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

https://doi.org/10.1016/j.dld.2013.01.006Get rights and content

Abstract

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.

Introduction

Colorectal cancer (CRC) is the second most common cause of death from malignant disease in Europe, resulting in 212,000 deaths in 2008 [1]. Four randomised controlled trials (RCTs) have demonstrated the efficacy of screening with guaiac-based faecal occult blood test (gFOBT) on CRC mortality [2], [3], [4], [5]. Many countries, including France, have thus launched gFOBT-based CRC screening programmes [6]. However, the benefit of CRC screening is modest, estimated between 1.2 and 1.6 death avoided per 1000 persons invited in the three RCTs with biennial non rehydrated gFOBT [4], [5], [7]. Moreover, the harm of these programmes has been insufficiently evaluated [3], [8], [9], [10].

Would the effectiveness of a CRC screening programme be measured by the reduction of all-cause or CRC specific mortality, both measures are obtained late after more than 10 years of follow up. Surrogate short term endpoints are necessary for an earlier estimation of the benefit-risk balance. We, and others, have demonstrated that participation and yield (i.e. benefit) obtained in RCTs are reproducible in the real-world through organized population-based programmes [11], [12], [13]. But, how about risk? Real-world data is needed. As stated by Sir Muir Gray “All screening programmes do harm, some do good as well”.

Our aim was to assess the harms of colonoscopy in a real world CRC screening programme with gFOBT.

Section snippets

Methods

We retrospectively analysed the complications of all colonoscopies performed in a cohort of residents undergoing a colonoscopy for a positive gFOBT between September 2003 and February 2010 within the population-based CRC screening programme organized in Alsace, a region in eastern France.

Colonoscopies and yield

Depending on administrative area and screening round, 45.0–54.3% of people invited were screened. A total of 10,277 colonoscopies were performed by 113 gastroenterologists in 10,024 persons (mean age 62.7 years; SD 7.0). Age and sex distribution of people having undergone a colonoscopy is presented in Appendix A. The rate of therapeutic colonoscopies was 48.5%. The positive predictive value was 6.3% for cancer, 29.8% for advanced neoplasia and 43.6% for neoplasia. The estimated false-positive

Main findings

The harm caused by colonoscopies was estimated in our programme at 10.0 serious AEs and 24.3 AEs per 1000 colonoscopies depending on the classification adopted. Most were mild, so the rate of moderate and severe AEs was 4.7 per 1000 colonoscopies. In contrast, mild AEs and incidents were frequent, reported in up to 97.0‰ of procedures. There was a strong correlation between harm and colonoscopy yield: 91.7% of moderate and severe AEs resulted from therapeutic procedures and their frequency

Conclusion

The harms of colonoscopy were underestimated in all RCTs on gFOBT CRC screening. They are greater in our real-world programme than in all RCTs but the British. The invited population should be informed that the complication rate of colonoscopy is around 7.5‰ major and 100‰ minor AEs. These results reinforce the imperious necessity for any screening programme to incorporate a rigorous quality assurance programme for all steps of the process designed to evaluate and minimize harm. One must

Funding

This study was performed as part of a quality assurance programme within the CRC screening programme in Alsace without dedicated funding. The sources of funding of ADECA Alsace, the association in charge of the programme, include the French Sickness Fund (Assurance Maladie), the French Ministry of Health and the Haut-Rhin and Bas-Rhin Administrations (Conseils Généraux du Haut-Rhin et du Bas-Rhin). They had no role in study design, data collection, analysis, and interpretation, or writing the

Conflict of interest

No competing interests to declare.

Acknowledgments

The authors thank John Brodersen and Bruno Heleno (Research Unit and Section of General Practice, Institute of Public Health, University of Copenhagen, Copenhagen, Denmark) and Guy Launoy (ERI3 Inserm Cancers et populations, CHU de Caen, Université de Caen Basse-Normandie, Caen, France) for their insightful comments and advice. They also thank all the GPs who participated in this screening programme, the participating gastroenterologists and pathologists for their contributions and all the

References (32)

  • E.J. Bini et al.

    Systematic evaluation of complications related to endoscopy in a training setting: a prospective 30-day outcomes study

    Gastrointestinal Endoscopy

    (2003)
  • C.W. Ko et al.

    Incidence of minor complications and time lost from normal activities after screening or surveillance colonoscopy

    Gastrointestinal Endoscopy

    (2007)
  • J.S. Mandel et al.

    Reducing mortality from colorectal cancer by screening for fecal occult blood

    New England Journal of Medicine

    (1993)
  • E. Lindholm et al.

    Survival benefit in a randomized clinical trial of faecal occult blood screening for colorectal cancer

    British Journal of Surgery

    (2008)
  • V.S. Benson et al.

    International Colorectal Cancer Screening Network. Colorectal cancer screening: a comparison of 35 initiatives in 17 countries

    International Journal of Cancer

    (2008)
  • O.D. Jørgensen et al.

    A randomised study of screening for colorectal cancer using faecal occult blood testing: results after 13 years and seven biennial screening rounds

    Gut

    (2002)
  • Cited by (25)

    • Colonoscopy-Related Mortality in a Fecal Immunochemical Test–Based Colorectal Cancer Screening Program

      2021, Clinical Gastroenterology and Hepatology
      Citation Excerpt :

      A substantial colonoscopy-related mortality would be needed to observe an increased mortality compared with the control subjects. Studies that reported on fatal complications within 30 days postcolonoscopy after a positive fecal occult blood test described 0–0.21 (95% CI, 0.0–1.16) fatal complications per 10,000 participants.6,7,15–19 However, those studies included small sample sizes of between 3000 and 60,000 colonoscopies and some indicated a suspected underestimation caused by incomplete registration.

    • Colorectal cancer screening: Systematic review of screen-related morbidity and mortality

      2017, Cancer Treatment Reviews
      Citation Excerpt :

      Ten studies reported whether surgical treatment was required, twelve studies reported whether perforation was related to polypectomy. Other complications from colonoscopy were reported in eighteen studies [7,12,16,20,25–27,30,32–34,37–39,43,44,46,47], including cardiovascular events, postpolypectomy syndrome, vasovagal reactions or abdominal pain or discomfort. None of the included studies reported any mortality after colonoscopy.

    • Screening for Colorectal Cancer: A Systematic Review and Meta-Analysis

      2016, Clinical Colorectal Cancer
      Citation Excerpt :

      Perforation as a harm of screening colonoscopy was reported based on the number of colonoscopies in 3 studies26,33,34 and by number of patients in 5 studies27,28,35-37 resulting in an estimated 0.41 perforations per 1000 colonoscopies (95% CI, 0.19-0.62) and 0.53 perforations per 1000 patients (95% CI, 0.37-0.69). Perforation as harm of follow-up colonoscopy was reported based on the number of colonoscopies in 5 studies24,26,38-40 and the number of patients in 10 studies,30-32,41-47 resulting in an estimated 1.04 perforations per 1000 colonoscopies (95% CI, 0.69-1.39) and 0.61 per 1000 patients (95% CI, 0.10-1.11). Perforation as a harm of screening FS was reported based on the number of sigmoidoscopies in 3 studies24,48,49 and the number of patients in 4 studies,31,45,50,51 resulting in an estimated 0.03 perforations per 1000 sigmoidoscopies (95% CI, 0.0-0.07) and 0.01 perforations per 1000 patients (95% CI, 0.0-0.03).

    • An Estimate of Severe Harms Due to Screening Colonoscopy: A Systematic Review

      2023, Journal of the American Board of Family Medicine
    View all citing articles on Scopus
    View full text