Colorectal cancer (CRC) is an important health care issue worldwide. According to the World Health Organization, there are approximately 1,000,000 new diagnoses of CRC each year, with mortality of more than 500,000. The socioeconomic impact of this problem provided the drive for rapidly expanding screening programs. In general, accurate detection and removal of the precursor lesions—colorectal adenomas—are considered to be powerful tools for fighting against CRC. Unexpectedly, however, in routine practice, the protection against CRC offered by colonoscopic screening is far from perfect. A recent study by Baxter and colleagues demonstrated that although colonoscopy was associated with decreased risk of subsequent CRC in the distal colon, no protective effect was found against cancers located on the right side of the colon. Why may colonoscopy so far fail to prevent CRCs?

Some polyps are simply not recognized because of patient-related factors, eg, suboptimal bowel preparation, inefficient withdrawal technique, or difficult anatomic conditions. Other polyps are missed as a consequence of insufficient awareness and training of the endoscopist, non-polypoid colorectal neoplasms (NP-CRNs) being an illustrative example in this regard. An increasing body of evidence presently indicates that NP-CRNs are common lesions worldwide. Detection and management of some of these lesions may prove to be more challenging, raising the hypothesis that these lesions may be at the origin of interval cancers.

In addition, surveillance practices after polypectomy are based on clinicopathologic features of adenomas, namely size, multiplicity, presence of any villous component, and grade of dysplasia. Unfortunately, evaluation and recording of these features in routine practice frequently lack precision and proper standardization, making it difficult to draw firm conclusions regarding follow-up intervals. All of these practical limitations eventually highlight the need to secure the quality of colonoscopic examination if interval cancers are to be prevented. It is reasonable to presume that high-quality colonoscopic practices will offer in turn considerable potential to refine the diagnosis of colorectal neoplasia, and, hence, to delineate subgroups of patients truly at risk for developing CRC. Implementation of such risk-stratification strategies and personalized medical care can ultimately lead to appropriate redirection of the limited economic resources.

At its core, quality improvement in gastrointestinal (GI) practice relies on continuous training, education, and information among all health care providers, whether gastroenterologists, GI trainees, endoscopy nurses, or GI pathologists. Over the past few years, it became clear that objective criteria are needed to assess the quality of colonoscopy, such as cecum intubation rate, quality of bowel preparation, withdrawal time, and adenoma detection rate. In this context, development of competence among practicing endoscopists to adequately detect and treat NP-CRNs deserves special attention. We describe a summary of the path to develop expertise in detection and management of NP-CRNs, based on experience at our academic GI unit.

The learning pyramid

For simplicity, let’s look at the well-known learning-pyramid by Miller, as illustrated in Fig. 1 . In general, development of practical skills is a stepwise process, starting with acquisition of basic knowledge , followed by in-depth information and development of practical skills—the so-called know-how and show-how —and finally exposure to concrete practical situations. If we extrapolate this model to the practice of GI endoscopy, in particular development of expertise in diagnosis of NP-CRN, the following scenarios are possible:

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  Imagine you are supervising a young GI trainee who performs a colonoscopy. The trainee tells you he or she identified a lesion in the right colon, but cannot find it again during withdrawal. You take over, but also without success. Three years later the patient is diagnosed with an interval cancer, probably emerging from a missed lesion at the same location. What would you do now? You would probably seek to review literature data pertaining to origins of interval cancers and discuss these with your students to improve clinical awareness in this regard.

  
  
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  Imagine again you are supervising a more experienced trainee. The trainee detects a large lesion with apparently flat morphology, but unfortunately he or she is not able to find it again during withdrawal. You tell the trainee that some of these lesions may herald the risk to more rapidly evolve into CRC. You take over and after careful inspection and selective chromoendoscopy, find a lateral spreading polyp, and remove it. It turns out to be a high-grade dysplastic adenoma. It is clear that mastering know-how about detection and showing how these lesions should be correctly managed are essential steps in providing endoscopy training in this regard.

  
  
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  Now imagine that the same trainee (meanwhile in the past year) detects a lesion and after evaluation with selective chromoendoscopy, describes it as a flat lesion with a central depression. The trainee properly lifts it with NaCl 9% and removes it in toto. It turns out to be a high-grade dysplastic adenoma. You tell the trainee that he or she did a very good job!

Learning pyramid by Miller. ( Adapted from Miller AG. The assessment of clinical skills/competence/performance. Acad Med 1990;65:S63–7; with permission.)