Colorectal polypectomy and endoscopic mucosal resection: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2024

1:  ESGE recommends cold snare polypectomy (CSP), to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of diminutive polyps (≤ 5 mm).Strong recommendation, high quality of evidence. 2:  ESGE recommends against the use of cold biopsy forceps excision because of its high rate of incomplete resection.Strong recommendation, moderate quality of evidence. 3:  ESGE recommends CSP, to include a clear margin of normal tissue (1-2 mm) surrounding the polyp, for the removal of small polyps (6-9 mm).Strong recommendation, high quality of evidence. 4:  ESGE recommends hot snare polypectomy for the removal of nonpedunculated adenomatous polyps of 10-19 mm in size.Strong recommendation, high quality of evidence. 5:  ESGE recommends conventional (diathermy-based) endoscopic mucosal resection (EMR) for large (≥ 20 mm) nonpedunculated adenomatous polyps (LNPCPs).Strong recommendation, high quality of evidence. 6:  ESGE suggests that underwater EMR can be considered an alternative to conventional hot EMR for the treatment of adenomatous LNPCPs.Weak recommendation, moderate quality of evidence. 7:  Endoscopic submucosal dissection (ESD) may also be suggested as an alternative for removal of LNPCPs of ≥ 20 mm in selected cases and in high-volume centers.Weak recommendation, low quality evidence. 8:  ESGE recommends that, after piecemeal EMR of LNPCPs by hot snare, the resection margins should be treated by thermal ablation using snare-tip soft coagulation to prevent adenoma recurrence.Strong recommendation, high quality of evidence. 9:  ESGE recommends (piecemeal) cold snare polypectomy or cold EMR for SSLs of all sizes without suspected dysplasia.Strong recommendation, moderate quality of evidence. 10:  ESGE recommends prophylactic endoscopic clip closure of the mucosal defect after EMR of LNPCPs in the right colon to reduce to reduce the risk of delayed bleeding.Strong recommendation, high quality of evidence. 11:  ESGE recommends that en bloc resection techniques, such as en bloc EMR, ESD, endoscopic intermuscular dissection, endoscopic full-thickness resection, or surgery should be the techniques of choice in cases with suspected superficial invasive carcinoma, which otherwise cannot be removed en bloc by standard polypectomy or EMR.Strong recommendation, moderate quality of evidence.

Association between endoscopist adenoma detection rate and serrated polyp detection: Retrospective analysis of over 200,000 screening colonoscopies

Background and study aims Serrated lesions have been identified as precursor lesions for 20% to 35% of colorectal cancers (CRCs) and may contribute to a significant proportion of interval-cancer. Sessile-serrated-lesions (SSLs), in particular, tend to be flat and located in the proximal colon, making their detection challenging and requiring expertise. It remains unclear whether the detection rate for serrated polyps should be considered as a quality indicator in addition to the adenoma detection rate (ADR). This study sought to assess whether the ADR has an effect on the detection rate for serrated polyps. atients and methods In this retrospective analysis, prospectively collected data from 212,668 screening colonoscopies performed between 2012 and September 2018 were included. Spearman correlation and Whitney-Mann U-test were used to assess the association of ADR and the detection rate of SSLs with (SDR) and without hyperplastic polyps (SPADRs), the sessile serrated detection rate (SSLDR) as well as the clinically relevant serrated detection rate (CRSDR), including all SSLs and traditional serrated adenoma, hyperplastic polyps (HPs) >10 mm anywhere in the colon or HPs > 5 mm proximal to the sigmoid. Results The overall mean ADR was 21.78% (standard deviation [SD] 9.27), SDR 21.08% (SD 11.44), SPADR 2.19% (SD 2.49), and CRSDR was 3.81% (3.40). Significant correlations were found between the ADR and the SDR, SPADR, SSLDR, and CRSDR (rho=0.73 vs. rho=0.51 vs. rho=0.51 vs. rho=0.63; all P <0.001). Endoscopists with a mean ADR ≥25% had significantly higher SDR, SPADR, and CRSDR than endoscopists with a mean ADR <25% (all P <0.001; Mann-Whitney U-Test). Conclusions This study shows that endoscopists with higher ADR detect significantly more serrated lesions than those with a lower ADR.

Detection of high-risk polyps at screening colonoscopy indicates risk for liver and biliary cancer death

BACKGROUND

Hepatobiliary cancers share risk factors with colorectal cancer (CRC), but there are no combined screening programs for these conditions.

AIMS

The aim of this study was to assess whether patients with high-risk colonic polyps are more likely to die from liver related tumors than patients with a negative colonoscopy.

METHODS

In this retrospective analysis of mortality data, Austrian screening participants were included. The absolute risk for hepatobiliary cancer death was calculated using the cumulative incidence method. We aimed to identify an association with time to death of hepatobiliary cancer by Cox proportional hazards model.

RESULTS

343,838 colonoscopies performed between 01/2007 and 12/2020 were included in the analysis, of which 17,678 (5.14%) revealed high-risk polyps. Overall hepatobiliary cancer mortality was more than twice as high in patients with high risk polyps (cumulative incidence 0.39%, 95% CI 0.37-0.41%) compared to patients with a negative colonoscopy (cumulative incidence 0.17%, 95% CI 0.17-0.17%). When adjusting for age and sex, having high-risk polyps at screening colonoscopy was significantly associated with hepatobiliary cancer death (HR 1.83, 95% CI 1.29- 2.59, p < 0.001).

CONCLUSIONS

Patients with certain colonic polyp characteristics are at increased risk for mortality of liver malignancies. Further studies are needed to determine whether a structured additional screening for liver diseases and consecutive malignancies might be beneficial in these patients.

Differences between men and women with respect to colorectal cancer mortality despite screening colonoscopy

BACKGROUND AND AIMS

Women aged 55 to 59 years have a similar prevalence rate and number needed to screen for colorectal adenomas as men at a 10-year younger age. The aim of this study was to determine sex-specific differences in colorectal cancer mortality and estimate the association with adenomas at screening colonoscopy.

METHODS

This retrospective study analyzed 323,139 individuals who underwent colonoscopy within a national colorectal cancer screening program in Austria between January 2007 and December 2020.

RESULTS

Median patient age was 60 years (interquartile range, 54-67), and the sex distribution in all age groups was nearly identical. Men had significantly higher odds of having an adenoma or serrated polyp, low-risk polyp, high-risk polyp, or colorectal cancer detected at colonoscopy than women (odds ratio [OR] 1.83; 95% confidence interval [CI], 1.80-1.86; OR, 1.46; 95% CI, 1.44-1.49; OR, 1.74; 95% CI, 1.69-1.80; and OR, 1.87; 95% CI, 1.70-2.05, respectively). Strikingly, male sex, when compared with female sex, was associated with an almost 2-fold (hazard ratio, 1.67; 95% CI, 1.05-2.67) increased risk to die from colorectal cancer when an adenoma or serrated polyp was found at the screening colonoscopy and a 4-fold (hazard ratio, 4.14; 95% CI, 2.72-6.3) increased risk when a high-risk polyp was found at the screening colonoscopy. The cumulative incidence for death of colorectal cancer for 60-year-old individuals was 8.5-fold higher in men as compared with women. Markedly, this sex gap narrowed with increasing age, whereas the difference in deaths of other causes remained similar in all age groups.

CONCLUSIONS

Our findings strengthen the necessity of sex-specific screening recommendations. Importantly, further prospective studies should focus on sex differences in tumor biology to propose personalized surveillance guidelines.

Colorectal Cancer and Precursor Lesion Prevalence in Adults Younger Than 50 Years Without Symptoms

Importance

Incidence of colorectal cancer (CRC) is increasing among younger adults. However, data on precursor lesions in patients who are asymptomatic, especially those aged younger than 50 years, are lacking.

Objective

To analyze the prevalence and number needed to screen (NNS) for adenomas, advanced adenomas, and serrated lesions, as well as the incidence of CRC in patients older than age 20 years.

Design, Setting, and Participants

This cohort study was conducted among 296 170 patients who received a screening colonoscopy within a national screening colonoscopy registry from 2012 to 2018 in Austria, including 11 103 patients aged younger than 50 years. CRC incidence was analyzed using data from Statistic Austria from 1988 to 2018. Data were analyzed in September 2021.

Main Outcome and Measures

The prevalence of adenomas and other lesions and the incidence of CRC in individuals aged 20 years or older were assessed.

Results

Among 296 170 patients included in the study (median [IQR] age, 60 [54-68] years; 150 813 females [50.9%]), 11 103 patients (3.7%) were aged younger than 50 years and 285 067 patients (96.3%) were aged 50 years or older. Among patients younger than age 50 years, 1166 individuals (10.5%; NNS = 9) had adenomas and 389 individuals (3.9%; NNS = 26) had at least 1 advanced adenoma, while among those aged 50 years or older, 62 384 individuals (21.9%; NNS = 5) had adenomas and 19 680 individuals (6.9%; NNS = 15) had at least 1 advanced adenoma. Among 1128 males aged 40 to 44 years, 160 individuals (14.2%; NNS = 7) had at least 1 adenoma, and among 1398 females aged 40 to 44 years, 114 individuals (8.1%; NNS = 12) had at least 1 adenoma. The prevalence of adenomas for individuals aged 45 to 49 years vs 50 to 54 years was 490 of 2879 males (17.1%; NNS = 6) vs 8269 of 40 935 males (20.2%; NNS = 5) and 284 of 2792 females (10.2%; NNS = 10) vs 4997 of 40 303 females (12.4%; NNS = 8), respectively. Prevalence of adenomas changed from 61 of 498 individuals (12.4%) in 2008 to 150 of 1064 individuals (14.1%) in 2018 among those younger than 50 years and from 2646 of 12 166 individuals (21.8%) to 10 673 of 37 922 individuals (28.2%) among those aged 50 years and older. The prevalence of advanced adenomas changed from 20 individuals (4.0%) in 2008 to 55 individuals (5.2%) in 2018 in individuals younger than 50 years and from 888 individuals (7.3%) in 2008 to 2578 individuals (6.8%) in 2018 among those aged 50 years and older. Among individuals younger than age 50 years, CRC incidence per 100 000 individuals changed from 9.1 incidents in 1988 to 10.2 incidents in 2018 among males (average annual percentage change [AAPC], 0.5%; 95% CI, 0.1% to 1.0%) and from 9.7 incidents in 1988 to 7.7 incidents in 2018 among females, with a nonsignificant AAPC (-0.2%; 95% CI, -0.7% to 0.3%). Among individuals aged 50 years or older, CRC incidence per 100 000 individuals changed from 168 incidents in 1988 to 97 incidents in 2018 among females (AAPC, -1.8%; 95% CI, -1.9% to -1.6%), and 217 incidents in 1988 to 143 incidents in 2018 among males (AAPC, -1.2%; 95% CI, -1.3% to -1.1%).

Conclusion

In this study, CRC incidence decreased after 1988 in Austria among individuals older than 50 years, while among patients younger than 50 years, incidence increased among males but decreased among females. Prevalence of adenomas increased in all age groups, while advanced adenoma prevalence increased among patients younger than 50 years but decreased in patients aged 50 years and older.

Polyp characteristics at screening colonoscopy and post-colonoscopy colorectal cancer mortality: a retrospective cohort study

BACKGROUND AND AIMS

Polyp size and high grade dysplasia in polyps at screening colonoscopy are considered risk factors for post-colonoscopy colorectal cancer (PCCRC) development and death, which might be averted by surveillance colonoscopy. However, robust evidence backing these risk factors is lacking. We aimed to investigate whether polyp size or dysplasia grade are associated with PCCRC mortality.

METHODS

This was a retrospective study including individuals of the Austrian Quality Certificate for Screening Colonoscopy scoped between 01/2007 and 12/2020. We investigated the association of polyp size and dysplasia in polyps with PCCRC mortality by Cox regression. Additionally, we assessed whether patients with certain polyp characteristics had similar risk for CRC death compared to the Austrian population by calculating standardized mortality ratios (SMR).

RESULTS

316,001 individuals were included. After a median follow-up time of 5.27 years (95% CI 5.25-5.29), a significant association of polyp size 10-20 mm (HR 4.00, 95% CI 2.46-6.50, p <0.001) as well as high-grade dysplasia (HR 6.61, 95% CI 3.31-13.2, p<0.001) with PCCRC death was observed. PCCRC mortality was significantly lower than the expected CRC mortality in the general population in patients with polyps <10 mm and without high grade dysplasia (SMR 0.27, 95% CI 0.21-0.33, p<0.001), which was not observed for patients with polyps ≥10 mm or with high-grade dysplasia (SMR 2.05, 95% CI 1.64-2.57, p < 0.001).

CONCLUSIONS

Polyp size ≥10 mm and high-grade dysplasia are associated with PCCRC mortality in screening patients. This data suggests that these patients might benefit most from surveillance colonoscopy.

Comparison of adenoma detection rate and proximal serrated polyp detection rate and their effect on post-colonoscopy colorectal cancer mortality in screening patients

BACKGROUND

Patients with serrated polyps are at increased risk for post-colonoscopy colorectal cancer (PCCRC); however, evidence for a dedicated serrated polyp detection rate is lacking. The aim of this study was to investigate the association of the proximal serrated polyp detection rate (PSDR) and adenoma detection rate (ADR) with PCCRC death.

METHODS

This was a retrospective analysis within the Austrian quality assurance program for screening colonoscopy. Spearman's rank coefficient was calculated for the assessment of association between ADR and PSDR. Whether ADR or PSDR were associated with colorectal cancer mortality was assessed by Cox proportional hazards model.

RESULTS

229 /729 screening colonoscopies performed by 308 endoscopists were analyzed. The ADR (hazard ratio [HR] per 1 percentage point increase 0.98, 95 %CI 0.96-0.99) as well as the PSDR (HR per 1 percentage point increase 0.97, 95 %CI 0.94-0.99) were significantly associated with PCCRC death. The correlation coefficient of the ADR and PSDR calculated at every colonoscopy was 0.70 (95 %CI 0.70-0.71), and the corresponding PSDR value for an ADR performance standard of 25 % was 11.1 %. At the end of the study period, 86 endoscopists (27.9 %) reached an ADR of > 25 % and a PSDR of > 11.1 %.

CONCLUSIONS

The ADR as well as the PSDR were associated with PCCRC death. Striving for a high PSDR in addition to a high ADR might reduce the risk for PCCRC mortality in patients undergoing screening colonoscopy.

[Quality Assurance of Screening Colonoscopy in Austria and Europe]

Die Vorsorgekoloskopie als effizientes Tool zur Reduktion von Kolorektalkarzinominzidenz und -mortalität ist nur dann effektiv, wenn sie unter hohen Qualitätsstandards durchgeführt wurde. Die European Society for Gastrointestinal Endoscopy gibt hierbei Key Performance Measures, wie die Adenomentdeckungsrate, die Zökumerreichsrate und die Rate an adäquater Vorbereitungsqualität, vor, auf die beim Screening geachtet werden sollten. Das „Qualitätszertifikat Darmkrebsvorsorge“, das als Qualitätssicherungsprogramm auf freiwilliger Basis von der Österreichischen Gesellschaft für Gastroenterologie und Hepatologie gemeinsam mit dem Dachverband der österreichischen Sozialversicherungsträger und der Österreichischen Krebshilfe für Endoskopiker:innen in ganz Österreich ins Leben gerufen wurde, überprüft diese Qualitätsparameter. Es wird ein Darmkrebsscreening auf höchsten Standards angestrebt, um somit die besten Outcomes für Patient:innen zu erzielen. Auch europaweit ist das Interesse an einer qualitätsgesicherten Vorsorgekoloskopie groß: Viele Länder, wie z. B. die Niederlande, Norwegen und das Vereinigte Königreich haben Programme, um die Qualität des Screenings zu überwachen und zu verbessern.

Hepatic T1-time predicts cardiovascular risk in all-comers referred for cardiovascular magnetic resonance

Background

Liver damage is frequently observed in patients with cardiovascular disease (CVD) but infrequently quantified. We hypothesized that in patients with CVD undergoing cardiac magnetic resonance (CMR), liver T1-times indicate liver damage and are associated with cardiovascular outcome.

Methods

We measured hepatic T1-times, displayed on standard cardiac T1-maps, in an all-comer CMR-cohort. At the time of CMR, we assessed validated general liver fibrosis scores. Kaplan-Meier estimates and Cox-regression models were used to investigate the association between hepatic T1-times and a composite endpoint of non-fatal myocardial infarction, heart failure hospitalization, and death.

Results

1022 participants (58±18 y/o, 47% female) were included (972 patients, 50 controls). Hepatic T1-times were 590±89ms in patients and 574±45ms in controls (p=0.052). They were significantly correlated with cardiac size and function, presence of atrial fibrillation, NT-pro-BNP levels, and gamma-glutamyl-transferase levels (p&lt;0.001 for all). During follow-up (58±31 months), a total of 280 (29%) events occurred. On Cox-regression, high hepatic T1-times yielded a significantly higher risk for events (adj.HR 1.66 [95% CI: 1.45–1.89] per 100ms increase, p&lt;0.001), even when adjusted for age, sex, left and right ventricular ejection fraction, NT-proBNP, and myocardial T1-time. On restricted cubic splines, we found that a hepatic T1-time exceeding 610ms was associated with excessive risk.

Conclusion

Hepatic T1-times on standard CMR scans were significantly associated with cardiac size and function, comorbidities, natriuretic peptides, and independently predicted cardiovascular mortality and morbidity. A hepatic T1-time &gt;610ms seems to indicate excessive risk.

Funding Acknowledgement

Type of funding sources: None.

Hepatic T1-Time Predicts Cardiovascular Risk in All-Comers Referred for Cardiovascular Magnetic Resonance: A Post-Hoc Analysis

BACKGROUND

Liver damage is frequently observed in patients with cardiovascular disease but infrequently quantified. We hypothesized that in patients with cardiovascular disease undergoing cardiac magnetic resonance, liver T1-times indicate liver damage and are associated with cardiovascular outcome.

METHODS

We measured hepatic T1-times, displayed on standard cardiac T1-maps, in an all-comer cardiac magnetic resonance-cohort. At the time of cardiac magnetic resonance, we assessed validated general liver fibrosis scores. Kaplan-Meier estimates and Cox-regression models were used to investigate the association between hepatic T1-times and a composite endpoint of non-fatal myocardial infarction, heart failure hospitalization, and death.

RESULTS

One thousand seventy-five participants (58±18 year old, 47% female) were included (972 patients, 50 controls, 53 participants with transient elastography). Hepatic T1-times were 590±89 ms in patients and 574±45 ms in controls (P=0.052). They were significantly correlated with cardiac size and function, presence of atrial fibrillation, NT-pro-BNP levels, and gamma-glutamyl-transferase levels (P<0.001 for all). During follow-up (58±31 months), a total of 280 (29%) events occurred. On Cox-regression, high hepatic T1-times yielded a significantly higher risk for events (adjusted hazard ratio, 1.66 [95% CI, 1.45-1.89] per 100 ms increase; P<0.001), even when adjusted for age, sex, left and right ventricular ejection fraction, NT-proBNP (N-terminal prohormone of brain natriuretic peptide), and myocardial T1-time. On receiver operating characteristic analysis and restricted cubic splines, we found that a hepatic T1-time exceeding 610 ms was associated with excessive risk.

CONCLUSIONS

Hepatic T1-times on standard cardiac magnetic resonance scans were significantly associated with cardiac size and function, comorbidities, natriuretic peptides, and independently predicted cardiovascular mortality and morbidity. A hepatic T1-time >610 ms seems to indicate excessive risk.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04220450.

Association of Adenoma Detection Rate and Adenoma Characteristics With Colorectal Cancer Mortality After Screening Colonoscopy

BACKGROUND & AIMS

The adenoma detection rate (ADR) and characteristics of previously resected adenomas are associated with colorectal cancer (CRC) incidence and mortality. However, the combined effect of both factors on CRC mortality is unknown.

PATIENTS AND METHODS

Using data of the Austrian quality assurance program for screening colonoscopy, we evaluated the combined effect of ADR and lesion characteristics on subsequent risk for CRC mortality. We analyzed mortality rates for individuals with low-risk adenomas (1-2 adenomas <10 mm), individuals with high-risk adenomas (advanced adenomas or ≥3 adenomas), and after negative colonoscopy (negative colonoscopy or small hyperplastic polyps) performed by endoscopists with an ADR <25% compared with ≥25%. Cox regression was used to determine the association of combined risk groups with CRC mortality, adjusted for age and sex.

RESULTS

We evaluated 259,885 colonoscopies performed by 361 endoscopists. A total of 165 CRC-related deaths occurred during the follow-up period, up to 12.2 years. In all risk groups, CRC mortality was higher when colonoscopy was performed by an endoscopist with an ADR <25%. Compared with negative colonoscopy with an ADR ≥25%, CRC mortality was similar for individuals with low-risk adenomas irrespective of ADR (for ADR ≥25%: adjusted hazard ratio [HR], 1.22; 95% confidence interval [CI], 0.59-2.49; for ADR <25%: adjusted HR, 1.25; 95% CI, 0.64-2.43) and after negative colonoscopy with ADR <25% (adjusted HR, 1.27; 95% CI, 0.81-2.00). Individuals with high-risk adenomas were at significantly higher risk for CRC death if colonoscopy was performed by an endoscopist with an ADR <25% (adjusted HR, 2.25; 95% CI, 1.18-4.31) but not if performed by an endoscopist with an ADR ≥25% (adjusted HR, 1.35; 95% CI, 0.61-3.02).

CONCLUSIONS

Our study adds important evidence for mandatory assessment and monitoring of performance quality in screening colonoscopy. High-quality colonoscopy was associated with a lower risk for CRC death, and the impact of ADR was strongest for individuals with high-risk adenomas.

New risk stratification after colorectal polypectomy reduces burden of surveillance without increasing mortality

BACKGROUND

The 2020 postpolypectomy surveillance guideline update of European Society for Gastrointestinal Endoscopy defines a more restrictive group of individuals in need for surveillance 3 years after colonoscopy.

AIM

The aim of this cohort study was to validate the new guideline recommendation.

METHODS

Based on a national quality assurance program, we compared the 2020 risk group definition with the previous 2013 recommendations for their strength of association with (1) colorectal cancer death, and (2) all-cause death.

RESULTS

A total of 265,608 screening colonoscopies were included in the study. Mean age was 61.1 years (SD ±9.0), and 50.6% were women. During a mean follow-up of 59.3 months (SD ±35.0), 170 CRC deaths and 7723 deaths of any cause were identified. 62.4% of colonoscopies were negative and 4.9% were assigned to surveillance after 3 years according to the 2020 guidelines versus 10.4% following the 2013 guidelines, which corresponds to a relative reduction in colonoscopies by 47%. The strength of association with CRC mortality was markedly higher with the 2020 surveillance group as compared to the 2013 guidelines (HR 2.56, 95% CI 1.62-4.03 vs. HR 1.73, 95% CI 1.13-2.62), while the magnitude of association with CRC mortality for low risk individuals was lower (HR 1.17, 95% CI 0.83-1.63 vs. 1.25, 95% CI 0.88-1.76).

CONCLUSIONS

Adherence to the updated guidelines reduces the burden of surveillance colonoscopies by 47% while preserving the efficacy of surveillance in preventing CRC mortality.

Interval cancer after colonoscopy in the Austrian National Screening Programme: influence of physician and patient factors

OBJECTIVE

Postscreening colorectal cancer (PSCRC) after screening colonoscopy is associated with endoscopists' performance and characteristics of resected lesions. Prior studies have shown that adenoma detection rate (ADR) is a decisive factor for PSCRC, but correlations with other parameters need further analysis and ADR may change over time.

DESIGN

Cohort study including individuals undergoing screening colonoscopy between 1/2008 and 12/2019 performed by physicians participating in a quality assurance programme in Austria. Data were linked with hospitalisation data for the diagnosis of PSCRC (defined as CRC diagnosis >6 months after colonoscopy). ADR was defined dynamically in relation to the time point of subsequent colonoscopies; high-risk groups of patients were those with an adenoma ≥10 mm, or with high-grade dysplasia, or villous or tubulovillous histology, or a serrated lesion ≥10 mm or with dysplasia, or colonoscopies with ≥3 lesions. Main outcome was PSCRC for each risk group (negative colonoscopy, hyperplastic polyps, low-risk and high-risk group of patients) after colonoscopy by endoscopists with an ADR <20% compared with endoscopists with an ADR ≥20%.

RESULTS

352 685 individuals were included in the study (51.0% women, median age 60 years) of which 10.5% were classified as high-risk group. During a median follow-up of 55.4 months, 241 (0.06%) PSCRC were identified; of 387 participating physicians, 19.6% had at least one PSCRC (8.4% two or more). While higher endoscopist ADR decreased PSCRC incidence (HR per 1% increase 0.97, 95% CI 0.95 to 0.98), affiliation to the high-risk group of patients was also associated with higher PSCRC incidence (HR 3.27, 95% CI 2.36 to 4.00). Similar correlations were seen with regards to high-risk, and advanced adenomas. The risk for PSCRC was significantly higher after colonoscopy by an endoscopist with an ADR <20% as compared with an endoscopist with an ADR ≥20% in patients after negative colonoscopy (HR 2.01, 95% CI 1.35 to 3.0, p<0.001) and for the high-risk group of patients (HR 2.51, 95% CI 1.49 to 4.22, p<0.001).

CONCLUSION

A dynamic calculation of the ADR takes into account changes over time but confirms the correlation of ADR and interval cancer. Both lesion characteristics and endoscopists ADR may play a similar role for the risk of PSCRC. This should be considered in deciding about appropriate surveillance intervals in the future.

More than one way: exploring the capabilities of different estimation approaches to joint models for longitudinal and time-to-event outcomes

The development of physical functioning after a caesura in an aged population is still widely unexplored. Analysis of this topic would need to model the longitudinal trajectories of physical functioning and simultaneously take terminal events (deaths) into account. Separate analysis of both results in biased estimates, since it neglects the inherent connection between the two outcomes. Thus, this type of data generating process is best modelled jointly. To facilitate this several software applications were made available. They differ in model formulation, estimation technique (likelihood-based, Bayesian inference, statistical boosting) and a comparison of the different approaches is necessary to identify their capabilities and limitations. Therefore, we compared the performance of the packages JM, joineRML, JMbayes and JMboost of the R software environment with respect to estimation accuracy, variable selection properties and prediction precision. With these findings we then illustrate the topic of physical functioning after a caesura with data from the German ageing survey (DEAS). The results suggest that in smaller data sets and theory driven modelling likelihood-based methods (expectation maximation, JM, joineRML) or Bayesian inference (JMbayes) are preferable, whereas statistical boosting (JMboost) is a better choice with high-dimensional data and data exploration settings.

Colonoscopist Performance and Colorectal Cancer Risk After Adenoma Removal to Stratify Surveillance: Two Nationwide Observational Studies

BACKGROUND AND AIMS

Colonoscopy surveillance after adenoma removal is an increasing burden in many countries. Surveillance recommendations consider characteristics of removed adenomas, but not colonoscopist performance. We investigated the impact of colonoscopist performance on colorectal cancer risk after adenoma removal.

METHODS

We compared colorectal cancer risk after removal of high-risk adenomas, low-risk adenomas, and after negative colonoscopy for all colonoscopies performed by colonoscopists with low vs high performance quality (adenoma detection rate <20% vs ≥20%) in the Polish screening program between 2000 and 2011, with follow-up until 2017. Findings were validated in the Austrian colonoscopy screening program.

RESULTS

A total of 173,288 Polish colonoscopies were included in the study. Of 262 colonoscopists, 160 (61.1%) were low performers, and 102 (38.9%) were high performers; 11.1% of individuals had low-risk and 6.6% had high-risk adenomas removed at screening; 82.2% had no adenomas. During 10 years of follow-up, 443 colorectal cancers were diagnosed. For low-risk adenoma individuals, colorectal cancer incidence was 0.55% (95% confidence interval [CI] 0.40-0.75) with low-performing colonoscopists vs 0.22% (95% CI 0.14-0.34) with high-performing colonoscopists (hazard ratio [HR] 2.35; 95% CI 1.31-4.21; P = .004). For individuals with high-risk adenomas, colorectal cancer incidence was 1.14% (95% CI 0.87-1.48) with low-performing colonoscopists vs 0.43% (95% CI 0.27-0.69) with high-performing colonoscopists (HR 2.69; 95% CI 1.62-4.47; P < .001). After negative colonoscopy, colorectal cancer incidence was 0.30% (95% CI 0.27-0.34) for individuals examined by low-performing colonoscopists, vs 0.15% (95% CI 0.11-0.20) for high-performing (HR 2.10; 95% CI 1.52-2.91; P < .001). The observed trends were reproduced in the Austrian validation cohort.

CONCLUSIONS

Our results suggest that endoscopist performance may be an important contributor in addition to polyp characteristics in determining colorectal cancer risk after colonoscopy screening.

Gradient boosting for linear mixed models

Gradient boosting from the field of statistical learning is widely known as a powerful framework for estimation and selection of predictor effects in various regression models by adapting concepts from classification theory. Current boosting approaches also offer methods accounting for random effects and thus enable prediction of mixed models for longitudinal and clustered data. However, these approaches include several flaws resulting in unbalanced effect selection with falsely induced shrinkage and a low convergence rate on the one hand and biased estimates of the random effects on the other hand. We therefore propose a new boosting algorithm which explicitly accounts for the random structure by excluding it from the selection procedure, properly correcting the random effects estimates and in addition providing likelihood-based estimation of the random effects variance structure. The new algorithm offers an organic and unbiased fitting approach, which is shown via simulations and data examples.

Impact of adenoma detection rate on detection of advanced adenomas and endoscopic adverse events in a study of over 200,000 screening colonoscopies

BACKGROUND AND AIMS

Adenoma detection rate (ADR) is the best established quality parameter for screening colonoscopy. Guidelines recommend a target ADR >25% because previous studies have shown that patients of endoscopists with higher ADRs have a lower risk of postcolonoscopy interval cancers. However, studies have shown that improvement in ADR mainly results in increased detection of clinically irrelevant nonadvanced adenomas (NAAs). The impact of ADR on the detection of advanced adenomas (AAs) as well as adverse event rates has yet to be determined.

METHODS

A total of 218,193 screening colonoscopies performed between 2007 and 2010 by 262 endoscopists within the Austrian quality assurance program were analyzed. We divided endoscopists into quintiles based on ADRs and calculated mean advanced ADRs (AADRs), NAA detection rates (NAADRs), and adverse event rates for each quintile. Spearman rank-order was used to calculate overall correlations between ADRs and AADRs as well as adverse event rates. Endoscopists with an ADR <25% were compared with those with an ADR >25%.

RESULTS

Fifty-one percent of patients were women. Mean ADR was 23.03% (95% confidence interval [CI], 21.93-24.13), AADRs 7.72% (95% CI, 7.19-8.25), and NAADRs 15.31% (95% CI, 14.36-16.27). Overall, there was a significant correlation between ADR and AADR (rho = .51; P < .001). When ADR was divided into quintiles, mean AADR increased with increasing ADR. Even in the highest ADR group (ADR, 31.36%-52.27%) there was a further increase in AADR with a mean of 10.75% (95% CI, 9.31-12.19). Importantly, NAADRs increased continuously with improvement in ADRs but never dissociated from a simultaneous improvement in AADRs. However, there was also a significant correlation of ADRs and endoscopic adverse events (rho = .26, P < .001), even if the perforation rate of .028% (95% CI, .004-.052) in the highest ADR group still remained within the accepted limits based on guidelines.

CONCLUSIONS

Increasing ADR is associated with improved detection of AAs and therefore is likely to prevent more cases of colorectal cancer. However, higher ADR was also associated with a higher rate of adverse events, although the adverse event rate was low.

Modeling the spatial variability in the spread and correlation of childhood malnutrition in Nigeria

The average nutritional status of children in Nigeria is, just as in most developing countries, still in an alarmingly bad condition. Prior studies have shown that this status relies on a series of different influences and can be measured by three anthropometric variables for stunting, wasting, and underweight. Different regression modeling techniques have been adopted over the years to explain the determinants and spatial clustering. Those indicators, however, show patterns that are not necessarily full filling requirements for ordinary regression models for the mean and are correlated among each other, a fact that has until now been ignored by most studies. Methods to model outcomes in the light of both, the whole distribution of and the correlation between two or more outcomes based on a set of covariates, have lately been developed. The aim of this paper is to make use of those methods to explain the underlying spatial structure in malnutrition in Nigeria. The study brings to limelight the pattern of spread as well as the interwoven relationships among childhood malnutrition indicators that would have otherwise remained unknown in Nigeria.

Resection rates and safety profile of cold vs. hot snare polypectomy in polyps sized 5-10 mm and 11-20 mm

BACKGROUND AND AIMS

Hot snare (HS) is widely used for the resection of adenomas >5 mm. The cold snare (CS) has a better safety profile and is more cost-effective. The aims of this study were to evaluate effectiveness and safety of CS polypectomy (CSP) compared to HS polypectomy (HSP) for adenomas sized 5-10 mm and 11-20 mm.

METHODS

4018 colonoscopies performed within "quality certificate for screening colonoscopy" with one polypectomy of an adenoma sized 5-20 mm each were included. Retrieval rates, complete resection rates and complication rates were assessed and compared between CSP and HSP for adenomas sized 5-10 mm and 11-20 mm. Histologic subgroups were additionally assessed.

RESULTS

Complete resection rates (5-10 mm: CSP: 89.4% vs. HSP: 87.9%, p = 0.33; 11-20 mm: CSP: 81.8% vs. 80.9%; p = 1), retrieval rates (5-10 mm: CSP: 99.5% vs. HSP: 99.4%, p = 0.76; 11-20 mm: CSP: 100% vs. HSP: 99%, p = 1) and complication rates (5-10 mm: CSP: 0.2% vs. HSP: 0.2%; p = 1; 11-20 mm: CSP: 0% vs. HSP: 1%, p = 1) were equal between CSP and HSP for adenomas sized 5-10 mm as well as 11-20 mm. For serrated adenomas sized 5-10 mm, HSP was superior to CSP (88.7% vs. 77.2%, p < 0.05) regarding the complete resection rate, but not for advanced adenomas (HSP: 89.1% vs. 87.3%, p = 0.69) or adenomas with high-grade dysplasia (HSP: 76.7% vs. 75%, p = 1).

CONCLUSION

This study further supports the use of CSP for polyps sized 5-10 mm and additionally suggests also using CSP for polyps sized 11-20 mm. These findings, as well as the best method for resection of serrated polyps should be validated in further studies.

Evaluation of adenomas per colonoscopy and adenomas per positive participant as new quality parameters in screening colonoscopy

BACKGROUND AND AIMS

The primary aim of this study was to evaluate adenomas per positive participant (APP) and adenomas per colonoscopy (APC) as new quality parameters in screening colonoscopy. Furthermore, we wanted to assess whether these parameters differ depending on the setting or profession.

METHODS

Colonoscopy records were obtained from the database of the Austrian certificate of quality for screening colonoscopy. The Spearman correlation was calculated to compare the adenoma detection rate (ADR), APC, APP, and advanced ADR. The parameters were compared between surgeons and internists and between private practices and hospitals by using the t test.

RESULTS

A total of 44,142 colonoscopies performed by 202 endoscopists were included. APC showed a strong correlation with ADR (r = 0.94; P < .01), and both showed a similar correlation with the advanced ADR (ADR: r = 0.47; P < 0.01, APC: r = 0.46; P < .01). APP showed weaker correlations compared with all other parameters (ADR: r = 0.36; P < .01; advanced ADR: r = 0.19; P < .01). Private practices did not differ in ADR, APP or APC from hospitals. Among endoscopists with ADRs of ≥25%, 7 (10.3%) had an APP in the lowest quartile, whereas no endoscopists had an APC in the lowest quartile.

CONCLUSIONS

APC did not reveal additional information to ADR, and thus there is no need to use it instead of or additionally to ADR. Although the APP identifies endoscopists who find few adenomas per procedure despite acceptable ADRs, this additional information might not be important in regard to sufficient colorectal cancer prevention, because these endoscopists still had high advanced ADRs.

Impact of high-volume, intermediate-volume and low-volume bowel preparation on colonoscopy quality and patient satisfaction: An observational study

Background

Although optimal bowel preparation is essential for high-quality screening colonoscopy, documentation of preparation quality, patient satisfaction and adherence is scarce.

Aim

The aim of this article is to compare low-volume (LV, 300 ml sodium picosulfate), intermediate-volume (IV, 2 l polyethylene glycol, PEG + ascorbic acid and sodium ascorbate), and high-volume (HV, 4 l PEG) purgatives.

Results

A total of 5000 individuals (50.5% women) were enrolled between March 2015 and July 2017 (LV:IV:HV = 3.61:1.54:1). Overall sex- and age-adjusted adenoma detection rate was 25.4% (LV 23.8%, IV 25.4%, HV 29.8%), median age was 59.6 years, and cleansing was successful in 96.8%. Success rates of bowel cleansing were highest with HV (97.6%), followed by LV (97.2%) and IV (95.3%) with OR 2.04 (CI 95% 1.20-3.45, p = 0.008) and OR 1.79 (CI 95% 1.27-2.50, p = 0.001), respectively, compared to IV. A total of 93.5% of the LV group would use the same purgative in the future, 73.2% of IV and 69.4% of HV. A total of 84.4% would prefer overnight preparation, 12.1% same-day preparation.

Conclusion

All purgatives investigated showed good bowel cleansing quality results, patient satisfaction and compliance. Improvement in patient information might lead to even higher participation rates in screening colonoscopy since one in five patients stated that bowel preparation worried him or her most prior to colonoscopy.

Effects of whole-body electromyostimulation combined with individualized nutritional support on body composition in patients with advanced cancer: a controlled pilot trial

BACKGROUND

Physical exercise and nutritional treatment are promising measures to prevent muscle wasting that is frequently observed in advanced-stage cancer patients. However, conventional exercise is not always suitable for these patients due to physical weakness and therapeutic side effects. In this pilot study, we examined the effect of a combined approach of the novel training method whole-body electromyostimulation (WB-EMS) and individualized nutritional support on body composition with primary focus on skeletal muscle mass in advanced cancer patients under oncological treatment.

METHODS

In a non-randomized controlled trial design patients (56.5% male; 59.9 ± 12.7 years) with advanced solid tumors (UICC III/IV, N = 131) undergoing anti-cancer therapy were allocated to a usual care control group (n = 35) receiving individualized nutritional support or to an intervention group (n = 96) that additionally performed a supervised physical exercise program in form of 20 min WB-EMS sessions (bipolar, 85 Hz) 2×/week for 12 weeks. The primary outcome of skeletal muscle mass and secondary outcomes of body composition, body weight and hand grip strength were measured at baseline, in weeks 4, 8 and 12 by bioelectrical impedance analysis and hand dynamometer. Effects of WB-EMS were estimated by linear mixed models. Secondary outcomes of physical function, hematological and blood chemistry parameters, quality of life and fatigue were assessed at baseline and week 12. Changes were analyzed by t-tests, Wilcoxon signed-rank or Mann-Whitney-U-tests.

RESULTS

Twenty-four patients of the control and 58 of the WB-EMS group completed the 12-week trial. Patients of the WB-EMS group had a significantly higher skeletal muscle mass (0.53 kg [0.08, 0.98]; p = 0.022) and body weight (1.02 kg [0.05, 1.98]; p = 0.039) compared to controls at the end of intervention. WB-EMS also significantly improved physical function and performance status (p < 0.05). No significant differences of changes in quality of life, fatigue and blood parameters were detected between the study groups after 12 weeks.

CONCLUSIONS

Supervised WB-EMS training is a safe strength training method and combined with nutritional support it shows promising effects against muscle wasting and on physical function in advanced-stage cancer patients undergoing treatment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02293239 (Date: November 18, 2014).

Circadian profiling reveals higher histamine plasma levels and lower diamine oxidase serum activities in 24% of patients with suspected histamine intolerance compared to food allergy and controls

Background

Histamine intolerance is thought to trigger manifold clinical symptoms after ingesting histamine‐rich food due to reduced activity of diamine oxidase (DAO). No study has hitherto systematically assessed daily fluctuations of histamine levels and DAO activities in symptomatic patients. The aim of the study was to investigate the presence of histamine intolerance, to therefore establish day profiles of histamine levels and DAO activities, and to compare the results between patients with suspected histamine intolerance, food allergy and healthy controls.

Methods

We determined day profiles of histamine plasma levels and DAO serum activities in 33 patients with suspected histamine intolerance, in 21 patients with proven food allergy and in 10 healthy control patients. Clinical symptoms, food intolerances and further clinical and laboratory chemical parameters were evaluated.

Results

Twenty‐four percent (8 of 33) suspected histamine‐intolerant patients showed elevated histamine levels during the day. That might be caused by constantly and significantly reduced DAO activities in these patients compared to food‐allergic and control patients. The remaining 25 patients presented normal histamine levels and DAO activities, but an increased prevalence of multiple food intolerances compared to the other subgroup of suspected histamine‐intolerants. There was no correlation between subjective complaints and serological histamine parameters in patients with suspected histamine intolerance.

Conclusions

We determined by daily profiling that decreased DAO activities correlated with elevated histamine levels in a subgroup of suspected histamine‐intolerants. This finding discriminates these patients from food intolerant individuals with similar clinical symptoms and strongly suggests the presence of histamine intolerance.

Quantile regression: A short story on how and why

Abstract:

Quantile regression quantifies the association of explanatory variables with a conditional quantile of a dependent variable without assuming any specific conditional distribution. It hence models the quantiles, instead of the mean as done in standard regression. In cases where either the requirements for mean regression, such as homoscedasticity, are violated or interest lies in the outer regions of the conditional distribution, quantile regression can explain dependencies more accurately than classical methods. However, many quantile regression papers are rather theoretical so the method has still not become a standard tool in applications. In this article, we explain quantile regression from an applied perspective. In particular, we illustrate the concept, advantages and disadvantages of quantile regression using two datasets as examples.

Psychosocial Variables Associated with Immunosuppressive Medication Non-Adherence after Renal Transplantation

INTRODUCTION

Non-adherence to immunosuppressive medication is regarded as an important factor for graft rejection and loss after successful renal transplantation. Yet, results on prevalence and relationship with psychosocial parameters are heterogeneous. The main aim of this study was to investigate the association of immunosuppressive medication non-adherence and psychosocial factors.

METHODS

In 330 adult renal transplant recipients (≥12 months posttransplantation), health-related quality of life, depression, anxiety, social support, and subjective medication experiences were assessed, and their associations with patient-reported non-adherence was evaluated.

RESULTS

33.6% of the patients admitted to be partially non-adherent. Non-adherence was associated with younger age, poorer social support, lower mental, but higher physical health-related quality of life. There was no association with depression and anxiety. However, high proportions of clinically relevant depression and anxiety symptoms were apparent in both adherent and non-adherent patients.

CONCLUSION

In the posttransplant follow-up, kidney recipients with lower perceived social support, lower mental and higher physical health-related quality of life, and younger age can be regarded as a risk group for immunosuppressive medication non-adherence. In follow-up contacts with kidney transplant patients, physicians may pay attention to these factors. Furthermore, psychosocial interventions to optimize immunosuppressive medication adherence can be designed on the basis of this information, especially including subjectively perceived physical health-related quality of life and fostering social support seems to be of importance.

Surveillance colonoscopy in Austria: Are we following the guidelines?

BACKGROUND AND STUDY AIM

The European guidelines for quality assurance in colorectal cancer screening and diagnosis contain postpolypectomy surveillance recommendations. They recommend follow-up intervals depending on the findings at index colonoscopy, and divide patients into a low-, intermediate- or high-risk group. The aim of this study was to assess the adherence of Austrian endoscopists to the European guidelines and to determine whether sending a reminder letter resulted in better adherence.

METHODS

A single reminder letter containing the guidelines was sent to all endoscopists who participated in the Certificate of Quality for Screening Colonoscopy program in Austria. Adherence was assessed before and after the letter had been sent. Factors associated with adherence were investigated.

RESULTS

We found poor baseline adherence to the guidelines. After the reminder letter, the adherence slightly improved in the low-risk group, but did not change in the intermediate-risk or high-risk groups. An adenoma detection rate of at least 20 % was associated with higher adherence rates. Generally, internists and hospitals showed better adherence compared with surgeons and private practices, respectively, both before and after the reminder letter.

CONCLUSION

A single reminder letter was not enough to improve the poor adherence to the European postpolypectomy surveillance guidelines. Thus, future studies are required to identify and eliminate all factors responsible for nonadherence to postpolypectomy guidelines in order to reach the goal of a safe, effective, and cost-effective colorectal cancer prevention tool in the near future.

An Update on Statistical Boosting in Biomedicine

Statistical boosting algorithms have triggered a lot of research during the last decade. They combine a powerful machine learning approach with classical statistical modelling, offering various practical advantages like automated variable selection and implicit regularization of effect estimates. They are extremely flexible, as the underlying base-learners (regression functions defining the type of effect for the explanatory variables) can be combined with any kind of loss function (target function to be optimized, defining the type of regression setting). In this review article, we highlight the most recent methodological developments on statistical boosting regarding variable selection, functional regression, and advanced time-to-event modelling. Additionally, we provide a short overview on relevant applications of statistical boosting in biomedicine.

Patient-reported non-adherence and immunosuppressant trough levels are associated with rejection after renal transplantation

Background

Different measures of non-adherence to immunosuppressant (IS) medication have been found to be associated with rejection episodes after successful transplantation. The aim of the current study was to investigate whether graft rejection after renal transplantation is associated with patient-reported IS medication non-adherence and IS trough level variables (IS trough level variability and percentage of sub-therapeutic IS trough levels).

Methods

Patient-reported non-adherence, IS trough level variability, percentage of sub-therapeutic IS trough levels, and acute biopsy-proven late allograft rejections were assessed in 267 adult renal transplant recipients who were ≥12 months post-transplantation.

Results

The rate of rejection was 13.5%. IS trough level variability, percentage of sub-therapeutic IS trough levels as well as patient-reported non-adherence were all significantly and positively associated with rejection, but not with each other. Logistic regression analyses revealed that only the percentage of sub-therapeutic IS trough levels and age at transplantation remained significantly associated with rejection.

Conclusions

Particularly, the percentage of sub-therapeutic IS trough levels is associated with acute rejections after kidney transplantation whereas IS trough level variability and patient-reported non-adherence seem to be of subordinate importance. Patient-reported non-adherence and IS trough level variables were not correlated; thus, non-adherence should always be measured in a multi-methodological approach. Further research concerning the best combination of non-adherence measures is needed.

Colorectal polypectomy and endoscopic mucosal resection (EMR): European Society of Gastrointestinal Endoscopy (ESGE) Clinical Guideline

1 ESGE recommends cold snare polypectomy (CSP) as the preferred technique for removal of diminutive polyps (size ≤ 5 mm). This technique has high rates of complete resection, adequate tissue sampling for histology, and low complication rates. (High quality evidence, strong recommendation.) 2 ESGE suggests CSP for sessile polyps 6 - 9 mm in size because of its superior safety profile, although evidence comparing efficacy with hot snare polypectomy (HSP) is lacking. (Moderate quality evidence, weak recommendation.) 3 ESGE suggests HSP (with or without submucosal injection) for removal of sessile polyps 10 - 19 mm in size. In most cases deep thermal injury is a potential risk and thus submucosal injection prior to HSP should be considered. (Low quality evidence, strong recommendation.) 4 ESGE recommends HSP for pedunculated polyps. To prevent bleeding in pedunculated colorectal polyps with head ≥ 20 mm or a stalk ≥ 10 mm in diameter, ESGE recommends pretreatment of the stalk with injection of dilute adrenaline and/or mechanical hemostasis. (Moderate quality evidence, strong recommendation.) 5 ESGE recommends that the goals of endoscopic mucosal resection (EMR) are to achieve a completely snare-resected lesion in the safest minimum number of pieces, with adequate margins and without need for adjunctive ablative techniques. (Low quality evidence; strong recommendation.) 6 ESGE recommends careful lesion assessment prior to EMR to identify features suggestive of poor outcome. Features associated with incomplete resection or recurrence include lesion size > 40 mm, ileocecal valve location, prior failed attempts at resection, and size, morphology, site, and access (SMSA) level 4. (Moderate quality evidence; strong recommendation.) 7 For intraprocedural bleeding, ESGE recommends endoscopic coagulation (snare-tip soft coagulation or coagulating forceps) or mechanical therapy, with or without the combined use of dilute adrenaline injection. (Low quality evidence, strong recommendation.)An algorithm of polypectomy recommendations according to shape and size of polyps is given (Fig. 1).

Trends in quality of screening colonoscopy in Austria

Background and study aim: Screening colonoscopy only effectively prevents colorectal cancer if performed with high quality. The aim of this study was to analyze the detection rates of premalignant colorectal lesions in screening colonoscopies performed within a nationwide quality control program for screening colonoscopy in Austria. Methods: Data from electronic records of the screening program from its implementation in 2007 until December 2014 were analyzed in order to calculate detection rates for adenomas, advanced adenomas, polyps, and proximal lesions, and rates of cecal intubation, sedation, complications, and adequate bowel preparation. Results were evaluated to identify trends and changes in quality parameters over the 8-year study period. Results: During the study period, 301 endoscopists provided data from 159 246 screening colonoscopies. Mean age of screened individuals was 61.1 years, and 49.1 % were women. Significant increases over time were found for age- and sex-adjusted adenoma detection rates (ADRs), which increased from a mean of 22.2 % (SD 10.7 %) in 2007/2008 to 24.2 % (SD 11.6 %) in 2013/2014. On average, each endoscopist increased their individual ADR by + 1.5 percentage points per 2-year period (95 % confidence interval [CI] 0.9 - 2.2 percentage points; P < 0.01). Similarly, detection rates for proximal lesions rose from 15.8 % (SD 9.8 %) to 21.7 % (SD 13.3 %  + 2.5 percentage points per 2-year period, 95 %CI 1.9 - 3.1 percentage points; P < 0.01). ADR in men increased from 27.6 % in 2007/2008 (SD 11.1 %) to 29.2 % in 2013/2014 (SD 12.7 %; P < 0.01); ADR in women increased from 14.2 % (SD 7.1 %) in 2007/2008 to 19.0 % (SD 10.5 %) in 2013/2014 (P < 0.01). Advanced adenoma detection rates decreased during the study period, from 11.4 % (SD 9.0 %) in 2007/2008 to 7.6 % (SD 5.4 %) in 2013/2014 (P = 0.06) in men, and from 5.5 % (SD 5.3 %) in 2007/2008 to 4.0 % (SD 4.1 %) in 2013/2014 in women (P = 0.21). Conclusions: This study showed an improvement in the quality of screening colonoscopies performed within a quality assurance program in Austria between 2007 and 2014. Although, overall ADR increased significantly during the study period, there was a decrease in the rate of advanced adenoma detection.

Risk factors cannot explain the higher prevalence rates of precancerous colorectal lesions in men

BACKGROUND

Prevalence of (pre)cancerous colorectal lesions are higher in men than in women, although transition rates from advanced lesions to cancer is similar in both sexes. Our aim was to investigate whether the sex-specific difference in incidence of premalignant colorectal lesions might be explained by the impact of risk factors.

METHODS

A cross-sectional study analysing health check-up examinations and screening colonoscopies performed within a national quality assurance program.

RESULTS

A total of 25 409 patients were included in this study, 50.8% were women. Median age for both sexes was 60 years (interquartile range (IQR) 54-67). A multivariable model showed that risk factors mediated only 0.6 of the 10.4% gender gap in adenoma and 0.47 of the 3.2% gender gap in advanced adenoma detection rate. Smoking was the only independent risk factor with a varying sex-specific effect (men OR 1.46, CI 1.29, 1.64, women OR 1.76, CI 1.53, 2.06) and advanced adenomas (men OR 1.06, CI 0.80-1.42; women OR 2.08, CI 1.52-2.83). Independent risk factors for adenomas were BMI (OR 1.35 per IQR, CI 1.25-1.47) and triglyceride level (OR 1.03 per IQR, CI 1.00-1.06); for advanced adenomas physical activity (none vs regular: OR 1.54, CI 1.18-2.00, occasional vs regular: OR 1.17, CI 1.00-1.38), cholesterol level (OR 1.13 per IQR, CI 1.02-1.25), blood glucose level (OR 1.05 per IQR, CI 1.01-1.09) and alcohol score (OR 1.09 per IQR, CI 1.01-1.18).

CONCLUSIONS

Risk factors cannot explain higher prevalence rates in men. Results of this study strongly underline the need for sex-specific screening recommendations.

Approaches to Regularized Regression - A Comparison between Gradient Boosting and the Lasso

BACKGROUND

Penalization and regularization techniques for statistical modeling have attracted increasing attention in biomedical research due to their advantages in the presence of high-dimensional data. A special focus lies on algorithms that incorporate automatic variable selection like the least absolute shrinkage operator (lasso) or statistical boosting techniques.

OBJECTIVES

Focusing on the linear regression framework, this article compares the two most-common techniques for this task, the lasso and gradient boosting, both from a methodological and a practical perspective.

METHODS

We describe these methods highlighting under which circumstances their results will coincide in low-dimensional settings. In addition, we carry out extensive simulation studies comparing the performance in settings with more predictors than observations and investigate multiple combinations of noise-to-signal ratio and number of true non-zero coeffcients. Finally, we examine the impact of different tuning methods on the results.

RESULTS

Both methods carry out penalization and variable selection for possibly highdimensional data, often resulting in very similar models. An advantage of the lasso is its faster run-time, a strength of the boosting concept is its modular nature, making it easy to extend to other regression settings.

CONCLUSIONS

Although following different strategies with respect to optimization and regularization, both methods imply similar constraints to the estimation problem leading to a comparable performance regarding prediction accuracy and variable selection in practice.

Sinus surgery postpones chronic Gram-negative lung infection: cohort study of 106 patients with cystic fibrosis

BACKGROUND

In patients with cystic fibrosis (CF) the sinuses are a bacterial reservoir for Gram-negative bacteria (GNB). From the sinuses the GNB can repeatedly migrate to the lungs. In a one-year follow-up study, endoscopic sinus surgery (ESS) with adjuvant therapy reduced the frequency of pulmonary samples positive for GNB. We investigated whether the effect is sustained.

METHODOLOGY

We report the effect of ESS and adjuvant therapy three years postoperatively in a CF cohort participating in this prospective clinical follow-up study. The primary endpoint was the lung infection status defined by Leeds criteria.

RESULTS

One hundred and six CF patients underwent ESS; 27 had improved lung infection status after three years. The prevalence of patients free of lung colonization with GNB significantly increased from 16/106 patients (15%) preoperatively to 35/106 patients (33%) after three years. The total cohort had decreasing lung function during follow-up; however, in 27 patients with improved lung infection status lung function was stable. Revision surgery was performed in 31 patients (28%).

CONCLUSION

ESS with adjuvant therapy significantly improves the lung infection status for at least three years in our cohort of patients with CF and may postpone chronic lung infection with GNB and thus stabilize lung function.

Distinct Effects of Chronic Dopaminergic Stimulation on Hippocampal Neurogenesis and Striatal Doublecortin Expression in Adult Mice

While adult neurogenesis is considered to be restricted to the hippocampal dentate gyrus (DG) and the subventricular zone (SVZ), recent studies in humans and rodents provide evidence for newly generated neurons in regions generally considered as non-neurogenic, e.g., the striatum. Stimulating dopaminergic neurotransmission has the potential to enhance adult neurogenesis in the SVZ and the DG most likely via D2/D3 dopamine (DA) receptors. Here, we investigated the effect of two distinct preferential D2/D3 DA agonists, Pramipexole (PPX), and Ropinirole (ROP), on adult neurogenesis in the hippocampus and striatum of adult naïve mice. To determine newly generated cells in the DG incorporating 5-bromo-2'-deoxyuridine (BrdU) a proliferation paradigm was performed in which two BrdU injections (100 mg/kg) were applied intraperitoneally within 12 h after a 14-days-DA agonist treatment. Interestingly, PPX, but not ROP significantly enhanced the proliferation in the DG by 42% compared to phosphate buffered saline (PBS)-injected control mice. To analyze the proportion of newly generated cells differentiating into mature neurons, we quantified cells co-expressing BrdU and Neuronal Nuclei (NeuN) 32 days after the last of five BrdU injections (50 mg/kg) applied at the beginning of 14-days DA agonist or PBS administration. Again, PPX only enhanced neurogenesis in the DG significantly compared to ROP- and PBS-injected mice. Moreover, we explored the pro-neurogenic effect of both DA agonists in the striatum by quantifying neuroblasts expressing doublecortin (DCX) in the entire striatum, as well as in the dorsal and ventral sub-regions separately. We observed a significantly higher number of DCX(+) neuroblasts in the dorsal compared to the ventral sub-region of the striatum in PPX-injected mice. These results suggest that the stimulation of hippocampal and dorsal striatal neurogenesis may be up-regulated by PPX. The increased generation of neural cells, both in constitutively active and quiescent neurogenic niches, might be related to the proportional higher D3 receptor affinity of PPX, non-dopaminergic effects of PPX, or altered motor behavior.

Tumor and Patient Characteristics of Individuals with Mismatch Repair Deficient Colorectal Cancer

AIMS

To investigate tumor and patient characteristics of individuals with mismatch repair (MMR)-deficient colorectal carcinomas.

METHODS

We immunhistochemically investigated tissue samples of 307 consecutive patients with colorectal cancer for defects in DNA MMR proteins (hMLH1, hMSH2, hMSH6, hPMS2) and those with mutations further for microsatellite instability (MSI) and BRAF V600E mutations.

RESULTS

32/308 (10.4%) tumors showed MMR deficiency. Seventy five percent (n = 24) had loss of hMLH1 and hPMS2 expression, 3% (n = 1) of hPMS2 alone, 18.8% (n = 6) of hMSH6 and hMSH2, 3% (n = 1) of hMSH2 alone. All MMR-deficient tumors showed high MSI. These tumors occurred preferably in the right-sided colon, in women and showed specific histological features. We obtained the family history of 18/32 patients; 2 (11.1%) met Amsterdam Criteria, 5 (27.8%) Bethesda Guidelines and 6 (33.3%) revised Bethesda Guidelines. BRAF V600E mutations were found in 16 (67%) of hMLH1 and none of the hMSH2 deficient tumors.

CONCLUSION

We suggest using immunhistochemical testing of tumor tissues with subsequent MSI analysis, which may be justified as a screening method for MMR deficiency in colorectal cancer, since it identifies patients with possibly hereditary defects and unalike response to chemotherapy.

Comparing the harmful effects of nontuberculous mycobacteria and Gram negative bacteria on lung function in patients with cystic fibrosis

Background

To better understand the relative effects of infection with nontuberculous mycobacteria and Gram negative bacteria on lung function decline in cystic fibrosis, we assessed the impact of each infection in a Danish setting.

Methods

Longitudinal registry study of 432 patients with cystic fibrosis contributing 53,771 lung function measures between 1974 and 2014. We used a mixed effects model with longitudinally structured correlation, while adjusting for clinically important covariates.

Results

Infections with a significant impact on rate of decline in %FEV1 were Mycobacterium abscessus complex with − 2.22% points per year (95% CI − 3.21 to − 1.23), Burkholderia cepacia complex − 1.95% (95% CI − 2.51 to − 1.39), Achromobacterxylosoxidans − 1.55% (95% CI − 2.21 to − 0.90), and Pseudomonas aeruginosa − 0.95% (95% CI − 1.24 to − 0.66). Clearing M. abscessus complex was associated with a change to a slower decline, similar in magnitude to the pre-infection slope.

Conclusions

In a national population we have demonstrated the impact on lung function of each chronic CF pathogen. M. abscessus complex was associated with the worst impact on lung function. Eradication of M. abscessus complex may significantly improve lung function.

Forceps versus snare polypectomies in colorectal cancer screening: are we adhering to the guidelines?

BACKGROUND AND STUDY AIMS

European guidelines for quality assurance in colorectal cancer screening recommend snare resection for polyps > 5 mm. The aim of this study was to investigate polypectomy technique according to lesion size and shape, and to assess adherence of endoscopists enrolled in the national quality assurance program to the European guidelines.

PATIENTS AND METHODS

This cohort study included screening colonoscopies performed between 2007 and 2013 within a quality assurance program in Austria. Resection technique was analyzed according to lesion characteristics and endoscopy facility (private practices, hospitals, outpatient clinics) before publication of the EU guidelines (2007 - 2010) and adherence to the guidelines after publication (2011 - 2013). All surveillance colonoscopies and examinations with missing data were excluded.

RESULTS

A total of 128 969 screening colonoscopies performed by 278 endoscopy units were included. The polyp detection rate was 39.6 % (n = 47 797) and 95.6 % of polyps were resected. Of polyps ≥ 5 mm, 46.0 % were resected using forceps and were therefore not treated in accordance with the guidelines. Forceps polypectomy of lesions 5 - 10 mm and > 10 mm decreased significantly in hospitals after implementation of the guidelines (both P < 0.0001). In private practices, there was no difference in forceps usage for polyps of 5 - 10 mm (P = 0.41) before and after the guidelines, and for polyps > 10 mm forceps usage even increased (P < 0.0001). Endoscopists' forceps removal rates for polyps ≥ 5 mm correlated significantly with respective adenoma detection rates (P = 0.0007, r p  - 0.187) and cecal intubation rates (P = 0.0001, r p  - 0.303). Among endoscopists in private practices, internists had slightly lower forceps removal rates for polyps ≥ 5 mm than surgeons, both before (47.2 % vs. 50.7 %; P = 0.014) and after publication of the guidelines (51.9 % vs. 53.5 %; P = 0.161).

CONCLUSIONS

This study confirmed the importance of the European guidelines. The inclusion of adequate resection technique as a quality indicator in colorectal cancer screening programs is recommended.

Hydrothermally modified slow release corn starch: a potential new therapeutic option for treating hypoglycemia in autoimmune hypoglycemia (Hirata's disease)

We report the successful treatment of autoimmune hypoglycemia in an 82-year-old non-diabetic Caucasian male with hydrothermally modified slow release corn starch, a product which is used in other conditions associated with hypoglycemia, most typically glycogen storage disease type I. An 82-year-old-Caucasian male presented with recurrent spontaneous hypoglycemia as low as 30 mg/dl following in-patient treatment for community acquired pneumonia. During a fasting-test, symptomatic hypoglycemia occurred. Plasma concentrations of c-peptide and insulin were considerably elevated. Autoimmune hypoglycemia was confirmed by the presence of insulin autoantibodies. While dietary restriction alone did not result in sufficient glucose control in this patient with autoimmune hypoglycemia, treatment with hydrothermally modified slow release corn starch led to stable euglycemia. This easy, well tolerated and non-invasive treatment may constitute a new therapeutic option for hypoglycemia in patients with autoimmune hypoglycemia who do not achieve sufficient control of hypoglycemia by dietary restriction alone.