Search

Introduction: In previous studies, the protective effect of colonoscopy was generally stronger for distal colorectal cancer than for proximal colorectal cancer (CRC). This study aimed to investigate whether reduction of CRC risk through colonoscopy varies according to major tumor markers and pathways of CRC., Methods: This is a population-based case-control study from Germany, including 2,132 patients with a first diagnosis of CRC and information on major molecular tumor markers and 2,486 control participants without CRC. Detailed participant characteristics were collected by standardized questionnaires. Information on previous colonoscopy was derived from medical records. Polytomous logistic regression was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for the association between previous colonoscopy and subtypes of CRC., Results: Overall, we observed strong risk reduction of CRC after colonoscopy that was weaker for microsatellite instable (MSI) than for non-MSI CRC (OR 0.70, 95% CI 0.50-0.97 vs OR 0.28, 95% CI 0.24-0.33), for CpG island methylator phenotype high CRC than for CpG island methylator phenotype low/negative CRC (OR 0.45, 95% CI 0.34-0.59 vs OR 0.29, 95% CI 0.25-0.34), for BRAF-mutated than for BRAF nonmutated CRC (OR 0.62, 95% CI 0.42-0.91 vs OR 0.30, 95% CI 0.25-0.35), for KRAS nonmutated than for KRAS-mutated CRC (OR 0.34, 95% CI 0.29-0.40 vs OR 0.26, 95% CI 0.20-0.32), and for CRC classified into the sessile serrated pathway than for CRC of the traditional pathway (OR 0.57, 95% CI 0.36-0.91 vs OR 0.30, 95% CI 0.25-0.37). After colonoscopy with the detection of adenomas or hyperplastic polyps, no risk reduction was found for sessile serrated pathway CRC, MSI, and BRAF-mutated subtypes., Discussion: Our study extends the molecular understanding of existing differences in risk reduction of proximal and distal CRCs reported by previous studies and may imply important information for improving strategies for timely detection of relevant precursors.

Introduction: Colonoscopy is an imperfect gold standard for detecting colorectal neoplasms because some proportion of adenomas may be missed, mainly small lesions. This proportion is expected to be higher in case of inadequate bowel cleansing, which is frequently seen in routine practice. We estimated the proportions of neoplasms that are in principle detectable by colonoscopy but might be missed in case of incomplete bowel preparation., Methods: For 8,193 participants of screening colonoscopy in South-Western Germany, recruited between 2005 and 2016, the prevalence and numbers of different findings were extracted from colonoscopy reports and compared according to the reported bowel preparation quality., Results: Bowel preparation quality was reported as good, poor, or was unspecified in 30.3%, 11.1%, and 58.6% of colonoscopy records. Reported prevalences of nonadvanced adenomas (NAAs) were similar among participants with poor and unspecified bowel preparation quality but substantially lower than among participants with good bowel preparation (adjusted prevalence rate ratio [RR] 0.86, 95% confidence interval [CI]: 0.77-0.96). The differences were observed for proximal but not for distal NAAs (RRs 0.82, 95% CI: 0.71-0.95 and 0.95, 95% CI: 0.82-1.10)., Discussion: Our study suggests that a significant proportion of NAAs located in the proximal colon might be missed during colonoscopy if bowel cleansing is not adequate. Major efforts should be made to further facilitate and enhance high-quality bowel preparation in routine screening practice.

Objectives: Many risk scores have been proposed to predict presence of advanced colorectal neoplasms, but a comprehensive comparison conducted in the same population is sparse. The aim of this study was to evaluate and directly compare the diagnostic performance of published risk prediction models for advanced colorectal neoplasms., Methods: Data were drawn from 2 cohorts of subjects undergoing screening colonoscopy in Germany, i.e., KolosSal (n = 16,195) and BliTz (n = 7,444). Absolute risks and relative risks were generated for the presence of at least 1 advanced neoplasm, taking the lowest risk group as the reference group. Performance of risk models was assessed by the area under the receiver operating characteristic curve (AUC) and compared by the net reclassification improvement., Results: The 2 cohorts included 1,917 (11.8%) and 848 (11.4%) participants with advanced neoplasm, respectively. Absolute risks were mostly between 5% and 10% among participants in the lowest risk group and between 15% and 20% among participants in the highest risk group, and relative risks mostly ranged from 2.0 to 4.0 across the risk models in both cohorts. The AUCs ranged from 0.58 to 0.65 in KolosSal and from 0.57 to 0.61 in BliTz for all risk scores. Compared to models with lower AUC, classification was significantly improved in most models with higher AUC., Discussion: Risk models for advanced colorectal neoplasms generally yielded modest discriminatory power, despite some variation in performance between models. Future studies should evaluate the performance of these risk models in racially diverse populations and investigate possible extensions, such as combination with polygenic risk scores.

Background: Red and processed meats have been shown to be associated with colorectal adenomas in many, but not all, studies, and the association according to the type of colorectal adenoma or the location in the colorectum is unclear. Objectives: We investigated the association of meat intake in relation to colorectal polyps and further investigated the association according to histologic subtypes and subsites in a large population-based screening study in Germany. Design: In this cross-sectional study, 15,950 participants aged ≥55 y underwent a screening colonoscopy. We calculated prevalence ratios (PRs) and 95% CIs for associations between meat intake and the most-advanced findings from a colonoscopy with the use of log binomial regression. Results: Overall, 3340 participants (20.4%) had nonadvanced adenomas, 1643 participants (10.0%) had advanced adenomas, and 189 participants (1.2%) had colorectal cancer. We observed no statistically significant association between red or processed meat consumption and the prevalence of any adenomas or advanced adenomas [highest compared with lowest: red meat, PR: 1.07 (95% CI: 0.83, 1.37); processed meat, PR: 1.11 (95% CI: 0.91, 1.36)]. In site-specific analyses, although no dose-response relation was observed, processed meat was positively associated with the prevalence of advanced adenomas in the rectum only (multiple times per day compared with <1 time/wk, PR: 1.87; 95% CI: 1.19, 2.95). Poultry intake was not associated with any outcome. Conclusions: On the basis of this large colonoscopy-based study, there are no significant associations between red or processed meat intake and the prevalence of any adenomas or advanced adenomas. However, processed meat may be positively associated with the prevalence of advanced adenomas in the rectum, but prospective cohort studies are needed to further clarify this association. There is no association between poultry consumption and the prevalence of colorectal polyps in this study., (© 2017 American Society for Nutrition.)

Epithelial-to-mesenchymal transition (EMT) contributes significantly to tumor progression and metastasis. The assessment of EMT-associated transcription factors could be a promising approach to identify biomarkers and potential therapeutic targets in colorectal cancer. In our study, we focused on the transcription factor "Sine oculis homeobox" (SIX) 1, which is a member of the superfamily of the homeobox genes and has been described to promote EMT in different types of tumors. Immunohistochemistry against SIX1 was performed on colorectal mucosa, adenomas, carcinomas-in situ and primary adenocarcinomas. An expression score was developed and subsequently assessed for its prognostic value in two independent cohorts. Cohort 1 consisted of 128 patients with stage I-III colorectal cancer; cohort 2 included 817 patients with stage I-III colorectal cancer who had participated in the DACHS study. HCT-116 cells were transfected with SIX1 plasmids and subjected to migration and colony formation assays. The expression of SIX1 increases gradually from mucosa to colorectal adenocarcinomas (p > 0.0001). Univariate and multivariate analyses reveal that high expression of SIX1 is associated with decreased overall survival (cohort 1: HR: 4.01, CI: 1.20-14.07, p = 0.025; cohort 2: HR: 1.43, CI: 1.014-2.02, p = 0.047). Overexpression of SIX1 induces a more mesenchymal-like phenotype in HCT-116 cells and enhances tumor migration. High expression of SIX1 is an independent prognostic marker in colorectal cancer. It might be a promising biomarker to stratify patients into different risk groups. Moreover, targeting SIX1 might be a novel therapeutic approach in patients with colorectal cancer., (© 2015 UICC.)

Background & Aims: The adenoma detection rate (ADR) is an important quality indicator of screening colonoscopy; it is inversely associated with risk of interval cancers and colorectal cancer mortality. We assessed trends in the ADR in the first 10 years of the German screening colonoscopy program., Methods: We calculated age-adjusted and age-specific detection rates of nonadvanced adenomas and advanced adenomas for each calendar year based on 4.4 million screening colonoscopies conducted from 2003 through 2012 and reported to the German screening colonoscopy registry., Results: We observed a steady and strong increase in rate of detection of nonadvanced adenomas in both sexes and all age groups. Age-adjusted rates of detection of nonadvanced adenomas increased from 13.3% to 22.3% among men and from 8.4% to 14.9% among women. This increase was mostly due to an increase in detection rates of adenomas <0.5 cm, and it is partly explained by an innovation effect (higher ADRs among incoming colonoscopists than among leaving colonoscopists, and relatively stable ADRs among continuing colonoscopists). Only modest increases were observed in detection rates of advanced adenomas (from 7.4% to 9.0% among men, and from 4.4% to 5.2% among women) and colorectal cancer. In 2012, overall ADR reached 31.3% and 20.1% in men and women, respectively., Conclusions: We observed a strong increase in ADRs from 2003 through 2012 in Germany. Although we cannot exclude the effects of secular trends in colorectal neoplasm prevalence, the observed increase was mainly the result of a steady increase in detection of nonadvanced adenomas (especially adenomas <0.5 cm). Further research should address potential implications for defining screening and surveillance intervals., (Copyright © 2015 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Guaiac-based fecal occult blood tests (gFOBTs) are the most widely used noninvasive tests for colorectal cancer screening. While it is well known that they detect only a minority of colorectal adenomas, evidence for the characteristics of adenomas associated with detection is sparse. We derived estimates of the positive likelihood ratio (LR+), a summary measure of diagnostic performance, according to adenoma characteristics by comparing findings at colonoscopy among 19,208 and 181,128 participants who underwent colonoscopy to follow-up a positive gFOBT and as a primary screening examination, respectively, in Bavaria, Germany, in 2007-2009. Age and sex-adjusted estimates of LR+ (95% confidence intervals, 95% CI) ranged from 1.09 (1.05-1.13) for adenomas <1 cm to 2.52 (2.30-2.75) for adenomas >2 cm, and were much higher for pedunculated adenomas (1.96, 95% CI 1.85-2.08) than for flat or sessile adenomas (1.11, 95% CI 1.02-1.21 and 1.12, 95% CI 1.08-1.16, respectively). Villous or tubulovillous structure and dysplasia were likewise associated with a higher chance to be detected by gFOBT. Diagnostic performance was worse for proximal than for distal adenomas (age and sex adjusted LR+:1.16, 95% CI 1.09-1.23 and 1.35, 95% CI 1.29-1.41, respectively) which was explained by the lower proportions of large, pedunculated and nontubular adenomas in the proximal colon. Size, pedunculated shape, and nontubular histology are the key determinants of detection which also explain lower detection rates of adenomas located in the proximal colon., (© 2014 UICC.)

Background: The adenoma detection rate (ADR) is an important surrogate measure of performance quality for screening colonoscopies., Objective: To demonstrate how physicians with unusual performance concerning the adenoma detection rate may be identified in screening colonoscopy databases., Design: Bayesian random-effects modeling and Winsorization of potential outliers were applied to develop a robust model for the majority of providers. Divergence was assessed with adjustment for multiple testing. The steps in the analysis were visualized by using funnel plots. Additionally, minimum requirements for the number of colonoscopies with 1 or more detected adenomas were derived., Setting: Data from 422 physicians offering screening colonoscopy and participating in a quality assurance program in Bavaria, Germany, were used., Patients: A total of 69,738 asymptomatic individuals 55 to 79 years of age., Intervention: Screening colonoscopy., Main Outcome Measurements: Physician-specific ADRs., Results: The overall ADR in the sample was 26%. From an initial model, 62 physicians (15%) were identified as potential outliers. A model with normally distributed random effects was then chosen as the robust null model. Of the potential outliers, 10 (16%) were confirmed as physicians with unusual performance at a false discovery rate of 5%. For all of them, the observed ADR was lower than expected, and together they accounted for 1.4% of all included colonoscopies., Limitations: Analysis of routine data., Conclusion: The applied statistical approach appears suitable to identify unusual performance in screening colonoscopy databases. Its application may help to evaluate and improve the quality of colonoscopy in population-based colorectal cancer screening programs., (Copyright © 2015 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Most colorectal cancers develop from adenomas. We aimed to estimate sex- and age-specific incidence rates of colorectal adenomas and to assess their potential implications for colorectal cancer screening strategies., Methods: Sex- and age-specific incidence rates of colorectal adenomas were derived by a birth cohort analysis using data from 4,322,085 screening colonoscopies conducted in Germany and recorded in a national database in 2003-2012. In addition, cumulative risks of colorectal cancer among colonoscopically neoplasm-free men and women were estimated by combining adenoma incidence rates with previously derived adenoma-colorectal cancer transition rates., Results: Estimated annual incidence in percentage (95% confidence interval) in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 was 2.4 (2.2-2.6), 2.3 (2.1-2.6), 2.4 (2.1-2.6), 2.2 (1.8-2.5), and 1.8 (1.2-2.3) among men, and 1.4 (1.3-1.5), 1.5 (1.4-1.7), 1.6 (1.4-1.8), 1.6 (1.3-1.8), and 1.2 (0.8-1.6) among women. Estimated 10- and 15-year risks of clinically manifest colorectal cancer were 0.1% and 0.5% or lower, respectively, in all groups assessed., Conclusions: Annual incidence rates of colorectal adenomas are below 2.5% and 2% among men and women, respectively, and show little variation by age., Impact: Risk of clinically manifest colorectal cancer is expected to be very small within 10 years and beyond after negative colonoscopy for men and women at all ages. The use of rescreening after a negative screening colonoscopy above 60 years of age may be very limited., (©2014 American Association for Cancer Research.)

Background and Study Aims: After screening colonoscopy, additional colonoscopies may be required for adenoma surveillance or diagnostic reasons. The aim of the present study was to explore their utilization and findings in routine practice., Patients and Methods: The study comprised an historical cohort of individuals participating in colonoscopy screening in 2006. Utilization and yield of neoplasms of additional colonoscopies performed in these individuals by the same physician ( < 6 months and 6 - 36 months after screening) between 2006 and 2009 were assessed using data of a colonoscopy quality assurance program in Bavaria, Germany. Screening including polypectomy, and short-term follow-up colonoscopy was assumed to have been completed within ≤ 6 months. Multivariate logistic regression was used to identify predictors of additional colonoscopy and advanced neoplasms (high risk adenoma or colorectal cancer [CRC]) among those with additional colonoscopy during the period of 6 - 36 months after screening., Results: A total of 51 301 individuals undergoing screening colonoscopy were included. Of these, 10.1 % (95 % confidence interval [CI] 9.8 % - 10.3 %) had an additional colonoscopy performed by the same physician between 6 and 36 months after screening. The percentages of those with additional colonoscopy were 5.7 % (95 %CI 5.5 % - 5.9 %), 18.6 % (95 %CI 17.8 % - 19.4 %), and 33.7 % (95 %CI 32.2 % - 35.2 %) after negative screening, low risk adenoma at screening, and high risk adenoma at screening, respectively. The overall findings were negative colonoscopy, low risk adenoma, high risk adenoma, and CRC in 68.6 % (95 %CI 67.3 % - 69.8 %), 24.1 % (95 %CI 23.0 % - 25.3 %), 6.7 % (95 %CI 6.0 % - 7.4 %), and 0.6 % (95 %CI 0.4 % - 0.8 %), respectively. Younger age, male sex, screen-detected adenomas, inflammatory bowel disease, and early repeat colonoscopy within 6 months were predictors of additional colonoscopy. Older age, male sex, screen-detected adenomas, and surveillance indications were associated with increased risk of advanced neoplasms at post-screening colonoscopy., Conclusion: The results indicate frequent utilization of additional colonoscopies along with substantial adenoma yield in the first 3 years after screening colonoscopy., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background: Most colorectal cancers (CRC) develop from adenomas. Knowledge of the natural history of colorectal adenomas, which is not directly observable for ethical reasons, is crucial for designing cost-effective CRC screening strategies., Methods: We derived transition rates from carriage of nonadvanced adenoma to carriage of advanced adenoma to carriage of CRC by sex and age in birth cohort analyses among 3,593,420 participants in the German screening colonoscopy program in 2003-2010., Results: Transition rates from advanced adenoma to CRC carriage were similar in men and women, but monotonically and significantly increased with age. Estimated annual transition percentages [(95% confidence interval (CI)] in age groups 55-59, 60-64, 65-69, 70-74, and 75-79 years were 2.6 (2.4-2.9), 3.1 (2.8-3.3), 3.8 (3.5-4.1), 5.1 (4.8-5.5), and 5.2 (4.6-5.8) among men, and 2.5 (2.2-2.7), 2.7 (2.4-3.0), 3.8 (3.5-4.1), 5.0 (4.5-5.4), and 5.6 (4.9-6.3) among women. Estimated annual transitions from carriage of nonadvanced to carriage of advanced adenoma were in a narrow range from 3.6% to 4.7% for all age and sex groups., Conclusions: Despite low annual transition rates, cumulative transition rates from advanced adenoma to CRC carriage are expected to exceed by 60%, 50%, and 40% for age intervals 55-80, 65-80, and 70-80 years, respectively, in both sexes. Cumulative transition rates from nonadvanced adenoma to CRC carriage are expected to be close to 30% for age interval 55-80 years, but less than 2% for age interval 75-80 years., Impact: Our results enhance the empirical basis for modeling CRC screening strategies.

Background: Studies have identified characteristics of adenomas detected on colonoscopy to be predictive of adenoma recurrence., Objective: To assess the role of both colonoscopy-related factors and polyp characteristics on the risk for colorectal cancer after colonoscopic polyp detection., Design: Population-based case-control study (3148 case participants and 3274 control participants)., Setting: Rhine-Neckar region of Germany., Patients: Case and control participants with physician-validated detection of polyps (other than hyperplastic polyps) at a previous colonoscopy in the past 10 years., Measurements: Detailed history and results of previous colonoscopies were obtained through interviews and medical records. Case and control participants were compared according to colonoscopy-related factors (incompleteness, poor bowel preparation, incomplete removal of all polyps, and no surveillance colonoscopy within 5 years) and polyp characteristics (≥ 1 cm, villous components or high-grade dysplasia, ≥ 3 polyps, and ≥ 1 proximal polyp). Odds ratios (ORs) and attributable fractions were derived by using multiple logistic regression and the Levin formula., Results: 155 case participants and 260 control participants with physician-validated polyp detection in the past 10 years were identified. The following characteristics were significantly more common among case participants than among control participants: not all polyps completely removed (29.0% vs. 9.6%; OR, 3.73 [95% CI, 2.11 to 6.60]), no surveillance colonoscopy within 5 years (26.5% vs. 11.5%; OR, 2.96 [CI, 1.70 to 5.16]), and detection of 3 or more polyps (14.2% vs. 7.3%; OR, 2.21 [CI, 1.07 to 4.54]). Odds ratios ranged from 1.12 to 1.42 and CIs included 1.00 for all other variables. Overall, 41.1% and 21.7% of cancer cases were statistically attributable to colonoscopy-related factors and polyp characteristics, respectively., Limitation: This was an observational study with potential for residual confounding and selection bias., Conclusion: Colonoscopy-related factors are more important than polyp characteristics for stratification of colorectal cancer risk after colonoscopic polyp detection in the community setting.

Background: Colorectal cancer is the most common cancer in Germany. Screening colonoscopies have been offered as a primary screening tool in Germany since the end of 2002., Objective: To estimate the numbers of clinically manifest colorectal cancers prevented by detection and removal of advanced adenomas in the initial 6 years of the program., Design: Markov model with single-year transitions., Setting: German screening colonoscopy program., Patients: Participants in the screening colonoscopy program from 2003 to 2008., Interventions: Screening colonoscopy with the removal of advanced colorectal neoplasms., Main Outcome Measurements: The expected numbers of incident colorectal cancers prevented by detection and removal of advanced adenomas., Results: An estimated total number of 73,024 cases of colorectal cancer might have developed from the removed advanced adenomas and become clinically manifest between 55 and 84 years of age in the absence of screening colonoscopy. This number exceeds the number of colorectal cancers diagnosed in 2002 by 27%. Among prevented cancers, 8%, 43%, and 49% would have occurred at ages 55 to 64, 65 to 74, and 75 to 84 years (median age 74 years), respectively; 60% and 40% would have occurred among men and women, respectively; and 22%, 32%, 25%, and 20% would have occurred within 1 to 5, 6 to 10, 11 to 15, and 16 to 30 years, respectively, after colonoscopy (median 10 years)., Limitations: Diagnoses of advanced adenomas are based on records from a large number of endoscopists and pathology laboratories., Conclusions: Despite relatively low screening participation, the German screening colonoscopy program is expected to make a major contribution to the prevention of colorectal cancer, even though most of the impact will only be seen in the longer run., (Copyright © 2010 American Society for Gastrointestinal Endoscopy. Published by Mosby, Inc. All rights reserved.)

Background & Aims: Screening recommendations for colorectal cancer (CRC) commonly take family history but no other risk factors into account. We compared and assessed risk factors of colorectal polyps in a large population undergoing screening colonoscopy., Methods: We conducted a population-based cross-sectional study that included 3349 subjects, 55 years or older (mean ages of men and women, 63.6 and 63.4 years, respectively), who underwent colonoscopy for the first time within the nationwide colonoscopy screening program in Germany. We calculated prevalences of colorectal polyps and estimated multivariate prevalence ratios (PRs) and population attributable fractions (PAFs)., Results: Overall, 654 subjects had hyperplastic polyps (20%), 675 had non-advanced adenomas (20%), 343 had advanced adenomas (10%), and 40 had CRC (1%). Risk factor prevalences and adjusted PRs were higher for male gender and smoking than for family history of CRC. PAFs for prevalence of non-advanced and advanced neoplasia were highest for male gender (23% and 23%, respectively), followed by smoking (7% and 9%, respectively), and family history of CRC (2% and 4%, respectively)., Conclusions: Male gender and smoking have a larger impact on the prevalence of colorectal neoplasia than family history, suggesting an extensive evaluation of additional risk stratification in population-based screening, particularly by sex., (Copyright © 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Screening colonoscopy has been offered in Germany since the end of 2002. Our aim was to estimate numbers of colorectal cancers prevented or detected early by screening colonoscopy in 2003-2010., Methods: Participation rates and prevalences of advanced adenomas and colorectal cancers at screening colonoscopy in 2003-2008 were obtained from the national screening colonoscopy database by age, sex and calendar year. For 2009 and 2010, levels were assumed to remain at those observed in 2008. These data were combined in Markov models with population figures and estimates of transition rates from advanced adenomas to preclinical colorectal cancer and from preclinical cancer to clinically manifest cancer, accounting for total mortality., Results: An estimated total number of 98 734 cases of colorectal cancer at ages 55-84 years are expected to have been prevented in Germany by removal of advanced adenomas by the end of 2010. These cancers might have become clinically manifest a median time period of 10 years after screening colonoscopy. Another 47 168 cases are expected to have been detected early at screening colonoscopy, often in a curable stage., Conclusion: Despite limited participation, the German screening colonoscopy program makes a major contribution to prevention and early detection of colorectal cancer.

Background & Aims: Screening colonoscopy is an effective method to reduce the incidence of and mortality from colorectal cancer (CRC). There is little empirical evidence available about the optimal interval for screening, making this a subject of debate. We associated the prevalence of advanced colorectal neoplasms with time since negative colonoscopies., Methods: In a study of participants in the German colonoscopy screening program, we determined the prevalence of colorectal neoplasias detected at screening colonoscopy among subjects who had undergone a previous colonoscopy without detection of polyps (negative colonoscopy). Data were compared with that from subjects who had not received colonoscopies., Results: No CRCs were detected in participants who had a previous negative colonoscopy an average of 11.9 years previously (n = 553), compared with the 8.4 CRC cases expected based on age- and gender-specific prevalences among participants who had not received a colonoscopy (n = 2701; standardized prevalence ratio [SPR] = 0.00; 95% confidence interval [CI]: 0.00-0.55). Prevalence of advanced adenoma was also much lower among subjects who had previous colonoscopies (SPR = 0.42; 95% CI: 0.25-0.68). Adjusted prevalence ratios (95% CIs) for detecting an advanced adenoma were 0.38 (95% CI: 0.16-0.90), 0.34 (95% CI: 0.15-0.74), 0.38 (95% CI: 0.16-0.90), and 0.53 (95% CI: 0.27-1.04) among participants with a negative colonoscopy conducted 1-5, 6-10, 11-15, and >16 years ago, respectively, compared to participants with no previous colonoscopy., Conclusions: The low risk of CRC and advanced adenomas after a negative colonoscopy supports suggestions that screening intervals be extended to > or =10 years., (Copyright 2010 AGA Institute. Published by Elsevier Inc. All rights reserved.)

In late 2002, colonoscopy was introduced as a primary screening tool for colorectal cancer (CRC) in Germany. We aimed to estimate the expected reduction in case numbers and incidence of CRC between 2003 and 2010 by detection and removal of advanced adenomas. Data from 1,875,708 women and men included in the national screening colonoscopy database were combined with estimates of transition rates of advanced adenomas and with national population projections. Despite relatively low screening participation, incident CRC cases are expected to be reduced by more than 15,000 between 2003 and 2010. The impact is expected to be largest in age groups 55-59, 60-64 and 65-69 in whom total case numbers in 2010 are expected to be reduced by 13%, 19% and 14% among women, and by 11%, 15% and 12%, respectively, among men. Our results forecast a major rapid reduction of the CRC burden in Germany by screening colonoscopy.

Objectives: To derive age and sex specific estimates of transition rates from advanced adenomas to colorectal cancer by combining data of a nationwide screening colonoscopy registry and national data on colorectal cancer (CRC) incidence., Design: Registry based study., Setting: National screening colonoscopy programme in Germany., Patients: Participants of screening colonoscopy in 2003 and 2004 (n = 840,149)., Main Outcome Measures: Advanced adenoma prevalence, colorectal cancer incidence, annual and 10 year cumulative risk of developing CRC among carriers of advanced adenomas according to sex and age (range 55-80+ years), Results: The age gradient is much stronger for CRC incidence than for advanced adenoma prevalence. As a result, projected annual transition rates from advanced adenomas to CRC strongly increase with age (from 2.6% in age group 55-59 years to 5.6% in age group >or=80 years among women, and from 2.6% in age group 55-59 years to 5.1% in age group >or=80 years among men). Projections of 10 year cumulative risk increase from 25.4% at age 55 years to 42.9% at age 80 years in women, and from 25.2% at age 55 years to 39.7% at age 80 years in men., Conclusions: Advanced adenoma transition rates are similar in both sexes, but there is a strong age gradient for both sexes. Our estimates of transition rates in older age groups are in line with previous estimates derived from small case series in the pre-colonoscopy era independent of age. However, our projections for younger age groups are considerably lower. These findings may have important implications for the design of CRC screening programmes.