Outcome of "indefinite for dysplasia" in inflammatory bowel disease: correlation with DNA flow cytometry and other risk factors of colorectal cancer

British Society of Gastroenterology guidelines on colorectal surveillance in inflammatory bowel disease

Patients with inflammatory bowel disease (IBD) remain at increased risk for colorectal cancer and death from colorectal cancer compared with the general population despite improvements in inflammation control with advanced therapies, colonoscopic surveillance and reductions in environmental risk factors. This guideline update from 2010 for colorectal surveillance of patients over 16 years with colonic inflammatory bowel disease was developed by stakeholders representing UK physicians, endoscopists, surgeons, specialist nurses and patients with GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodological support.An a priori protocol was published describing the approach to three levels of statement: GRADE recommendations, good practice statements or expert opinion statements. A systematic review of 7599 publications, with appraisal and GRADE analysis of trials and network meta-analysis, where appropriate, was performed. Risk thresholding guided GRADE judgements.We made 73 statements for the delivery of an IBD colorectal surveillance service, including outcome standards for service and endoscopist audit, and the importance of shared decision-making with patients.Core areas include: risk of colorectal cancer, IBD-related post-colonoscopy colorectal cancer; service organisation and supporting patient concordance; starting and stopping surveillance, who should or should not receive surveillance; risk stratification, including web-based multivariate risk calculation of surveillance intervals; colonoscopic modalities, bowel preparation, biomarkers and artificial intelligence aided detection; chemoprevention; the role of non-conventional dysplasia, serrated lesions and non-targeted biopsies; management of dysplasia, both endoscopic and surgical, and the structure and role of the multidisciplinary team in IBD dysplasia management; training in IBD colonoscopic surveillance, sustainability (green endoscopy), cost-effectiveness and patient experience. Sixteen research priorities are suggested.

Low-coverage whole genome sequencing of low-grade dysplasia strongly predicts advanced neoplasia risk in ulcerative colitis

BACKGROUND

The risk of developing advanced neoplasia (AN; colorectal cancer and/or high-grade dysplasia) in ulcerative colitis (UC) patients with a low-grade dysplasia (LGD) lesion is variable and difficult to predict. This is a major challenge for effective clinical management.

OBJECTIVE

We aimed to provide accurate AN risk stratification in UC patients with LGD. We hypothesised that the pattern and burden of somatic genomic copy number alterations (CNAs) in LGD lesions could predict future AN risk.

DESIGN

We performed a retrospective multicentre validated case-control study using n=270 LGD samples from n=122 patients with UC. Patients were designated progressors (n=40) if they had a diagnosis of AN in the ~5 years following LGD diagnosis or non-progressors (n=82) if they remained AN-free during follow-up. DNA was extracted from the baseline LGD lesion, low-coverage whole genome sequencing performed and data processed to detect CNAs. Survival analysis was used to evaluate CNAs as predictors of future AN risk.

RESULTS

CNA burden was significantly higher in progressors than non-progressors (p=2×10-6 in discovery cohort) and was a very significant predictor of AN risk in univariate analysis (OR=36; p=9×10-7), outperforming existing clinical risk factors such as lesion size, shape and focality. Optimal risk prediction was achieved with a multivariate model combining CNA burden with the known clinical risk factor of incomplete LGD resection. Within-LGD lesion genetic heterogeneity did not confound risk prediction.

CONCLUSION

Measurement of CNAs in LGD is an accurate predictor of AN risk in inflammatory bowel disease and is likely to support clinical management.

Surveillance and Management of Dysplasia and Malignancy in Inflammatory Bowel Disease

The paradigm for surveilling and managing inflammatory bowel disease-associated colorectal dysplasia has changed as high-definition colonoscopy and chromoendoscopy have significantly improved the visualization of dysplasia, and endoscopic mucosal resection has made more lesions endoscopically resectable. However, these patients are at high risk of recurrent dysplasia and cancer and require intensive colonoscopic surveillance. Patients with invisible high-grade dysplasia, invisible multifocal low-grade dysplasia, and colorectal cancer should be considered for surgical resection. Total proctocolectomy removes all at-risk tissue. Subtotal colectomy with ileorectal anastomosis can be considered in select patients (ie, advanced age, poor functional status, and with no rectal inflammation or dysplasia).

Low coverage whole genome sequencing of low-grade dysplasia strongly predicts colorectal cancer risk in ulcerative colitis

Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer (CRC), and this risk increases dramatically in those who develop low-grade dysplasia (LGD). However, there is currently no accurate way to risk-stratify patients with LGD, leading to both over- and under-treatment of cancer risk. Here we show that the burden of somatic copy number alterations (CNAs) within resected LGD lesions strongly predicts future cancer development. We performed a retrospective multi-centre validated case-control study of n=122 patients (40 progressors, 82 non-progressors, 270 LGD regions). Low coverage whole genome sequencing revealed CNA burden was significantly higher in progressors than non-progressors (p=2×10-6 in discovery cohort) and was a very significant predictor of CRC risk in univariate analysis (odds ratio = 36; p=9×10-7), outperforming existing clinical risk factors such as lesion size, shape and focality. Optimal risk prediction was achieved with a multivariate model combining CNA burden with the known clinical risk factor of incomplete LGD resection. The measurement of CNAs in LGD lesions is a robust, low-cost and rapidly translatable predictor of CRC risk in IBD that can be used to direct management and so prevent CRC in high-risk individuals whilst sparing those at low-risk from unnecessary intervention.

Systematic review with meta-analysis: incidence and factors for progression to advanced neoplasia in inflammatory bowel disease patients with indefinite and low-grade dysplasia

BACKGROUND

Due to limited research on the natural history of indefinite for dysplasia (IND) and low-grade dysplasia (LGD) in inflammatory bowel disease (IBD), the management of these patients is controversial.

AIMS

This systematic review and meta-analysis aimed to estimate the incidence and identify the risk factors for advanced neoplasia in IBD patients with IND and LGD.

METHODS

PubMed, Embase and Cochrane Central Register of Controlled Trials were searched until 24 December, 2021, to identify studies that reported pathological results of follow-up colonoscopy or surgery in IBD patients with IND and LGD. The main outcomes were the incidence and risk factors for advanced neoplasia in IBD patients with IND and LGD.

RESULTS

Based on the analysis of 38 studies, the pooled incidences of advanced neoplasia in IBD patients with IND and LGD were 9.9% (95% CI 4.4%-15.4%) and 10.7% (95% CI 7.0%-14.4%) respectively. The risk factors for advanced neoplasia in IND patients were primary sclerosing cholangitis (PSC) and aneuploidy. The risk factors for advanced neoplasia in LGD patients included male, PSC, previous IND, colonic stricture, index lesion ≥1 cm, distal location, multifocal lesions, distal and flat lesions, nonpolypoid/flat lesions and invisible lesions.

CONCLUSIONS

The incidence of advanced neoplasia was similar between IND and LGD in IBD patients, as high as one in ten, so more rigorous surveillance is also suggested in IND patients. Since the effects of most factors were derived from the pooled results of only two to three studies, further research was needed to confirm our results.

Inflammation-Associated Microsatellite Alterations Caused by MSH3 Dysfunction Are Prevalent in Ulcerative Colitis and Increase With Neoplastic Advancement

OBJECTIVES:

Inflammation-associated microsatellite alterations (also known as elevated microsatellite alterations at selected tetranucleotide repeats [EMAST]) result from IL-6–induced nuclear-to-cytosolic displacement of the DNA mismatch repair (MMR) protein MSH3, allowing frameshifts of dinucleotide or longer microsatellites within DNA. MSH3 also engages homologous recombination to repair double-strand breaks (DSBs), making MSH3 deficiency contributory to both EMAST and DSBs. EMAST is observed in cancers, but given its genesis by cytokines, it may be present in non-neoplastic inflammatory conditions. We examined ulcerative colitis (UC), a preneoplastic condition from prolonged inflammatory duration.

METHODS:

We assessed 70 UC colons without neoplasia, 5 UC specimens with dysplasia, 14 UC-derived colorectal cancers (CRCs), and 19 early-stage sporadic CRCs for microsatellite instability (MSI) via multiplexed polymerase chain reaction capable of simultaneous detection of MSI-H, MSI-L, and EMAST. We evaluated UC specimens for MSH3 expression via immunohistochemistry.

RESULTS:

UC, UC with dysplasia, and UC-derived CRCs demonstrated dinucleotide or longer microsatellite frameshifts, with UC showing coincident reduction of nuclear MSH3 expression. No UC specimen, with or without neoplasia, demonstrated mononucleotide frameshifts. EMAST frequency was higher in UC-derived CRCs than UC (71.4% vs 31.4%, P = 0.0045) and higher than early-stage sporadic CRCs (66.7% vs 26.3%, P = 0.0426). EMAST frequency was higher with UC duration >8 years compared with ≤8 years (40% vs 16%, P = 0.0459).

DISCUSSION:

Inflammation-associated microsatellite alterations/EMAST are prevalent in UC and signify genomic mutations in the absence of neoplasia. Duration of disease and advancement to neoplasia increases frequency of EMAST. MSH3 dysfunction is a potential contributory pathway toward neoplasia in UC that could be targeted by therapeutic intervention.

Systematic review with meta-analysis: IBD-associated colonic dysplasia prognosis in the videoendoscopic era (1990 to present)

INTRODUCTION

The prognosis of dysplasia in patients with IBD is largely determined from observational studies from the pre-videoendoscopic era (pre-1990s) that does not reflect recent advances in endoscopic imaging and resection.

AIMS

To better understand the risk of synchronous colorectal cancer and metachronous advanced neoplasia (ie high-grade dysplasia or cancer) associated with dysplasia diagnosed in the videoendoscopic era, and to stratify risk according to a lesion's morphology, endoscopic resection status or whether it was incidentally detected on biopsy of macroscopically normal colonic mucosa (ie invisible).

METHODS

A systematic search of original articles published between 1990 and February 2020 was performed. Eligible studies reported on incidence of advanced neoplasia at follow-up colectomy or colonoscopy for IBD-dysplasia patients. Quantitative and qualitative analyses were performed.

RESULTS

Thirty-three studies were eligible for qualitative analysis (five for the meta-analysis). Pooled estimated proportions of incidental synchronous cancers found at colectomy performed for a pre-operative diagnosis of visible high-grade dysplasia, invisible high-grade dysplasia, visible low-grade dysplasia and invisible low-grade dysplasia were 13.7% (95% CI 0.0-54.1), 11.4% (95% CI 4.6-20.3), 2.7% (95% CI 0.0-7.1) and 2.4% (95% CI 0.0-8.5) respectively. The lowest incidences of metachronous advanced neoplasia, for dysplasia not managed with immediate colectomy but followed up with surveillance, tended to be reported by the studies where high definition imaging and/or chromoendoscopy was used and endoscopic resection of visible dysplasia was histologically confirmed.

CONCLUSIONS

The prognosis of IBD-dysplasia diagnosed in the videoendoscopic era appears to have been improved but the quality of evidence remains low. Larger, prospective studies are needed to guide management. PROSPERO registration no: CRD42019105736.

Association Between Indefinite Dysplasia and Advanced Neoplasia in Patients With Inflammatory Bowel Diseases Undergoing Surveillance

BACKGROUND & AIMS

Little is known about the clinical significance of indefinite dysplasia (IND) in patients with inflammatory bowel diseases (IBD) undergoing colonoscopic surveillance for colorectal neoplasia.

METHODS

We conducted a retrospective cohort analysis of 492 patients with colonic IBD for 8 or more years or concomitant primary sclerosing cholangitis, with no history of advanced colorectal neoplasia (high-grade dysplasia or colorectal cancer) or colectomy, undergoing colorectal neoplasia surveillance at a tertiary IBD referral center from 2001 through 2017. Subjects received consistent histopathologic grading of dysplasia. We collected data on time to development of (advanced) colorectal neoplasia or colectomy using Kaplan Meier methods. We identified factors independently associated with (advanced) colorectal neoplasia with multivariable Cox regression analysis.

RESULTS

After 2149 person-years of follow-up, 53 patients (10.8%) received a diagnosis of IND without prior or synchronous low-grade dysplasia (LGD). Compared to patients without dysplasia, patients with IND had a significantly higher risk of advanced colorectal neoplasia (adjusted hazard ratio, 6.85; 95% CI, 1.78-26.4) and colorectal neoplasia (adjusted hazard ratio, 3.25; 95% CI, 1.50-7.05), but not colectomy (P = .78). Compared to IND, LGD was associated with a significantly higher risk of advanced colorectal neoplasia (P = .05). Following a diagnosis of no dysplasia, IND only, or LGD, the incidence rates of advanced colorectal neoplasia were 0.4% per patient-year, 3.1% per patient-year, and 8.4% per patient-year, respectively.

CONCLUSIONS

In a retrospective analysis of patients with IBD undergoing colorectal neoplasia surveillance with consistent histopathologic grading of dysplasia, IND was independently associated with a significant increase in risk of advanced colorectal neoplasia. These findings require validation and if confirmed, a reappraisal of the colorectal neoplasia surveillance guidelines.

Diagnosis and management of inflammatory bowel disease-associated neoplasia: considerations in the modern era

Patients with inflammatory bowel disease (IBD) are at an increased risk of developing intestinal neoplasia-particularly colorectal neoplasia, including dysplasia and colorectal cancer (CRC)-as a primary consequence of chronic inflammation. While the current incidence of CRC in IBD is lower compared with prior decades, due, in large part, to more effective therapies and improved colonoscopic technologies, CRC still accounts for a significant proportion of IBD-related deaths. The focus of this review is on the pathogenesis; epidemiology, including disease- and patient-related risk factors; diagnosis; surveillance; and management of IBD-associated neoplasia.

Inflammatory bowel disease- and Barrett's esophagus-associated neoplasia: the old, the new, and the persistent struggles

Early diagnosis of and adequate therapy for premalignant lesions in patients with inflammatory bowel disease (IBD) and Barrett's esophagus (BE) has been shown to decrease mortality. Endoscopic examination with histologic evaluation of random and targeted biopsies remains the gold standard for early detection and adequate treatment of neoplasia in both these diseases. Although eventual patient management (including surveillance and treatment) depends upon a precise histologic assessment of the initial biopsy, accurately diagnosing and grading IBD- and BE-associated dysplasia is still considered challenging by many general as well as subspecialized pathologists. Additionally, there are continuing updates in the literature regarding the diagnosis, surveillance, and treatment of these disease entities. This comprehensive review discusses the cancer risk, detailed histopathological features, diagnostic challenges, and updates as well as the latest surveillance and treatment recommendations in IBD- and BE-associated dysplasia.

Utility of DNA Flow Cytometric Analysis of Paraffin-embedded Tissue in the Risk Stratification and Management of 'Indefinite for dysplasia' in Patients With Inflammatory Bowel Disease

BACKGROUND AND AIMS

The clinical significance of 'indefinite for dysplasia' [IND] in patients with inflammatory bowel disease remains unclear. Currently, no biomarker can reliably differentiate reactive changes from true dysplasia and/or risk stratify IND.

METHODS

A total of 52 IND colon biopsies were analysed by DNA flow cytometry. The follow-up result of each biopsy was determined by reviewing all subsequent biopsies and endoscopic reports for the occurrence of high-grade dysplasia [HGD] or colorectal cancer [CRC] at the site of previous biopsy or in the same segment of colon.

RESULTS

The overall 1-, 3-, 5-, and 7-year detection rates of HGD or CRC in all 52 IND cases were 4.6% (95% confidence interval [CI], 0.0%-10.6%), 18.2% [95% CI, 3.5%-30.7%], 26.3% [95% CI, 8.4%-40.7%], and 31.6% [95% CI, 11.2%-47.4%], respectively. More interestingly, 10.6% of IND cases with aneuploidy were subsequently found to have HGD or CRC within 1 year [95% CI, 0.0%-23.7%], with 36.4% [95% CI, 7.1%-56.5%], 51.7% [95% CI, 16.1%-72.2%], and 59.8% [95% CI, 21.4%-79.5%] detected within 3, 5, and 7 years, respectively. By comparison, in the setting of normal DNA content, 1-, 3-, 5-, and 7-year detection rates of HGD or CRC were 0.8% [95% CI, 0.0%-2.7%], 3.3% [95% CI, 0.0%-9.6%], 5.2% [95% CI, 0.0%-14.7%], and 6.5% [95% CI, 0.0%-18.1%], respectively. Only the presence of aneuploidy was found to be a significant predictor of HGD or CRC with the estimated univariate and multivariate hazard ratios of 13.8 [p = 0.016] and 50.3 [p = 0.010], respectively.

CONCLUSIONS

IND may not be a low-risk condition for HGD or CRC. In this regard, the presence of aneuploidy can identify a subset of IND cases that are at increased risk for subsequent detection of HGD or CRC.

Clonal evolution of colorectal cancer in IBD

Optimizing the management of colorectal cancer (CRC) risk in IBD requires a fundamental understanding of the evolutionary process underpinning tumorigenesis. In IBD, clonal evolution begins long before the development of overt neoplasia, and is probably accelerated by the repeated cycles of epithelial wounding and repair that are characteristic of the condition. Here, we review the biological drivers of mutant clone selection in IBD with particular reference to the unique histological architecture of the intestinal epithelium coupled with the inflammatory microenvironment in IBD, and the unique mutation patterns seen in IBD-driven neoplasia when compared with sporadic adenomas and CRC. How these data can be leveraged as evolutionary-based biomarkers to predict cancer risk is discussed, as well as how the efficacy of CRC surveillance programmes and the management of dysplasia can be improved. From a research perspective, the longitudinal surveillance of patients with IBD provides an under-exploited opportunity to investigate the biology of the human gastrointestinal tract over space and time.

Clinical Aspects of Idiopathic Inflammatory Bowel Disease: A Review for Pathologists

CONTEXT

-Idiopathic inflammatory bowel disease manifests with different clinical phenotypes showing varying behavior and risk for neoplasia. The clinical questions that are posed to pathologists differ depending on phase of the disease and the clinical circumstances. Understanding the clinical aspects of the dynamic disease process will enhance the role of pathology in optimizing the care of patients with inflammatory bowel disease.

OBJECTIVE

-To review clinical and surgical aspects of inflammatory bowel disease that are relevant to practicing pathologists.

DATA SOURCES

-The literature was reviewed.

CONCLUSIONS

-Diagnosis and management of inflammatory bowel disease require an integrated evaluation of clinical, endoscopic, radiologic, and pathologic features. Therefore, close interaction between clinicians and pathologists is crucial. Having this team approach improves understanding of the pertinent clinical and surgical aspects of the disease and assists in the recognition of unusual presentation of variants, as well as mimics of idiopathic inflammatory bowel disease, by pathologists.

Combining aneuploidy and dysplasia for colitis' cancer risk assessment outperforms current surveillance efficiency: a meta-analysis

PURPOSE

Cancer risk assessment for ulcerative colitis patients by evaluating histological changes through colonoscopy surveillance is still challenging. Thus, additional parameters of high prognostic impact for the development of colitis-associated carcinoma are necessary. This meta-analysis was conducted to clarify the value of aneuploidy as predictor for individual cancer risk compared with current surveillance parameters.

METHODS

A systematic web-based search identified studies published in English that addressed the relevance of the ploidy status for individual cancer risk during surveillance in comparison to neoplastic mucosal changes. The resulting data were included into a meta-analysis, and odds ratios (OR) were calculated for aneuploidy or dysplasia or aneuploidy plus dysplasia.

RESULTS

Twelve studies addressing the relevance of aneuploidy compared to dyplasia were comprehensively evaluated and further used for meta-analysis. The meta-analysis revealed that aneuploidy (OR 5.31 [95 % CI 2.03, 13.93]) is an equally effective parameter for cancer risk assessment in ulcerative colitis patients as dysplasia (OR 4.93 [1.61, 15.11]). Strikingly, the combined assessment of dysplasia and aneuploidy is superior compared to applying each parameter alone (OR 8.99 [3.08, 26.26]).

CONCLUSIONS

This meta-analysis reveals that aneuploidy is an equally effective parameter for individual cancer risk assessment in ulcerative colitis as the detection of dysplasia. More important, the combined assessment of dysplasia and aneuploidy outperforms the use of each parameter alone. We suggest image cytometry for ploidy assessment to become an additional feature of consensus criteria to individually assess cancer risk in UC.