UEG press release

Failures in colonoscopy affecting detection of colorectal cancer across Europe

March 26, 2019

Failures in colonoscopy affecting detection of colorectal cancer across Europe 

(Vienna, March 26, 2019) Leading European gastroenterologists are calling for widespread improvements in the quality of colonoscopies throughout the continent to help reduce colorectal cancer (CRC) mortality rates.

Colonoscopy is a widely performed procedure for patients with lower gastrointestinal symptoms, conducted to aid CRC detection and explore causes of unexplained changes in bowel habits. An integral element of CRC screening programmes, it is fundamental that colonoscopy procedures are of the highest possible quality to maximise early cancer detection and ensure patient comfort and wellbeing.

Leading CRC expert, Professor Evelien Dekker, from United European Gastroenterology (UEG), explains, “Progression from non-cancerous polyps to colorectal cancer will usually take between 10-15 years, leaving a long window of opportunity to detect and even prevent this disease. Besides prevention, early detection of colorectal cancer can lead to a 90% chance of survival and, to ensure these survival rates are achieved, high levels of quality in colonoscopy procedures are essential.”

Experts also believe that the Netherlands can act as a best practice example for the rest of Europe after becoming the second European country to report on quality indicators of colonoscopy.[1] Their CRC screening programme demonstrates the highest participation levels across the continent [73%] and recent pilot and implementation studies have taken place to investigate the most effective way of organising screening programmes, including the choice of the screening method and how to encourage participation from members of the public.[2] “Our studies concluded that the Faecal Immunochemical Test (FIT) is the optimal screening method”, commented Professor Dekker. “Those with a positive result are referred for a colonoscopy.”

A key indicator of colonoscopy quality are rates of post-colonoscopy colorectal cancer (PCCRC)[3], which occurs when individuals receive a negative colonoscopy result but are subsequently diagnosed with cancer. Whilst this can be the result of a rapidly growing new tumour that was not present during the colonoscopy, it is more commonly an indicator of suboptimal endoscopy quality. PCCRCs are more likely to be diagnosed at a later stage than screen-detected cancer[4], decreasing the chance of survival.

To ensure colonoscopies are performed at a quality level that minimises the incidence of PCCRCs, the Dutch CRC screening programme outlines certain criteria and requirements for endoscopists conducting the procedure (see Table 1). In line with this, the European Society of Gastrointestinal Endoscopy (ESGE), in collaboration with UEG, has recommended seven key performance measures that should be adopted across Europe. (see Table 2)

“We believe that our Dutch experience can serve as an example for colonoscopy quality assurance programmes across Europe”, comments Professor Dekker. “As well as ensuring that the programme maximises detection rates, the criteria assesses patient comfort scores so we can analyse and account for the wellbeing of our patients. Performing procedures that are as comfortable as possible for patients will help to reduce the negative stigma associated with colonoscopies.”

Colorectal Cancer Awareness Month 

CRC is the second most common cancer in the EU, with over 378,000 new cases each year[5]. With almost 175,000 deaths annually, it’s the EU’s second largest cancer killer behind lung cancer[6].

To raise awareness of CRC, European Colorectal Cancer Awareness Month takes place throughout March. To mark the month, UEG have developed an animated video to educate European policymakers, members of the public and healthcare professionals on the importance of reducing CRC incidence and mortality rates through participation in cost-effective screening and heightening awareness of key CRC symptoms and risk factors.

View the Face Up To Colorectal Cancer video

Table 1: Overview of all quality criteria for endoscopists performing colonoscopy with the Dutch CRC screening programme, defined by the national working group for quality requirements of colonoscopy[7]

Quality Criteria


Accreditation Criterion

Audit Criterion

Qualifications and Experience

Professional registration

Endoscopists are responsible for professional and re-registration according to the Individual Health Care Occupations Act




Accreditation based on the final attainment levels for an endoscopist according to the Dutch Society of Gastroenterologists



Number of colonoscopies

Total number of colonoscopies performed

≥500 lifetime

≥200 per year

Number of polypectomies

Number of polypectomies performed

≥50 lifetime

≥50 per year

Completeness of Examination

(Unadjusted) cecal intubation rate

Percentage of colonoscopies with cecal intubation

≥90% (unadjusted)

≥95% (unadjusted)

Bowel preparation

Percentage of colonoscopies in which the colon is sufficiently clean to inspect the mucosa



Withdrawal time

Percentage of negative colonoscopies* with a withdrawal time of at least 6 minutes



Detection Rates

Cancer detection rate

Percentage of colonoscopies in which (more than) one cancer is detected



Adenoma detection rate

Percentage of colonoscopies in which (more than) one adenoma is detected



Mean number of adenomas per colonoscopy

Mean number of adenomas per procedure (colonoscopy)



Mean number of adenomas per positive colonoscopy

Mean number of adenomas per positive procedure (colonoscopy)



Removal Rates

Polyp removal rate

Percentage of polyps removed relative to the total number of polyps detected at colonoscopy



Polyp retrieval rate

Percentage of polyps retrieved for histologic evaluation relative to the total number of polyps detected at colonoscopy





The percentage of cancers that were tattooed, except from those cancers located in the cecum and up to 4cm from the dentate line



Wellbeing of Patients

Adverse event record

Keeping a complete adverse event record



Adverse events during colonoscopy

Percentage of colonoscopies in which an adverse event occurred (up to 30 days after the procedure)



Perforation rate colonoscopy

Perforation rate of all colonoscopies (up to 30 days after the procedure)



Perforation rate polypectomy

Perforation rate for colonoscopies with polypectomy (up to 30 days after the procedure)



Polypectomy bleeding

The rate of bleeding for colonoscopies with polypectomy (up to 30 days after the procedure)



Patient Satisfaction

Comfort score

Percentage of colonoscopies in which the patient experiences moderate or severe discomfort



*Negative colonoscopies are colonoscopies in which no colorectal polyps or CRC has been detected.

Table 2: The European Society of Gastrointestinal Endoscopy (ESGE) and United Gastroenterology’s (UEG) list of seven key performance measures for lower gastrointestinal endoscopy[8]

Performance Measure


1.     Rate of adequate bowel preparation

Minimum standard 90%

2.     Cecal intubation rate

Minimum standard 90%

3.     Adenoma detection rate

Minimum standard 25%

4.     Appropriate polypectomy technique

Minimum standard 80%

5.     Complication rate

Minimum standard not set

6.     Patient experience

Minimum standard not set

7.     Appropriate post-polypectomy surveillance recommendations

Minimum standard not set

Notes to Editors

For further information, or to arrange an expert interview, please contact Luke Paskins on +44 (0)1444 811099 or media@ueg.eu

About Professor Evelien Dekker

Professor Evelien Dekker is a member of the UEG Public Affairs Committee and a CRC screening expert at the Amsterdam University Medical Centers (location AMC), Dept of Gastroenterology and Hepatology, The Netherlands.

About UEG

UEG, or United European Gastroenterology, is a professional non-profit organisation combining all the leading European medical specialist and national societies focusing on digestive health. Together, its member societies represent over 30,000 specialists, working across medicine, surgery, paediatrics, gastrointestinal oncology and endoscopy. This makes UEG the most comprehensive organisation of its kind in the world, and a unique platform for collaboration and the exchange of knowledge.

To advance the standards of gastroenterological care and knowledge across the world and to reduce the burden of digestive diseases, UEG offers numerous activities and initiatives, including:

  • UEG Week, the biggest congress of its kind in Europe, and one of the two largest in the world
  • UEG Education, the universal source of knowledge in gastroenterology, providing online and classroom courses, a huge online library and delivering the latest GI news, fostering debate and discussion
  • Activity Grants, promoting and funding educational projects in the field of digestive health to advance and harmonise the training and continuing education of professionals
  • UEG Journal, covering translational and clinical studies from all areas of gastroenterology
  • Public Affairs, promoting research, prevention, early diagnosis and treatment of digestive diseases, and helping develop an effective health policy for Europe
  • Quality of Care, European-based and English clinical practice guidelines, clinical standards, consensus, position papers and standard protocols in the field of digestive health, are available in the repository

Find out more about UEG’s work by visiting www.ueg.eu or contact:              
Luke Paskins on +44 (0)1444 811099 or media@ueg.eu 


  1. Gastrointestinal Endoscopy. 2019. Quality assurance of colonoscopy within the Dutch national colorectal cancer screening program.
  2. Dutch Ministry of Public Health. 2019. Available at: https://www.rivm.nl/bevolkingsonderzoek-darmkanker-voor-professionals/achtergrond-en-ontwikkelingen/feiten-en-cijfers. (Accessed 14 March 2019).
  3. BMJ. Post-colonoscopy colorectal cancer (PCCRC) rates vary considerably depending on the method used to calculate them: a retrospective observational population-based study of PCCRC in the English National Health Service. Available at: https://gut.bmj.com/content/64/8/1248. (Accessed 14 March 2019).
  4. United European Gastroenterology. One in four cases of CRC diagnosed within two years of a negative screening result. Available at: https://www.ueg.eu/press/releases/ueg-press-release/article/one-in-four-cases-of-crc-diagnosed-within-two-years-of-a-negative-screening-result/. (Accessed 14 March 2019).
  5. ECIS. Estimates of cancer incidence and mortality in 2018, for all cancer sites. Available at: https://ecis.jrc.ec.europa.eu/explorer.php?$0-0$1-AE28$4-1,2$3-All$6-0,14$5-2008,2008$7-8$2-All$CEstByCancer$X0_8-3$CEstRelativeCanc$X1_8-3$X1_9-AE28. (Accessed 14 March 2019).
  6. ECIS. Estimates of cancer incidence and mortality in 2018, for all cancer sites. Available at: https://ecis.jrc.ec.europa.eu/explorer.php?$0-0$1-AE28$4-1,2$3-All$6-0,14$5-2008,2008$7-8$2-All$CEstByCancer$X0_8-3$CEstRelativeCanc$X1_8-3$X1_9-AE28/. (Accessed 14 March 2019).
  7. Gastrointestinal Endoscopy. 2019. Quality assurance of colonoscopy within the Dutch national colorectal cancer screening program.
  8. NCBI. 2017.Performance measures for lower gastrointestinal endoscopy: a European Society of Gastrointestinal Endoscopy (ESGE) quality improvement initiative. Available at:  https://www.ncbi.nlm.nih.gov/pubmed/28507745. (Accessed 14 March 2019).


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