of red meat, and fried foods typical of the region of México. It is important to establish intervention methods, as well as genetic counseling to relatives of patients with CRC.

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.

Type 2 diabetes and the risk of colorectal polyps: A retrospective nationwide population-based study

The incidence rates of type 2 diabetes mellitus (T2DM) and colorectal polyps have been increasing over the last decades. However, direct associations between T2DM and colorectal polyps have not been extensively reported. We will explore the relationship between T2DM and colorectal polyps.In the retrospective study, we classified DM and NonDM groups (control) from 993,516 people in Taiwan nationwide population insurance database from the period of 2000 to 2013. We collected data on income and comorbidities through the international classification of diseases, ninth revision-clinical modification (ICD-9-CM) codes.The T2DM group had a higher incidence rate of colorectal polyps (31.97%, 95% confidence interval [CI] = 30.97-33.28) than the control group (25.9%, 95% CI = 25.1-26.72), and the crude incidence ratio was 1.235 (95% CI = 1.174-1.300). In 13 years of follow-up (2000-2013), T2DM was linked to a significantly higher cumulative probability of colorectal polyps (log-rank test: P = .0001).Patients with T2DM had a 1.23-fold higher risk of new colorectal polyps than control patients in 13 years of follow-up. We explain the T2DM increases incidence for colorectal polyps in long term follow-up.

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.

ACG Clinical Guidelines: Colorectal Cancer Screening 2021

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC screening efforts are directed toward removal of adenomas and sessile serrated lesions and detection of early-stage CRC. The purpose of this article is to update the 2009 American College of Gastroenterology CRC screening guidelines. The guideline is framed around several key questions. We conducted a comprehensive literature search to include studies through October 2020. The inclusion criteria were studies of any design with men and women age 40 years and older. Detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC are discussed. We also provide recommendations on the role of aspirin for chemoprevention, quality indicators for colonoscopy, approaches to organized CRC screening and improving adherence to CRC screening. CRC screening must be optimized to allow effective and sustained reduction of CRC incidence and mortality. This can be accomplished by achieving high rates of adherence, quality monitoring and improvement, following evidence-based guidelines, and removing barriers through the spectrum of care from noninvasive screening tests to screening and diagnostic colonoscopy. The development of cost-effective, highly accurate, noninvasive modalities associated with improved overall adherence to the screening process is also a desirable goal.

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.

Association between known risk factors and colorectal cancer risk in Indigenous people participating in the Ontario Familial Colon Cancer Registry

Introduction

Colorectal cancer is one of the most common cancers in Ontario and imposes a high burden on many Indigenous populations. There are two aims for this short communication: ■ Highlight colorectal risk factor findings from a population-based case-control study■ Highlight trends and challenges of colorectal cancer research in Indigenous populations in Ontario.

Methods

Prevalences of cigarette smoking, obesity, fruit and vegetable consumption, and family history of colorectal cancer were estimated using the Indigenous identifier in the Ontario Familial Colon Cancer Registry for 1999-2007 and then compared for cases and controls using age-adjusted odds ratios (ors) with 95% confidence intervals (cis).

Results

The registry search identified 66 Indigenous cases and 23 Indigenous controls. Cigarette smoking (or: 1.88; 95% ci: 0.63 to 5.60) and obesity (or: 2.16; 95% ci: 0.72 to 6.46) were higher in cases, but not statistically significantly so.

Conclusions

Findings were consistent with previous literature describing Indigenous populations. A small sample size and poor Indigenous identification questions make it challenging to comprehensively understand cancer risk factors and burden in Indigenous populations.

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.

Effects of Family History on Relative and Absolute Risks for Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND & AIMS

Guidelines recommend that individuals with familial colorectal cancer undergo colonoscopy surveillance instead of average-risk screening. However, these recommendations vary widely. To substantiate appropriate surveillance strategies, precise and valid evidence-based risk estimates are needed for individuals with a family history of colorectal cancer (CRC).

METHODS

We systematically searched MEDLINE, EMBASE, and Cochrane from inception to July 2018 for case-control and cohort studies investigating the effect of family history on CRC risk. We calculated summary estimates of pooled relative risks (RRs) using a random-effects model. Life tables were created to convert RR estimates into absolute risk estimates.

RESULTS

We screened 4417 articles and identified 42 eligible case-control and 20 cohort studies. In case-control studies, the RR for CRC in patients with 1 first-degree relative (FDR with CRC) was 1.92 (95% CI, 1.53-2.41) and 1.37 (95% CI, 0.76-2.46) for cohort studies. For individuals with 2 or more FDRs with CRC, the RR was 2.81 in case-control studies (95% CI, 1.73-4.55) and 2.40 in cohort studies (95% CI, 1.76-3.28). For individuals having a FDR diagnosed with CRC at an age younger than 50 years, the RR for CRC in their FDRs was 3.57 in case-control studies (95% CI, 1.07-11.85) and 3.26 in cohort studies (95% CI, 2.82-3.77). The cumulative absolute risks for CRC at 85 years in Western Europe were 4.8% for persons with 1 FDR with CRC (95% CI, 2.7%-8.3%), 8.2% for individuals with 2 or more FDRs (95% CI, 6.1%-10.9%), and 11% for persons with a FDR diagnosed with CRC at an age younger than 50 years (95% CI, 9.5%-12.4%).

CONCLUSIONS

In this systematic review and meta-analysis, we found that the RR of CRC among FDRs is lower than previously expected, especially based on cohort studies. Risk estimates are affected by the number of relatives with CRC and their age at diagnosis. Intensified colonoscopy surveillance strategies could be considered for high-risk groups. PROSPERO trial identification no: CRD42018103058.

The effect of diagnostic delay attributable to the healthcare system on the prognosis of colorectal cancer

OBJECTIVES

To analyse the effect of a delay attributable to the healthcare system on a consecutive cohort of outpatients diagnosed with colorectal cancer in the healthcare area of Ourense (Spain).

PATIENTS AND METHODS

We performed a retrospective cohort study that included patients diagnosed between 2009 and 2017. Delay attributable to the healthcare system was defined as the time between the first consultation with symptoms and the diagnostic confirmation. A logistic regression model was performed to evaluate the relationship between stage IV CRC and diagnostic delay. To analyse which variables were associated independently with overall mortality and mortality due to CRC we used a Cox regression model.

RESULTS

575 patients were included (men 64.5%, age 71.9 ± 11.5 years), with a delay attributable to the healthcare system of 115 ± 153 days. None of the variables analysed were associated with tumour stage at diagnosis. With a mean follow-up of 30.6 ± 21 months, 121 patients died (79.3% due to CRC). The variables independently associated with CRC-related mortality were metastatic CRC (HR 50.65, 95% CI 12.28-209), age (HR 1.04, 95% CI 1.02-1.05) and colonoscopy requested from the Primary Healthcare level (HR 0.55, 95% CI 0.36-0.88).

CONCLUSIONS

Diagnostic delay attributable to the healthcare system is not related to the prognosis or stage of CRC. However, a direct referral to colonoscopy from the Primary Healthcare level reduces the risk of mortality in our patients.

Lower Relative Contribution of Positive Family History to Colorectal Cancer Risk with Increasing Age: A Systematic Review and Meta-Analysis of 9.28 Million Individuals

OBJECTIVES

Existing algorithms predicting the risk of colorectal cancer (CRC) assign a fixed score for family history of CRC. Whether the increased CRC risk attributed to family history of CRC was higher in younger patients remains inconclusive. We examined the risk of CRC associated with family history of CRC in first-degree relative (FDR) according to the age of index subjects (<40 vs. ≥40; <50 vs. ≥50; and <60 vs. ≥60 years).

METHODS

Ovid Medline, EMBASE, and gray literature from the reference lists of all identified studies were searched from their inception to March 2017. We included case-control/cohort studies that investigated the relationship between family history of CRC in FDR and prevalence of CRC. Two reviewers independently selected articles according to the PRISMA guideline. A random effects meta-analysis pooled relative risks (RR).

RESULTS

We analyzed 9.28 million subjects from 63 studies. A family history of CRC in FDR confers a higher risk of CRC (RR = 1.76, 95% CI = 1.57-1.97, p < 0.001). This increased risk was higher in younger individuals (RR = 3.29, 95% CI = 1.67-6.49 for <40 years versus RR = 1.42, 95% CI = 1.24-1.62 for ≥40 years, p = 0.017; RR = 2.81, 95% CI = 1.94-4.07 for <50 years versus RR = 1.47, 95% CI = 1.28-1.69 for ≥50 years, p = 0.001). No publication bias was identified, and the findings are robust in subgroup analyses.

CONCLUSIONS

The increase in relative risk of CRC attributed to family history was found to be higher in younger individuals. Family history of CRC could be assigned a higher score for younger subjects in CRC risk prediction algorithms. Future studies should examine if such approach may improve their predictive capability.

Symptom or faecal immunochemical test based referral criteria for colorectal cancer detection in symptomatic patients: a diagnostic tests study

BACKGROUND

Symptom based referral criteria for colorectal cancer (CRC) detection are the cornerstone of the strategy to improve prognosis in CRC. In 2017, the National Institute for Health and Care Excellence (NICE) updated their referral criteria (2017 NG12). Recently, several studies have evaluated the faecal haemoglobin (f-Hb) concentration in this setting. The aim of this study is to evaluate the diagnostic accuracy of the 2017 NG12 referral criteria and to compare them with the CG27 referral criteria, the f-Hb concentration and two f-Hb based prediction model: COLONPREDICT and FAST Score.

METHODS

This is a post-hoc diagnostic test study performed within the COLONPREDICT study database (1572 patients, CRC prevalence 13.6%). We assessed symptoms, the 2017 NG12 and CG27 referral criteria and determined the f-Hb before performing a colonoscopy. We compared the discriminatory ability using the area under the curve (AUC) and the sensitivity and specificity at pre-stablished thresholds with the McNemar's test.

RESULTS

The 2017 NG12 referral criteria discriminatory ability (AUC 0.53; 95% confidence interval- CI 0.49-0.57) was inferior to the CG27 version (AUC 0.59; 95% CI 0.55-0.63; p = 0.01), the f-Hb concentration (AUC 0.86; 95% CI 0.84-0-89; p < 0.001), the COLONPREDICT Score (AUC 0.92; 95% CI 0.91-0.94; p < 0.001) or the FAST Score (AUC 0.87; 95% CI 0.85-0.89; p < 0.001). The number of patients meeting each criteria were as follows: 2017 NG12 and CG27 = 94.1% and 52.2%; f-Hb ≥20 and ≥ 10 μg/g faeces = 38.6 and 44.3%; COLONPREDICT Score ≥ 5.6 and ≥ 3.2 = 29.4 and 63.2% and FAST Score ≥ 4.50 and ≥ 2.12 = 37.1 and 87.0%. The 2017 NG12 criteria were more sensitive (100%) than the CG27 criteria (68.2%), the f-Hb (≥20 μg/g) (91.2%), the f-Hb (≥10 μg/g) (93.5%), the COLONPREDICT Score (≥5.6) (90.1%) and the FAST Score (≥4.50) (89.8%) (p ≤ 0.001) and equivalent to the COLONPREDICT Score (≥3.5) (99.5%) or the FAST Score (≥2.12) (100.0%) (p = 1). However, their specificity (6.8%) was significantly lower than any of the evaluated criteria (50.3%, 69.6%, 63.4%, 78.7%, 45.8%, 71.3%, 13.9%; p < 0.001).

CONCLUSION

Referral criteria based on f-Hb measurement, either as a single test or within prediction models, are more accurate than symptom-based referral criteria for CRC detection in symptomatic patients.

Symptom Severity and Quality of Life Among Long-term Colorectal Cancer Survivors Compared With Matched Control Subjects: A Population-Based Study

BACKGROUND

Data are lacking regarding physical functioning, psychological well-being, and quality of life among colorectal cancer survivors >10 years postdiagnosis.

OBJECTIVE

The purpose of this study was to examine self-reported physical functioning, quality of life, and psychological well-being in long-term colorectal cancer survivors compared with age- and sex-matched unaffected control subjects.

DESIGN

Participants completed a cross-sectional survey.

SETTINGS

The colorectal cancer survivors and unaffected control subjects were recruited from the Ontario Familial Colorectal Cancer Registry.

PATIENTS

A population-based sample of colorectal cancer survivors (N = 296) and their age- and sex-matched unaffected control subjects (N = 255) were included. Survivors were, on average, 15 years postdiagnosis.

MAIN OUTCOME MEASURES

Quality of life was measured with the Functional Assessment of Cancer Therapy-General scale, bowel dysfunction with the Memorial Sloan-Kettering Cancer Center scale, urinary dysfunction with the International Consultation on Incontinence Questionnaire-Short Form, fatigue with the Functional Assessment of Chronic Illness Therapy-Fatigue scale, and depression with the Center for Epidemiologic Studies-Depression scale.

RESULTS

In linear mixed-model analyses adjusting for income, education, race, and comorbid medical conditions, survivors reported good emotional, functional, physical, and overall quality of life, comparable to control subjects. Fatigue and urinary functioning did not differ significantly between survivors and control subjects. Survivors reported significantly higher social quality of life and lower depression compared with unaffected control subjects. The only area where survivors reported significantly worse deficits was in bowel dysfunction, but the magnitude of differences was relatively small.

LIMITATIONS

Generalizability is limited by moderately low participation rates. Findings are likely biased toward healthy participants. No baseline assessment was available to examine change in outcomes over time.

CONCLUSIONS

Long-term colorectal cancer survivors appear to have comparable quality of life and, in some areas, better well-being than their unaffected peers. Bowel dysfunction may continue to be an ongoing issue even 15 years after colorectal cancer diagnosis. Overall quality of life can be expected to be good in this group of older survivors. See Video Abstract at http://links.lww.com/DCR/A476.

Risk of colorectal cancer among immigrants to Ontario, Canada

Background

The risk of colorectal cancer (CRC) varies around the world and between females and males. We aimed to compare the risk of CRC among immigrants to Ontario, Canada, to its general population.

Methods

We used an exposure-control matched design. We identified persons in the Immigration, Refugees and Citizenship Canada Permanent Resident Database with first eligibility for the Ontario Health Insurance Plan between July 1, 1991 and June 30, 2008 at age 40 years or older, and matched five controls by year of birth and sex on the immigrant’s first eligibility date. We identified CRC from the Ontario Cancer Registry between the index date and December 31, 2014. All analyses were stratified by sex. We calculated crude and relative rates of CRC. We estimated risk of CRC over time by the Kaplan-Meier method and compared immigrants to controls in age and sex stratified strata using log-rank tests. We modeled the hazard of CRC using Cox proportional hazards regression, accounting for within-cluster correlation by a robust sandwich variance estimation approach, and assessed an interaction with time since eligibility.

Results

Among females, 1877 cases of CRC were observed among 209,843 immigrants, and 16,517 cases among 1,049,215 controls; the crude relative rate among female immigrants was 0.623. Among males, 1956 cases of CRC were observed among 191,792 immigrants and 18,329 cases among 958,960 controls; the crude relative rate among male immigrants was 0.582.. Comparing immigrants to controls in all age and sex stratified strata, the log rank test p < 0.0001 except for females aged > = 75 years at index, where p = 0.01. The age-adjusted hazard ratio (HR) for CRC among female immigrants was 0.63 (95% CI 0.59, 0.67) during the first 10 years, and 0.66 (95% CI 0.59, 0.74) thereafter. Among male immigrants the age-adjusted HR = 0.55 (95% CI 0.52, 0.59) during the first 10 years and increased to 0.63 (95% CI 0.57, 0.71) thereafter. The adjusted HR > = 1 only among immigrants born in Europe and Central Asia.

Conclusions

The risk of CRC among immigrants to Ontario relative to controls varies by origin and over time since immigration.

Performance report cards increase adenoma detection rate

BACKGROUND AND STUDY AIMS

Adenoma detection rate (ADR) is an important measure of colonoscopy quality, as are polyp, advanced ADR, and adenocarcinoma detection rates. We investigated whether performance report cards improved these outcome measures.

PATIENTS AND METHODS

Endoscopists were given report cards comparing their detection rates to the institutional mean on an annual basis. Detection rates were evaluated at baseline, 1 year after report cards (Year 1), and 2 years after report cards (Year 2). Endoscopists were unaware of the study and received no other interventions. The primary outcome was ADR and secondary outcomes were polyp detection rate (PDR), advanced ADR, and adenocarcinoma detection rate. Multivariate regression was performed to adjust for temporal trends in patient, endoscopists, and procedural factors.

RESULTS

 Seventeen physicians performed 3,118 screening colonoscopies in patients with positive FOBT or family history of colon cancer. The ADR increased from 34.5 % (baseline) to 39.4 % (Year 1) and 41.2 % (Year 2) ( P  = 0.0037). The PDR increased from 45 % (baseline) to 48.8 % (Year 1) and 51.8 % (Year 2) ( P  = 0.011). There was no significant improvement in advanced ADR or adenocarcinoma detection rates. On multivariate analysis, the ADR increased by 22 % in Year 1 ( P  = 0.03) and 30 % in Year 2 ( P  = 0.008). Among physicians with a baseline ADR < 25 %, improvement in ADR was even greater, increasing 2.2 times by the end of the study ( P  = 0.004). Improvements in ADR were not correlated with specialty although gastroenterologists were 52 % more likely to find an adenoma than general surgeons.

CONCLUSIONS

 Annual performance report cards increased adenoma detection rates, especially among physicians with low ADR < 25 %.

Repeat Colonoscopy within 6 Months after Initial Outpatient Colonoscopy in Ontario: A Population-Based Cross-Sectional Study

BACKGROUND

The goal of this study is to examine utilization of early repeat colonoscopy ≤ 6 months after an index procedure.

METHODS

We identified persons having repeat colonoscopy ≤ 6 months following outpatient colonoscopy without prior colonoscopy ≤ 5 years or prior diagnosis of colorectal cancer (CRC). We modeled repeat colonoscopy using a generalized estimating equation with an exchangeable correlation structure to account for clustering of patients by endoscopist.

RESULTS

The population included 334,663 persons, 7,892 (2.36%) of whom had an early repeat colonoscopy within 6 months. Overall, endoscopist prior year colonoscopy volume was inversely related to repeat ≤ 6 months. Repeat colonoscopy ≤ 6 months varied by the clinical setting of the index colonoscopy (adjusted OR = 1.41 (95% CI 1.29-1.55)) at nonhospital facilities compared to teaching or community hospitals. Among those who had polypectomy or biopsy, the adjusted OR for early repeat ≤ 6 months was elevated among those whose index colonoscopy was at a nonhospital facility (OR 1.44, 95% CI 1.30-1.60), compared to those at a teaching hospital or community hospital.

CONCLUSIONS

Repeat colonoscopy ≤ 6 months after an index procedure is associated with the clinical setting of the index colonoscopy.

Barriers of Female Breast, Colorectal, and Cervical Cancer Screening Among American Indians-Where to Intervene?

Female breast, colorectal, and cervical cancer are three common cancers among people in the United States. Both their incidence and mortality rates can be dramatically reduced if effective prevention and intervention programs are developed and implemented, because these cancers are preventable through regular screenings. American Indians in the United States especially in the Northern Plains have a disproportionally high burden of these cancers. As a hard-to-reach population group, less attention has been paid to American Indians regarding cancer screening compared with other population groups. This study examined barriers experienced by American Indians residing in South Dakota regarding three cancer sites: female breast, colorectal, and cervical cancer through a community-based survey. A total of 199 participants were recruited and factors significantly associated with cancer screening included knowledge about cancer screening, geographic access to PCPs, encouragement by doctors, as well as socioeconomic barriers. Meanwhile, integrating geographic access, socioeconomic deprivation, and geographic distribution of American Indians, the study identified geographic areas of low access to cancer screening where hard-to-reach populations resided. Results from the study will provide crucial information for the development of targeted intervention programs to increase the acceptability and uptake of cancer screening among American Indians.

Colorectal Cancer Screening in Average Risk Populations: Evidence Summary

Introduction. The objectives of this systematic review were to evaluate the evidence for different CRC screening tests and to determine the most appropriate ages of initiation and cessation for CRC screening and the most appropriate screening intervals for selected CRC screening tests in people at average risk for CRC. Methods. Electronic databases were searched for studies that addressed the research objectives. Meta-analyses were conducted with clinically homogenous trials. A working group reviewed the evidence to develop conclusions. Results. Thirty RCTs and 29 observational studies were included. Flexible sigmoidoscopy (FS) prevented CRC and led to the largest reduction in CRC mortality with a smaller but significant reduction in CRC mortality with the use of guaiac fecal occult blood tests (gFOBTs). There was insufficient or low quality evidence to support the use of other screening tests, including colonoscopy, as well as changing the ages of initiation and cessation for CRC screening with gFOBTs in Ontario. Either annual or biennial screening using gFOBT reduces CRC-related mortality. Conclusion. The evidentiary base supports the use of FS or FOBT (either annual or biennial) to screen patients at average risk for CRC. This work will guide the development of the provincial CRC screening program.

Risk prediction models for colorectal cancer in people with symptoms: a systematic review

Background

Colorectal cancer (CRC) is the fourth leading cause of cancer-related death in Europe and the United States. Detecting the disease at an early stage improves outcomes. Risk prediction models which combine multiple risk factors and symptoms have the potential to improve timely diagnosis. The aim of this review is to systematically identify and compare the performance of models that predict the risk of primary CRC among symptomatic individuals.

Methods

We searched Medline and EMBASE to identify primary research studies reporting, validating or assessing the impact of models. For inclusion, models needed to assess a combination of risk factors that included symptoms, present data on model performance, and be applicable to the general population. Screening of studies for inclusion and data extraction were completed independently by at least two researchers.

Results

Twelve thousand eight hundred eight papers were identified from the literature search and three through citation searching. 18 papers describing 15 risk models were included. Nine were developed in primary care populations and six in secondary care. Four had good discrimination (AUROC > 0.8) in external validation studies, and sensitivity and specificity ranged from 0.25 and 0.99 to 0.99 and 0.46 depending on the cut-off chosen.

Conclusions

Models with good discrimination have been developed in both primary and secondary care populations. Most contain variables that are easily obtainable in a single consultation, but further research is needed to assess clinical utility before they are incorporated into practice.

Electronic supplementary material

The online version of this article (doi:10.1186/s12876-016-0475-7) contains supplementary material, which is available to authorized users.

Colorectal cancer screening by colonoscopy: putting it into perspective

Implementation of nationwide screening programs aims to decrease the disease burden of colorectal cancer (CRC) in the general population. Globally, most population screening programs for CRC are carried out by either fecal occult blood test, flexible sigmoidoscopy or colonoscopy. For screening programs with colonoscopy as the primary method, only circumstantial evidence from observational studies is available to prove its effectiveness, suggesting that colonoscopy effectively reduces CRC incidence and mortality. Currently, large randomized trials are being conducted to corroborate these findings. Besides the direct effect of a screening program for CRC, its protective effect is further enhanced by enrolment of patients that underwent polypectomy in surveillance programs. However, despite CRC screening and surveillance colonoscopies, interval CRC still occur. Those are predominantly located in the right-sided colon and potential explanations, besides unfavorable tumor characteristics, are preventable operator-dependent factors relating to the quality of the colonoscopy procedure. In an effort to reduce differences in endoscopists' performance and thereby the occurrence of interval CRC, quality indicators of colonoscopy have been introduced. In addition, emerging advanced colonoscopy techniques might contribute to improvement in polyp detection and removal. Meticulous inspection of the colonic mucosa not only results in the detection of advanced and relevant lesions, but also in the removal of many diminutive and small lesions leading to an increasing number of surveillance colonoscopies, known as the 'high-detection paradox'. More data on the cost-effectiveness of high-quality colonoscopy as a primary screening method and surveillance programs with intervals based on optimal risk stratification are eagerly awaited.

Colonoscopy Reduces Colorectal Cancer Incidence and Mortality in Patients With Non-Malignant Findings: A Meta-Analysis

OBJECTIVES

Observational studies have shown that colonoscopy reduces colorectal cancer (CRC) incidence and mortality in the general population. We aimed to conduct a meta-analysis quantifying the magnitude of protection by colonoscopy, with screening and diagnostic indications, against CRC in patients with non-malignant findings and demonstrating the potentially more marked effect of screening over diagnostic colonoscopy.

METHODS

PubMed, EMBASE, and conference abstracts were searched through 30 April 2015. The primary outcomes were overall CRC incidence and mortality. Pooled relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random-effect models.

RESULTS

Eleven observational studies with a total of 1,499,521 individuals were included. Pooled analysis showed that colonoscopy was associated with a 61% RR reduction in CRC incidence (RR: 0.39; 95% CI: 0.26-0.60; I(2)=93.6%) and a 61% reduction in CRC mortality (RR: 0.39; 95% CI: 0.35-0.43; I(2)=12.0%) in patients with non-malignant findings, although there was high heterogeneity for the outcome of CRC incidence. After excluding one outlier study, there was low heterogeneity for the outcome of incidence (I(2)=44.7%). Subgroup analysis showed that the effect of screening colonoscopy was more prominent, corresponding to an 89% reduction in CRC incidence (RR: 0.11; 95% CI: 0.08-0.15), in comparison with settings involving diagnostic colonoscopy (RR: 0.51; 95% CI: 0.43-0.59; P<0.001).

CONCLUSIONS

On the basis of this meta-analysis of observational studies, CRC incidence and mortality in patients with non-malignant findings are significantly reduced after colonoscopy. The effect of screening colonoscopy on CRC incidence is more marked than diagnostic colonoscopy.

Ten-year incidence of colorectal cancer following a negative screening sigmoidoscopy: an update from the Colorectal Cancer Prevention (CoCaP) programme

OBJECTIVE

To examine the rates of colorectal cancer (CRC) following a negative screening sigmoidoscopy.

DESIGN

Cohort study.

SETTING

An integrated healthcare delivery organisation in California, USA.

PARTICIPANTS

72,483 men and women aged 50 years and above who had a negative screening sigmoidoscopy between 1994 and 1996. Those at elevated risk of CRC due to inflammatory bowel disease, prior polyps or CRC, or a strong family history of CRC were excluded.

MAIN OUTCOME MEASURES

Incidence rates of distal and proximal CRC. Standardised Incidence Ratios were used to compare annual incidence rates of distal and proximal CRC in the cohort to expected rates based on Surveillance, Epidemiology, and End Results data. Additionally, rate ratios (RR) and rate differences (RD) comparing the incidence rate of distal CRC in years 6+ postscreening with that in years 1-5 were calculated.

RESULTS

Incidence rates of distal CRC were lower than those in the San Francisco Bay area population at large during each of the first 10 years postsigmoidoscopy screening. However, the incidence of distal CRC rose steadily, from 3 per 100,000 in the first year of follow-up to 40 per 100,000 in the 10th year. During the second half of follow-up, the rate of distal CRC was twice as high as in the first half (RR 2 .08, 95% CI 1.38 to 3.16; RD 14 per 100,000 person-years, 95% CI 6 to 22).

CONCLUSIONS

Though still below population levels, the incidence of CRC during years 6-10 following a negative sigmoiodoscopy is appreciably higher than during the first 5 years.

A systematic review and economic evaluation of diagnostic strategies for Lynch syndrome

BACKGROUND

Lynch syndrome (LS) is an inherited autosomal dominant disorder characterised by an increased risk of colorectal cancer (CRC) and other cancers, and caused by mutations in the deoxyribonucleic acid (DNA) mismatch repair genes.

OBJECTIVE

To evaluate the accuracy and cost-effectiveness of strategies to identify LS in newly diagnosed early-onset CRC patients (aged < 50 years). Cascade testing of relatives is employed in all strategies for individuals in whom LS is identified.

DATA SOURCES AND METHODS

Systematic reviews were conducted of the test accuracy of microsatellite instability (MSI) testing or immunohistochemistry (IHC) in individuals with CRC at risk of LS, and of economic evidence relating to diagnostic strategies for LS. Reviews were carried out in April 2012 (test accuracy); and in February 2012, repeated in February 2013 (economic evaluations). Databases searched included MEDLINE (1946 to April week 3, 2012), EMBASE (1980 to week 17, 2012) and Web of Science (inception to 30 April 2012), and risk of bias for test accuracy was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) quality appraisal tool. A de novo economic model of diagnostic strategies for LS was developed.

RESULTS

Inconsistencies in study designs precluded pooling of diagnostic test accuracy results from a previous systematic review and nine subsequent primary studies. These were of mixed quality, with significant methodological concerns identified for most. IHC and MSI can both play a part in diagnosing LS but neither is gold standard. No UK studies evaluated the cost-effectiveness of diagnosing and managing LS, although studies from other countries generally found some strategies to be cost-effective compared with no testing. The de novo model demonstrated that all strategies were cost-effective compared with no testing at a threshold of £20,000 per quality-adjusted life-year (QALY), with the most cost-effective strategy utilising MSI and BRAF testing [incremental cost-effectiveness ratio (ICER) = £5491 per QALY]. The maximum health benefit to the population of interest would be obtained using universal germline testing, but this would not be a cost-effective use of NHS resources compared with the next best strategy. When the age limit was raised from 50 to 60 and 70 years, the ICERs compared with no testing increased but remained below £20,000 per QALY (except for universal germline testing with an age limit of 70 years). The total net health benefit increased with the age limit as more individuals with LS were identified. Uncertainty was evaluated through univariate sensitivity analyses, which suggested that the parameters substantially affecting cost-effectiveness: were the risk of CRC for individuals with LS; the average number of relatives identified per index patient; the effectiveness of colonoscopy in preventing metachronous CRC; the cost of colonoscopy; the duration of the psychological impact of genetic testing on health-related quality of life (HRQoL); and the impact of prophylactic hysterectomy and bilateral salpingo-oophorectomy on HRQoL (this had the potential to make all testing strategies more expensive and less effective than no testing).

LIMITATIONS

The absence of high-quality data for the impact of prophylactic gynaecological surgery and the psychological impact of genetic testing on HRQoL is an acknowledged limitation.

CONCLUSIONS

Results suggest that reflex testing for LS in newly diagnosed CRC patients aged < 50 years is cost-effective. Such testing may also be cost-effective in newly diagnosed CRC patients aged < 60 or < 70 years. Results are subject to uncertainty due to a number of parameters, for some of which good estimates were not identified. We recommend future research to estimate the cost-effectiveness of testing for LS in individuals with newly diagnosed endometrial or ovarian cancer, and the inclusion of aspirin chemoprevention. Further research is required to accurately estimate the impact of interventions on HRQoL.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42012002436.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Colorectal Cancer Screening

Colorectal cancer (CRC) is a leading cause of cancer morbidity and mortality in the Western world. Advances in surgical and medical management have led to improved outcomes; however, the prognosis of CRC is often poor when detected at a symptomatic stage. Most cases of CRC develop over years from removable well-defined precursor lesions, and asymptomatic, curable disease may be detected by convenient noninvasive tests. These features make CRC a suitable candidate for screening, and several options are available. This article outlines the evidence for established CRC screening tests along with a discussion on newer tests and ongoing research.

The impact of stratifying by family history in colorectal cancer screening programs

In the province-wide colorectal cancer (CRC) screening program in Ontario, Canada, individuals with a family history of CRC are offered colonoscopy screening and those without are offered guaiac fecal occult blood testing (gFOBT, Hemoccult II). We used microsimulation modeling to estimate the cumulative number of CRC deaths prevented and colonoscopies performed between 2008 and 2038 with this family history-based screening program, compared to a regular gFOBT program. In both programs, we assumed screening uptake increased from 30% (participation level in 2008 before the program was launched) to 60%. We assumed that 11% of the population had a family history, defined as having at least one first-degree relative diagnosed with CRC. The programs offered screening between age 50 and 74 years, every two years for gFOBT, and every ten years for colonoscopy. Compared to opportunistic screening (2008 participation level kept constant at 30%), the gFOBT program cumulatively prevented 6,700 more CRC deaths and required 570,000 additional colonoscopies by 2038. The family history-based screening program increased these numbers to 9,300 and 1,100,000, a 40% and 93% increase, respectively. If biennial gFOBT was replaced with biennial fecal immunochemical test (FIT), annual Hemoccult Sensa or five-yearly sigmoidoscopy screening, both the added benefits and colonoscopies required would decrease. A biennial gFOBT screening program that identifies individuals with a family history of CRC and recommends them to undergo colonoscopy screening would prevent 40% (range in sensitivity analyses: 20-51%) additional deaths while requiring 93% (range: 43-116%) additional colonoscopies, compared to a regular gFOBT screening program.

Colorectal cancer screening and subsequent incidence of colorectal cancer: results from the 45 and Up Study

OBJECTIVE

To investigate the association of colorectal cancer (CRC) screening history and subsequent incidence of CRC in New South Wales, Australia.

DESIGN, SETTING AND PARTICIPANTS

A total of 196,464 people from NSW recruited to the 45 and Up Study, a large Australian population-based prospective study, by completing a baseline questionnaire distributed from January 2006 to December 2008. Individuals without pre-existing cancer were followed for a mean of 3.78 years (SD, 0.92 years) through linkage to population health datasets.

MAIN OUTCOME MEASURES

Incidence of CRC; hazard ratio (HR) according to screening history, adjusted for age, sex, body mass index, income, education, remoteness, family history, aspirin use, smoking, diabetes, alcohol use, physical activity and dietary factors.

RESULTS

Overall, 1096 cases of incident CRC accrued (454 proximal colon, 240 distal colon, 349 rectal and 53 unspecified cancers). Ever having undergone CRC screening before baseline was associated with a 44% reduced risk of developing CRC during follow-up (HR, 0.56; 95% CI, 0.49-0.63) compared with never having undergone screening. This effect was more pronounced for those reporting endoscopy (HR, 0.50; 95% CI, 0.43-0.58) than those reporting faecal occult blood testing (FOBT) (HR, 0.61; 95% CI, 0.52-0.72). Associations for all screening exposures were strongest for rectal cancer (HR, 0.35; 95% CI, 0.27-0.45) followed by distal colon cancer (HR, 0.60; 95% CI, 0.46-0.78), while relationships were weaker for cancers of the proximal colon (HR, 0.76; 95% CI, 0.62-0.92).

CONCLUSION

CRC incidence is lower among individuals with a history of CRC screening, through either FOBT or endoscopy, compared with individuals who have never had CRC screening, lasting for at least 4 years after screening.

Impact of sigmoidoscopy and colonoscopy on colorectal cancer incidence and mortality: an evidence-based review of published prospective and retrospective studies

Screening for colorectal cancer (CRC) using sigmoidoscopy or colonoscopy is now common in many developed countries. This concise, evidence-based review looks at the impact of sigmoidoscopy or colonoscopy screening on CRC incidence, CRC mortality and overall mortality. Data from controlled retrospective and prospective (observational or randomized) studies have generally shown that sigmoidoscopy and colonoscopy, whether for diagnostic, screening or surveillance purposes, are associated with a significant reduction in CRC incidence and CRC mortality. The data on their impact on overall mortality is much more limited, with most studies unable to report a reduction in overall mortality. The results of three meta-analyses have confirmed these conclusions. As expected, sigmoidoscopy has a predominant effect on left-sided CRC, although some studies have shown modest effects on right-sided colon cancer as well. Most studies on colonoscopy have demonstrated that the protective effect applies to both right and left-sided cancer, although the protection seemed better on the left side. Despite the introduction of other screening and diagnostic modalities for the colon, such as computed tomography colonography and colonic capsule endoscopy, lower endoscopy will continue to be an important mode of screening for CRC and evaluating the colon.

Pleiotropic effects of genetic risk variants for other cancers on colorectal cancer risk: PAGE, GECCO and CCFR consortia

OBJECTIVE

Genome-wide association studies have identified a large number of single nucleotide polymorphisms (SNPs) associated with a wide array of cancer sites. Several of these variants demonstrate associations with multiple cancers, suggesting pleiotropic effects and shared biological mechanisms across some cancers. We hypothesised that SNPs previously associated with other cancers may additionally be associated with colorectal cancer. In a large-scale study, we examined 171 SNPs previously associated with 18 different cancers for their associations with colorectal cancer.

DESIGN

We examined 13 338 colorectal cancer cases and 40 967 controls from three consortia: Population Architecture using Genomics and Epidemiology (PAGE), Genetic Epidemiology of Colorectal Cancer (GECCO), and the Colon Cancer Family Registry (CCFR). Study-specific logistic regression results, adjusted for age, sex, principal components of genetic ancestry, and/or study specific factors (as relevant) were combined using fixed-effect meta-analyses to evaluate the association between each SNP and colorectal cancer risk. A Bonferroni-corrected p value of 2.92×10(-4) was used to determine statistical significance of the associations.

RESULTS

Two correlated SNPs--rs10090154 and rs4242382--in Region 1 of chromosome 8q24, a prostate cancer susceptibility region, demonstrated statistically significant associations with colorectal cancer risk. The most significant association was observed with rs4242382 (meta-analysis OR=1.12; 95% CI 1.07 to 1.18; p=1.74×10(-5)), which also demonstrated similar associations across racial/ethnic populations and anatomical sub-sites.

CONCLUSIONS

This is the first study to clearly demonstrate Region 1 of chromosome 8q24 as a susceptibility locus for colorectal cancer; thus, adding colorectal cancer to the list of cancer sites linked to this particular multicancer risk region at 8q24.

Effect of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality: systematic review and meta-analysis of randomised controlled trials and observational studies

OBJECTIVES

To review, summarise, and compare the evidence for effectiveness of screening sigmoidoscopy and screening colonoscopy in the prevention of colorectal cancer occurrence and deaths.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and observational studies.

DATA SOURCES

PubMed, Embase, and Web of Science. Two investigators independently extracted characteristics and results of identified studies and performed standardised quality ratings.

ELIGIBILITY CRITERIA

Randomised controlled trials and observational studies in English on the impact of screening sigmoidoscopy and screening colonoscopy on colorectal cancer incidence and mortality in the general population at average risk.

RESULTS

For screening sigmoidoscopy, four randomised controlled trials and 10 observational studies were identified that consistently found a major reduction in distal but not proximal colorectal cancer incidence and mortality. Summary estimates of reduction in distal colorectal cancer incidence and mortality were 31% (95% confidence intervals 26% to 37%) and 46% (33% to 57%) in intention to screen analysis, 42% (29% to 53%) and 61% (27% to 79%) in per protocol analysis of randomised controlled trials, and 64% (50% to 74%) and 66% (38% to 81%) in observational studies. For screening colonoscopy, evidence was restricted to six observational studies, the results of which suggest tentatively an even stronger reduction in distal colorectal cancer incidence and mortality, along with a significant reduction in mortality from cancer of the proximal colon. Indirect comparisons of results of observational studies on screening sigmoidoscopy and colonoscopy suggest a 40% to 60% lower risk of incident colorectal cancer and death from colorectal cancer after screening colonoscopy even though this incremental risk reduction was statistically significant for deaths from cancer of the proximal colon only.

CONCLUSIONS

Compelling and consistent evidence from randomised controlled trials and observational studies suggests that screening sigmoidoscopy and screening colonoscopy prevent most deaths from distal colorectal cancer. Observational studies suggest that colonoscopy compared with flexible sigmoidoscopy decreases mortality from cancer of the proximal colon. This added value should be examined in further research and weighed against the higher costs, discomfort, complication rates, capacities needed, and possible differences in compliance.

Reduced risk of colorectal cancer up to 10 years after screening, surveillance, or diagnostic colonoscopy

BACKGROUND & AIMS

Data from randomized controlled trials on the effects of screening colonoscopies on colorectal cancer (CRC) incidence and mortality are not available. Observational studies have suggested that colonoscopies strongly reduce the risk of CRC, but there is little specific evidence on the effects of screening colonoscopies.

METHODS

We performed a population-based case-control study of 3148 patients with a first diagnosis of CRC (cases) and 3274 subjects without CRC (controls) from the Rhine-Neckar region of Germany from 2003 to 2010. Detailed information on previous colonoscopy and potential confounding factors was collected by standardized personal interviews. Self-reported information on colonoscopies and their indications was validated by medical records. We used multiple logistic regression to assess the association between colonoscopy conducted for specific indications within the past 10 years and risk of CRC.

RESULTS

A history of colonoscopy was associated with a reduced subsequent risk of CRC, independently of the indication for the examination. However, somewhat stronger associations were found for examinations with screening indications (adjusted odds ratio [OR] 0.09, 95% confidence interval [CI] 0.07-0.13) than for examinations with diagnostic indications, such as positive fecal occult blood test result (OR, 0.33; 95% CI, 0.19-0.57), surveillance after a preceding colonoscopy (OR, 0.33; 95% CI, 0.24-0.45), rectal bleeding (OR, 0.28; 95% CI, 0.20-0.40), abdominal symptoms (OR, 0.15; 95% CI, 0.10-0.21), or other (OR, 0.21; 95% CI, 0.14-0.30). Colonoscopy was also associated with a reduced risk of cancer in the right colon, regardless of the indication, although to a smaller extent than for other areas of the colon (OR for screening colonoscopy, 0.22; 95% CI, 0.14-0.33).

CONCLUSIONS

In a population-based case-control study, the risk of CRC was strongly reduced up to 10 years after colonoscopy for any indication. Risk was particularly low after screening colonoscopy, even for cancer in the right colon.

Identification of Genetic Susceptibility Loci for Colorectal Tumors in a Genome-Wide Meta-analysis

BACKGROUND & AIMS

Heritable factors contribute to the development of colorectal cancer. Identifying the genetic loci associated with colorectal tumor formation could elucidate the mechanisms of pathogenesis.

METHODS

We conducted a genome-wide association study that included 14 studies, 12,696 cases of colorectal tumors (11,870 cancer, 826 adenoma), and 15,113 controls of European descent. The 10 most statistically significant, previously unreported findings were followed up in 6 studies; these included 3056 colorectal tumor cases (2098 cancer, 958 adenoma) and 6658 controls of European and Asian descent.

RESULTS

Based on the combined analysis, we identified a locus that reached the conventional genome-wide significance level at less than 5.0 × 10(-8): an intergenic region on chromosome 2q32.3, close to nucleic acid binding protein 1 (most significant single nucleotide polymorphism: rs11903757; odds ratio [OR], 1.15 per risk allele; P = 3.7 × 10(-8)). We also found evidence for 3 additional loci with P values less than 5.0 × 10(-7): a locus within the laminin gamma 1 gene on chromosome 1q25.3 (rs10911251; OR, 1.10 per risk allele; P = 9.5 × 10(-8)), a locus within the cyclin D2 gene on chromosome 12p13.32 (rs3217810 per risk allele; OR, 0.84; P = 5.9 × 10(-8)), and a locus in the T-box 3 gene on chromosome 12q24.21 (rs59336; OR, 0.91 per risk allele; P = 3.7 × 10(-7)).

CONCLUSIONS

In a large genome-wide association study, we associated polymorphisms close to nucleic acid binding protein 1 (which encodes a DNA-binding protein involved in DNA repair) with colorectal tumor risk. We also provided evidence for an association between colorectal tumor risk and polymorphisms in laminin gamma 1 (this is the second gene in the laminin family to be associated with colorectal cancers), cyclin D2 (which encodes for cyclin D2), and T-box 3 (which encodes a T-box transcription factor and is a target of Wnt signaling to β-catenin). The roles of these genes and their products in cancer pathogenesis warrant further investigation.

Identification of germline genomic copy number variation in familial pancreatic cancer

Adenocarcinoma of the pancreas is a significant cause of cancer mortality, and up to 10 % of cases appear to be familial. Heritable genomic copy number variants (CNVs) can modulate gene expression and predispose to disease. Here, we identify candidate predisposition genes for familial pancreatic cancer (FPC) by analyzing germline losses or gains present in one or more high-risk patients and absent in a large control group. A total of 120 FPC cases and 1,194 controls were genotyped on the Affymetrix 500K array, and 36 cases and 2,357 controls were genotyped on the Affymetrix 6.0 array. Detection of CNVs was performed by multiple computational algorithms and partially validated by quantitative PCR. We found no significant difference in the germline CNV profiles of cases and controls. A total of 93 non-redundant FPC-specific CNVs (53 losses and 40 gains) were identified in 50 cases, each CNV present in a single individual. FPC-specific CNVs overlapped the coding region of 88 RefSeq genes. Several of these genes have been reported to be differentially expressed and/or affected by copy number alterations in pancreatic adenocarcinoma. Further investigation in high-risk subjects may elucidate the role of one or more of these genes in genetic predisposition to pancreatic cancer.

Association of total energy intake and macronutrient consumption with colorectal cancer risk: results from a large population-based case-control study in Newfoundland and Labrador and Ontario, Canada

Background

Diet is regarded as one of the most important environmental factors associated with colorectal cancer (CRC) risk. A recent report comprehensively concluded that total energy intake does not have a simple relationship with CRC risk, and that the data were inconsistent for carbohydrate, cholesterol and protein. The objective of this study was to identify the associations of CRC risk with dietary intakes of total energy, protein, fat, carbohydrate, fiber, and alcohol using data from a large case-control study conducted in Newfoundland and Labrador (NL) and Ontario (ON), Canada.

Methods

Incident colorectal cancer cases (n = 1760) were identified from population-based cancer registries in the provinces of ON (1997-2000) and NL (1999-2003). Controls (n = 2481) were a random sample of residents in each province, aged 20-74 years. Family history questionnaire (FHQ), personal history questionnaire (PHQ), and food frequency questionnaire (FFQ) were used to collect study data. Logistic regression was used to evaluate the association of intakes of total energy, macronutrients and alcohol with CRC risk.

Results

Total energy intake was associated with higher risk of CRC (OR: 1.56; 95% CI: 1.21-2.01, p-trend = 0.02, 5^th versus 1^st quintile), whereas inverse associations emerged for intakes of protein (OR: 0.85, 95%CI: 0.69-1.00, p-trend = 0.06, 5^th versus 1^st quintile), carbohydrate (OR: 0.81, 95%CI: 0.63-1.00, p-trend = 0.05, 5^th versus 1^st quintile) and total dietary fiber (OR: 0.84, 95% CI:0.67-0.99, p-trend = 0.04, 5^th versus 1^st quintile). Total fat, alcohol, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, and cholesterol were not associated with CRC risk.

Conclusion

This study provides further evidence that high energy intake may increase risk of incident CRC, whereas diets high in protein, fiber, and carbohydrate may reduce the risk of the disease.

Predictors of delayed-stage colorectal cancer: are we neglecting critical demographic information?

PURPOSE

We sought to distinguish roles of demographic variables and bowel segments as predictors of delayed versus early stage colorectal cancer in California.

METHODS

Demographic and anatomic variables for 66,806 colorectal cancers were extracted from the California Cancer Registry for 2004-2008 and analyzed using logistic regression as delayed versus early stage.

RESULTS

Odds ratios (OR) for binary stage categories comparing age <40 (OR=2.58; 95% CI=2.26-2.94), 40-49 (1.71; 95%=1.60-1.83) and 75+ (1.05; 1.02-1.09) relative to 50-74 years were computed. Compared with non-Hispanic whites, ORs for stage categories were: 1.05; 0.99-1.13 (non-Hispanic blacks), 1.08; 1.02-1.13 (Hispanics), and 1.05; 1.00-1.10 (Asian/others). Females had higher odds of delayed diagnosis (1.09; 1.06-1.13) than males. Descending ORs were measured for successively lower to highest socioeconomic status (SES) quintiles (OR 4:5=1.08; 1.03-1.14, OR 3:5=1.13; 1.08-1.19, OR 2:5=1.18; 1.12- 1.24, and OR 1:5=1.21; 1.14-1.28).

CONCLUSIONS

Younger and older than age 50-74; females; Hispanic ethnicity; bowel segment contrasts (right/left, proximal/distal, cecum plus appendix/distal), and lower SES were independent predictors of delayed diagnosis. Low SES was the most robust predictor of delayed diagnosis, independent of other covariates. Approximately 77% of delayed diagnoses were in non-Hispanic whites and Asian/others. These findings illustrate the value of a community SES index for targeting egalitarian colorectal cancer screening.

Testing women with endometrial cancer to detect Lynch syndrome

PURPOSE

Women with endometrial cancer as a result of Lynch syndrome may not be identified as such by Amsterdam II criteria. We estimated the costs and benefits of different testing criteria to identify Lynch syndrome in women with endometrial cancer.

METHODS

We developed a Markov Monte Carlo simulation model to compare six criteria for Lynch syndrome testing for women with endometrial cancer: Amsterdam II criteria; age younger than 50 years with at least one first-degree relative having a Lynch-associated cancer at any age (FDR); immunohistochemistry (IHC) triage if age younger than 50 years; IHC triage if age younger than 60 years; IHC triage at any age if 1 FDR; and IHC triage of all endometrial cancers. Net health benefit was life expectancy, and primary outcome was the incremental cost-effectiveness ratio (ICER). The model estimated the number of new colorectal cancers associated with each strategy.

RESULTS

IHC triage of women with endometrial cancer having at least 1 FDR yielded a favorable ICER of $9,126 per year of life gained. This strategy would subject fewer cases to IHC but identify more mutation carriers than age thresholds of 50 or 60 years. IHC triage of all endometrial cancers could identify the most mutation carriers and prevent the most colorectal cancers but at considerable cost ($648,494 per year of life gained).

CONCLUSION

IHC triage of women with endometrial cancer at any age having at least 1 FDR with a Lynch-associated cancer is a cost-effective strategy for detecting Lynch syndrome.

Cancer risks for monoallelic MUTYH mutation carriers with a family history of colorectal cancer

Cancer risks for a person who has inherited a MUTYH mutation from only one parent (monoallelic mutation carrier) are uncertain. Using the Colon Cancer Family Registry and Newfoundland Familial Colon Cancer Registry, we identified 2,179 first- and second-degree relatives of 144 incident colorectal cancer (CRC) cases who were monoallelic or biallelic mutation carriers ascertained by sampling population complete cancer registries in the United States, Canada and Australia. Using Cox regression weighted to adjust for sampling on family history, we estimated that the country-, age- and sex-specific standardized incidence ratios (SIRs) for monoallelic mutation carriers, compared to the general population, were: 2.04 (95% confidence interval, CI 1.56-2.70; p < 0.001) for CRC, 3.24 (95%CI 2.18-4.98; p < 0.001) for gastric cancer, 3.09 (95%CI 1.07-12.25; p = 0.07) for liver cancer and 2.33 (95%CI 1.18-5.08; p = 0.02) for endometrial cancer. Age-specific cumulative risks to age 70 years, estimated using the SIRs and US population incidences, were: for CRC, 6% (95%CI 5-8%) for men and 4% (95%CI 3-6%) for women; for gastric cancer, 2% (95%CI 1-3%) for men and 0.7% (95%CI 0.5-1%) for women; for liver cancer, 1% (95%CI 0.3-3%) for men and 0.3% (95%CI 0.1-1%) for women and for endometrial cancer, 4% (95%CI 2-8%). There was no evidence of increased risks for cancers of the brain, pancreas, kidney, lung, breast or prostate. Monoallelic MUTYH mutation carriers with a family history of CRC, such as those identified from screening multiple-case CRC families, are at increased risk of colorectal, gastric, endometrial and possibly liver cancers.

Cigarette smoking, genetic variants in carcinogen-metabolizing enzymes, and colorectal cancer risk

The risk of colorectal cancer associated with smoking is unclear and may be influenced by genetic variation in enzymes that metabolize cigarette carcinogens. The authors examined the colorectal cancer risk associated with smoking and 26 variants in carcinogen metabolism genes in 1,174 colorectal cancer cases and 1,293 population-based controls recruited in Canada by the Ontario Familial Colorectal Cancer Registry from 1997 to 2001. Adjusted odds ratios were calculated by multivariable logistic regression. Smoking for >27 years was associated with a statistically significant increased colorectal cancer risk (adjusted odds ratio (AOR) = 1.25, 95% confidence interval (CI): 1.02, 1.53) in all subjects. Colorectal cancer risk associated with smoking was higher in males for smoking status, duration, and intensity. The CYP1A1-3801-CC (AOR = 0.47, 95% CI: 0.23, 0.94) and CYP2C9-430-CT (AOR = 0.82, 95% CI: 0.68, 0.99) genotypes were associated with decreased risk, and the GSTM1-K173N-CG (AOR = 1.99, 95% CI: 1.21, 3.25) genotype was associated with an increased risk of colorectal cancer. Statistical interactions between smoking and genetic variants were assessed by comparing logistic regression models with and without a multiplicative interaction term. Significant interactions were observed between smoking status and SULT1A1-638 (P = 0.02), NAT2-857 (P = 0.01), and CYP1B1-4390 (P = 0.04) variants and between smoking duration and NAT1-1088 (P = 0.02), SULT1A1-638 (P = 0.04), and NAT1-acetylator (P = 0.03) status. These findings support the hypothesis that prolonged cigarette smoking is associated with increased risk of colorectal cancer and that this risk may be modified by variation in carcinogen metabolism genes.

Population-based prevalence estimates of history of colonoscopy or sigmoidoscopy: review and analysis of recent trends

BACKGROUND

Lower GI endoscopy, such as colonoscopy or sigmoidoscopy, is thought to have a substantial impact on colorectal cancer incidence and mortality through detection and removal of precancerous lesions and early cancers. We aimed to review prevalence estimates of history of colonoscopy or sigmoidoscopy in the general population and to analyze recent trends.

METHODS

A systematic review of the medical literature, including MEDLINE (1966 to August 2008) and EMBASE (1980 to August 2008), was undertaken, supplemented by searches of the European Health Interview & Health Examination Surveys database and bibliographies. Detailed age-specific and sex-specific prevalence estimates from the United States were obtained from the Behavioral Risk Factor Surveillance System surveys 2002, 2004, and 2006.

RESULTS

The search yielded 55 studies that met our inclusion criteria. The majority of the reports (43) originated from the United States. Other countries of origin included Australia (2), Austria (2), Canada (5), France (1), Germany (1), and Greece (1). Estimates from the United States were generally increasing over time up to 56% (2006) for lifetime use of colonoscopy or sigmoidoscopy in people aged 50 years and older. Analysis of national survey data showed higher prevalences among men aged 55 years and older than for women of the same age. Prevalences were highest for people aged 70 to 79 years.

CONCLUSION

Data from outside the United States were extremely limited. Prevalence estimates from the United States indicate that a considerable and increasing proportion of the population at risk has had at least 1 colonoscopy or sigmoidoscopy in their lives, although differences between age and sex groups persist. Prevalences of previous colonoscopy or sigmoidoscopy need to be taken into account in the interpretation of time trends in, and variation across, populations of colorectal cancer incidence and mortality.

Combination of sigmoidoscopy and a fecal immunochemical test to detect proximal colon neoplasia

BACKGROUND & AIMS

The combination of sigmoidoscopy and a sensitive fecal occult blood test was recommended as one strategy for colorectal cancer screening by the US Preventive Services Task Force in 2008. However, there have been no studies to evaluate the sensitivity of a one-time screen that uses both flexible sigmoidoscopy and a fecal immunochemical test (FIT) to detect advanced colorectal neoplasia.

METHODS

We analyzed data from 21,794 asymptomatic persons who had undergone colonoscopy and a FIT. Analyses were performed with the following assumptions: colonoscopy would be performed for any positive FIT result; colonoscopy would be performed if the FIT result was negative and if advanced neoplasia was detected in the rectosigmoid (or plus descending) colon. The sensitivities and specificities of the combination of sigmoidoscopy and the FIT in detecting advanced neoplasia in the proximal colon were determined.

RESULTS

When colonoscopy was performed for a positive FIT result alone, for a positive sigmoidoscopy finding, and for a positive FIT result or sigmoidoscopy finding, the sensitivities in detection of advanced proximal neoplasia were 22.3%, 16.3%, and 31.7%, respectively. The sensitivities for detection of proximal invasive cancer were 58.3%, 8.3%, and 62.5%, respectively.

CONCLUSIONS

The combination of sigmoidoscopy and FIT can detect advanced proximal neoplasia better than either test alone. The incremental yield of advanced neoplasm detection by a screening program that uses both a FIT and sigmoidoscopy is approximately 10%. The FIT adds the most in terms of finding proximal cancers in a screening program that uses both tests. The combination of sigmoidoscopy and FIT is a viable and useful screening option.