Diagnosis and management of dysplasia in patients with ulcerative colitis and Crohn's disease of the colon

Histological differentiation between sporadic and colitis-associated intestinal cancer in a nationwide study: A propensity-score-matched analysis

BACKGROUND AND AIM

Colitis-associated intestinal cancer (CAC) can develop in patients with inflammatory bowel disease; however, the malignant grade of CAC may differ from that of sporadic colorectal cancer (CRC). Therefore, we compared histological findings distinct from cancer stage between CAC and sporadic CRC to evaluate the features of CAC.

METHODS

We reviewed the clinical and histological data collected from a nationwide database in Japan between 1983 and 2020. Patient characteristics were compared to distinguish ulcerative colitis (UC), Crohn's disease (CD), and sporadic CRC. Comparisons were performed by using all collected data and propensity score-matched data.

RESULTS

A total of 1077 patients with UC-CAC, 297 with CD-CAC, and 136 927 with sporadic CRC were included. Although the prevalence of well or moderately differentiated adenocarcinoma (Tub1 and Tub2) decreased according to tumor progression for all diseases (P < 0.01), the prevalence of other histological findings, including signet ring cell carcinoma, mucinous carcinoma, poorly differentiated adenocarcinoma, or squamous cell carcinoma, was significantly higher in CAC than in sporadic CRC. Based on propensity score-matched data for 982 patients with UC and 268 with CD, the prevalence of histological findings other than Tub1 and Tub2 was also significantly higher in those with CAC. At pT4, mucinous carcinoma occurred at a significantly higher rate in patients with CD (45/86 [52.3%]) than in those with sporadic CRC (13/88 [14.8%]) (P < 0.01).

CONCLUSION

CAC, including early-stage CAC, has a higher malignant grade than sporadic CRC, and this difference increases in significance with tumor progression.

Diagnostic Challenges during Inflammation and Cancer: Current Biomarkers and Future Perspectives in Navigating through the Minefield of Reactive versus Dysplastic and Cancerous Lesions in the Digestive System

In the setting of pronounced inflammation, changes in the epithelium may overlap with neoplasia, often rendering it impossible to establish a diagnosis with certainty in daily clinical practice. Here, we discuss the underlying molecular mechanisms driving tissue response during persistent inflammatory signaling along with the potential association with cancer in the gastrointestinal tract, pancreas, extrahepatic bile ducts, and liver. We highlight the histopathological challenges encountered in the diagnosis of chronic inflammation in routine practice and pinpoint tissue-based biomarkers that could complement morphology to differentiate reactive from dysplastic or cancerous lesions. We refer to the advantages and limitations of existing biomarkers employing immunohistochemistry and point to promising new markers, including the generation of novel antibodies targeting mutant proteins, miRNAs, and array assays. Advancements in experimental models, including mouse and 3D models, have improved our understanding of tissue response. The integration of digital pathology along with artificial intelligence may also complement routine visual inspections. Navigating through tissue responses in various chronic inflammatory contexts will help us develop novel and reliable biomarkers that will improve diagnostic decisions and ultimately patient treatment.

New sights of immunometabolism and agent progress in colitis associated colorectal cancer

Colitis associated colorectal cancer is a disease with a high incidence and complex course that develops from chronic inflammation and deteriorates after various immune responses and inflammation-induced attacks. Colitis associated colorectal cancer has the characteristics of both immune diseases and cancer, and the similarity of treatment models contributes to the similar treatment dilemma. Immunometabolism contributes to the basis of life and is the core of many immune diseases. Manipulating metabolic signal transduction can be an effective way to control the immune process, which is expected to become a new target for colitis associated colorectal cancer therapy. Immune cells participate in the whole process of colitis associated colorectal cancer development by transforming their functional condition via changing their metabolic ways, such as glucose, lipid, and amino acid metabolism. The same immune and metabolic processes may play different roles in inflammation, dysplasia, and carcinoma, so anti-inflammation agents, immunomodulators, and agents targeting special metabolism should be used in combination to prevent and inhibit the development of colitis associated colorectal cancer.

Small Bowel Carcinoma in the Setting of Inflammatory Bowel Disease

Small bowel carcinomas are rare in the general population, but the incidence is increasing. Patients with inflammatory bowel diseases (IBDs) are at significantly higher risk of small bowel adenocarcinomas than their non-IBD counterparts, with Crohn's patients having at least a 12-fold increased risk and ulcerative colitis patients with a more controversial and modest 2-fold increased risk compared with the general population. IBD patients with small bowel carcinomas present with nonspecific symptoms that overlap with typical IBD symptoms, and this results in difficulty making a preoperative diagnosis. Cross-sectional imaging is rarely diagnostic, and most cancers are found incidentally at the time of surgery performed for an IBD indication. As such, most small bowel carcinomas are found at advanced stages and carry a poor prognosis. Oncologic surgical resection is the treatment of choice for patients with locoregional disease with little evidence available to guide adjuvant therapy. Patients with metastatic disease are treated with systemic chemotherapy, and surgery is reserved for palliation in this population. Prognosis is poor with few long-term survivors reported.

Characteristics and outcomes of rectal cancer in patients with inflammatory bowel disease: a single-center experience

The increased risk of colorectal cancer (CRC) in patients with inflammatory bowel disease (IBD) has been well documented in the literature. The present study aimed to assess the characteristics and outcomes of rectal cancer in patients with IBD. This study was a retrospective review of a prospectively maintained IRB-approved database at Cleveland Clinic Florida. Rectal cancer patients with or without IBD treated with curative surgery between 2016 and 2020 were compared for demographics, disease characteristics, and pathologic and oncologic outcomes. The primary outcomes were 3-year overall survival (OS) and disease-free survival (DFS). Secondary outcomes were clinicopathologic outcomes including disease stage, tumor histology and histologic features, and treatments received. 238 patients with rectal cancer were included, 15 (6.3%) of whom had IBD. IBD patients were significantly younger (52.9 vs 60.3 years, p = 0.033), presented more often with cT1-2 tumors (64.3% vs 30.4%, p = 0.008), and signet-ring cell pathology (14.3% vs 2%, p = 0.02). IBD patients received neoadjuvant chemoradiation less often (40% vs 72.6%, p = 0.029) and had shorter time between diagnosis and surgery (7.5 vs 25 weeks, p = 0.013) than did non-IBD patients. Both groups had similar OS (36 vs 34.7 months, p = 0.431) and DFS (36 vs 32.9 months, p = 0.121). IBD patients with rectal cancer tend to present at a younger age, with a less invasive disease, and signet-ring carcinomas, and receive neoadjuvant treatment less often than non-IBD patients. Based on low level of evidence, IBD and non-IBD rectal cancer patients might have similar survival.

Incidental Dysplasia During Total Proctocolectomy With Ileoanal Pouch: Is It Associated With Worse Outcomes?

BACKGROUND

Patients with inflammatory bowel disease (IBD) are at increased risk of colorectal cancer. In cases of invisible or nonendoscopically resectable dysplasia found at colonoscopy, total proctocolectomy with ileal pouch anal anastomosis can be offered with good long-term outcomes; however, little is known regarding cancer-related outcomes when dysplasia is found incidentally after surgery on final pathology.

METHODS

Using our prospectively collected pouch registry, we identified patients who had preoperative colonic dysplasia or dysplasia found only after colectomy. Patients with cancer preoperatively or after colectomy were excluded. Included patients were divided into 3 groups: PRE (+preoperative biopsy, negative final pathology), BOTH (+preoperative biopsy and final pathology), and POST (negative preoperative biopsy, +final pathology). Long-term outcomes in the 3 groups were assessed.

RESULTS

In total, 517 patients were included: PRE = 125, BOTH = 254, POST = 137. After a median follow-up of 12 years (IQR 3-21), there were no differences in overall, disease-free, or pouch survival between groups. Cancer/dysplasia developed in 11 patients: 3 (2%) in the PRE, 5 (2%) in the BOTH, and 3 (2%) in the POST group. Only 1 cancer-related death occurred in the entire cohort (PRE group). Disease-free survival at 10 years was 98% for all groups (P = .97). Pouch survival at 10 years was 96% for PRE, 99% for BOTH, and 97% for POST (P = .24).

CONCLUSIONS

The incidental finding of dysplasia on final pathology after proctocolectomy was not associated with worsened outcomes compared with preoperatively diagnosed dysplasia.

Considerations for Colorectal Neoplasia Detection in Inflammatory Bowel Disease Clinical Trials

BACKGROUND

High-quality colonoscopic surveillance can lead to earlier and increased detection of colorectal neoplasia in patients with inflammatory bowel disease (IBD). In IBD clinical trials, endoscopy is used to assess mucosal disease activity before and after treatment but also provides an opportunity to surveil for colorectal neoplasia during follow-up.

SUMMARY

Best practices for colorectal cancer identification in IBD clinical trials require engagement and collaboration between the clinical trial sponsor, site endoscopist and/or principal investigator, and central read team. Each team member has unique responsibilities for maximizing dysplasia detection in IBD trials.

KEY MESSAGES

Sponsors should work in accordance with scientific guidelines to standardize imaging procedures, design the protocol to ensure the trial population is safeguarded, and oversee trial conduct. The site endoscopist should remain updated on best practices to tailor sponsor protocol-required procedures to patient needs, examine the mucosa for disease activity and potential dysplasia during all procedures, and provide optimal procedure videos for central read analysis. Central readers may detect dysplasia or colorectal cancer and a framework to report these findings to trial sponsors is essential. Synergistic relationships between all team members in IBD clinical trials provide an important opportunity for extended endoscopic evaluation and colorectal neoplasia identification.

Restorative pouch surgery following proctocolectomy for inflammatory bowel disease: past experience and future direction

Major advancements in surgery for patients suffering proctocolitis from ulcerative colitis (UC) or selected patients with Crohn's disease (CD) have emerged in a relatively short time. Historically, patients underwent a proctocolectomy with end ileostomy, however, a restorative proctocolectomy with an ileal pouch-anal anastomosis (IPAA) was introduced in the late 1970s in the United Kingdom and gave patients the opportunity to avoid a permanent stoma. Initially designed as a hand-sewn "S" shaped pouch, with the invention of the linear stapler, a "J" shaped pouch was described in Japan, and subsequent advances in the United States largely contributed to the pelvic pouch's evolution to the standard of care in the management of patients with inflammatory bowel disease (IBD). The procedure was then divided into different stages depending on the medical condition of the patient and minimally invasive techniques (laparoscopic & robotic surgery) have continued to advance the success of the operation. Unfortunately, pouch complications occur, and seem to be occurring at an increasing frequency with the adoption of minimally invasive surgery. The field of reoperative pouch surgery has emerged to offer patients the opportunity to restore their quality of life (QOL) without the need for a permanent ostomy. Many patients with signs of pouch failure such as pouchitis, fistulae, pain and obstruction are diagnosed with Crohn's of the pouch, but many have mechanical complications that can be corrected with surgery, rather than offering pouch excision with a permanent ostomy (continent or traditional). Patients with Crohn's may be offered an IPAA but they will not have success if they, like patients with UC, have mechanical complications leading to their pouch failure. Patients who undergo reoperative pouch surgery do well with an acceptable QOL.

Detection of Colorectal Adenocarcinoma and Grading Dysplasia on Histopathologic Slides Using Deep Learning

Colorectal cancer (CRC) is one of the most common types of cancer among men and women. The grading of dysplasia and the detection of adenocarcinoma are important clinical tasks in the diagnosis of CRC and shape the patients' follow-up plans. This study evaluated the feasibility of deep learning models for the classification of colorectal lesions into four classes: benign, low-grade dysplasia, high-grade dysplasia, and adenocarcinoma. To this end, a deep neural network was developed on a training set of 655 whole slide images of digitized colorectal resection slides from a tertiary medical institution; and the network was evaluated on an internal test set of 234 slides, as well as on an external test set of 606 adenocarcinoma slides from The Cancer Genome Atlas database. The model achieved an overall accuracy, sensitivity, and specificity of 95.5%, 91.0%, and 97.1%, respectively, on the internal test set, and an accuracy and sensitivity of 98.5% for adenocarcinoma detection task on the external test set. Results suggest that such deep learning models can potentially assist pathologists in grading colorectal dysplasia, detecting adenocarcinoma, prescreening, and prioritizing the reviewing of suspicious cases to improve the turnaround time for patients with a high risk of CRC. Furthermore, the high sensitivity on the external test set suggests the model's generalizability in detecting colorectal adenocarcinoma on whole slide images across different institutions.

Prognostic value of primary tumor sidedness in patients with non-metastatic IBD related CRC - Is it the exception to the rule?

BACKGROUND

Although primary tumor sidedness (PTS) has a known prognostic role in sporadic colorectal cancer (CRC), its role in Inflammatory Bowel Disease related CRC (IBD-CRC) is largely unknown. Thus, we aimed to evaluate the prognostic role of PTS in patients with IBD-CRC.

METHODS

All eligible patients with surgically treated, non-metastatic IBD-CRC were retrospectively identified from institutional databases at ten European and Asian academic centers. Long term endpoints included recurrence-free (RFS) and overall survival (OS). Multivariable Cox proportional hazard regression as well as propensity score analyses were performed to evaluate whether PTS was significantly associated with RFS and OS.

RESULTS

A total of 213 patients were included in the analysis, of which 32.4% had right-sided (RS) tumors and 67.6% had left-sided (LS) tumors. PTS was not associated with OS and RFS even on univariable analysis (5-year OS for RS vs LS tumors was 68.0% vs 77.3%, respectively, p = 0.31; 5-year RFS for RS vs LS tumors was 62.8% vs 65.4%, respectively, p = 0.51). Similarly, PTS was not associated with OS and RFS on propensity score matched analysis (5-year OS for RS vs LS tumors was 82.9% vs 91.3%, p = 0.79; 5-year RFS for RS vs LS tumors was 85.1% vs 81.5%, p = 0.69). These results were maintained when OS and RFS were calculated in patients with RS vs LS tumors after excluding patients with rectal tumors (5-year OS for RS vs LS tumors was 68.0% vs 77.2%, respectively, p = 0.38; 5-year RFS for RS vs LS tumors was 62.8% vs 59.2%, respectively, p = 0.98).

CONCLUSIONS

In contrast to sporadic CRC, PTS does not appear to have a prognostic role in IBD-CRC.

State-of-the-art surgery for Crohn's disease: Part II-colonic Crohn's disease and associated neoplasms

Despite advances in medical therapy, surgery continues to play a vital role in the management of Crohn's disease and its complications. Continuing from Part I of this series (small intestine/ileal disease), we focus next on colonic Crohn's disease and associated neoplasms. We will first review the surgical management of medical-refractory Crohn's colitis and its complications and then examine cancer risk, surveillance, and surgical management of Crohn's-associated colorectal dysplasia and malignancy. We conclude with a discussion of restoration of gastrointestinal continuity following colonic surgery for Crohn's disease.

Molecular Network Analyses Implicate Death-Associated Protein Kinase 3 (DAPK3) as a Key Factor in Colitis-Associated Dysplasia Progression

BACKGROUND

Ulcerative colitis (UC) is a progressive disorder that elevates the risk of colon cancer development through a colitis-dysplasia-carcinoma sequence. Gene expression profiling of colitis-associated lesions obtained from patients with varied extents of UC can be mined to define molecular panels associated with colon cancer development.

METHODS

Differential gene expression profiles of 3 UC clinical subtypes and healthy controls were developed for the GSE47908 microarray data set of healthy controls, left-sided colitis, pancolitis, and colitis-associated dysplasia (CAD) using limma R.

RESULTS

A gene ontology enrichment analysis of differentially expressed genes (DEGs) revealed a shift in the transcriptome landscape as UC progressed from left-sided colitis to pancolitis to CAD, from being immune-centric to being cytoskeleton-dependent. Hippo signaling (via Yes-associated protein [YAP]) and Ephrin receptor signaling were the top canonical pathways progressively altered in concert with the pathogenic progression of UC. A molecular interaction network analysis of DEGs in left-sided colitis, pancolitis, and CAD revealed 1 pairwise line, or edge, that was topologically important to the network structure. This edge was found to be highly enriched in actin-based processes, and death-associated protein kinase 3 (DAPK3) was a critical member and sole protein kinase member of this network. Death-associated protein kinase 3 is a regulator of actin-cytoskeleton reorganization that controls proliferation and apoptosis. Differential correlation analyses revealed a negative correlation for DAPK3-YAP in healthy controls that flipped to positive in left-sided colitis. With UC progression to CAD, the DAPK3-YAP correlation grew progressively more positive.

CONCLUSION

In summary, DAPK3 was identified as a candidate gene involved in UC progression to dysplasia.

The P2X7 Receptor Promotes Colorectal Inflammation and Tumorigenesis by Modulating Gut Microbiota and the Inflammasome

Background: Given the role of the P2X7 receptor (P2X7R) in inflammatory bowel diseases (IBD), we investigated its role in the development and progression of colitis-associated colorectal cancer (CA-CRC). Methods: CA-CRC was induced in P2X7R^+/+ and P2X7R^−/− mice with azoxymethane (AOM) combined with dextran sodium sulfate (DSS). In a therapeutic protocol, P2X7R^+/+ mice were treated with a P2X7R-selective inhibitor (A740003). Mice were evaluated with follow-up video endoscopy with endoluminal ultrasound biomicroscopy. Colon tissue was analyzed for histological changes, densities of immune cells, expression of transcription factors, cytokines, genes, DNA methylation, and microbiome composition of fecal samples by sequencing for 16S rRNA. Results: The P2X7R^+/+ mice displayed more ulcers, tumors, and greater wall thickness, than the P2X7R^−/− and the P2X7R^+/+ mice treated with A740003. The P2X7R^+/+ mice showed increased accumulation of immune cells, production of proinflammatory cytokines, activation of intracellular signaling pathways, and upregulation of NLRP3 and NLRP12 genes, stabilized after the P2X7R-blockade. Microbial changes were observed in the P2X7R^−/− and P2X7R^+/+-induced mice, partially reversed by the A740003 treatment. Conclusions: Regulatory mechanisms activated downstream of the P2X7R in combination with signals from a dysbiotic microbiota result in the activation of intracellular signaling pathways and the inflammasome, amplifying the inflammatory response and promoting CA-CRC development.

Predicting Colorectal Cancer Occurrence in IBD

Patients with colonic inflammatory bowel disease (IBD) are at an increased risk of developing colorectal cancer (CRC), and are therefore enrolled into a surveillance programme aimed at detecting dysplasia or early cancer. Current surveillance programmes are guided by clinical, endoscopic or histological predictors of colitis-associated CRC (CA-CRC). We have seen great progress in our understanding of these predictors of disease progression, and advances in endoscopic technique and management, along with improved medical care, has been mirrored by the falling incidence of CA-CRC over the last 50 years. However, more could be done to improve our molecular understanding of CA-CRC progression and enable better risk stratification for patients with IBD. This review summarises the known risk factors associated with CA-CRC and explores the molecular landscape that has the potential to complement and optimise the existing IBD surveillance programme.

From inflammation to colitis-associated colorectal cancer in inflammatory bowel disease: Pathogenesis and impact of current therapies

The risk of colorectal cancer (CRC) is higher in patients with inflammatory bowel disease (IBD). Population-based data from patients with ulcerative colitis (UC) estimate that the risk of CRC is approximately 2- to 3-fold that of the general population; patients with Crohn's disease appear to have a similar increased risk. However, the true extent of colitis-associated cancer (CAC) in undertreated IBD is unclear. Data suggest that the size (i.e., severity and extent) and persistence of the inflammatory process is largely responsible for the development of CRC in IBD. As patients with IBD and CRC have a worse prognosis than those without a history of IBD, the impact of current therapies for IBD on CAC is of importance. Chronic inflammation of the gut has been shown to increase the risk of developing CAC in both UC and CD. Therefore, control of inflammation is pivotal to the prevention of CAC. This review presents an overview of the current knowledge of CAC in IBD patients, focusing on the role of inflammation in the pathogenesis of CAC and the potential for IBD drugs to interfere with the process of carcinogenesis by reducing the inflammatory process or by modulating pathways directly involved in carcinogenesis.

Role of topical tacrolimus in the management of proctitis, perianal manifestations in Crohn's disease, and chronic pouchitis: a systematic review

Several published studies have evaluated the safety and effectiveness of oral and intravenous tacrolimus for the management of patients with inflammatory bowel disease (IBD). However, little is known about the effectiveness of topical tacrolimus in this patient population. The aim of this systematic review was to evaluate the current state of literature to evaluate the safety and effectiveness of rectal administration of topical tacrolimus, in the form of suppository, ointment, and/or enema in patients with ulcerative proctitis, perianal Crohn's disease (CD), and chronic refractory pouchitis. Electronic database searches were conducted in international databases since their inception until February 2020. Study subjects were categorized into three groups: topical tacrolimus for patients with proctitis, perianal CD, and chronic refractory pouchitis. The primary end point of this study was the remission rate. Secondary end points were response rate and the incidence of AEs. Eleven studies were included in the final assessment in this systematic review. This provided information from 188 patients. Tacrolimus was administered topically as suppositories, ointment, or enema. Clinical remission was achieved in 57.1%, 57.14%, and 70.0% in patients with proctitis, fistulizing perianal CD, and chronic pouchitis. The most commonly reported side effect was perianal itching and burning. Reversible nephrotoxicity occurred in a single patient. No clear correlation was found between blood levels and clinical outcomes. Topical tacrolimus is effective for a subset of patients with IBD. The adverse effects were minimal and tolerable. Well-designed randomized clinical trials are warranted to establish the appropriate dose and administration method.

Biomarkers for Early Detection of Colitis-associated Colorectal Cancer - Current Concepts, Future Trends

Colitis-associated colorectal cancer (CAC) remains a critical complication of ulcerative colitis (UC) with a mortality of approximately 15%, which makes early CAC diagnosis crucial. The current standard of surveillance, with repetitive colonoscopies and histological testing of biopsied mucosa samples, is burdensome and expensive, and therefore less invasive methods and reliable biomarkers are needed. Significant progress has been made, thanks to continuous extensive research in this field, however, no clinically relevant biomarker has been established so far. This review of the current literature presents the genetic and molecular differences between CAC and sporadic colorectal cancer and covers progress made in the early detection of CAC carcinogenesis. It focuses on biomarkers under development, which can easily be tested in samples of body fluids or breath and, once made clinically available, will help to differentiate between progressors (UC patients who will develop dysplasia) from non-progressors and enable early intervention to decrease the risk of cancer development.

Colorectal cancer in Crohn's colitis is associated with advanced tumor invasion and a poorer survival compared with ulcerative colitis: a retrospective dual-center study

PURPOSE

Colorectal cancer is a well-recognized complication of inflammatory bowel diseases (IBD), such as ulcerative colitis (UC) and Crohn's colitis (CC). In this study, we assess the clinico-pathological features and outcomes of patients with colorectal cancer from UC in comparison with CC.

METHODS

Data of all patients with colitis-associated cancer (CAC) who underwent surgery at Erlangen or Würzburg University Clinic between 1995 and 2015 were selected. Clinical, histopathological, and survival data were analyzed retrospectively.

RESULTS

Of all 88 patients with CAC, 20 patients had Crohn's colitis and 68 patients had ulcerative colitis. We observed a young median age at tumor diagnosis (49.5 years UC; 45.5 years CC, p = 0.208) in both diseases and a long median disease duration before CAC (19 years UC; 18 years CC; p = 0.840). Patients with CC suffered more often from rectal cancer (14 (70.0%) in CC; 23 (33.8%) in UC; p = 0.005) and advanced tumor stages (8 (47.0%) pT4 in CC; 14 (25.0%) pT4/ypT4 in UC; p = 0.008). Five-year overall survival rate was 39.3% for CC and 67.1% for UC (p = 0.009 for difference between the groups). Survival did not differ significantly between UC and CC in the multivariate analysis after correction for UICC tumor stage.

CONCLUSION

CAC in CC showed advanced tumor stages associated with reduced survival compared with CAC in UC. This may be explained by less intense surveillance in patients with CC leading to delayed cancer diagnosis.

Landscape of cell heterogeneity and evolutionary trajectory in ulcerative colitis-associated colon cancer revealed by single-cell RNA sequencing

Objective

The goal of this study was to get preliminary insight on the intra-tumor heterogeneity in colitis-associated cancer (CAC) and to reveal a potential evolutionary trajectory from ulcerative colitis (UC) to CAC at the single-cell level.

Methods

Fresh samples of tumor tissues and adjacent UC tissues from a CAC patient with pT3N1M0 stage cancer were examined by single-cell RNA sequencing (scRNA-seq). Data from The Cancer Genome Atlas (TCGA) and The Human Protein Atlas were used to confirm the different expression levels in normal and tumor tissues and to determine their relationships with patient prognosis.

Results

Ultimately, 4,777 single-cell transcriptomes (1,220 genes per cell) were examined, of which 2,250 (47%) and 2,527 (53%) originated from tumor and adjacent UC tissues, respectively. We defined the composition of cancer-associated stromal cells and identified six cell clusters, including myeloid, T and B cells, fibroblasts, endothelial and epithelial cells. Notable pathways and transcription factors involved in these cell clusters were analyzed and described. Moreover, the precise cellular composition and developmental trajectory from UC to UC-associated colon cancer were graphed, and it was predicted that CD74, CLCA1, and DPEP1 played a potential role in disease progression.

Conclusions

scRNA-seq technology revealed intra-tumor cell heterogeneity in UC-associated colon cancer, and might provide a promising direction to identify novel potential therapeutic targets in the evolution from UC to CAC.

Endoscopic Diagnosis of Nonpedunculated Dysplasia during Surveillance of Ulcerative Colitis: A Survey-Based Multinational Study

Background/Aims

Endoscopic diagnosis of dysplasia or colitic cancer in patients with ulcerative colitis (UC) is more challenging than that of colorectal neoplasia in non-colitic patients. We aimed to evaluate the accuracy of the endoscopic diagnosis of “nonpedunculated” dysplasia or colitic cancer in UC patients.

Methods

Ten endoscopists from four countries were surveyed using photographs of 61 histologically confirmed dysplastic or non-dysplastic lesions retrieved from the UC registry database of Asan Medical Center. The participants provided their assessment based on the given photographs and their intention to perform biopsy.

Results

The overall diagnostic performance of the 10 participants is summarized as follows sensitivity of 88.2% (95% confidence interval [CI], 84.3% to 91.5%), specificity of 34.8% (95% CI, 29.1% to 40.8%), positive predictive value of 63.0% (95% CI, 60.8% to 65.2%), negative predictive value of 70.2% (95% CI, 62.7% to 76.6%), and accuracy of 64.6% (95% CI, 60.7% to 68.4%). The interobserver agreement on the intention to perform a biopsy was poor (Fleiss kappa=0.169). Of the three endoscopic characteristics of the lesions, including ulceration, distinctness of the borders, and pit patterns, only neoplastic pit patterns were significantly predictive of dysplasia (odds ratio, 3.710; 95% CI, 2.001 to 6.881). The diagnostic sensitivity and specificity of neoplastic pit patterns were 68.2% (95% CI, 63.0% to 73.2%) and 63.3% (95% CI, 57.3% to 69.1%), respectively.

Conclusions

Diagnostic performance based on the endoscopist’s intention to perform a biopsy for nonpedunculated potentially dysplastic lesions in UC patients was suboptimal according to this survey-based study.

KRAS amplification in metastatic colon cancer is associated with a history of inflammatory bowel disease and may confer resistance to anti-EGFR therapy

Mutations in RAS occur in 30-50% of metastatic colorectal carcinomas (mCRCs) and correlate with resistance to anti-EGFR therapy. Consequently, mCRC biomarker guidelines state RAS mutational testing should be performed when considering EGFR inhibitor treatment. However, a small subset of mCRCs are reported to harbor RAS amplification. In order to elucidate the clinicopathologic features and anti-EGFR treatment response associated with RAS amplification, we retrospectively reviewed a large cohort of mCRC patients that underwent targeted next-generation sequencing and copy number analysis for KRAS, NRAS, HRAS, BRAF, and PIK3CA. Molecular testing was performed on 1286 consecutive mCRC from 1271 patients as part of routine clinical care, and results were correlated with clinicopathologic findings, mismatch repair (MMR) status and follow-up. RAS amplification was detected in 22 (2%) mCRCs and included: KRAS, NRAS, and HRAS for 15, 5, and 2 cases, respectively (6-21 gene copies). Patients with a KRAS-amplified mCRC were more likely to report a history of inflammatory bowel disease (p < 0.001). In contrast, mutations in KRAS were associated with older patient age, right-sided colonic origin, low-grade differentiation, mucinous histology, and MMR proficiency (p ≤ 0.017). Four patients with a KRAS-amplified mCRC and no concomitant RAS/BRAF/PIK3CA mutations received EGFR inhibitor-based therapy, and none demonstrated a clinicoradiographic response. The therapeutic impact of RAS amplification was further evaluated using a separate, multi-institutional cohort of 23 patients. Eight of 23 patients with KRAS-amplified mCRC received anti-EGFR therapy and all 8 patients exhibited disease progression on treatment. Although the number of KRAS-amplified mCRCs is limited, our data suggest the clinicopathologic features associated with mCRC harboring a KRAS amplification are distinct from those associated with a KRAS mutation. However, both alterations seem to confer EGFR inhibitor resistance and, therefore, RAS testing to include copy number analyses may be of consideration in the treatment of mCRC.

Neutrophil extracellular traps-associated protein peptidyl arginine deaminase 4 immunohistochemical expression in ulcerative colitis and its association with the prognostic predictors

Neutrophil extracellular traps (NETs) are incriminated in several immune and inflammatory diseases including ulcerative colitis (UC). Analysis of colonic tissues for NETs-related markers in UC carries prognostic and therapeutic implications. This work aims to evaluate the immunohistochemical (IHC) expression of NETs-associated-protein arginine deaminase 4 (PAD4) in colonic biopsies from UC patients in comparison to normal colon (NC). Association between PAD4 expression level and histopathologic grade, patient's therapeutic response and other clinicopathological prognostic predictors in UC are determined. This cohort study included biopsies from 42 UC patients and 11 NC controls. Clinicopathological data including patient's age at diagnosis, gender, presenting symptoms, anatomical disease extent, extra-intestinal manifestations, type and response to therapy and surgical interventions were recorded and tabulated. Histopathological grading of disease activity and associated epithelial changes were assessed. PAD4 immunostaining was conducted using Horseradish Peroxidase technique and scored semiquantitatively considering intensity and percentage of nuclear staining of lamina propria inflammatory cells. Appropriate statistical tests were applied. Anti-PAD4 was localized mainly in the nuclei of lamina propria infiltrating neutrophils. It was expressed more significantly in UC (95.2 %) compared to NC (p 0.001). Increased PAD4 expression level was significantly associated with increasing histopathologic grade, anatomical disease extent, lacking response to therapy and subjection to radical surgery (p:0.001, = 0.038, 0.046, 0.046 respectively). Age, gender, presenting symptoms, extra-intestinal manifestations and epithelial changes showed insignificant associations. This study characterizes a subset of UC patients with high histopathological grade of activity, pancolonic involvement, strong/moderate PAD4 expression levels and who are unresponsive to routine medical therapeutic regimens rendering them candidates for radical surgery. In conjunction with histopathological grading, IHC evaluation of PAD4 in UC is recommended to guide patient's selection for targeted therapy using the novel-discovered selective PAD4 inhibitors.

Efficacy of various endoscopic modalities in detecting dysplasia in ulcerative colitis: A systematic review and network meta-analysis

BACKGROUND

Longstanding ulcerative colitis (UC) is associated with an increased risk of colonic neoplasia. Various endoscopic modalities, such as chromoendoscopy (CE), narrow band imaging (NBI) and random biopsy have been introduced for surveillance, however, there exists a paucity of direct comparisons between them. We aimed to conduct a network meta-analysis of randomized controlled trials (RCTs) performed for surveillance of neoplasia in UC.

AIM

To provide a comparative evaluation of the efficacy of the above-mentioned various modalities.

METHODS

We searched MEDLINE/PubMed, Web of Science, Embase, Google Scholar and Cochrane Central Registry through May 2016 for RCTs evaluating the efficacy of endoscopic modalities for surveillance of neoplasia in UC. The primary outcomes of interest were dysplasia (low- or high-grade) detection rates per biopsy and per patient, and dysplasia numbers per patient. Studies were simultaneously analyzed using a random-effects network meta-analysis under the Bayesian framework to identify the modality with the highest dysplasia detection rate. The best ranking probability for the dysplasia detection rate was analyzed by surface under the cumulative ranking (SUCRA) technique.

RESULTS

Six prospective RCTs of a total 1038 patients were identified. We identified 4 different modalities; white light (WL) high definition (HD) or standard definition (SD), CE HD, and NBI HD. For dysplasia per biopsy, direct meta-analysis showed superiority of NBI HD over WL HD and CE HD over WL SD. Network meta-analysis demonstrated the rank order of best modality as NBI HD, CE HD, WL HD and WL SD with close SUCRA scores of the first two. For dysplasia per patient, direct meta-analyses showed equivocal results between each modality. Network meta-analysis demonstrated the rank order of best modality as WL HD, NBI HD, CE HD and WL SD with small differences of the SUCRA score among the first two. For dysplasia numbers per patient, direct meta-analysis showed superiority of CE HD over WL SD. Network meta-analysis demonstrated the rank order of best modality as WL HD, NBI HD, CE HD, and WL SD with small differences of the SUCRA score among the first three.

CONCLUSION

We demonstrated that there were small differences among WL HD, NBI HD, and CE HD, while WL SD was inferior, in detecting dysplasia in UC.

Intestinal Stem Cell Aging: Origins and Interventions

Regenerative processes that maintain the function of the gastrointestinal (GI) epithelium are critical for health and survival of multicellular organisms. In insects and vertebrates, intestinal stem cells (ISCs) regenerate the GI epithelium. ISC function is regulated by intrinsic, local, and systemic stimuli to adjust regeneration to tissue demands. These control mechanisms decline with age, resulting in significant perturbation of intestinal homeostasis. Processes that lead to this decline have been explored intensively in Drosophila melanogaster in recent years and are now starting to be characterized in mammalian models. This review presents a model for age-related regenerative decline in the fly intestine and discusses recent findings that start to establish molecular mechanisms of age-related decline of mammalian ISC function.

Evolutionary history of human colitis-associated colorectal cancer

OBJECTIVE

IBD confers an increased lifetime risk of developing colorectal cancer (CRC), and colitis-associated CRC (CA-CRC) is molecularly distinct from sporadic CRC (S-CRC). Here we have dissected the evolutionary history of CA-CRC using multiregion sequencing.

DESIGN

Exome sequencing was performed on fresh-frozen multiple regions of carcinoma, adjacent non-cancerous mucosa and blood from 12 patients with CA-CRC (n=55 exomes), and key variants were validated with orthogonal methods. Genome-wide copy number profiling was performed using single nucleotide polymorphism arrays and low-pass whole genome sequencing on archival non-dysplastic mucosa (n=9), low-grade dysplasia (LGD; n=30), high-grade dysplasia (HGD; n=13), mixed LGD/HGD (n=7) and CA-CRC (n=19). Phylogenetic trees were reconstructed, and evolutionary analysis used to reveal the temporal sequence of events leading to CA-CRC.

RESULTS

10/12 tumours were microsatellite stable with a median mutation burden of 3.0 single nucleotide alterations (SNA) per Mb, ~20% higher than S-CRC (2.5 SNAs/Mb), and consistent with elevated ageing-associated mutational processes. Non-dysplastic mucosa had considerable mutation burden (median 47 SNAs), including mutations shared with the neighbouring CA-CRC, indicating a precancer mutational field. CA-CRCs were often near triploid (40%) or near tetraploid (20%) and phylogenetic analysis revealed that copy number alterations (CNAs) began to accrue in non-dysplastic bowel, but the LGD/HGD transition often involved a punctuated 'catastrophic' CNA increase.

CONCLUSIONS

Evolutionary genomic analysis revealed precancer clones bearing extensive SNAs and CNAs, with progression to cancer involving a dramatic accrual of CNAs at HGD. Detection of the cancerised field is an encouraging prospect for surveillance, but punctuated evolution may limit the window for early detection.

Differences in colonic crypt morphology of spontaneous and colitis-associated murine models via second harmonic generation imaging to quantify colon cancer development

Background

Colorectal cancer remains the second leading cause of cancer death in the United States, and increased risk in patients with ulcerative colitis (a subset of inflammatory bowel disease) has motivated studies into early markers of dysplasia. The development of clinically translatable multiphoton imaging systems has allowed for the potential of in vivo label-free imaging of epithelial crypt structures via autofluorescence and/or second harmonic generation (SHG). SHG has been used to investigate collagen structures in various types of cancer, though the changes that colorectal epithelial collagen structures undergo during tumor development, specifically colitis-associated tumors, have not been fully investigated.

Methods

This study used two murine models, using A/J mice, one for spontaneous carcinoma and one for colitis-associated carcinoma, to investigate and quantify SHG image features that could potentially inform future study designs of endoscopic multiphoton imaging systems. The spontaneous tumor model comprised a series of six weekly injections of azoxymethane (AOM model). The colitis-associated tumor model comprised a single injection of AOM, followed by cycles of drinking water with dissolved dextran sodium sulfate salt (AOM-DSS model). SHG images of freshly resected murine colon were acquired with a multiphoton imaging system, and image features, such as crypt size, shape and distribution, were quantified using an automated algorithm.

Results

The comparison of quantified features of crypt morphology demonstrated the ability of our quantitative image feature algorithms to detect differences between spontaneous (AOM model) and colitis-associated (AOM-DSS model) murine colorectal tissue specimens. There were statistically significant differences in the mean and standard deviation of nearest neighbor (distance between crypts) and circularity between the Control cohort, AOM and AOM-DSS cohorts. We also saw significance between AOM and AOM-DSS cohorts when calculating nearest neighbor in images acquired at fixed depths.

Conclusion

The results provide insight into the ability of SHG imaging to yield relevant data about the crypt microstructure in colorectal epithelium, specifically the potential to distinguish between spontaneous and colitis-associated murine models using quantification of crypt shape and distribution, informing future design of translational multiphoton imaging systems and protocols.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5639-8) contains supplementary material, which is available to authorized users.

Endoscopic detection and resection of dysplasia in inflammatory bowel disease-techniques with videos

BACKGROUND

Patients with ulcerative colitis and Crohn's colitis have an increased risk of developing dysplasia and colorectal cancer as compared to the general population; surveillance colonoscopy is recommended in this patient population.

METHODS

This review of the published literature aimed to assess the published evidence.

RESULTS

Detection of dysplasia requires examination of mucosa with targeted biopsies of the visible lesions as well as random biopsies to detect invisible lesions. Newer endoscopic techniques, in particular chromoendoscopy, increase the yield of identifying dysplastic lesions. The surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients International Consensus (SCENIC) guidelines recommends that colonoscopy using chromoendoscopy is the optimal endoscopic surveillance strategy to detect dysplasia. Once dysplastic lesions are discovered on surveillance endoscopic examination, careful and meticulous descriptions of lesions is mandatory to aid in further decision making. Management of dysplastic lesions in inflammatory bowel disease patients depends on endoscopic (morphological) and histologic findings and patient characteristics such as age, general condition of the patient, and patient preferences. Endoscopic mucosal resection, endoscopic submucosal dissection, and surgery are different therapeutic options for colonic dysplastic lesions detected in the setting of inflammatory bowel disease.

CONCLUSIONS

In this review, we discuss the various techniques for endoscopic resection of dysplasia in patients with inflammatory bowel disease. Further research is required to determine the optimal approach to diagnosis and management of dysplasia in patients with inflammatory bowel disease.

Primary sclerosing cholangitis and inflammatory bowel disease comorbidity: an update of the evidence

Comorbid primary sclerosing cholangitis (PSC) and inflammatory bowel disease (IBD) represent a unique disease phenotype with a different risk profile than PSC or IBD alone. While the pathogenetic mechanisms behind both diseases remain unclear, recent studies have targeted several immune-mediated pathways in an attempt to find a potential therapeutic target. Patients with PSC-associated IBD typically exhibit pancolitis with a right-to-left intestinal inflammatory gradient associated with a greater incidence of backwash ileitis and rectal sparing. Although there is an increased incidence of pancolitis in this population, bowel symptoms tend to be less significant than in IBD alone. Likewise, the degree of inflammation and symptoms of PSC-associated IBD are characteristically less clinically significant. Despite the relatively quiescent clinical presentation of PSC-associated IBD, there is an increased risk for colorectal and hepatobiliary malignancy making vigilance for malignancy essential.

Colorectal cancer in inflammatory bowel disease: review of the evidence

Inflammatory bowel disease (IBD)-related colorectal cancer (CRC) is responsible for approximately 2% of the annual mortality from CRC overall, but 10-15% of the annual deaths in IBD patients. IBD-related CRC patients are also affected at a younger age than sporadic CRC patients, and have a 5-year survival rate of 50%. Despite optimal medical treatment, the chronic inflammatory state inherent in IBD increases the risk for high-grade dysplasia and CRC, with additional input from genetic and environmental risk factors and the microbiome. Recognizing risk factors, implementing appropriate surveillance, and identifying high-risk patients are key to managing the CRC risk in IBD patients. Chemoprevention strategies exist, and studies evaluating their efficacy are underway. Once dysplasia or invasive cancer is diagnosed, appropriate surgical resection and postoperative treatment and surveillance are necessary. Here, we discuss the current state of IBD-related CRC, prevalence, risk factors, and evidence for surveillance, prophylaxis, and treatment recommendations.

Downregulation of trefoil factor-3 expression in the rectum is associated with the development of ulcerative colitis-associated cancer

Diagnostic markers facilitate more selective screening and treatment strategies for ulcerative colitis (UC)-associated cancer (UCAC). The expression of trefoil factor-3 (TFF3), which is involved in mucosal protection and repair in the gastrointestinal tract, was analyzed and its significance for UCAC was evaluated. A total of 145 patients with UC who underwent proctocolectomies were enrolled, including 15 patients (10.8%) with UCAC. TFF3 expression in the rectal mucosa and in cancer cells was assessed using immunohistochemistry, and the expression in UCAC and sporadic colorectal cancer was compared. Analyzing the mucinous granules of goblet cells located in crypts revealed that the non-cancerous rectal mucosa of patients with UCAC had significantly lower mean TFF3 staining scores compared with patients with UC without UCAC or patients with sporadic cancer. TFF3 staining score was revealed to be an independent predictor of UCAC development. These results indicated that low TFF3 expression in the rectal mucosa was associated with the development of UCAC. Thus, TFF3 expression in the rectal mucosa may be a useful biomarker for monitoring patients with UC.

Reviewing the Risk of Colorectal Cancer in Inflammatory Bowel Disease After Liver Transplantation for Primary Sclerosing Cholangitis

The presence of concomitant primary sclerosing cholangitis (PSC) with inflammatory bowel disease (IBD) represents a distinct disease phenotype that carries a higher risk of colorectal cancer (CRC) than the average IBD patient. Given that liver transplantation (LT) is the only treatment that offers a survival benefit in PSC patients with hepatic dysfunction, management decisions in IBD patients' post-LT for PSC are frequently encountered. One such consideration is the risk of CRC in this immunosuppressed cohort. With most studies showing an increased risk of CRC post-LT in these IBD patients, a closer look at the associated risk factors of CRC and the adopted surveillance strategies in this subset of patients is warranted. Low-dose ursodeoxycholic acid has shown a potential chemopreventive effect in PSC-IBD patients pre-LT; however, a favorable effect remains to be seen in post-LT group. Also, further studies are necessary to assess the benefit of 5 aminosalicylate therapy. Annual surveillance colonoscopy in the post-LT period is recommended for PSC-IBD patients subset given their high risk for CRC.

Frequency of Surveillance and Impact of Surveillance Colonoscopies in Patients With Ulcerative Colitis Who Developed Colorectal Cancer

BACKGROUND

The risk of developing colorectal cancer (CRC) in patients with chronic ulcerative colitis (UC) is increased. The aim of this study was to evaluate if patients who developed CRC in the setting of UC were undergoing guideline-recommended surveillance colonoscopies and to determine the impact of surveillance on the staging of CRC.

PATIENTS AND METHODS

Data was obtained from the Veterans Affairs healthcare system to identify patients with UC and CRC. Stage 0 and I were considered early-stage CRC, whereas stage ≥ II were considered advanced-stage CRC. Patients were considered to have adequate surveillance if they had a colonoscopy within 2 years before developing CRC. We conducted a case-case analysis using multivariable logistic regression to estimate the odds ratio for presenting with advanced-stage CRC associated with lack of adequate surveillance.

RESULTS

Of the 48 patients, the majority were white (70.8%) and male (100%). Sixty-nine percent of patients had inadequate surveillance. In multivariable analysis, prior adherence to CRC surveillance was associated with a decreased risk of presenting with advanced-stage CRC (vs. early-stage CRC) (adjusted odds ratio, 0.20; 95% confidence interval, 0.05-0.85; P = .029).

CONCLUSION

The majority of patients who developed CRC in the setting of UC underwent inadequate surveillance, and they were more likely to present with advanced-stage CRC.

Qingchang Wenzhong Decoction Attenuates DSS-Induced Colitis in Rats by Reducing Inflammation and Improving Intestinal Barrier Function via Upregulating the MSP/RON Signalling Pathway

Ulcerative colitis (UC) is a chronic, nonspecific, inflammatory disease for which an effective treatment is lacking. Our previous study found that Qingchang Wenzhong Decoction (QCWZD) can significantly improve the clinical symptoms of UC and ameliorate dextran sulphate sodium- (DSS-) induced ulcerative colitis in rats by downregulating the IP10/CXCR3 axis-mediated inflammatory response. The purpose of the present study was to further explore the mechanism of QCWZD for UC in rats models, which were established by 7-day administration of 4.5% dextran sulphate sodium solution. QCWZD was administered daily for 7 days; then we determined the serum macrophage-stimulating protein concentration (MSP) and recepteur d'origine nantais (RON) expression and its downstream proteins (protein kinase B [Akt], phosphorylated [p] Akt, occludin, zona occluden- [ZO-] 1, and claudin-2) in colon tissue using Western blotting and quantitative polymerase chain reaction. In DSS-induced UC, QCWZD significantly alleviated colitis-associated inflammation, upregulated serum MSP expression and RON expression in the colon, reduced the pAkt levels, promoted colonic occluding and ZO-1 expression, and depressed claudin-2 expression. In conclusion, the MSP/RON signalling pathway plays an important role in the pathogenesis of UC by involving the inflammatory response and improving intestinal barrier function. QCWZD appears to attenuate DSS-induced UC in rats by upregulating the MSP/RON signalling pathway.

The Role of Proinflammatory Pathways in the Pathogenesis of Colitis-Associated Colorectal Cancer

Patients with inflammatory bowel disease (IBD) are at an increased risk of developing colorectal cancer (CRC). The risk factors of CRC in IBD patients include long disease duration, extensive colitis, severe histological inflammation, and coexistence with primary sclerosing cholangitis (PSC). Several molecular pathways that contribute to sporadic CRC are also involved in the pathogenesis of colitis-associated CRC. It is well established that long-standing chronic inflammation is a key predisposing factor of CRC in IBD. Proinflammatory pathways, including nuclear factor kappa B (NF-κB), IL-6/STAT3, cyclooxygenase-2 (COX-2)/PGE₂, and IL-23/Th17, promote tumorigenesis by inducing the production of inflammatory mediators, upregulating the expression of antiapoptotic genes, and stimulating cell proliferation as well as angiogenesis. Better understanding of the underlying mechanisms may provide some promising targets for prevention and therapy. This review aims to elucidate the role of these signaling pathways in the pathogenesis of colitis-associated CRC using evidence-based approaches.

Effects of indigo naturalis on colonic mucosal injuries and inflammation in rats with dextran sodium sulphate-induced ulcerative colitis

The effects of indigo naturalis (IN), which is a traditional Chinese herbal formulation, have been clinically demonstrated in treating refractory ulcerative colitis (UC). The present study aimed to verify the effects and mechanisms of IN in experimental UC rats. A total of 48 male Sprague-Dawley rats were randomly divided into six groups: Chow, model, high-dose IN, medium-dose IN, low-dose IN and mesalazine (a bowel-specific aminosalicylate drug) groups. The models were administered 3.5% dextran sodium sulphate solution for 7 days. The treatment groups were administered IN or mesalazine and then sacrificed and sampled on day 8. Disease activity index (DAI), histological damage score (HDS) and myeloperoxidase (MPO) activity were used to evaluate the severity of UC. Colon and serum cytokines were detected using liquid-phase chip technology and the expression of occludin protein in colonic mucosa was assessed by immunohistochemistry and western blot analysis. The results indicated that the oral administration of IN may reduce DAI, HDS and MPO activity. IN also reduced the expression of inflammatory cytokines and increased the expression of colonic mucosal repair-related cytokines and occludin protein. These results highlight the potential of IN as a therapeutic agent for treating UC through its action of inflammation control and colonic mucosal damage repair.

The molecular landscape of colitis-associated carcinogenesis

In spite of the well-established histopathological phenotyping of IBD-associated preneoplastic and neoplastic lesions, their molecular landscape remains to be fully elucidated. Several studies have pinpointed the initiating role of longstanding/relapsing inflammatory insult on the intestinal mucosa, with the activation of different pro-inflammatory cytokines (TNF-α, IL-6, IL-10, IFN-γ), chemokines and metabolites of arachidonic acid resulting in the activation of key transcription factors such as NF-κB. Longstanding inflammation may also modify the intestinal microbiota, prompting the overgrowth of genotoxic microorganisms, which may act as further cancer promoters. Most of the molecular dysregulation occurring in sporadic colorectal carcinogenesis is documented in colitis-associated adenocarcinoma too, but marked differences have been established in both their timing and prevalence. Unlike sporadic cancers, TP53 alterations occur early in IBD-related carcinogenesis, while APC dysregulation emerges mainly in the most advanced stages of the oncogenic cascade. From the therapeutic standpoint, colitis-associated cancers are associated with a lower prevalence of KRAS mutations than the sporadic variant. Epigenetic changes, including DNA methylation, histone modifications, chromatin remodeling, and non-coding RNAs, are significantly involved in colitis-associated cancer development and progression. The focus now is on identifying diagnostic and prognostic biomarkers, with a view to ultimately designing patient-tailored therapies.

Acute toxicity and surgical complications after preoperative (chemo)radiation therapy for rectal cancer in patients with inflammatory bowel disease

PURPOSE

Preoperative therapy reduces local recurrences and may facilitate surgery in rectal cancer patients. However, in patients with inflammatory bowel disease (IBD) this treatment is often withheld due to the perceived risk of excessive side-effects, even though evidence is limited. The purpose of this study is to investigate the effects of preoperative therapy on acute toxicity and post-operative complications in IBD patients with rectal cancer.

METHODS

The Dutch pathology registry (PALGA) was searched for patients with IBD and rectal cancer treated between January 1991 and May 2010. Histopathology and clinical charts were reviewed to confirm IBD diagnosis and evaluate clinical and pathological characteristics.

RESULTS

Out of 161 patients, 66 received preoperative therapy (41%), including short-course radiation therapy (SC-RT), long course radiation therapy (LC-RT), and chemoradiation therapy (CRT) in 32, 13, and 21 patients respectively. Grade≥3 acute toxicity occurred in 0 patients (0.0%), 1 patient (7.7%), and 6 patients (28.6%) respectively (p=0.004). Systemic corticosteroids were used by 10.5% of patients at time of treatment. Grade≥3 post-operative 30-day complication rate (28.1% overall) was not associated with type of preoperative therapy.

CONCLUSION

Results did not show excessive rates of toxicity or post-operative complications and support the use of standard preoperative therapies for rectal cancer (especially SC-RT) in IBD patients with relatively indolent disease. Caution is warranted in patients with active IBD, since the exact impact of active bowel inflammation could not be determined retrospectively. Prospective studies should investigate the influence of active IBD on acute and late toxicity in patients receiving pelvic irradiation.

Crohn's disease: risk factor for colorectal cancer

Background Crohn's disease is an inflammatory disease that can reach any part of the gastrointestinal tract. This disease has been associated with an increased neoplastic risk, including colorectal carcinoma.

Objective The objective of this work is to describe the mechanisms present in two diseases, and that are responsible for the increased risk in Crohn's disease.

Methods A bibliographic research was conducted in PubMed database. In addition to the articles obtained with an inserted query in Pubmed, other references relevant to the topic in question were included.

Results Colorectal cancer risk varies according to the presence of certain factors, and an example of this is Crohn's disease. Chronic inflammation seems to be an important contribution to carcinogenesis, since it creates a microenvironment suitable for the onset and progression of the disease. There are molecular changes that are common to two conditions, thus justifying the fact of Crohn's disease being a risk factor for colorectal carcinoma. The disease control with an appropriate therapy and with surveillance are two ways to control this risk.

Conclusions A proinflammatory state is the cornerstone in the association between Crohn's disease and colorectal carcinoma. The implementation of surveillance strategies allowed a decrease in morbidity and mortality associated with this cancer.

Downregulation of the Deiminase PADI2 Is an Early Event in Colorectal Carcinogenesis and Indicates Poor Prognosis

Peptidyl arginine deiminases (PADI) are a family of enzymes that catalyze the poorly understood posttranslational modification converting arginine residues into citrullines. In this study, the role of PADIs in the pathogenesis of colorectal cancer was investigated. Specifically, RNA expression was analyzed and its association with survival in a cohort of 98 colorectal cancer patient specimens with matched adjacent mucosa and 50 controls from donors without cancer. Key results were validated in an independent collection of tumors with matched adjacent mucosa and by mining of a publicly available expression data set. Protein expression was analyzed by immunoblotting for cell lines or IHC for patient specimens that further included 24 cases of adenocarcinoma with adjacent dysplasia and 11 cases of active ulcerative colitis. The data indicate that PADI2 is the dominantly expressed PADI enzyme in colon mucosa and is upregulated during differentiation. PADI2 expression is low or absent in colorectal cancer. Frequently, this occurs already at the stage of low-grade dysplasia. Mucosal PADI2 expression is also low in ulcerative colitis. The expression level of PADI2 in tumor and adjacent mucosa correlates with differential survival: low levels associate with poor prognosis.

IMPLICATIONS

Downregulation of PADI2 is an early event in the pathogenesis of colorectal cancer associated with poor prognosis and points toward a possible role of citrullination in modulating tumor cells and their microenvironment. Mol Cancer Res; 14(9); 841-8. ©2016 AACR.

Gastrointestinal stem cells in health and disease: from flies to humans

The gastrointestinal tract of complex metazoans is highly compartmentalized. It is lined by a series of specialized epithelia that are regenerated by specific populations of stem cells. To maintain tissue homeostasis, the proliferative activity of stem and/or progenitor cells has to be carefully controlled and coordinated with regionally distinct programs of differentiation. Metaplasias and dysplasias, precancerous lesions that commonly occur in the human gastrointestinal tract, are often associated with the aberrant proliferation and differentiation of stem and/or progenitor cells. The increasingly sophisticated characterization of stem cells in the gastrointestinal tract of mammals and of the fruit fly Drosophila has provided important new insights into these processes and into the mechanisms that drive epithelial dysfunction. In this Review, we discuss recent advances in our understanding of the establishment, maintenance and regulation of diverse intestinal stem cell lineages in the gastrointestinal tract of Drosophila and mice. We also discuss the field's current understanding of the pathogenesis of epithelial dysfunctions.

Status of colitis-associated cancer in ulcerative colitis

Surgical therapy for ulcerative colitis (UC) depends on the medical therapy administered for the patient’s condition. UC is a benign disease. However, it has been reported that the rare cases of cancer in UC patients are increasing, and such cases have a worse prognosis. Recently, surgical therapy has greatly changed, there has been quite an increase in the number of UC patients with high-grade dysplasia and/or cancer. These lesions are known as colitis-associated cancer (CAC). The relationship between inflammation and tumorigenesis is well-established, and in the last decade, a great deal of supporting evidence has been obtained from genetic, pharmacological, and epidemiological studies. Inflammatory bowel disease, especially UC, is an important risk factor for the development of colon cancer. We should determine the risk factors for UC patients with cancer based on a large body of data, and we should attempt to prevent the increase in the number of such patients using these newly identified risk factors in the near future. Actively introducing the surgical treatment in addition to medical treatment should be considered. Several physicians should analyze UC from their unique perspectives in order to establish new clinically relevant diagnostic and treatment methods in the future. This article discusses CAC, including its etiology, mechanism, diagnosis, and treatment in UC patients.

Impaired outcome colitis-associated rectal cancer versus sporadic cancer

BACKGROUND

The surgical management of colitis-associated rectal cancer (CARC) is not well defined. This study determines outcomes after surgery for CARC compared with sporadic rectal cancer.

MATERIALS AND METHODS

This is a retrospective cohort study comparing 27 patients with CARC with 54 matched patients with sporadic cancer. Matching criteria included age, gender, neoadjuvant chemoradiation, and American Joint Committee on Cancer stage. Outcome measures were disease-free and overall survival, tumor characteristics, and postoperative morbidity.

RESULTS

Compared to those with sporadic rectal cancer, patients with CARC underwent proctocolectomy more frequently (21 [78%] versus 6 [22%] P < 0.001) and were more likely to have mucinous tumors (11 [40.7%] versus 12 [22.3%] P = 0.03). Overall 3-y survival was significantly reduced in CARC patients compared with patients with sporadic rectal cancer. Those with CARC undergoing segmental proctectomy only demonstrated reduced overall and disease-free survival compared to patients with sporadic rectal cancer and to colitis patients undergoing proctocolectomy (P = 0.002).

CONCLUSIONS

Patients with CARC undergoing proctectomy demonstrate reduced disease-free survival versus those undergoing proctocolectomy, and versus patients with sporadic rectal cancer undergoing proctectomy. These findings warrant further study and suggest that proctocolectomy should be considered the preferred surgical approach for CARC.

The role of endoscopy in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a group of chronic immune-mediated disorders of the gastrointestinal tract. It is often the result of the interaction of genetic and environmental factors. The role of endoscopy in disease surveillance is unprecedented. However, there is considerable debate in therapeutic goals in IBD patients, ranging from the resolution of clinical symptoms to mucosal healing. Furthermore, deep remission has recently been advocated for altering disease course in these patients. Additionally, neoplasia continues to be a significant cause of morbidity and mortality in IBD patients. This review discussed the role of several endoscopic techniques in assessing mucosal healing and neoplasia with emphasis on novel non-invasive endoscopic techniques.