Colonoscopy examination does not always detect colorectal cancer (CRC)— some patients develop CRC after negative findings from an examination. When this occurs before the next recommended ...examination, it is called interval cancer. From a colonoscopy quality assurance perspective, that term is too restrictive, so the term post-colonoscopy colorectal cancer (PCCRC) was created in 2010. However, PCCRC definitions and methods for calculating rates vary among studies, making it impossible to compare results. We aimed to standardize the terminology, identification, analysis, and reporting of PCCRCs and CRCs detected after other whole-colon imaging evaluations (post-imaging colorectal cancers PICRCs).
A 20-member international team of gastroenterologists, pathologists, and epidemiologists; a radiologist; and a non-medical professional met to formulate a series of recommendations, standardize definitions and categories (to align with interval cancer terminology), develop an algorithm to determine most-plausible etiologies, and develop standardized methodology to calculate rates of PCCRC and PICRC. The team followed the Appraisal of Guidelines for Research and Evaluation II tool. A literature review provided 401 articles to support proposed statements; evidence was rated using the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. The statements were voted on anonymously by team members, using a modified Delphi approach.
The team produced 21 statements that provide comprehensive guidance on PCCRCs and PICRCs. The statements present standardized definitions and terms, as well as methods for qualitative review, determination of etiology, calculation of PCCRC rates, and non-colonoscopic imaging of the colon.
A 20-member international team has provided standardized methods for analysis of etiologies of PCCRCs and PICRCs and defines its use as a quality indicator. The team provides recommendations for clinicians, organizations, researchers, policy makers, and patients.
Accurate endoscopic differentiation would enable to resect and discard small and diminutive colonic lesions, thereby increasing cost-efficiency. Current classification systems based on narrow band ...imaging (NBI), however, do not include neoplastic sessile serrated adenomas/polyps (SSA/Ps). We aimed to develop and validate a new classification system for endoscopic differentiation of adenomas, hyperplastic polyps and SSA/Ps <10 mm.
We developed the Workgroup serrAted polypS and Polyposis (WASP) classification, combining the NBI International Colorectal Endoscopic classification and criteria for differentiation of SSA/Ps in a stepwise approach. Ten consultant gastroenterologists predicted polyp histology, including levels of confidence, based on the endoscopic aspect of 45 polyps, before and after participation in training in the WASP classification. After 6 months, the same endoscopists predicted polyp histology of a new set of 50 polyps, with a ratio of lesions comparable to daily practice.
The accuracy of optical diagnosis was 0.63 (95% CI 0.54 to 0.71) at baseline, which improved to 0.79 (95% CI 0.72 to 0.86, p<0.001) after training. For polyps diagnosed with high confidence the accuracy was 0.73 (95% CI 0.64 to 0.82), which improved to 0.87 (95% CI 0.80 to 0.95, p<0.01). The accuracy of optical diagnosis after 6 months was 0.76 (95% CI 0.72 to 0.80), increasing to 0.84 (95% CI 0.81 to 0.88) considering high confidence diagnosis. The combined negative predictive value with high confidence of diminutive neoplastic lesions (adenomas and SSA/Ps together) was 0.91 (95% CI 0.83 to 0.96).
We developed and validated the first integrative classification method for endoscopic differentiation of small and diminutive adenomas, hyperplastic polyps and SSA/Ps. In a still image evaluation setting, introduction of the WASP classification significantly improved the accuracy of optical diagnosis overall as well as SSA/P in particular, which proved to be sustainable after 6 months.
Characterization of colonic lesions in inflammatory bowel disease (IBD) remains challenging. We developed an endoscopic classification of visual characteristics to identify colitis-associated ...neoplasia using multimodal advanced endoscopic imaging (Frankfurt Advanced Chromoendoscopic IBD LEsions FACILE classification).
The study was conducted in three phases: 1) development - an expert panel defined endoscopic signs and predictors of dysplasia in IBD and, using multivariable logistic regression created the FACILE classification; 2) validation - using 60 IBD lesions from an image library, two assessments of diagnostic accuracy for neoplasia were performed and interobserver agreement between experts using FACILE was determined; 3) reproducibility - the reproducibility of the FACILE classification was tested in gastroenterologists, trainees, and junior doctors after completion of a training module.
The experts initially selected criteria such as morphology, color, surface, vessel architecture, signs of inflammation, and lesion border. Multivariable logistic regression confirmed that nonpolypoid lesion, irregular vessel architecture, irregular surface pattern, and signs of inflammation within the lesion were predictors of dysplasia. Area under the curve of this logistic model using a bootstrapped estimate was 0.76 (0.73 - 0.78). The training module resulted in improved accuracy and kappa agreement in all nonexperts, though in trainees and junior doctors the kappa agreement was still moderate and poor, respectively.
We developed, validated, and demonstrated reproducibility of a new endoscopic classification (FACILE) for the diagnosis of dysplasia in IBD using all imaging modalities. Flat shape, irregular surface and vascular patterns, and signs of inflammation predicted dysplasia. The diagnostic performance of all nonexpert participants improved after a training module.
Several studies have raised warnings about the limited effectiveness of colonoscopy for the prevention of colorectal cancer (CRC), especially of the proximal colon. Two major categories of factors ...might be responsible for the development of interval cancers, namely technical, endoscopist-dependent factors and biological characteristics of the cancer that lead to more rapid tumour progression. Recognition of endoscopist-dependent factors is critical, as these factors are probably amenable to correction through improved awareness and education of endoscopists, using quality metrics (such as adenoma detection rates and cecal intubation rates) for objective evaluation and feedback. In this article, the current literature regarding the incidence of, and potential explanations for, interval CRCs is outlined. Although there is probably an interaction between technical and biology-related factors--and an attempt to dissect the biology from the technology might be fraught with difficulties--a structured analysis of individual cases of interval cancer might help in the continuous monitoring of the quality of colonoscopy, and ultimately might reduce the number of interval CRCs.
The management of inflammatory bowel disease (IBD) has changed since the mid‐1990s (e.g., use of thiopurines/anti‐TNFα agents, improved surveillance programs), possibly affecting cancer risk. To ...establish current cancer risk in IBD, updates are warranted from cohorts covering this time span, and detailed enough to study associations with phenotype and medication. We studied intestinal‐, extra‐intestinal‐ and overall cancer risk in the Dutch population‐based IBDSL cohort. In total, 1,157 Crohn's disease (CD) and 1,644 ulcerative colitis (UC) patients were diagnosed between 1991 and 2011, and followed until 2013. Standardized incidence ratios (SIRs) were calculated for CD and UC separately, as well as for gender‐, phenotype‐, disease duration‐, diagnosis era‐ and medication groups. We found an increased risk for colorectal cancer in CD patients with colon involvement (SIR 2.97; 95% CI 1.08–6.46), but not in the total CD or UC population. In addition, CD patients were at increased risk for hematologic‐ (2.41; 1.04–4.76), overall skin‐ (1.55; 1.06–2.19), skin squamous cell‐ (SCC; 3.83; 1.83–7.04) and overall cancer (1.28; 1.01–1.60), whereas UC patients had no increased risk for extra‐intestinal‐ and overall cancer. Finally, in a medication analysis on CD and UC together, long‐term immunosuppression exposure (>12 months) was associated with an increased risk for hematologic cancer, non‐Hodgkin lymphoma, SCC and overall cancer, and this increase was mainly attributed to thiopurines. IBD patients with long‐term immunosuppression exposure can be considered as having a higher cancer risk, and our data support the advice in recent IBD guidelines to consider skin cancer screening in these patients.
What's new?
The management of inflammatory bowel disease (IBD) has changed markedly since the mid‐1990s, possibly affecting cancer risk. To establish current cancer risk, updates are warranted from cohorts covering this timespan and detailed enough to study associations with phenotype and medication. Here, using the Dutch population‐based IBDSL cohort, the authors found that colorectal cancer risk is currently lower in both CD and UC than previously mentioned in literature. CD patients however show an increased overall cancer risk. Altogether, long‐term immunosuppression exposure brings an additional cancer risk to IBD patients, a finding that may be relevant in other auto‐immune diseases with similar medication.
Background Several studies examined the rate of colorectal cancer (CRC) developed during colonoscopy surveillance after CRC resection (ie, metachronous CRC mCRC), yet the underlying etiology is ...unclear. Objective To examine the rate and likely etiology of mCRCs. Design Population-based, multicenter study. Review of clinical and histopathologic records, including data of the national pathology database and The Netherlands Cancer Registry. Setting National cancer databases reviewed at 3 hospitals in South-Limburg, The Netherlands. Patients Total CRC population diagnosed in South-Limburg from January 2001 to December 2010. Interventions Colonoscopy. Main Outcome Measurements We defined an mCRC as a second primary CRC, diagnosed >6 months after the primary CRC. By using a modified algorithm to ascribe likely etiology, we classified the mCRCs into cancers caused by non-compliance with surveillance recommendations, inadequate examination, incomplete resection of precursor lesions (CRC in same segment as previous advanced adenoma), missed lesions, or newly developed cancers. Results We included a total of 5157 patients with CRC, of whom 93 (1.8%) had mCRCs, which were diagnosed on an average of 81 months (range 7-356 months) after the initial CRC diagnosis. Of all mCRCs, 43.0% were attributable to non-compliance with surveillance advice, 43.0% to missed lesions, 5.4% to incompletely resected lesions, 5.4% to newly developed cancers, and 3.2% to inadequate examination. Age-adjusted and sex-adjusted logistic regression analyses showed that mCRCs were significantly smaller in size (odds ratio OR 0.8; 95% confidence interval CI, 0.7-0.9) and more often poorly differentiated (OR 1.7; 95% CI, 1.0-2.8) than were solitary CRCs. Limitations Retrospective evaluation of clinical data. Conclusion In this study, 1.8% of all patients with CRC developed mCRCs, and the vast majority were attributable to missed lesions or non-compliance with surveillance advice. Our findings underscore the importance of high-quality colonoscopy to maximize the benefit of post-CRC surveillance.
Background & Aims Colorectal cancer surveillance guidelines rely on clinicohistologic features of adenomas. Unfortunately, in common practice, recording of these features lacks precision and ...uniformity, which might hamper appropriate follow-up decisions. Confocal laser endomicroscopy (CLE) is a novel technology that allows real-time in vivo microscopy of the mucosa and provides accurate histopathology. The aims of this study were (1) to define and validate differential features of adenomatous and nonadenomatous colorectal polyps by chromoendoscopy-guided CLE (C-CLE) and (2) to assess predictive value of this technique for diagnosis of colorectal neoplasia. Methods Patients at risk for colorectal cancer were prospectively investigated by using CLE. During extubation, fluorescein 10% was used in conjunction with acriflavine hydrochloride 0.05% to characterize global tissue architecture as well as cytonuclear features of colorectal epithelium. Ex vivo histology was used as gold standard. Reproducibility tests were performed. Results In total, 116 colorectal polyps from 72 patients were examined. Ex vivo histology showed 68 adenomas, 6 invasive carcinomas, 30 hyperplastic polyps, and 12 inflammatory polyps. C-CLE of adenomas revealed lack of epithelial surface maturation, crypt budding, altered vascular pattern, and loss of cell polarity. In contrast, C-CLE of nonadenomatous polyps revealed epithelial surface maturation, and minor abnormalities of crypt architecture and of vascular pattern, and maintained cell polarity. Adenoma dysplasia score reliably discriminated high-grade dysplasia from low-grade dysplasia (accuracy, 96.7%). Interobserver agreement was high (K coefficients: pathologist, 0.92; endomicroscopist, 0.88). In vivo histology predicted ex vivo data with sensitivity of 97.3%, specificity of 92.8%, and accuracy of 95.7%. Conclusions C-CLE accurately discriminates adenomatous from nonadenomatous colorectal polyps and enables evaluation of degree of dysplasia during ongoing endoscopy. This technology might offer considerable potential to ultimately fine-tune surveillance programs, particularly in high-risk groups.
Background and study aims
We conducted a systematic review and meta‐analysis of population‐based studies to explore pooled prevalence and magnitude of electrolyte changes after bowel preparation for ...colonoscopy based on the most recent guidelines.
Patients and methods
PubMed and Cochrane were queried for population‐based studies examining changes in electrolyte values after bowel preparation, published by July 1, 2021. We report prevalences of serum hypokalemia, hyponatremia, hyperphosphatemia, and hypocalcemia after bowel preparation and changes in mean electrolyte values after vs. before bowel preparation using sodium phosphate (NaP) and polyethylene glycol (PEG).
Results
Thirteen studies met the inclusion criteria; 2386 unique patients were included. Overall, hypokalemia was found in 17.2% (95% CI 6.7, 30.9) in the NaP group vs. 4.8% (95% CI 0.27, 13.02) in the PEG group. The magnitude of potassium decrease after NaP bowel preparation was significantly increased compared to PEG (mean difference −0.38; 95% CI −0.49 to −0.27, P < 0.001). No study reported on major complications.
Conclusions
Hypokalemia was found in 17.2% of patients after bowel preparation with NaP and in 4.8% of patients with PEG, a finding that is clinically relevant with respect to choosing the type of bowel preparation. The magnitude of the potassium decrease after NaP was significantly higher compared to PEG. These data provide the evidence that supports the recommendation of the European Society of Gastrointestinal Endoscopy against routine use of NaP for bowel preparation.
Background and Aims Bowel preparation for colonoscopy should not cause significant shifts in systemic electrolyte concentrations. We recently encountered 2 cases of severe postcolonoscopy hypokalemia ...with fatal consequences, prompting us to conduct a study to explore the magnitude of and risk factors for hypokalemia associated with bowel preparation. We paid specific attention to higher-risk subgroups, in particular, diuretic users, hospitalized patients, and patients estimated at to be high risk by the gastroenterologist. Methods From January 1 to December 31, 2014, we included all patients at risk for hypokalemia (diuretic users, hospitalized patients, and patients estimated at high risk by the gastroenterologist) who underwent colonoscopy at our institution. We measured serum potassium levels before low-volume polyethylene glycol bowel preparation for colonoscopy. In a subset of patients who had normal serum potassium levels before bowel cleansing, serum potassium levels after bowel cleansing also were measured. Results In total, 5515 colonoscopies were performed, including 1822 procedures in diuretic users or hospitalized patients. Of these, 77 (4.2%) patients had hypokalemia before bowel cleansing. A logistic regression model showed that hospitalized patients were more likely to have hypokalemia than non-hospitalized patients. 301 patients with normal potassium levels had potassium controls after bowel cleansing, of whom 71 (23.6%) developed hypokalemia. A logistic regression model showed that diuretic users were more likely to develop hypokalemia than those who did not use diuretics. Conclusions Hypokalemia is frequently encountered after low-volume polyethylene glycol bowel cleansing in high-risk patients. Additional large-scale studies are needed on the prevalence of hypokalemia in unselected populations undergoing bowel cleansing and on the occurrence of potentially very serious side effects in order to decide on screening of high-risk groups in daily clinical practice. (Clinical trial registration number: NTR5400.)
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