Endoscopy 2022; 54(03): 278-280
DOI: 10.1055/a-1722-2999
Editorial

Avoiding a plane crash with colonoscopy

Referring to Beaton D et al. p. 270–277
Michal F. Kaminski
1   Department of Cancer Prevention and Department of Oncological Gastroenterology, The Maria Sklodowska-Curie National Research Institute of Oncology, Warsaw, Poland
2   Department of Gastroenterology, Hepatology and Oncology, Medical Center for Postgraduate Education, Warsaw, Poland
3   Institute of Health and Society, University of Oslo, Oslo, Norway
› Author Affiliations

Post-colonoscopy colorectal cancer (PCCRC) is a cancer diagnosed following an apparently cancer-negative colonoscopy [1]. What does it have in common with a plane crash? It is catastrophic for the patient because it happens after examination giving false reassurance and fails to prevent or detect potentially lethal cancer. It may be catastrophic for health care providers by inducing stress, negative perception, or legal consequences for the physician and provider. Finally, the majority of PCCRCs, similarly to plane crashes, result from human factors and are preventable [1]. However, unlike the aviation industry, which sets rigorous training standards for personnel, and requires safety checklists and root cause analyses of crashes, the medical community has, for many years, disregarded the human factors associated with PCCRC. This is likely to be the reason for unacceptably high PCCRC rates and their wide variation between providers [2]. Only recently, the World Organization of Endoscopy (WEO) reached consensus statements on PCCRC and recommended review of individual PCCRC cases along with a root cause analysis to determine the most plausible explanation [1].

In this issue of Endoscopy, Beaton et al. present a retrospective analysis of PCCRC cases reviewed in accordance with the WEO algorithms [3]. The analysis included 48 PCCRC cases (9.1 %) identified among 527 patients diagnosed with colorectal cancer (CRC) between January 2015 and December 2016 in a single organization in the UK. Out of the 48 PCCRCs, 16 (33.3 %) occurred 4 years after colonoscopy and were considered to be new CRCs, whereas the remaining 32 (66.7 %) underwent root cause analysis and categorization into interval and non-interval type using the WEO algorithms by two independent consultant gastroenterologists with an expertise in the PCCRC field. The root cause analysis identified that 91 % of the PCCRCs resulted from missed lesions, either after adequate or inadequate (cecum not reached or inadequate bowel preparation) examination ([Table 1]). The most plausible explanation for these PCCRCs changed according to the criteria used for ‘adequate’ examination, with the requirement for photo-documentation leading to a significant increase in cases of ‘possible missed lesion, examination inadequate’ (25 % without mandatory photo-documentation to 63 % with mandatory photo-documentation). The remaining cause identified was ‘detected lesion, not resected’ in 9 %; there were no PCCRC cases due to incomplete resection of a detected lesion.

Table 1

Summary of studies reporting root cause analysis of post-colonoscopy colorectal cancer.

Beaton et al.[3]

Beaton et al.[3]+ photograph of cecum

Anderson et al. [4]

Pabby et al. [5]

le Clercq et al. [6]

Patients diagnosed with CRC in one hospital 2015–2016, UK

Patients diagnosed with CRC in one hospital 2015–2016, UK

Patients diagnosed with CRC in one hospital 2010–2017, UK, high proportion of high risk patients

Patients after adenoma removal under surveillance, only complete examinations, USA

Patients diagnosed with CRC in one region in the Netherlands 2001–2010

PCCRC n = 32

PCCRC n = 32

PCCRC n = 107

PCCRC n = 13

PCCRC n = 147

Possible missed lesion, exam adequate

66 %

28 %

27 %

23 %

58 %

Possible missed lesion, exam inadequate

25 %

63 %

58 %

23 %

20 %

Detected lesion, not resected

9 %

9 %

8 %

23 %

not stated

Likely incomplete resection

0 %

0 %

7 %

31 %

9 %

*Newly developed cancers

16/48 (33 %)

Excluded

16/48 (33 %)

Excluded

Excluded

Not stated

13 %

CRC, colorectal cancer; PCCRC, post-colonoscopy colorectal cancer.

What do we learn from the root cause analysis in the context of the current and previously published studies ([Table 1]) [3] [4] [5] [6]? The majority of PCCRCs (70 %–90 %) are attributable to potentially avoidable human factors and their proportion depends on the length of observation after colonoscopy (the shorter the observation the more likely the human factor). The majority of PCCRCs (80 %–90 %) attributable to human factors are due to missed lesions. Of those, 60 % are caused by inadequate examination, either due to inadequate bowel preparation, incomplete or likely incomplete examination. This is consistent with the data reporting that 50 % of PCCRCs occurred in the right colon (proximal colon to the splenic flexure), and that the two most common locations for PCCRCs were ascending colon (25 %) or rectum (23 %) [3]. In addition, 10 % of PCCRCs occur due to lesions that are detected but not resected. Taking these findings together, it seems that the majority of PCCRCs are caused by administrative or decision-making errors. Fail-safe mechanisms in colonoscopy could ensure that patients with inadequate preparation, incomplete examination or unresected lesions are scheduled for repeat colonoscopy. Interestingly, incomplete polyp resection generates only 10 % of PCCRCs, a figure much lower than the 30 % suggested in previous studies of adenoma cohorts [5].

“The review of individual post-colonoscopy colorectal cancer (PCCRC) cases along with a root cause analysis shows that two major efforts are needed to decrease the risk of PCCRC. First, fail-safe mechanisms are essential to ensure that patients with inadequate bowel preparation, incomplete examination, unresected lesions, or scheduled surveillance get the repeat examination in due time. Second, high quality inspection is mandatory for all colonoscopies, which requires multifaceted interventions, including endoscopist training, benchmarking, and technological aids.”

A second analysis performed by Beaton et al. included categorization into interval and non-interval type using WEO algorithms [3]. This analysis revealed that 27 % of PCCRCs were either interval cancers (detected before scheduled surveillance colonoscopy time) or non-interval type A (detected at surveillance colonoscopy). This really highlights an essential role of colonoscopy quality in PCCRC prevention [7]. Similarly, 42 % of PCCRCs were non-interval cancers type C (detected after diagnostic colonoscopy without planned surveillance). It has been demonstrated that high quality negative examination (which does not require further surveillance), defined as complete examination without neoplastic findings, with adequate bowel preparation, and performed by an endoscopist with a high adenoma detection rate, results in long-term (up to 17 years) protection from CRC [8]. Therefore, it seems that 70 % of PCCRCs that occur after complete colonoscopy with adequate bowel preparation are due to suboptimal quality of mucosal inspection during colonoscopy. To avoid this, structured training for endoscopists, feedback and benchmarking of colonoscopy quality measures, and technological improvements such as computer-assisted detection aids are essential. Finally, a non-interval type B cancer (detected after recommended surveillance time) accounted for 31 % of PCCRCs, and again, guides us to the need for fail-safe mechanisms to ensure that patients are compliant with the recommended surveillance schedule.

In summary, the review of individual PCCRC cases along with a root cause analysis shows that two major efforts are needed to decrease the risk of PCCRC. First, fail-safe mechanisms are essential to ensure that patients with inadequate bowel preparation, incomplete examination, unresected lesions, or scheduled surveillance get the repeat examination in due time. Second, high quality inspection is mandatory for all colonoscopies, which requires multifaceted interventions, including endoscopist training, benchmarking, and technological aids. These efforts for decreasing the risk of PCCRC are very similar to those successfully introduced by the aviation industry to reduce the risk of plane crash.



Publication History

Article published online:
31 January 2022

© 2022. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

 
  • References

  • 1 Rutter MD, Beintaris I, Valori R. et al. World Endoscopy Organization consensus statements on post-colonoscopy and post-imaging colorectal cancer. Gastroenterology 2018; 155: 909-925
  • 2 Burr NE, Derbyshire E, Taylor J. et al. Variation in post-colonoscopy colorectal cancer across colonoscopy providers in English National Health Service: population based cohort study. BMJ 2019; 367: 16090
  • 3 Beaton D, Beintaris I, Rutter MD. Utilization and reproducibility of World Endoscopy Organization post-colonoscopy colorectal cancer algorithms: retrospective analysis. Endoscopy 2022; 54: 270-277
  • 4 Anderson R, Burr NE, Valori R. Causes of post-colonoscopy colorectal cancers based on World Endoscopy Organization system of analysis. Gastroenterology 2020; 158: 1287-1299
  • 5 Pabby A, Schoen RE, Weissfeld JL. et al. Analysis of colorectal cancer occurrence during surveillance colonoscopy in the dietary Polyp Prevention Trial. Gastrointest Endosc 2005; 61: 385-391
  • 6 le Clercq CM, Bouwens MW, Rondagh EJ. et al. Postcolonoscopy colorectal cancers are preventable: a population-based study. Gut 2014; 63: 957-963
  • 7 Kaminski MF, Regula J, Kraszewska E. et al. Quality indicators for colonoscopy and the risk of interval cancer. N Engl J Med 2010; 362: 1795-1803
  • 8 Pilonis ND, Bugajski M, Wieszczy P. et al. Long-term colorectal cancer incidence and mortality after a single negative screening colonoscopy. Ann Intern Med 2020; 173: 81-91