Screening colonoscopy for colorectal cancer prevention: results from a German online registry on 269000 cases

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

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

Effects of Hot Pack Therapy on Post-Colonoscopy Pain: A Prospective, Randomized, Controlled Study

BACKGROUND

Post-colonoscopy pain (PCP) is a negative condition that causes physical and psychological distress to patients and may lead to noncompliance with treatment and follow-up. The most common hypothesis for the cause of PCP is the inflation of the lumen with air to examine the mucosa. There are no previous studies that have examined the effects of thermal therapy in patients with PCP.

AIMS

In this study, we aimed to investigate the effects of the Hot Pack (HP) method in patients with PCP.

DESIGN

Randomized, controlled, prospective study.

METHODS

Patients were randomized 1:1 into 2 groups of HP and control. In the HP group, hot packs of 40-45°C, kept in a hydrocollator heating unit for 30-35 minutes and wrapped in towels, were applied to the umbilical and hypogastric region of patients in the supine position for 30 minutes. Visual analog scale (VAS) scores were used to measure the pain after colonoscopy. Visual analog scores at 1, 6, and 24 hours were recorded and compared in both groups.

RESULTS

There was a significant difference in the presence and severity of pain between the two groups at 1 and 6 hours after colonoscopy (p < .001 and p = .004, respectively). There was no significant difference in pain scores at 24 hours between two groups.

CONCLUSIONS

This study showed that the application of HP to patients after colonoscopy is effective in reducing pain in the early period.

Development and validation of an artificial intelligence-based system for predicting colorectal cancer invasion depth using multi-modal data

OBJECTIVES

Accurate endoscopic optical prediction of the depth of cancer invasion is critical for guiding an optimal treatment approach of large sessile colorectal polyps but was hindered by insufficient endoscopists expertise and inter-observer variability. We aimed to construct a clinically applicable artificial intelligence (AI) system for the identification of presence of cancer invasion in large sessile colorectal polyps.

METHODS

A deep learning-based colorectal cancer invasion calculation (CCIC) system was constructed. Multi-modal data including clinical information, white light (WL) and image-enhanced endoscopy (IEE) were included for training. The system was trained using 339 lesions and tested on 198 lesions across three hospitals. Man-machine contest, reader study and video validation were further conducted to evaluate the performance of CCIC.

RESULTS

The overall accuracy of CCIC system using image and video validation was 90.4% and 89.7%, respectively. In comparison with 14 endoscopists, the accuracy of CCIC was comparable with expert endoscopists but superior to all the participating senior and junior endoscopists in both image and video validation set. With CCIC augmentation, the average accuracy of junior endoscopists improved significantly from 75.4% to 85.3% (P = 0.002).

CONCLUSIONS

This deep learning-based CCIC system may play an important role in predicting the depth of cancer invasion in colorectal polyps, thus determining treatment strategies for these large sessile colorectal polyps.

Second Cancer After Additive Chemotherapy in Patients With Colon Cancer

BACKGROUND

Additive chemotherapeutic treatment of UICC-stage -III / IV colon cancer with fluorouracil, leucovorin and oxaliplatin is widely accepted as current standard of treatment after R0-resection. However, as patients.. survival is increasing, long-term side effects of chemotherapeutic agents such as second cancer development are becoming increasingly important.

PATIENTS

We therefore investigated a total of 2 856 Patients with UICC-stage III / IV colon cancer, 223 of whom (7.8%) had developed a subsequent second cancer.

RESULTS

Median follow-up was 73.2 months (range 209.9 months, 95%-CI 69.8-76.9). Most frequent second cancers were prostate cancer (18.4%), colon cancer (16.1%), breast cancers (8.1%), lung cancer (8.1%), rectal cancer (4.9%) and uterine cancer (4.9%). However, in comparison to non-treated patients this did not represent a significantly increased risk for subsequent second cancer in patients after treatment with additive chemotherapy. Of interest, our data suggest a significantly decreased second cancer rate in patients treated with FOLFOX compared to FUFOL for additive treatment.

CONCLUSIONS

Second cancer development was not increased after additive chemotherapy for colon cancer, which is a novel aspect in the ongoing discussions on reduction of adjuvant treatment to 3 months or treatment of lymph node negative patients. Novelty and Impact Statement To our knowledge, this is the first population-based study analyzing second cancer development after additive chemotherapy in patients with UICC III-IV colon cancer. The results have an important impact on the surveillance and long-term follow-up of cancer patients.

Prevalence of colorectal cancer and its precursor lesions in symptomatic patients under 55 years of age undergoing total colonoscopy: results of a large retrospective, multicenter, controlled endoscopy study

PURPOSE

Colorectal cancer (CRC) is the second most common cancer in Germany. Around 60,000 people were diagnosed CRC in 2016 in Germany. Since 2019, screening colonoscopies are offered in Germany for men by the age of 50 and for women by the age of 55. It is recently discussed if women should also undergo a screening colonoscopy by the age of 50 and if there are any predictors for getting CRC.

METHODS

Colonoscopies of 1553 symptomatic patients younger than 55 years were compared with colonoscopies of 1075 symptomatic patients older than 55 years. We analyzed if there are any significant differences between those two groups in the prevalence of CRC and its precursor lesions or between symptomatic men and women. We evaluated if there is a correlation between abdominal symptoms and the prevalence of CRC.

RESULTS

In 164/1553 symptomatic patients, 194 (12.5%) polyps were detected. In total, six colorectal carcinomas (0.4%) were detected. There were no significant differences between men and women. In symptomatic patients ≥ 55 years, significantly more polyps were found (p<0.0001; 26.6% vs. 12.5%). Totally, 286 polyps (26.6%) were removed in 1075 symptomatic patients older than 55 years. Anorectal bleeding was the only abdominal symptom being a significant indicator for the prevalence of the occurrence of colon and rectum cancer in both groups (p=0.03, OR=2.73 95%-CI [1.11;6.70]), but with only low sensitivity (44%).

CONCLUSION

Due to no significant differences in men and women, we recommend screening colonoscopies also for women by the age of 50.

Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force

IMPORTANCE

Colorectal cancer (CRC) remains a significant cause of morbidity and mortality in the US.

OBJECTIVE

To systematically review the effectiveness, test accuracy, and harms of screening for CRC to inform the US Preventive Services Task Force.

DATA SOURCES

MEDLINE, PubMed, and the Cochrane Central Register of Controlled Trials for relevant studies published from January 1, 2015, to December 4, 2019; surveillance through March 26, 2021.

STUDY SELECTION

English-language studies conducted in asymptomatic populations at general risk of CRC.

DATA EXTRACTION AND SYNTHESIS

Two reviewers independently appraised the articles and extracted relevant study data from fair- or good-quality studies. Random-effects meta-analyses were conducted.

MAIN OUTCOMES AND MEASURES

Colorectal cancer incidence and mortality, test accuracy in detecting cancers or adenomas, and serious adverse events.

RESULTS

The review included 33 studies (n = 10 776 276) on the effectiveness of screening, 59 (n = 3 491 045) on the test performance of screening tests, and 131 (n = 26 987 366) on the harms of screening. In randomized clinical trials (4 trials, n = 458 002), intention to screen with 1- or 2-time flexible sigmoidoscopy vs no screening was associated with a decrease in CRC-specific mortality (incidence rate ratio, 0.74 [95% CI, 0.68-0.80]). Annual or biennial guaiac fecal occult blood test (gFOBT) vs no screening (5 trials, n = 419 966) was associated with a reduction of CRC-specific mortality after 2 to 9 rounds of screening (relative risk at 19.5 years, 0.91 [95% CI, 0.84-0.98]; relative risk at 30 years, 0.78 [95% CI, 0.65-0.93]). In observational studies, receipt of screening colonoscopy (2 studies, n = 436 927) or fecal immunochemical test (FIT) (1 study, n = 5.4 million) vs no screening was associated with lower risk of CRC incidence or mortality. Nine studies (n = 6497) evaluated the test accuracy of screening computed tomography (CT) colonography, 4 of which also reported the test accuracy of colonoscopy; pooled sensitivity to detect adenomas 6 mm or larger was similar between CT colonography with bowel prep (0.86) and colonoscopy (0.89). In pooled values, commonly evaluated FITs (14 studies, n = 45 403) (sensitivity, 0.74; specificity, 0.94) and stool DNA with FIT (4 studies, n = 12 424) (sensitivity, 0.93; specificity, 0.85) performed better than high-sensitivity gFOBT (2 studies, n = 3503) (sensitivity, 0.50-0.75; specificity, 0.96-0.98) to detect cancers. Serious harms of screening colonoscopy included perforations (3.1/10 000 procedures) and major bleeding (14.6/10 000 procedures). CT colonography may have harms resulting from low-dose ionizing radiation. It is unclear if detection of extracolonic findings on CT colonography is a net benefit or harm.

CONCLUSIONS AND RELEVANCE

There are several options to screen for colorectal cancer, each with a different level of evidence demonstrating its ability to reduce cancer mortality, its ability to detect cancer or precursor lesions, and its risk of harms.

Is routine colonoscopy necessary for patients who have an unequivocal computerised tomography diagnosis of acute diverticulitis?

AIMS

To assess the incidence of underlying colorectal malignancy in patients admitted as an emergency with a CT diagnosis of acute diverticulitis and determine the need for routine follow up colonoscopy.

METHODS

A retrospective study was performed on all patients who had been admitted to our surgical unit with CT diagnosed diverticulitis from September 2016 to September 2018 (n = 125).

RESULTS

11 patients (8.8%) required emergency resection with no underlying malignancy found. 76 patients (61%) had a follow up colonoscopy after being discharged. 4 patients were found to have an underlying colorectal malignancy, one of them suspected on CT and another an incidentally detected caecal polyp cancer. Therefore 3/87(3.4%) had an unexpected cancer diagnosis and all those in the diseased segment were within complicated diverticulitis.

CONCLUSION

Nowadays, multi-slice CT scanners are so good at giving an accurate assessment of colonic pathology. In our study, 96.6% of the patients with a CT diagnosis of acute diverticulitis had no underlying malignancy in the diseased segment with all the cancers within complicated diverticulitis. With such a low yield of underlying malignancy in uncomplicated diverticulitis, we question the need for routine follow up colonoscopy when there is no CT suspicion of malignancy in these patients.

Routine Colonoscopy After Acute Diverticulitis: is it Warranted?

PURPOSE

Recent evidence suggests routine colonoscopy after acute diverticulitis is not necessary but remains debatable. The aim of this study was to investigate the incidence of follow-up colonoscopic finding of adenoma, advanced neoplastic lesion, and adenocarcinoma after diverticulitis.

MATERIALS AND METHODS

A retrospective review of all cases of acute diverticulitis admitted from November 2015 to April 2018 was performed. Data collected included demographics, computed tomography (CT) findings, and findings of the follow-up colonoscopy within 12 months.

RESULTS

A total of 368 patients were admitted for acute diverticulitis. A total of 366 patients underwent CT scan for diagnosis. Of whom, 185 patients (50.5%) had a follow-up colonoscopy; 115 (31.4%) did not have a follow-up colonoscopy, and the remaining have had a recent colonoscopy. The overall incidence of adenomas was 25.9% (n=48) and advanced colonic neoplasia 1.62% (n=3) in patients who underwent follow-up colonoscopy.

CONCLUSIONS

The finding of advanced colonic neoplasia in follow-up colonoscopy after an acute episode of CT-proven diverticulitis is equivalent to, or less than, that of the population colorectal cancer screening program. Routine colonoscopy is not necessary unless there are other concerning symptoms/CT findings.

Alarming endoscopic data in young and older asymptomatic people: Results of an open access, unlimited age colonoscopic screening for colorectal cancer

There is a lack of a national organized screening program for colorectal cancer in Greece, and asymptomatic detection is usually the result of individual decisions. The collection of epidemiologic endoscopic data from a population of interest would therefore provide valuable information for future treatment guidance, especially during periods of economic austerity. The current cross-sectional study included 380 asymptomatic, average risk individuals undergoing screening colonoscopy for the first time, during the period of one year in a tertiary public hospital in Athens. Descriptive and analytic epidemiologic data were analyzed. The prevalence of adenomas and advanced lesions were compared between the younger and older cohort, and a regression model was applied for risk evaluation. The mean age of participants was 63 years, and 53% were male. A significant proportion of patients presented with polyps (51.5%) and 25% of them had lesions in the proximal colon. The prevalence of adenomas and advanced adenomas was 29.5 and 11.8%, respectively. Similar high prevalence rates of lesions were identified in the cohort of individuals <50 years of age and the older cohort (>50 years of age). Regression models identified age, number and size of polyps as the major risk factors for the detection of adenomas. The increase of advanced lesions in the older and younger cohort requires confirmation by larger studies. Overall, the results of the present study indicate the requirement for a well-organized screening colonoscopy program starting from as early as 40 years of age. This program may confer an additional endoscopic burden with socioeconomic consequences in a country with limited health resources.

Meta-analysis of the role of colonoscopy after an episode of left-sided acute diverticulitis

Background

Routine colonoscopy was traditionally recommended after acute diverticulitis to exclude coexistent malignancy. Improved CT imaging may make routine colonoscopy less required over time but most guidelines still recommend it. The aim of this review was to assess the role of colonoscopy in patients with CT‐proven acute diverticulitis.

Methods

PubMed and Embase were searched for studies reporting the prevalence of advanced colorectal neoplasia (ACN) or colorectal carcinoma in patients who underwent colonoscopy within 1 year after CT‐proven left‐sided acute diverticulitis. The prevalence was pooled using a random‐effects model and, if possible, compared with that among asymptomatic controls.

Results

Seventeen studies with 3296 patients were included. The pooled prevalence of ACN was 6·9 (95 per cent c.i. 5·0 to 9·4) per cent and that of colorectal carcinoma was 2·1 (1·5 to 3·1) per cent. Only two studies reported a comparison with asymptomatic controls, showing comparable risks (risk ratio 1·80, 95 per cent c.i. 0·66 to 4·96). In subgroup analysis of patients with uncomplicated acute diverticulitis, the prevalence of colorectal carcinoma was only 0·5 (0·2 to 1·2) per cent.

Conclusion

Routine colonoscopy may be omitted in patients with uncomplicated diverticulitis if CT imaging is otherwise clear. Patients with complicated disease or ongoing symptoms should undergo colonoscopy.

Clinicopathologic Features of Colorectal Polyps in Shahid Beheshti University of Medical Sciences (SBMU)

Aim: This study was designed to report epidemiologic findings of polyps in Iranian patients, and predict histology of polyp regarding to demographic and colonoscopic findings. Background: Classification of colorectal polyps had been revised in the past two decades and there is a need for polyp categorization in the Iranian Health System. Patients and methods: In this retrospective study, the medical records of patients with colonoscopic diagnosis of polyp in pathology departments of SBMU affiliated teaching hospitals were reviewed. Patient’s slides evaluated and demographics findings were assessed. The anatomical location, macroscopic appearance including size and histological assessment of all polyps were recorded. Results: From total number of 1106 polyps (detected in 862 patients), adenomatous polyps (638 [57.7%]) were the most prevalent findings, followed by colon mucosal tag (184[16.6%]), hyperplastic and serrated polyps (122[11%]), inflammatory polyps (110[9.9%]), hamartomatous (21[1.9%]), and malignant lesions (13[1.2%]). Multivariate logistic regression showed age (each one year increasing age; odds ratio [OR] = 1.026, 95%confidence interval [CI] = 1.016–1.036, p < 0.0001), location of polyp (right colon; OR = 1.905, 95%CI = 1.366–2.656, p < 0.0001), and polyp size of 5-10 mm (OR = 1.662, 95%CI = 1.214–2.276, p = 0.002), and polyp size of >10 mm (OR = 2.778, 95%CI = 1.750–4.411, p< 0.0001) were independently associated with neoplastic polyps. Also, polyp size of >10 mm (OR= 2.613, 95%CI= 1.083-6.307, p=0.033), tubulovillous pattern of polyp (OR= 3.508, 95%CI= 1.666-7.387, p=0.001) and villous pattern of polyp (OR= 10.444, 95%CI= 4.211-25.905, p<0.0001) were associated with high grade dysplasia in neoplastic polyps. Conclusion: Increased age, location of polyp (right colon), increased size of polyp and villous component of polyp could classify patients in high risk groups.

Appendicitis as a manifestation of colon cancer: should we image the colon after appendicectomy in patients over the age of 40 years?

BACKGROUND

Appendicitis can be secondary to caecal pathology (polyp or cancer). Increasing age is a risk factor for malignancy coexisting with appendicitis. There is an increased coexistence of cancer post-appendicectomy in patients aged 50-54 years. This study investigates whether post-appendicectomy patients aged over 40 years should receive further colorectal imaging and follow-up.

METHODS

Retrospective data were collected for 1633 patients aged 40 years and over who underwent appendicectomy in a 10-year period (1st January 2004-31st December 2014). Data were analysed for patients with histological confirmation of acute appendicitis. Incidental appendicular tumours were excluded.

RESULTS

One thousand fifty-five (64%) patients had histological confirmation of acute appendicitis (median age 52 years; range 40-96 years). Six hundred three patients (57%) were aged 40-54 years; 452 patients (43%) were aged 55 years or over. Twenty-six (2.5%) patients were investigated post-appendicectomy. Three (11.5%) had caecal pathology: 2 adenocarcinoma, 1 benign caecal polyp. Ten (2.2%) patients aged 55 years or over had caecal pathology. Seven (1.6%) were diagnosed with caecal cancer. No patients below age 54 years were diagnosed with caecal cancer. The incidence of caecal cancer in the study population was 0.66% (40-54.9 years 0%; 55 years and over 1.6%). Patients aged 55 years or over were more likely to develop caecal pathology than patients aged 40-54 years (p = 0.006). The odds ratio of developing caecal pathology was 6.8 times greater (95% CI 1.49-31.29) in people aged 55 years and over.

CONCLUSIONS

Patients aged 55 years or over who have undergone appendicectomy should be offered colonoscopy to exclude coexistent caecal pathology.

Low endoscopy bleeding risk in patients with congenital bleeding disorders

INTRODUCTION

Haemophilia A and haemophilia B, von Willebrand disease (VWD), factor VII deficiency and factor XI deficiency are congenital bleeding disorders predisposing to bleeding during invasive procedures. The ageing population of people with congenital bleeding disorders will likely increasingly require gastrointestinal endoscopy. The bleeding risk postgastrointestinal endoscopy and optimal prophylactic treatment regimens are not well described.

METHODS

We performed a retrospective chart review at the McGill University Health Centre. Adult patients with haemophilia A or B, VWD, FVII deficiency and FXI deficiency who underwent gastrointestinal endoscopic procedures were included. Bleeding prophylaxis included combinations of plasma-derived factor (VWD) or recombinant factor (haemophilia A and haemophilia B), desmopressin and/or tranexamic acid. Our primary outcome was the 72-hour postendoscopy bleeding rate.

RESULTS

One hundred and four endoscopies were performed in 48 patients. Haemophilia A (45.3% of endoscopies) was the most common bleeding disorder, followed by VWD (38.5%), FXI deficiency (8.7%), haemophilia B (4.8%) and FVII deficiency (2.9%). All patients were reviewed by the Haemophilia Treatment Center with peri-procedure treatment protocols put in place as required. The overall 72-hour bleeding rate was 0.96%, confidence interval (CI) 95% (0.17%-5.25%). The colonoscopic postpolypectomy bleeding rate was 1/21 (4.8%, CI 95% (0.9%-22.7%)) in comparison with the general population rate of 0.3%-10% for high-risk endoscopy (including colonoscopic polypectomy).

CONCLUSION

To the best of our knowledge, this is the largest study describing patients with inherited bleeding disorders undergoing gastrointestinal endoscopy. The bleeding risk is not significantly higher to the general population when haemostatically managed by a team experienced in bleeding disorders.

Is there a role for routine colonoscopy in the follow-up after acute appendicitis?

BACKGROUND

Mechanical obstruction of the appendiceal lumen is proposed as a possible factor in the pathogenesis of acute appendicitis. Hence, patients over the age of 40 are often referred to a follow-up colonoscopy after admission for acute appendicitis. The use of CT scans question whether routine colonoscopy still has a place in follow-up for these patients.

METHODS

All patients aged over 40 years with confirmed acute appendicitis admitted to St. Olav's Hospital in the period from 2010 to 2015 were included in this retrospective study. Findings and distribution of significant colorectal neoplasms (cancer and advanced adenomas) within three years after the admission were evaluated.

RESULTS

Fifty-four (7.4%) of the 731 patients were found to have colonic neoplasms; 9 patients (1.2%) were found to have colorectal cancer of which 7 were located on the right side, 22 patients (3.0%) were found to have advanced adenomas and 23 patients (3.1%) were found to have non-advanced adenomas. The sensitivity and specificity for CT to discover cancer was 0.25 and 0.97, respectively. A total of 316 patients (43.2%) had colonoscopy within three years after admission.

CONCLUSION

There may be an increased risk of colorectal neoplasms in patients over the age of 40 admitted with acute appendicitis. There seems to be an increased proportion of right-sided cancer relatively to other colonic locations. The sensitivity for CT scans to discover colorectal cancer in this group is low. Further studies are needed to decide whether routine colonoscopy is indicated after acute appendicitis in patients over 40 years.

CMOST: an open-source framework for the microsimulation of colorectal cancer screening strategies

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related mortality. CRC incidence and mortality can be reduced by several screening strategies, including colonoscopy, but randomized CRC prevention trials face significant obstacles such as the need for large study populations with long follow-up. Therefore, CRC screening strategies will likely be designed and optimized based on computer simulations. Several computational microsimulation tools have been reported for estimating efficiency and cost-effectiveness of CRC prevention. However, none of these tools is publicly available. There is a need for an open source framework to answer practical questions including testing of new screening interventions and adapting findings to local conditions.

METHODS

We developed and implemented a new microsimulation model, Colon Modeling Open Source Tool (CMOST), for modeling the natural history of CRC, simulating the effects of CRC screening interventions, and calculating the resulting costs. CMOST facilitates automated parameter calibration against epidemiological adenoma prevalence and CRC incidence data.

RESULTS

Predictions of CMOST were highly similar compared to a large endoscopic CRC prevention study as well as predictions of existing microsimulation models. We applied CMOST to calculate the optimal timing of a screening colonoscopy. CRC incidence and mortality are reduced most efficiently by a colonoscopy between the ages of 56 and 59; while discounted life years gained (LYG) is maximal at 49-50 years. With a dwell time of 13 years, the most cost-effective screening is at 59 years, at $17,211 discounted USD per LYG. While cost-efficiency varied according to dwell time it did not influence the optimal time point of screening interventions within the tested range.

CONCLUSIONS

Predictions of CMOST are highly similar compared to a randomized CRC prevention trial as well as those of other microsimulation tools. This open source tool will enable health-economics analyses in for various countries, health-care scenarios and CRC prevention strategies. CMOST is freely available under the GNU General Public License at https://gitlab.com/misselwb/CMOST.

Complication Rates in Colonoscopy Screening for Cancer

BACKGROUND

Screening colonoscopy has been offered in Germany since 2002. Complications during colonoscopy were reported to be rare, but data on potential complications after colonoscopy are sparse. We aimed to comprehensively assess the frequency of complications arising during or within four weeks of screening colonoscopy.

METHODS

Residents of the German federal state of Saarland without a history of colorectal cancer and without previous polypectomy who underwent a screening colonoscopy between 2010 and 2013 were included. A follow-up was conducted three months after the screening colonoscopy, including participant questionnaires and subsequent validation of self-reported complications arising during or within four weeks of screening colonoscopy, by reviewing colonoscopy records and contacting the treating physicians. A comprehensive mortality follow-up was conducted for non-responders.

RESULTS

We recruited a total of 5527 participants from 26 practices (median age 61 years, 52% women). 5252 (95%) fully completed the questionnaire on complications and met the inclusion criteria for analysis. Among these participants, 16 cases of physician-confirmed bleeding (0.30%) and four cases of physician-confirmed perforation (0.08%) occurred during or within four weeks of colonoscopy. According to consistent reports from patients and physicians, bleeding and perforation led to hospitalization in 5 (0.095%) and 2 (0.04%) cases, respectively. Three participants died within three months of colo - noscopy. In none of these cases was the cause of death related to colonoscopy.

CONCLUSION

We found the risk of complications of screening colonoscopy to be low, even when taking into account a potential delay of up to four weeks.

Effectiveness of Screening Colonoscopy to Prevent Colorectal Cancer Among Medicare Beneficiaries Aged 70 to 79 Years: A Prospective Observational Study

BACKGROUND

No randomized, controlled trials of screening colonoscopy have been completed, and ongoing trials exclude persons aged 75 years or older. The Medicare program, however, reimburses screening colonoscopy without an upper age limit.

OBJECTIVE

To evaluate the effectiveness and safety of screening colonoscopy to prevent colorectal cancer (CRC) in persons aged 70 to 74 and those aged 75 to 79 years.

DESIGN

Large-scale, population-based, prospective study. The observational data were used to emulate a target trial with 2 groups: colonoscopy screening and no screening.

SETTING

United States.

PARTICIPANTS

1 355 692 Medicare beneficiaries (2004 to 2012) aged 70 to 79 years at average risk for CRC who used Medicare preventive services and had no previous diagnostic or surveillance colonoscopies in the past 5 years.

MEASUREMENTS

8-year risk for CRC and 30-day risk for adverse events.

RESULTS

In beneficiaries aged 70 to 74 years, the 8-year risk for CRC was 2.19% (95% CI, 2.00% to 2.37%) in the screening colonoscopy group and 2.62% (CI, 2.56% to 2.67%) in the no-screening group (absolute risk difference, -0.42% [CI, -0.24% to -0.63%]). Among those aged 75 to 79 years, the 8-year risk for CRC was 2.84% (CI, 2.54% to 3.13%) in the screening colonoscopy group and 2.97% (CI, 2.92% to 3.03%) in the no-screening group (risk difference, -0.14% [CI, -0.41 to 0.16]). The excess 30-day risk for any adverse event in the colonoscopy group was 5.6 events per 1000 individuals (CI, 4.4 to 6.8) in the 70- to 74-year age group and 10.3 per 1000 (CI, 8.6 to 11.1) in the 75- to 79-year age group.

LIMITATION

CRC-specific mortality was not available, but CRC incidence and stage were studied at diagnosis.

CONCLUSION

Screening colonoscopy may have had a modest benefit in preventing CRC in beneficiaries aged 70 to 74 years and a smaller benefit in older beneficiaries. The risk for adverse events was low but greater among older persons.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Expert opinions and scientific evidence for colonoscopy key performance indicators

Colonoscopy is a widely performed procedure with procedural volumes increasing annually throughout the world. Many procedures are now performed as part of colorectal cancer screening programmes. Colonoscopy should be of high quality and measures of this quality should be evidence based. New UK key performance indicators and quality assurance standards have been developed by a working group with consensus agreement on each standard reached. This paper reviews the scientific basis for each of the quality measures published in the UK standards.

Post-Colonoscopy Complications: A Systematic Review, Time Trends, and Meta-Analysis of Population-Based Studies

OBJECTIVES

Many studies around the world addressed the post-colonoscopy complications, but their pooled prevalence and time trends are unknown. We performed a systematic review and meta-analysis of population-based studies to examine the pooled prevalence of post-colonoscopy complications ("perforation", "bleeding", and "mortality"), stratified by colonoscopy indication. Temporal variability in the complication rate was assessed.

METHODS

We queried Pubmed, Embase, and the Cochrane library for population-based studies examining post-colonoscopy complications (within 30 days), performed from 2001 to 2015 and published by 1 December 2015. We determined pooled prevalence of perforations, post-colonoscopy bleeding, post-polypectomy bleeding, and mortality.

RESULTS

We retrieved 1,074 studies, of which 21 met the inclusion criteria. Overall, pooled prevalences for perforation, post-colonoscopy bleeding, and mortality were 0.5/1,000 (95% confidence interval (CI) 0.4-0.7), 2.6/1,000 (95% CI 1.7-3.7), and 2.9/100,000 (95% CI 1.1-5.5) colonoscopies. Colonoscopy with polypectomy was associated with a perforation rate of 0.8/1,000 (95% CI 0.6-1.0) and a post-polypectomy bleeding rate of 9.8/1,000 (95% CI 7.7-12.1). Complication rate was lower for screening/surveillance than for diagnostic examinations. Time-trend analysis showed that post-colonoscopy bleeding declined from 6.4 to 1.0/1,000 colonoscopies, whereas the perforation and mortality rates remained stable from 2001 to 2015. Overall, considerable heterogeneity was observed in most of the analyses.

CONCLUSIONS

Worldwide, the post-colonoscopy complication rate remained stable or even declined over the past 15 years. The findings of this meta-analysis encourage continued efforts to achieve and maintain safety targets in colonoscopy practice.

The potential of imaging techniques as a screening tool for colorectal cancer: a cost-effectiveness analysis

OBJECTIVE

Imaging may be promising for colorectal cancer (CRC) screening, since it has test characteristics comparable with colonoscopy but is less invasive. We aimed to assess the potential of CT colonography (CTC) and MR colonography (MRC) in terms of (cost-effectiveness) using the Adenoma and Serrated pathway to Colorectal CAncer model.

METHODS

We compared several CTC and MRC strategies with 5- or 10-yearly screening intervals with no screening, 10-yearly colonoscopy screening and biennial faecal immunochemical test (FIT) screening. We assumed trial-based participation rates in the base-case analyses and varied the rates in sensitivity analyses. Incremental lifetime costs and health effects were estimated from a healthcare perspective.

RESULTS

The health gain of CTC and MRC was similar and ranged from 0.031 to 0.048 life-year gained compared with no screening, for 2-5 screening rounds. Lifetime costs per person for MRC strategies were €60-110 higher than those for CTC strategies with an equal number of screening rounds. All imaging-based strategies were cost-effective compared with no screening. FIT screening was the dominant screening strategy, leading to most LYG and highest cost-savings. Compared with three rounds of colonoscopy screening, CTC with five rounds was found to be cost-effective in an incremental analysis of imaging strategies. Assumptions on screening participation have a major influence on the ordering of strategies in terms of costs and effects.

CONCLUSION

CTC and MRC have potential for CRC screening, compared with no screening and compared with three rounds of 10-yearly colonoscopy screening. When taking FIT screening as the reference, imaging is not cost-effective. Participation is an important driver of effectiveness and cost estimates.

ADVANCES IN KNOWLEDGE

This is the first study to assess the cost-effectiveness of MRC screening for CRC.

Use of automated irrigation pumps improves quality of bowel preparation for colonoscopy

AIM: To evaluate the effectiveness of automated irrigation pumps (AIPs) in improving the quality of the bowel preparation and the yield of colonoscopy.

METHODS: A retrospective observational study was conducted at a single medical center. Outpatient colonoscopies performed during a 4-mo time period when AIPs were not in use, were compared to colonoscopies performed during control period. The main outcomes measured were quality of bowel preparation, procedures aborted due to poor preparation, recommendations to repeat at short interval due to sub-optimal bowel preparation and adenoma detection rates.

RESULTS: One thousand and thirty-seven colonoscopies were included. A higher proportion of cases did not achieve a satisfactory bowel preparation when AIPs were not used (24.4% vs 10.3%, P < 0.01). The number of procedures aborted due to inadequate preparation was not significantly different, however a repeat procedure at a short interval was recommended in a higher proportion of cases when AIPs were not used (21.3% vs 6.9%, P < 0.01). Good or excellent preparation was 2.91 (95%CI: 2.04-4.15) times more likely when AIPs were used. Detection of polyps and adenomas was not significantly different.

CONCLUSION: AIP use during colonoscopy results in a higher proportion of colonic preparation rated as satisfactory, although polyp detection rate is not significantly affected. Recommendations for repeat colonoscopy at shorter interval significantly decrease with the use of AIPs. This study supports the use of the irrigation pumps in endoscopy units to improve the quality of colonoscopy.

Optimal use of colonoscopy and fecal immunochemical test for population-based colorectal cancer screening: a cost-effectiveness analysis using Japanese data

OBJECTIVE

There have been few cost-effectiveness analyses of population-based colorectal cancer screening in Japan, and there is no consensus on the optimal use of total colonoscopy and the fecal immunochemical test for colorectal cancer screening with regard to cost-effectiveness and total colonoscopy workload. The present study aimed to examine the cost-effectiveness of colorectal cancer screening using Japanese data to identify the optimal use of total colonoscopy and fecal immunochemical test.

METHODS

We developed a Markov model to assess the cost-effectiveness of colorectal cancer screening offered to an average-risk population aged 40 years or over. The cost, quality-adjusted life-years and number of total colonoscopy procedures required were evaluated for three screening strategies: (i) a fecal immunochemical test-based strategy; (ii) a total colonoscopy-based strategy; (iii) a strategy of adding population-wide total colonoscopy at 50 years to a fecal immunochemical test-based strategy.

RESULTS

All three strategies dominated no screening. Among the three, Strategy 1 was dominated by Strategy 3, and the incremental cost per quality-adjusted life-years gained for Strategy 2 against Strategies 1 and 3 were JPY 293 616 and JPY 781 342, respectively. Within the Japanese threshold (JPY 5-6 million per QALY gained), Strategy 2 was the most cost-effective, followed by Strategy 3; however, Strategy 2 required more than double the number of total colonoscopy procedures than the other strategies.

CONCLUSIONS

The total colonoscopy-based strategy could be the most cost-effective for population-based colorectal cancer screening in Japan. However, it requires more total colonoscopy procedures than the other strategies. Depending on total colonoscopy capacity, the strategy of adding total colonoscopy for individuals at a specified age to a fecal immunochemical test-based screening may be an optimal solution.

Long-Term Impact of the Dutch Colorectal Cancer Screening Program on Cancer Incidence and Mortality-Model-Based Exploration of the Serrated Pathway

BACKGROUND

We aimed to predict the long-term colorectal cancer incidence, mortality, and colonoscopy demand of the recently implemented Dutch colorectal cancer screening program.

METHODS

The Adenoma and Serrated pathway to Colorectal Cancer model was set up to simulate the Dutch screening program consisting of biennial fecal immunochemical testing combined with the new Dutch surveillance guidelines, between 2014 and 2044. The impact of screening and surveillance was evaluated under three sets of natural history assumptions differing in the contribution of the serrated pathway to colorectal cancer incidence. In sensitivity analyses, other assumptions concerning the serrated pathway were varied. Model-predicted outcomes were yearly colorectal cancer incidence, mortality, and colonoscopy demand per year.

RESULTS

Assuming an aging population, colorectal cancer incidence under 30 years of screening is predicted to decrease by 35% and 31% for a contribution of 0% and 30% of the serrated pathway to colorectal cancer, respectively. For colorectal cancer mortality, reductions are 47% and 45%. In 2044, 110,000 colonoscopies will be required annually assuming no contribution of the serrated pathway (27 per 1,000 individuals in the screening age range). Including the serrated pathway influences predicted screening effectiveness if serrated lesions are neither detected nor treated at colonoscopy, and/or if colorectal cancers arising from serrated lesions have substantially lower survival rates than those arising from adenomas.

CONCLUSIONS

The Dutch screening program will markedly decrease colorectal cancer incidence and mortality but considerable colonoscopy resources will be required.

IMPACT

Predictions of long-term screening effectiveness are preferably based on both pathways to colorectal cancer to transparently describe the impact of uncertainties regarding the serrated pathway on long-term predictions.

Benefit of adjuvant chemotherapy in patients with T4 UICC II colon cancer

Background

Colorectal cancer is the third most common cancer and a major cause of morbidity and mortality worldwide. Adjuvant chemotherapy is considered the standard of care in patients with UICC stage III colon cancer after R0 resection. Adjuvant therapy was not shown to be beneficial in patients with UICC stage II colon cancer. However, there is an ongoing discussion as to whether adjuvant chemotherapy may be beneficial for a subgroup of UICC II patients in a “high-risk situation” (such as T4).

Methods

We investigated a Bavarian population-based (2.1 million inhabitants) cohort of 1937 patients with UICC II CRC treated between 2002 and 2012 in regard of the benefit of adjuvant chemotherapy for large (T4) tumors. Patients older than 80 years of age were excluded. Of 1937 patients, 240 had a T4 tumor (12 %); 77 of all T4 patients received postoperative chemotherapy (33 %). Kaplan-Meier analysis and Cox regression models were used for survival analyses.

Results

Patients with a T4 tumor who received postoperative chemotherapy had a highly significant survival benefit in respect of overall survival (p < 0.001) and recurrence-free survival (p = 0.008). However, no difference was observed between oxaliplatin-containing and non-oxaliplatin-containing treatment regimens. G2 and G3 tumors were found to particularly benefit from adjuvant treatment. Chemotherapy, age at diagnosis, and tumor grading remained independent risk factors in the multivariate cox regression analysis.

Conclusion

Our retrospective study demonstrated the significant benefit of adjuvant chemotherapy in the T4 subgroup of patients with UICC II colon cancer. Our data suggest that adjuvant chemotherapy should be seriously considered in these patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1404-9) contains supplementary material, which is available to authorized users.

The incidence of colon cancer among patients diagnosed with left colonic or sigmoid acute diverticulitis is higher than in the general population

BACKGROUND

Considering the low incidence of colon cancer after an initial episode of colonic diverticulitis in some categories of patients, some authors suggested to exempt them from colonoscopy. However, this incidence has never been compared to that of a reference population, and predictors of cancer are still poorly investigated. We aimed to determine the 1-year incidence of colon cancer at the site of diverticulitis in patients diagnosed with left colonic or sigmoid acute diverticulitis, to compare this incidence to a reference population to state whether endoscopy is required or not, and to identify predicting factors of cancer to better target subpopulations needing that examination.

METHODS

All patients admitted at the University Hospitals of Geneva for left colonic or sigmoid acute diverticulitis were included. Patients with a previous history of colon cancer or non-available for follow-up were excluded. Demographic data, haemoglobin values, and the Hinchey score were documented. This cohort was matched with the Geneva Cancer Registry to look for cancer occurrence at the site of diverticulitis within 1 year. Predictors of cancer were assessed using univariate logistic regression and the risk of cancer by comparing observed cases to a reference population using standardized incidence ratios.

RESULTS

The final cohort included 506 patients. Eleven (2.2 %) had a diagnosis of cancer at the site of diverticulitis within 1 year. The mean age was significantly different between patients with cancer and others. No predictor of cancer could be identified, except a trend for an increased risk with advancing age (p = 0.067). The standardized incidence ratios showed a 44-fold increased risk of cancer among the cohort compared to the reference population.

CONCLUSIONS

Colonoscopy should be continued after an initial diagnosis of left colonic or sigmoid acute diverticulitis, irrespective of the clinical or radiological presentations.

Diagnostic impact of routine colonoscopy following acute diverticulitis: A multicenter study in 808 patients and controls

BACKGROUND

The diagnosis of acute diverticulitis is mainly based on clinical, biological and computed tomography (CT)-scan findings. Elective colonoscopy is recommended after medical treatment, to rule out another diagnosis and to detect associated conditions; however, the relevance of this recommendation has been questioned.

PATIENTS AND METHODS

Between January 2005 and December 2011, we retrospectively identified in three referral centers the consecutive patients whom underwent a colonoscopy after the medical treatment of a CT scan-proven acute diverticulitis episode. We excluded from the analysis patients with haematochezia or recent change in bowel habits. Sex and age-matched asymptomatic patients undergoing a screening colonoscopy were chosen as a control group. We collected and compared the results of colonoscopy and histological findings in both groups.

RESULTS

We matched 404 patients whom underwent a colonoscopy after an episode of acute diverticulitis with 404 control patients. Their mean age was 60.9 years, with 59% being women. Colorectal adenoma, advanced adenoma and cancer detection rates in acute diverticulitis patients were 12.1%, 2.7% and 0.25%, respectively; versus 14.6% (p = 0.35), 6.7% (p = 0.01) and 0.25% respectively, in control patients.

CONCLUSIONS

Diagnosis rates for adenomas and for colorectal cancer during a colonoscopy scheduled after acute diverticulitis were similar than those of control patients undergoing a screening colonoscopy, while the detection rate of advanced adenomas was lower. We suggest that colonoscopy should be indicated only in selected patients, i.e. those presenting with reasonable doubt on initial CT-scan, those with alarm symptoms, and those with identified risk factors for colorectal cancer.

Detection of colon polyps by a novel, polymer pattern-based full blood test

Numerous studies have shown that early screening for the presence of pre-cancerous colon polyps and their subsequent removal decreases the risk of developing colon cancer. Colonoscopy is currently the most effective screening method, but due to the invasive nature of the procedure many patients avoid forgo testing. Futhermore, the procedure itself requires perfect execution by the gastroenterologist. Against this backdrop, a non-invasive blood screening method for the detection of colon polyps that has higher sensitivity than current screening techniques would be beneficial in the early identification of patients at risk for colon cancer. A prospective, double-blinded, controlled clinical study was designed to demonstrate the diagnostic performance of Polyp Specific Polymer analysis, a novel laboratory methodology. The primary objective of this clinical trial was to estimate the diagnostic accuracy of the Polyp Specific Polymer analysis for colon polyps using colonoscopy and histological tests as the diagnostic accuracy standards. Secondary objectives of this trial included estimating positive and negative predictive values for colon polyps, investigating reliability, determining covariates influencing diagnostic accuracy and obtaining absolute and relative frequencies of valid test results.In patients undergoing screening colonoscopy and histology examination, a sensitivity of 72.4% and a specificity of 62.3% could be proven.These results indicate that using this improved screening method it is possible to effectively identify the highest-risk candidates for endoscopy, thereby advancing the goal of decreasing the incidence or mortality of colorectal cancer in the selected population. Moreover, this diagnostic tool has potential socio-economic implications, conserving healthcare resources by enabling higher patient selectivity for endoscopy and eventual transfer to curative prevention via polypectomy.By combining the best-established low-risk screening elements together with a validated, highly sensitive blood test as described in this study, a steadfast increase in the estimation of colorectal cancer-risk before colonoscopy can be expected.

Harms of colonoscopy in a colorectal cancer screening programme with faecal occult blood test: a population-based cohort study

BACKGROUND AND AIMS

To assess the harms of colonoscopy in a real world colorectal cancer screening programme with faecal occult blood test.

METHODS

Retrospective cohort study of all colonoscopies performed in patients aged 50-74 for a positive guaiac-based faecal occult blood test between September 2003 and February 2010 within the screening programme in progress in Alsace (France). Adverse events were recorded through prospective voluntary reporting by gastroenterologists and retrospective postal surveys addressed to persons screened and their general practitioners.

RESULTS

Of 10,277 colonoscopies, 250 adverse events were recorded, 48 (4.7 ‰, 95% CI 3.4-6.0) of them being moderate or severe, mainly 10 (1.0 ‰, 95% CI 0.4-1.6) perforations and 31 (3.0 ‰, 95% CI 2.0-4.1) bleeding. 91.7% of moderate and severe adverse events were the result of a therapeutic procedure. Of 103 serious adverse events, eight (7.8%) were considered preventable. Gastroenterologists reported 52.2% of moderate and severe adverse events. A mild adverse event or an incident was reported in up to 97.0 ‰ (95% CI 83.2-110.7) colonoscopies.

CONCLUSION

The harms of colonoscopy were underestimated in all randomized controlled trials on colorectal cancer screening with faecal occult blood test. They are greater in a real world programme, estimated at 7.5 major and 100 minor adverse events per 1000 colonoscopies.

Endoscopic evaluation of the colon after an episode of diverticulitis: a call for a more selective approach

PURPOSE

Routine colonic evaluation is advised after an episode of diverticulitis to exclude colorectal cancer. In the recent years, the possible relation between diverticulitis and colorectal cancer has been subject of debate. The aim of this study is to evaluate the benefit of routine colonic endoscopy after an episode of diverticulitis.

METHODS

Records of all consecutive patients presenting with a radiologically confirmed episode of diverticulitis between 2007 and 2010 were retrieved from an in-hospital database. Patients who subsequently underwent colonic evaluation were included. The endoscopic detection rate of hyperplastic polyps, adenomas and advanced colonic neoplasia was assessed. Findings were categorized on the basis of the most advanced lesion identified.

RESULTS

Three hundred and seven patients presented with a radiologically confirmed primary episode of diverticulitis. Two hundred and five patients underwent colonic evaluation. Hyperplastic polyps were found in15 (6.8 %), adenomas in 18 (8.8 %) and advanced neoplastic lesions in 7 (3.4 %) patients. Only two patients had a colorectal malignancy.

CONCLUSION

There appears to be no benefit in performing routine colonic evaluation after an episode of diverticulitis as the incidence of colorectal cancer is almost equal to that of the general population. A more selective approach might therefore be justified. Potentially, only patients with persisting abdominal complaints after an episode of diverticulitis should be offered colonic evaluation to definitively exclude causal pathology.

Routine colonoscopy following acute uncomplicated diverticulitis

BACKGROUND

The evidence supporting current recommendations that the colon should be evaluated following an initial episode of acute diverticulitis is poor. The aim of this study was to clarify whether acute uncomplicated diverticulitis is a valid indication for subsequent colonoscopy/computed tomography (CT) colonography.

METHODS

This was a retrospective longitudinal study of patients with an initial presentation of acute uncomplicated diverticulitis on the basis of CT criteria, at a single institution between January 2004 and December 2008.

RESULTS

A radiological diagnosis of acute uncomplicated diverticulitis was made in 292 patients. Some 205 patients underwent subsequent colonic evaluation or had undergone colonoscopy/CT colonography within the preceding 2 years. Colorectal polyps were present in 50 patients (24·4 per cent). Twenty patients (9·8 per cent) had hyperplastic polyps and 19 (9·3 per cent) had adenomas. Eleven patients (5·4 per cent) had advanced colonic neoplasia, including one (0·5 per cent) with a colorectal cancer. One patient had inflammatory bowel disease (IBD). The patients with colorectal cancer and IBD had clinical indicators that independently warranted colonoscopy. None of the 87 patients who did not undergo colonic evaluation had a diagnosis of colorectal cancer registered with the New Zealand Cancer Registry.

CONCLUSION

The yield of advanced colonic neoplasia in this cohort was equivalent to, or less than that detected on screening asymptomatic average-risk individuals. In the absence of other indications, subsequent evaluation of the colon may not be required to confirm the diagnosis of diverticulitis.

Increased risk of adenomas in individuals with a family history of colorectal cancer: results of a meta-analysis

OBJECTIVE

It is unclear to what extent the increased risk of colorectal cancer in individuals with a family history of colorectal cancer and no known genetic disorders is associated with a higher adenoma prevalence. Our aim is to estimate the relative difference in adenoma prevalence and its age-pattern in individuals with a family history of colorectal cancer compared to those without.

METHODS

We performed a literature search to identify colonoscopy studies reporting the adenoma prevalence by age. Using multilevel logistic regression, we examined how the adenoma prevalence by age differed between individuals with and without a family history of colorectal cancer. We excluded members of families with a known genetic disorder.

RESULTS

Thirteen colonoscopy studies were identified. The adenoma prevalence was significantly higher in individuals with a family history than in those without (OR 1.7, 95% CI 1.4-3.5). The adenoma prevalence increased with age (OR per year of age 1.06, 95% CI 1.05-1.07). The age trend did not differ significantly between the two groups.

CONCLUSION

Individuals with a family history of colorectal cancer have a considerably higher prevalence of adenomas compared to individuals without a family history. This is consistent with their increased risk of colorectal cancer.

Eight years of colonoscopic bowel cancer screening in Germany: initial findings and projections

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.

Malignant colorectal polyps

Nowadays, the number of cases in which malignant colorectal polyps are removed is increasing due to colorectal cancer screening programmes. Cancerous polyps are classified into non-invasive high grade neoplasia (NHGN), when the cancer has not reached the muscularis mucosa, and malignant polyps, classed as T1, when they have invaded the submucosa. NHGN is considered cured with polypectomy, while the prognosis for malignant polyps depends on various morphological and histological factors. The prognostic factors include, sessile or pedunculated morphology of the polyp, whether partial or en bloc resection is carried out, the degree of differentiation of the carcinoma, vascular or lymphatic involvement, and whether the polypectomy resection margin is tumor free. A malignant polyp at T1 is considered cured with polypectomy if it is a pedunculated polyp (Ip of the Paris classification), it has been completely resected, it is not poorly differentiated, the resection edge is not affected by the tumor and there is no vascular or lymphatic involvement. The sessile malignant polyp (Is of the Paris classification) at T1 is considered not cured with polypectomy. Only in some cases (e.g. older people with high surgical risk) local excision (polypectomy or endoscopic submucosal dissection or conventional endoscopic mucosal resection) is considered the definitive treatment.

Characterization of forces applied by endoscopists during colonoscopy by using a wireless colonoscopy force monitor

BACKGROUND

To perform a colonoscopy, the endoscopist maneuvers the colonoscope through a series of loops by applying force to the insertion tube. Colonoscopy insertion techniques are operator dependent but have never been comprehensively quantified.

OBJECTIVE

To determine whether the Colonoscopy Force Monitor (CFM), a device that continually measures force applied to the insertion tube, can identify different force application patterns among experienced endoscopists.

DESIGN

Observational study of 6 experienced endoscopists performing routine diagnostic and therapeutic colonoscopy in 30 patients.

SETTING

Outpatient ambulatory endoscopy center.

PATIENTS

Adult male and female patients between 30 and 75 years of age undergoing routine colonoscopy.

INTERVENTIONS

CFM monitoring of force applied to the colonoscope insertion tube during colonoscopy.

MAIN OUTCOME MEASUREMENTS

Maximum and mean linear and torque force, time derivative of force, combined linear and torque vector force, and total manipulation time.

RESULTS

The CFM demonstrates differences among endoscopists for maximum and average push/pull and mean torque forces, time derivatives of force, combined push/torque force vector, and total manipulation time. Endoscopists could be grouped by force application patterns.

LIMITATIONS

Only experienced endoscopists using conscious sedation in the patients were studied. Sample size was 30 patients.

CONCLUSIONS

This study demonstrates that CFM allows continuous force monitoring, characterization, and display of similarities and differences in endoscopic technique. CFM has the potential to facilitate training by enabling trainees to assess, compare, and quantify their techniques and progress.