Cancers complicating inflammatory bowel disease

Anal Neoplasia in Inflammatory Bowel Disease: Classification Proposal, Epidemiology, Carcinogenesis, and Risk Management Perspectives

Patients with inflammatory bowel disease [IBD] may develop, similarly to individuals from general population, rare cases of human papilloma virus [HPV]-related anal canal squamous cell carcinoma [SCC] and intra-epithelial precursor lesions, as well as very rare cases of anal canal adenocarcinoma. Patients with chronic perianal Crohn's disease [CD] are at substantial risk of developing SCC or adenocarcinoma from the fistula-lining epithelium, as well as SCC or adenocarcinoma arising from chronic anorectal ulcerations or strictures. Based on this lesion stratification, we provide in this review tailored incidence estimates and we propose an IBD-specific classification of all types of anal neoplasia that may occur in patients with IBD. After reviewing putative carcinogenesis of all types of neoplasia, we conclude that HPV vaccination could reduce the incidence of HPV-related lesions, although an anal screening programme related to these lesions is not mandatory on the sole basis of IBD. By contrast, we point out that all patients with chronic perianal CD should be explored in depth, including biopsies under anaesthesia and fistula curettage when necessary, in case of any change in anal symptoms ─in particular new, increasing, unexplained pain. Finally, we conclude that there is an urgent need for elaborating and evaluating surveillance algorithms in patients with chronic perianal CD, in order to avoid cancers with late diagnosis and poor prognosis.

Card9-dependent IL-1β regulates IL-22 production from group 3 innate lymphoid cells and promotes colitis-associated cancer

Inflammatory bowel diseases (IBD) are key risk factors for the development of colorectal cancer, but the mechanisms that link intestinal inflammation with carcinogenesis are insufficiently understood. Card9 is a myeloid cell-specific signaling protein that regulates inflammatory responses downstream of various pattern recognition receptors and which cooperates with the inflammasomes for IL-1β production. Because polymorphisms in Card9 were recurrently associated with human IBD, we investigated the function of Card9 in a colitis-associated cancer (CAC) model. Card9-/- mice develop smaller, less proliferative and less dysplastic tumors compared to their littermates and in the regenerating mucosa we detected dramatically impaired IL-1β generation and defective IL-1β controlled IL-22 production from group 3 innate lymphoid cells. Consistent with the key role of immune-derived IL-22 in activating STAT3 signaling during normal and pathological intestinal epithelial cell (IEC) proliferation, Card9-/- mice also exhibit impaired tumor cell intrinsic STAT3 activation. Our results imply a Card9-controlled, ILC3-mediated mechanism regulating healthy and malignant IEC proliferation and demonstrates a role of Card9-mediated innate immunity in inflammation-associated carcinogenesis.

Expression profile of intestinal stem cell markers in colitis-associated carcinogenesis

The intestinal epithelium has two distinct two stem cell populations, namely, crypt base columnar (CBC) cells and +4 cells. Several specific markers have been identified for each stem cell population. In this study, we examined the expression profiles of these markers in colitis-associated carcinogenesis (CAC) to investigate whether they can be used as biomarkers for the early detection of dysplasia. The expression of intestinal stem cell (ISC) markers was measured by real-time polymerase chain reaction during CAC that was induced by azoxymethane and dextran sodium sulfate treatment. CBC stem cell markers increased continuously with tumor development, whereas a +4 cell expression profile was not present. CBC stem cell population was suppressed in the acute colitis and then expanded to repopulate the crypts during the regeneration period. Notably, RNA in situ hybridization revealed that all dysplasia and cancer samples showed increased expression of CBC stem cell markers in more than one-third of the tumor height, whereas regenerative glands had CBC stem cell markers confined to the lower one-third of the crypt. These results suggest that CBC stem cell markers could be a useful tool for the early detection of colitis-induced tumors.

Gut Microbiota, Inflammation, and Colorectal Cancer

Colorectal cancer is the second-leading cause of cancer-related deaths in the United States and fourth-leading cause of cancer-related deaths worldwide. While cancer is largely considered to be a disease of genetic and environmental factors, increasing evidence has demonstrated a role for the microbiota (the microorganisms associated with the human body) in shaping inflammatory environments and promoting tumor growth and spread. Herein, we discuss both human data from meta'omics analyses and data from mechanistic studies in cell culture and animal models that support specific bacterial agents as potentiators of tumorigenesis-including Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, and colibactin-producing Escherichia coli. Further, we consider how microbes can be used in diagnosing colorectal cancer and manipulating the tumor environment to encourage better patient outcomes in response to immunotherapy treatments.

Infliximab Is Not Associated With Increased Risk of Malignancy or Hemophagocytic Lymphohistiocytosis in Pediatric Patients With Inflammatory Bowel Disease

BACKGROUND AND AIMS

Immunosuppressive therapy for inflammatory bowel disease (IBD) in pediatric patients is thought to increase the risk of malignancy and lymphoproliferative disorders, including hemophagocytic lymphohistiocytosis (HLH). We compared unadjusted incidence rates of malignancy and HLH in pediatric patients with IBD exposed to infliximab (IFX) with patients not exposed to biologics and calculated standardized incidence ratios (SIRs).

METHODS

We collected and analyzed data from 5766 participants in a prospective study of long-term outcomes of pediatric patients with IBD (NCT00606346), from May 31, 2007 through June 30, 2016. Patients were 17 years old or younger and had Crohn's disease, ulcerative colitis, or IBD-unclassified with 24,543.0 patient-years of follow-up. We estimated incidence rates for malignancy and HLH as events/1000 patient-years of follow-up. We calculated age-, sex-, and race-adjusted SIRs, with 95% confidence intervals (CIs), using the Surveillance, Epidemiology, and End Results Program (SEER) database.

RESULTS

Thirteen of the 15 patients who developed a malignancy and all 5 of the patients who developed HLH had been exposed to thiopurines; 10 patients with malignancy had also been exposed to a biologic agent. Unadjusted incidence rates showed no increased risk of malignancy (0.46/1000 patient-years) or HLH (0.0/1000 patient-years) in patients exposed to IFX as the only biologic vs those unexposed to biologics (malignancy: 1.12/1000 patient-years; HLH: 0.56/1000 patient-years). SIRs did not demonstrate an increased risk of malignancy among patients exposed to IFX (SIR, 1.69; 95% CI, 0.46-4.32) vs patients not exposed to a biologic agent (SIR, 2.17; 95% CI, 0.59-5.56), even when patients were stratified by thiopurine exposure.

CONCLUSIONS

In determination of age-, sex-, and race-adjusted SIRs using data from a large clinical study and the SEER database, we found that IFX exposure did not associate with increased risk of malignancy or HLH in pediatric patients with IBD. Thiopurine exposure is an important precedent event for the development of malignancy or HLH in pediatric patients with IBD.

Sildenafil Suppresses Inflammation-Driven Colorectal Cancer in Mice

Intestinal cyclic guanosine monophosphate (cGMP) signaling regulates epithelial homeostasis and has been implicated in the suppression of colitis and colon cancer. In this study, we investigated the cGMP-elevating ability of the phosphodiesterase-5 (PDE5) inhibitor sildenafil to prevent disease in the azoxymethane/dextran sulfate sodium (AOM/DSS) inflammation-driven colorectal cancer model. Treatment of mice with sildenafil activated cGMP signaling in the colon mucosa and protected against dextran-sulfate sodium (DSS)-induced barrier dysfunction. In mice treated with AOM/DSS, oral administration of sildenafil throughout the disease course reduced polyp multiplicity by 50% compared with untreated controls. Polyps that did form in sildenafil treated mice were less proliferative and more differentiated compared with polyps from untreated mice, but apoptosis was unaffected. Polyps in sildenafil treated mice were also less inflamed; they exhibited reduced myeloid-cell infiltration and reduced expression of iNOS, IFNγ, and IL6 compared with untreated controls. Most of the protection conferred by sildenafil was during the initiation stage of carcinogenesis (38% reduction in multiplicity). Administration of sildenafil during the later promotion stages did not affect multiplicity but had a similar effect on the polyp phenotype, including increased mucus production, and reduced proliferation and inflammation. In summary, the results demonstrate that oral administration of sildenafil suppresses polyp formation and inflammation in mice treated with AOM/DSS. This validation of PDE5 as a target highlights the potential therapeutic value of PDE5 inhibitors for the prevention of colitis-driven colon cancer in humans. Cancer Prev Res; 10(7); 377-88. ©2017 AACRSee related editorial by Piazza, p. 373.

Systematic review with meta-analysis: use of 5-aminosalicylates and risk of colorectal neoplasia in patients with inflammatory bowel disease

BACKGROUND

The relationship of 5-aminosalicylates' use with the risk of colorectal neoplasia in patients with inflammatory bowel disease (IBD) has been the focus of a growing body of research.

AIM

To investigate this association through an updated meta-analysis of observational studies.

METHODS

PubMed, Scopus and major conference proceedings were searched up to December 2016. The identified studies were evaluated for publication bias and heterogeneity. Pooled relative risk (RR) estimates were calculated using random-effect models. Detailed subgroup analyses were performed. The GRADE approach was used to assess the quality of evidence.

RESULTS

Thirty-one independent observational studies including 2137 cases of colorectal neoplasia (of which 76% were cancers) were incorporated. Between-study heterogeneity was moderate, while strong suspicion of small-study effects was raised. The overall analysis revealed a protective association between 5-aminosalicylates' use and colorectal neoplasia (RR = 0.57, 95% CI: 0.45-0.71). When the analysis was stratified according to study design and setting, the association was significant in cohort (RR = 0.65, 95% CI: 0.43-0.99; n = 10) and case-control studies (RR = 0.53, 95% CI: 0.40-0.70; n = 21), population-based (RR = 0.70, 95% CI: 0.52-0.94; n = 12) and hospital-based studies (RR = 0.46, 95% CI: 0.34-0.61; n = 19). Exposure to 5-aminosalicylates was protective against cancer (RR = 0.58, 95% CI: 0.45-0.74) and dysplasia (RR = 0.54, 95% CI: 0.35-0.84). The reduction in colorectal neoplasia risk was strong in ulcerative colitis (RR = 0.50, 95% CI: 0.38-0.64), but nonsignificant in Crohn's disease (RR = 0.76, 95% CI: 0.43-1.33). Mesalazine (mesalamine) use was protective (RR = 0.70, 95% CI: 0.51-0.94) with evidence of a dose-effect. The effect of sulfasalazine was marginally nonsignificant (RR = 0.72, 95% CI: 0.51-1.01).

CONCLUSIONS

Our findings support a potential chemopreventive role of 5-aminosalicylates in IBD. Further, high-quality prospective research is warranted.

Full-Spectrum Endoscopy Improves Surveillance for Dysplasia in Patients With Inflammatory Bowel Diseases

BACKGROUND & AIMS

Inflammatory bowel diseases (IBDs) increase the risk of colorectal cancer. Surveillance colonoscopy with chromoendoscopy is recommended, but conventional forward-viewing colonoscopy (FVC) detects dysplasia with low levels of sensitivity. Full-spectrum endoscopy (FUSE) incorporates 2 additional lateral cameras to the forward camera of the colonoscope, allowing endoscopists to view behind folds and in blind spots, which might increase dysplasia detection. We compared FUSE vs FVC in the detection of dysplasia in patients with IBDs.

METHODS

We performed a prospective, randomized, cross-over, tandem colonoscopy study comparing FVC vs FUSE in 52 subjects with IBD undergoing surveillance for neoplasia in Australia (23 with Crohn's colitis, 29 with ulcerative colitis; median age, 45.0 y; 60% male; mean IBD duration, 16.4 y). All subjects met national IBD surveillance inclusion criteria; 27 were assigned randomly to groups that underwent FVC followed by FUSE, and 25 were assigned to groups that underwent FUSE followed by FVC. All procedures were performed from February 2014 through December 2015. Random biopsy specimens were collected and visible lesions were collected; all were analyzed histologically. The primary end point was dysplasia missed by the first colonoscopy detected by the second colonoscopy. Dysplasia was diagnosed by an expert gastrointestinal pathologist blinded to the colonoscope allocation in consensus with a second expert pathologist.

RESULTS

FVC missed 71.4% of dysplastic lesions per lesion whereas FUSE missed 25.0% per lesion (P = .0001); FVC missed 75.0% of dysplastic lesions per subject and FUSE missed 25.0% per subject (P = .046). FUSE identified a mean of 0.37 dysplastic lesions and FVC identified a mean of 0.13 dysplastic lesions (P = .044). The total colonoscopy times were similar (21.2 min for FUSE vs 19.1 min for FVC; P = .32), but withdrawal time was significantly longer for FUSE (15.8 min) than for FVC (12.0 min) (P = .03). Correcting for per-unit withdrawal time, the mean dysplasia miss rate per subject was significantly lower for FUSE (0.19) than for FVC (0.83; P < .0001). Targeted tissue acquisition identified significantly more dysplastic lesions than random biopsies (P < .0001).

CONCLUSIONS

In a prospective cross-over study of IBD patients undergoing surveillance colonoscopy, we found panoramic views obtained by full-spectrum endoscopy increased the number of dysplastic lesions detected, compared with conventional forward-viewing colonoscopy. Trial no: ACTRN12616000047493.

Ulcerative colitis

Ulcerative colitis is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide. The pathogenesis is multifactorial, involving genetic predisposition, epithelial barrier defects, dysregulated immune responses, and environmental factors. Patients with ulcerative colitis have mucosal inflammation starting in the rectum that can extend continuously to proximal segments of the colon. Ulcerative colitis usually presents with bloody diarrhoea and is diagnosed by colonoscopy and histological findings. The aim of management is to induce and then maintain remission, defined as resolution of symptoms and endoscopic healing. Treatments for ulcerative colitis include 5-aminosalicylic acid drugs, steroids, and immunosuppressants. Some patients can require colectomy for medically refractory disease or to treat colonic neoplasia. The therapeutic armamentarium for ulcerative colitis is expanding, and the number of drugs with new targets will rapidly increase in coming years.

Detection and characterization of murine colitis and carcinogenesis by molecularly targeted contrast-enhanced ultrasound

AIM

To study mucosal addressin cellular adhesion molecule-1 (MAdCAM-1) and vascular endothelial growth factor (VEGF)-targeted contrast enhanced ultrasound (CEUS) for the assessment of murine colitis and carcinogenesis.

METHODS

C57BL/6 mice were challenged with 3% dextran sodium-sulfate (DSS) for three, six or nine days to study the development of acute colitis. Ultrasound was performed with and without the addition of unspecific contrast agents. MAdCAM-1-targeted contrast agent was used to detect and quantify MAdCAM-1 expression. Inflammatory driven colorectal azoxymethane (AOM)/DSS-induced carcinogenesis was examined on day 42 and 84 using VEGF-targeted contrast agent. Highly specific tissue echogenicity was quantified using specialized software. Sonographic findings were correlated to tissue staining, western blot analysis and immunohistochemistry to quantify the degree of inflammation and stage of carcinogenesis.

RESULTS

Native ultrasound detected increased general bowel wall thickening that correlated with more progressed and more severe DSS-colitis (healthy mice: 0.3 mm ± 0.03 vs six days DSS: 0.5 mm ± 0.2 vs nine days DSS: 0.6 mm ± 0.2, P < 0.05). Moreover, these sonographic findings correlated well with clinical parameters such as weight loss (r² = 0.74) and histological damage (r² = 0.86) (P < 0.01). In acute DSS-induced murine colitis, CEUS targeted against MAdCAM-1 detected and differentiated stages of mild, moderate and severe colitis via calculation of mean pixel contrast intensity in decibel (9.6 dB ± 1.6 vs 12.9 dB ± 1.4 vs 18 dB ± 3.33, P < 0.05). Employing the AOM/DSS-induced carcinogenesis model, tumor development was monitored by CEUS targeted against VEGF and detected a significantly increased echogenicity in tumors as compared to adjacent healthy mucosa (healthy mucosa, 1.6 dB ± 1.4 vs 42 d, 18.2 dB ± 3.3 vs 84 d, 18.6 dB ± 4.9, P < 0.01). Tissue echogenicity strongly correlated with histological analysis and immunohistochemistry findings (VEGF-positive cells in 10 high power fields of healthy mucosa: 1 ± 1.2 vs 42 d after DSS start: 2.4 ± 1.6 vs 84 d after DSS start: 3.5 ± 1.3, P < 0.01).

CONCLUSION

Molecularly targeted CEUS is a highly specific and non-invasive imaging modality, which characterizes murine intestinal inflammation and carcinogenesis in vivo.

Locoregional Effects of Microbiota in a Preclinical Model of Colon Carcinogenesis

Inflammation and microbiota are critical components of intestinal tumorigenesis. To dissect how the microbiota contributes to tumor distribution, we generated germ-free (GF) Apc^Min/+ and Apc^Min/+ ;Il10^-/- mice and exposed them to specific-pathogen-free (SPF) or colorectal cancer-associated bacteria. We found that colon tumorigenesis significantly correlated with inflammation in SPF-housed Apc^Min/+ ;Il10^-/- , but not in Apc^Min/+ mice. In contrast, small intestinal neoplasia development significantly correlated with age in both Apc^Min/+ ;Il10^-/- and Apc^Min/+ mice. GF Apc^Min/+ ;Il10^-/- mice conventionalized by an SPF microbiota had significantly more colon tumors compared with GF mice. Gnotobiotic studies revealed that while Fusobacterium nucleatum clinical isolates with FadA and Fap2 adhesins failed to induce inflammation and tumorigenesis, pks⁺Escherichia coli promoted tumorigenesis in the Apc^Min/+ ;Il10^-/- model in a colibactin-dependent manner, suggesting colibactin is a driver of carcinogenesis. Our results suggest a distinct etiology of cancers in different locations of the gut, where colon cancer is primarily driven by inflammation and the microbiome, while age is a driving force for small intestine cancer. Cancer Res; 77(10); 2620-32. ©2017 AACR.

The Protective Role of Type I Interferons in the Gastrointestinal Tract

The immune system of the gastrointestinal (GI) tract manages the significant task of recognizing and eliminating pathogens while maintaining tolerance of commensal bacteria. Dysregulation of this delicate balance can be detrimental, resulting in severe inflammation, intestinal injury, and cancer. Therefore, mechanisms to relay important signals regulating cell growth and immune reactivity must be in place to support GI homeostasis. Type I interferons (IFN-I) are a family of pleiotropic cytokines, which exert a wide range of biological effects including promotion of both pro- and anti-inflammatory activities. Using animal models of colitis, investigations into the regulation of intestinal epithelium inflammation highlight the role of IFN-I signaling during fine modulation of the immune system. The intestinal epithelium of the gut guides the immune system to differentiate between commensal and pathogenic microbiota, which relies on intimate links with the IFN-I signal-transduction pathway. The current paradigm depicts an IFN-I-induced antiproliferative state in the intestinal epithelium enabling cell differentiation, cell maturation, and proper intestinal barrier function, strongly supporting its role in maintaining baseline immune activity and clearance of damaged epithelia or pathogens. In this review, we will highlight the importance of IFN-I in intestinal homeostasis by discussing its function in inflammation, immunity, and cancer.

Safety of treatments for inflammatory bowel disease: Clinical practice guidelines of the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD)

Inflammatory bowel diseases are chronic conditions of unknown etiology, showing a growing incidence and prevalence in several countries, including Italy. Although the etiology of Crohn's disease and ulcerative colitis is unknown, due to the current knowledge regarding their pathogenesis, effective treatment strategies have been developed. Several guidelines are available regarding the efficacy and safety of available drug treatments for inflammatory bowel diseases. Nevertheless, national guidelines provide additional information adapted to local feasibility, costs and legal issues related to the use of the same drugs. These observations prompted the Italian Group for the Study of Inflammatory Bowel Disease (IG-IBD) to establish Italian guidelines on the safety of currently available treatments for Crohn's disease and ulcerative colitis. These guidelines discuss the use of aminosalicylates, systemic and low bioavailability corticosteroids, antibiotics (metronidazole, ciprofloxacin, rifaximin), thiopurines, methotrexate, cyclosporine A, TNFα antagonists, vedolizumab, and combination therapies. These guidelines are based on current knowledge derived from evidence-based medicine coupled with clinical experience of a national working group.

NADPH oxidase 1 supports proliferation of colon cancer cells by modulating reactive oxygen species-dependent signal transduction

Reactive oxygen species (ROS) play a critical role in cell signaling and proliferation. NADPH oxidase 1 (NOX1), a membrane-bound flavin dehydrogenase that generates O₂^˙̄, is highly expressed in colon cancer. To investigate the role that NOX1 plays in colon cancer growth, we used shRNA to decrease NOX1 expression stably in HT-29 human colon cancer cells. The 80–90% decrease in NOX1 expression achieved by RNAi produced a significant decline in ROS production and a G₁/S block that translated into a 2–3-fold increase in tumor cell doubling time without increased apoptosis. The block at the G₁/S checkpoint was associated with a significant decrease in cyclin D₁ expression and profound inhibition of mitogen-activated protein kinase (MAPK) signaling. Decreased steady-state MAPK phosphorylation occurred concomitant with a significant increase in protein phosphatase activity for two colon cancer cell lines in which NOX1 expression was knocked down by RNAi. Diminished NOX1 expression also contributed to decreased growth, blood vessel density, and VEGF and hypoxia-inducible factor 1α (HIF-1α) expression in HT-29 xenografts initiated from NOX1 knockdown cells. Microarray analysis, supplemented by real-time PCR and Western blotting, revealed that the expression of critical regulators of cell proliferation and angiogenesis, including c-MYC, c-MYB, and VEGF, were down-regulated in association with a decline in hypoxic HIF-1α protein expression downstream of silenced NOX1 in both colon cancer cell lines and xenografts. These studies suggest a role for NOX1 in maintaining the proliferative phenotype of some colon cancers and the potential of NOX1 as a therapeutic target in this disease.

Azathioprine for refractory ulcerative proctitis: A retrospective multicenter study

BACKGROUND

Efficacy of azathioprine (AZA) in refractory ulcerative proctitis (UP) is unknown.

METHODS

All patients treated with AZA for refractory UP in three referral centers between 2002 and 2012 were included. "Treatment success" in the long-term was defined as the absence of colectomy during follow-up, no need for anti-TNF during follow-up, no ongoing systemic steroids use, no adverse event leading to AZA withdrawal, and clinically quiescent disease at last follow-up.

RESULTS

Of the 1279 adult patients with ulcerative colitis, 25 patients were treated with AZA for refractory UP (median disease duration 4.9 years). Of these, 4 had no short-term clinical assessment. Of the remaining 21, 4 were primary non responders to AZA, 7 discontinued AZA for adverse events and 10 showed clinical improvement. At the long-term assessment at last follow up after a median of 46 months, 5 patients had treatment success and were still on AZA treatment, the remaining 20 were treatment failures. Of these, 5 discontinued AZA for adverse events and 15 were treated with infliximab (clinical response in 11 patients, primary non-response in one patient, and 3 underwent colectomy).

CONCLUSION

AZA may be efficacious in maintaining clinical response in one-fifth of patients with refractory UP in a real-life setting.

Chemoprevention of colorectal cancer in inflammatory bowel disease

INTRODUCTION

Patients with inflammatory bowel disease are at an increased risk of colorectal cancer when compared to the general population. Chronic inflammation is thought to be the underlying cause, and medications that reduce inflammation have the potential to reduce the risk of colorectal cancer. Areas covered: After conducting a PubMed search for relevant literature, we examined several classes of medications that have been studied as potential chemopreventive agents. These include 5-aminosalicylates, thiopurines, tumor necrosis factor antagonists, ursodeoxycholic acid, NSAIDs, and statins. Expert commentary: While each class of medications has some data to support its use in chemoprevention, the majority of the evidence in each case argues against the routine use of these medications solely for a chemopreventive benefit.

The effects of aminosalicylates or thiopurines on the risk of colorectal cancer in inflammatory bowel disease

BACKGROUND

Whether aminosalicylates or thiopurines reduce the risk of colorectal cancer (CRC) in inflammatory bowel (IBD) disease is controversial.

AIM

To assess simultaneously the chemopreventive effect of aminosalicylates or thiopurines in a case-control study nested in the CESAME observational cohort that enrolled consecutive patients with IBD between May 2004 and June 2005. Patients were followed up to December 2007.

METHODS

Study population comprised 144 case patients who developed CRC from the diagnosis of IBD (65 and 79 cases diagnosed, respectively, before and from 2004, starting year of the prospective observational period of CESAME) and 286 controls matched for gender, age, IBD subtype and year of diagnosis, and cumulative extent of colitis. Exposure to aminosalicylates or thiopurines was defined by an exposure to the treatment during the year of the diagnosis of cancer. The propensity of receiving 5-ASA and thiopurines was quantified by a composite score taking into account patient and IBD characteristics. The role of aminosalicylates or thiopurines was assessed by multivariate analysis. Propensity scores and the history of primary sclerosing cholangitis were entered into the multivariate model for adjustment.

RESULTS

By multivariate analysis adjusted for propensity, a significant protective effect of exposure to drugs during the year of cancer was found for aminosalicylates (OR = 0.587, 95% CI: 0.367-0.937, P = 0.0257), but not for thiopurines (OR = 0.762, 95% CI: 0.432-1.343, P = 0.3468).

CONCLUSION

In a case-control study nested in the CESAME cohort, a significant decrease in the risk of colorectal cancer in IBD was associated with exposure to aminosalicylates, not to thiopurines.

Endoscopic Detection of Small Bowel Dysplasia and Adenocarcinoma in Crohn's Disease: A Prospective Cohort-Study in High-Risk Patients

BACKGROUND AND AIMS

Crohn's disease [CD] is associated with an increased risk of small bowel adenocarcinoma [SBA]. There are no recommendations on endoscopic screening of SBA in CD patients. The aim of this study was to evaluate the feasibility and value of endoscopic screening for SBA in CD patients at high-risk of SBA.

METHODS

We performed an exploratory multi-centre study in a prospective cohort of CD patients at high-risk of SBA defined as long-term small bowel disease without bowel resection for the past 10 years. Depending on the location of the disease, baseline upper and/or lower enteroscopies were performed. Random and targeted biopsies using chromoendoscopy were taken. Patients were followed-up for at least 1 year after inclusion.

RESULTS

In total, 101 patients [62 men; median age: 48 years; median duration of disease: 19 years] were recruited in ten centres. The endoscopic procedure was incomplete in 47 cases because of impassable strictures and dilation was performed in four patients. Indeterminate small bowel dysplasia was identified in two patients at endoscopic screening; SBA was confirmed in one after surgical resection. With an at least 1-year follow-up duration, two additional cases of SBA were identified in patients who underwent surgery for obstruction, resulting in a 33% sensitivity rate for SBA endoscopic screening.

CONCLUSION

In a cohort of high-risk patients, the prevalence of dysplasia and SBA on CD was 4%. Because of its low sensitivity, endoscopic screening cannot be recommended for surveillance in CD patients at high-risk of SBA.

Incidence of renal cell carcinoma in inflammatory bowel disease patients with and without anti-TNF treatment

OBJECTIVE

We aimed to study the risk of renal cell carcinoma (RCC) with anti-tumor necrosis factor (anti-TNF) therapy in inflammatory bowel disease (IBD) and rheumatic diseases (RD) and calculate standardized incidence ratios (SIRs) in IBD.

MATERIALS AND METHODS

This was a retrospective case-control and cohort study spanning 25 years, including IBD and RD patients with a diagnosis of RCC (1990-2014) identified through the electronic database of a tertiary referral center.

RESULTS

RCC was confirmed in seven anti-TNF-exposed (TNF+) and 21 anti-TNF-naive (TNF-) IBD and one TNF+ and 26 TNF- RD patients. In IBD-RCC, younger age at RCC diagnosis [median (interquartile range) 46 (42-58) vs. 63 (52-75) years; P=0.02], immunosuppressive therapy (100 vs. 24%; P<0.0004), partial nephrectomy (86 vs. 33%; P=0.02), and surgery less than 1 month after diagnosis of RCC (71 vs. 14%; P=0.004) were associated with anti-TNF. Compared with IBD, RD patients were older at RCC diagnosis [70 (60-77) vs. 59 (47-69) years; P=0.02] with less nephron-sparing surgery (26 vs. 54%; P=0.04) and more symptomatic (44 vs. 14%; P=0.02) and advanced tumors (30 vs. 7%; P=0.04). SIRs in IBD-RCC TNF- and TNF+ were 5.4 (95% confidence interval 2.9-9.2) and 7.1 (2.3-16.5) in male patients and 8.5 (3.7-16.8) and 4.8 (0.6-17.3) in female patients, respectively. The risk for RCC associated with anti-TNF in IBD was 0.8 (0.3-2.5) in men and 1.4 (0.2-5.5) in women.

CONCLUSION

The favorable patient and tumor profiles in IBD with anti-TNF may suggest incidentally discovered RCC on abdominal imaging. SIRs for IBD-RCC were not increased after anti-TNF exposure.

Therapeutic management of inflammatory bowel disease in real-life practice in the current era of anti-TNF agents: analysis of the French administrative health databases 2009-2014

BACKGROUND

Management of inflammatory bowel disease (IBD) has evolved in the last decade.

AIM

To assess IBD therapeutic management, including treatment withdrawal and early treatment use in the current era of anti-TNF agents (anti-TNFs).

METHODS

All patients affiliated to the French national health insurance diagnosed with IBD were included from 2009 to 2013 and followed up until 31 December 2014. Medication uses, treatment sequences after introduction of thiopurine or anti-TNF monotherapies or both (combination therapy), surgical procedures and hospitalisations were assessed.

RESULTS

A total of 210 001 patients were diagnosed with IBD [Crohn's disease (CD), 100 112; ulcerative colitis (UC), 109 889]. Five years after diagnosis, cumulative probabilities of anti-TNF monotherapy and combination therapy exposures were 33.8% and 18.3% in CD patients and 12.9% and 7.4% in UC patients, respectively. Among incident patients who received thiopurines or anti-TNFs, the first treatment was thiopurine in 69.1% of CD and 78.2% of UC patients. Among patients treated with anti-TNFs, 45.2% and 54.5% of CD patients and 38.2% and 39.9% of UC patients started monotherapy and combination therapy within 3 months after diagnosis, respectively; 31.3% of CD and 27.1% of UC incident patients withdrew from thiopurine or anti-TNFs for more than 3 months after their first course of treatment. Five years after diagnosis, the cumulative risks of first intestinal resection in CD patients and colectomy in UC patients were 11.9% and 5.7%, respectively.

CONCLUSIONS

Step-up approach remains the predominant strategy, while exposure to anti-TNFs is high. Surgery rates are low. Treatment withdrawal in IBD is more common than expected.

Small Bowel Neoplasms and Polyps

The small intestine is a relatively privileged organ that only rarely develops malignant or even benign tumors. Given this rarity, the relative inaccessibility of the organ during routine endoscopic procedures, and the typical absence or nonspecific nature of clinical manifestations, these tumors often go undiagnosed. Treatment and prognosis are tailored to each histological subtype of tumor. This chapter will discuss the epidemiology, presentation, diagnostics, and management for the most common small bowel tumors, and will highlight the importance of recognizing patients at higher risk of small bowel neoplasia.

The Changing Phenotype of Inflammatory Bowel Disease

It is widely known that there have been improvements in patient care and an increased incidence of Inflammatory Bowel Disease (IBD) worldwide in recent decades. However, less well known are the phenotypic changes that have occurred; these are discussed in this review. Namely, we discuss the emergence of obesity in patients with IBD, elderly onset disease, mortality rates, colorectal cancer risk, the burden of medications and comorbidities, and the improvement in surgical treatment with a decrease in surgical rates in recent decades.

Pro-Tumoral Inflammatory Myeloid Cells as Emerging Therapeutic Targets

Since the observation of Virchow, it has long been known that the tumor microenvironment constitutes the soil for the infiltration of inflammatory cells and for the release of inflammatory mediators. Under certain circumstances, inflammation remains unresolved and promotes cancer development. Here, we review some of these indisputable experimental and clinical evidences of cancer related smouldering inflammation. The most common myeloid infiltrate in solid tumors is composed of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). These cells promote tumor growth by several mechanisms, including their inherent immunosuppressive activity, promotion of neoangiogenesis, mediation of epithelial-mesenchymal transition and alteration of cellular metabolism. The pro-tumoral functions of TAMs and MDSCs are further enhanced by their cross-talk offering a myriad of potential anti-cancer therapeutic targets. We highlight these main pro-tumoral mechanisms of myeloid cells and give a general overview of their phenotypical and functional diversity, offering examples of possible therapeutic targets. Pharmacological targeting of inflammatory cells and molecular mediators may result in therapies improving patient condition and prognosis. Here, we review experimental and clinical findings on cancer-related inflammation with a major focus on creating an inventory of current small molecule-based therapeutic interventions targeting cancer-related inflammatory cells: TAMs and MDSCs.

Protective Role for TWEAK/Fn14 in Regulating Acute Intestinal Inflammation and Colitis-Associated Tumorigenesis

Inflammatory bowel disease causes chronic, relapsing intestinal inflammation that can lead to the development of colorectal cancer. Members of the TNF superfamily are key regulators of intestinal inflammation. In particular, TNF-like weak inducer of apoptosis (TWEAK) and its receptor, Fn14, are involved in normal and pathologic intestinal tissue remodeling. In this study, we show that the TWEAK/Fn14 signaling complex plays a protective role during the acute stage of intestinal inflammation and contributes to the prevention of colitis-associated cancer during chronic inflammation through its proapoptotic effects. Colitis was induced in Fn14-/- and Fn14+/+ wild-type littermates by administering 3% dextran sodium sulfate (DSS) for 7 days followed by 2-week recovery; azoxymethane (AOM) administration followed by two cycles of DSS/recovery was used to induce tumors. Reciprocal bone marrow chimeric mice were generated to compare hematopoietic and nonhematopoietic-specific effector tissues. Fn14-/- mice had enhanced susceptibility to colitis compared with Fn14+/+ controls as assessed by endoscopic and histologic inflammatory scores, daily weight loss, and mortality rates during recovery after DSS administration. Bone marrow transfer experiments showed that both hematopoietic and nonhematopoietic components are involved in protection against colitis. Tumor lesions were found in the colons of most Fn14-/- mice, but not Fn14+/+ controls. AOM/DSS administration enhanced susceptibility to tumorigenesis in Fn14-/- mice. Overall, these findings show that Fn14 plays a protective role during the acute stages of intestinal inflammation, and its absence promotes the development of colitis-associated cancer. Cancer Res; 76(22); 6533-42. ©2016 AACR.

DNA Damage and Oxidative DNA Damage in Inflammatory Bowel Disease

BACKGROUND AND AIMS

Inflammation has long been regarded as a major contributor to cellular oxidative damage and to be involved in the promotion of carcinogenesis.

METHODS

We aimed to investigate the oxidative damage in inflammatory bowel disease [IBD] patients through a case-control and prospective study involving 344 IBD patients and 294 healthy controls. DNA damage and oxidative DNA damage were measured by comet assay techniques, and oxidative stress by plasmatic lipid peroxidation, protein carbonyls, and total antioxidant capacity.

RESULTS

Higher DNA damage [p < 0.001] was found both in Crohn's disease [CD] (9.7 arbitrary units [AU]; interquartile range [IQR]: 6.2-14.0) and ulcerative colitis [UC] [7.1 AU; IQR: 4.4-11.7], when compared with controls [5.4 AU; IQR: 3.8-6.8], and this was also the case with oxidative DNA damage [p < 0.001] [CD: 3.6 AU; IQR: 1.8-6.8; UC: 4.6 AU; IQR: 2.4-8.1], when compared with controls: 2.3 AU; IQR: 1.2-4.2]. Stratifying patients into groups according to therapy (5-aminosalicylic acid [5-ASA], azathioprine, anti-TNF, and combined therapy [azathioprine and anti-TNF]) revealed significant between-group differences in the level of DNA damage, both in CD and UC, with the combined therapy exhibiting the highest DNA damage levels [11.6 AU; IQR: 9.5-14.3, and 12.4 AU; IQR: 10.6-15.0, respectively]. Among CD patients, disease behaviour [B1 and B2], and age at diagnosis over 40 years [A3] stand as risk factors for DNA damage. For UC patients, the risk factors found for DNA damage were disease activity, treatment, age at diagnosis under 40 years [A1 + A2] and disease locations [E2 and E3].

CONCLUSIONS

In IBD there is an increase in DNA damage, and treatment, age at diagnosis and inflammatory burden seem to be risk factors.

Total and cancer mortality in a cohort of ulcerative colitis and Crohn's disease patients: The Florence inflammatory bowel disease study, 1978-2010

BACKGROUND

There is no consensus on the leading causes of death among inflammatory bowel diseases (IBD) patients.

AIM

We present the results of an extended follow-up of the population-based Florence IBD cohort, including 689 ulcerative colitis and 231 Crohn's disease patients.

METHODS

The causes of death of cohort members were determined through linkage with the local mortality registry. We calculated standardized mortality ratios (SMR) and 95% confidence intervals (95%CI) by applying gender-, age- and calendar time-death rates to person-years at risk.

RESULTS

Ulcerative colitis patients had overall mortality comparable to the general population (SMR 0.99, 95%CI 0.85-1.14), though being at increased risk of dying from Hodgkin's disease (SMR 11.74, 95%CI 2.94-46.94), rectal cancer (SMR 3.69, 95%CI 1.66-8.22) and Alzheimer's disease (2.40, 95%CI 1.00-5.76). Crohn's disease patients had an increased overall mortality (SMR 1.79, 95%CI 1.39-2.27) and were at higher risk of dying from cancer (SMR 2.57, 95%CI 1.28-5.13) and non-cancer diseases of the respiratory system (SMR 2.51, 95%CI 1.05-6.04), brain cancer (SMR 6.26, 95%CI 1.57-25.02) and non-cancer diseases of the genitourinary system (SMR 4.38, 95%CI 1.10-17.52).

CONCLUSIONS

IBD patients should be offered counselling on risk reduction strategies, as much of their mortality excess is potentially avoidable.

Colorectal Cancer and Dysplasia in Inflammatory Bowel Disease: A Review of Disease Epidemiology, Pathophysiology, and Management

Crohn disease and ulcerative colitis are chronic inflammatory bowel diseases (IBD) characterized by recurrent episodes of mucosal inflammation. This chronic mucosal inflammation has several potential consequences, one of which is the occurrence of colitis-associated colorectal cancer. Over the past decade, our understanding of the epidemiology, pathophysiology, and overall approach to diagnosing and managing colitis-associated colorectal cancer has grown considerably. In the current review article, we outline these advancements and highlight areas in need of further research. Cancer Prev Res; 9(12); 887-94. ©2016 AACR.

Chemotherapy Tolerance and Oncologic Outcomes in Patients With Colorectal Cancer With and Without Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD), comprising Crohn disease and ulcerative colitis, is a risk factor for colorectal cancer (CRC). Chemotherapy toxicity may exacerbate IBD symptoms and vice versa, but data are limited. We evaluated chemotherapy tolerance and oncologic outcomes in patients with CRC with and without IBD.

PATIENTS AND METHODS

Medical records of patients with CRC with and without IBD treated between 2008 and 2013 were reviewed. Where possible, patients were matched by age, sex, stage, and diagnosis year. Chemotherapy tolerance and survival outcomes were compared between patients with IBD and without IBD.

RESULTS

A total of 158 subjects with CRC were included: 80 patients had IBD and 78 matched control patients did not have IBD. Between cases and controls, there were no significant differences in demographic data, stage of CRC, and cancer treatments, with equivalent numbers of patients receiving surgery, radiation, and chemotherapy. Patients with IBD experienced more CRC treatment alterations than those without IBD (74% vs. 44%, P = .03), largely due to a higher frequency of treatment delays among patients with IBD. Differences in stage-specific 5-year overall survival (OS) and recurrence-free survival (RFS) in patients with and without IBD were not significant, except for stage IV patients with IBD who had significantly shorter OS than those without IBD. Patients with histologically active IBD did not require more chemotherapy alterations than patients with inactive IBD.

CONCLUSION

In this series, patients with CRC with IBD experienced more treatment alterations (mostly delays) than those without IBD. Patients with stage IV CRC with IBD had shorter survival than patients without IBD.

Health Care Maintenance for the Pediatric Patient With Inflammatory Bowel Disease

Nearly one-quarter of patients with inflammatory bowel disease (IBD) are younger than 20 years of age at diagnosis. Furthermore, the incidence of IBD in children continues to increase. Nevertheless, variation in management exists within the care of patients with IBD with regards to disease screening and preventive care. A multidisciplinary approach that involves the general practitioner and pediatric gastroenterologist is needed to routinely monitor growth, bone health, vitamin and mineral deficiencies, vaccination status, and endoscopic surveillance. It is also important to monitor for extraintestinal manifestations of IBD that may affect the liver, joints, skin, and eyes. The purpose of this article is to provide an updated overview of comprehensive care for pediatric patients with IBD.

Higher Risk for Hematological Malignancies in Inflammatory Bowel Disease: A Nationwide Population-based Study in Taiwan

OBJECTIVES

The relationship between inflammatory bowel disease (IBD) and cancer remains unclear especially in Asian populations. Therefore, we conducted a nationwide population-based study in Taiwan to reveal the cancer risk in patients with IBD.

METHODS

Using the national health database of Taiwan, we identified 3,348 IBD patients without previous cancer, including 685 with Crohn's disease (CD) and 2,663 with ulcerative colitis (UC), as a cohort from 1998 to 2012 and followed them up until 2013. Standardized incidence ratios (SIRs) of overall and site-specific cancers in CD and UC patients in comparison with the general population were analyzed.

RESULTS

Regarding overall cancer risk analysis, both CD (SIR 1.4, 95% confidence interval (CI) 0.9-2.1) and UC (SIR 0.93, 95% CI 0.7-1.1) patients did not have a higher risk. In site-specific cancer risk analysis, CD (SIR 14.08, P<0.01) and UC (SIR 2.51, P=0.02) patients had a higher risk of hematological malignancies. The risk of colorectal cancer (CRC) did not increase significantly in either CD (SIR 0.96, P=0.7) or UC (SIR 1.39, P=0.22) patients.

CONCLUSIONS

This first nationwide population-based study in Asia reveals a significantly higher risk for hematological malignancies in IBD patients. This finding may highlight the importance of screening for hematological malignancies in patients with IBD in the future.

Inflammatory Bowel Disease Phenotype as Risk Factor for Cancer in a Prospective Multicentre Nested Case-Control IG-IBD Study

BACKGROUND AND AIMS

Cancer risk in inflammatory bowel disease [IBD] is still debated. In a prospective, multicentre, nested case-control study, we aimed to characterise incident cases of cancer in IBD. The role of immunomodulators vs clinical characteristics of IBD as risk factors for cancer was also investigated.

MATERIALS AND METHODS

From January 2012 to December 2014, each IBD patient with incident cancer was matched with two IBD patients without cancer for: IBD type, gender, and age. Risk factors were assessed by multivariate regression analysis.

RESULTS

IBD patients considered numbered 44619: 21953 Crohn's disease [CD], 22666 ulcerative colitis [UC]. Cancer occurred in 174 patients: 99 CD [CD-K], 75 UC [UC-K]. Controls included 198 CD [CD-C], 150 UC [UC-C]. Cancer incidence in IBD was 3.9/1000, higher in CD (4.5/1000 [99/21,953]) than in UC (3.3/1000 [75/22,666]; p = 0.042). Cancers involved: digestive system [36.8%], skin [13.2%], urinary tract [12.1%], lung [8.6%], breast [8%], genital tract [6.9%], thyroid [4.6%], lymphoma [3.5%], others [6.3%]. In CD, penetrating behaviour and combined thiopurines and tumour necrosis factor alpha [TNFα] antagonists were risk factors for cancer overall: odds ratio [OR] (95% confidence interval [CI] 2.33 [1.01-5.47]); 1.97 [1.1-3.5]; and for extracolonic cancers 3.9 [1.56-10.1]; 2.15 [1.17-4.1], respectively. In UC, risk factors were pancolitis and disease-related surgery for cancer overall (OR: 2.52 [1.26-5.1]; 5.09 [1.73-17.1]); disease-related surgery for colorectal cancer [CRC] (OR 3.6 [1.0-12]); and extensive and left-sided vs distal UC for extracolonic cancers (OR: 2.55 [1.15-5.9]; 2.6 [1.04-6.6]), respectively.

CONCLUSIONS

In a multicentre study, penetrating CD and extensive UC were risk factors for cancer overall. Cancer incidence was higher in CD than in UC.

Genomic Alterations Observed in Colitis-Associated Cancers Are Distinct From Those Found in Sporadic Colorectal Cancers and Vary by Type of Inflammatory Bowel Disease

BACKGROUND & AIMS

Patients with inflammatory bowel diseases, such as Crohn's disease (CD) and ulcerative colitis (UC), are at increased risk for small bowel or colorectal cancers (colitis-associated cancers [CACs]). We compared the spectrum of genomic alterations in CACs with those of sporadic colorectal cancers (CRCs) and investigated differences between CACs from patients with CD vs UC.

METHODS

We studied tumor tissues from patients with CACs treated at Memorial Sloan Kettering Cancer Center or Weill Cornell Medical College from 2003 through 2015. We performed hybrid capture-based next-generation sequencing analysis of >300 cancer-related genes to comprehensively characterize genomic alterations.

RESULTS

We performed genomic analyses of 47 CACs (from 29 patients with UC and 18 with CD; 43 primary tumors and 4 metastases). Primary tumors developed in the ileum (n = 2), right colon (n = 18), left colon (n = 6), and rectosigmoid or rectum (n = 21). We found genomic alterations in TP53, IDH1, and MYC to be significantly more frequent, and mutations in APC to be significantly less frequent, than those reported in sporadic CRCs by The Cancer Genome Atlas or Foundation Medicine. We identified genomic alterations that might be targeted by a therapeutic agent in 17 of 47 (36%) CACs. These included the mutation encoding IDH1 R132; amplification of FGFR1, FGFR2, and ERBB2; and mutations encoding BRAF V600E and an EML4-ALK fusion protein. Alterations in IDH1 and APC were significantly more common in CACs from patients with CD than UC.

CONCLUSIONS

In an analysis of CACs from 47 patients, we found significant differences in the spectrum of genomic alterations in CACs compared with sporadic CRCs. We observed a high frequency of IDH1 R132 mutations in patients with CD but not UC, as well as a high frequency of MYC amplification in CACs. Many genetic alterations observed in CACs could serve as therapeutic targets.

Chronic immunosuppression does not potentiate the malignant progression of mucinous pancreatic cystic lesions

BACKGROUND

Premalignant mucinous pancreatic cystic lesions (mPCLs) are increasingly identified.

AIMS

In this study, we aim to assess the effect of selected immunosuppressive therapies on the progression of mPCLs, including side-branch intraductal papillary mucinous neoplasms and mucinous cystic neoplasms.

METHODS

We performed a retrospective cohort study of patients with mPCLs diagnosed over a 24-year period who received chronic immunosuppression. Controls were matched on age at cyst diagnosis (±11 yrs) and cyst size (±8 mm). Measured outcomes included increase in cyst size, development of "worrisome features" as defined by consensus guidelines, progression to malignancy, and rate of surgical resection.

RESULTS

39 patients (mean age 60 yrs) with mPCLs were on immunosuppression. Leading indications for immunosuppression were solid organ transplant (n = 14), inflammatory bowel disease (n = 6), and rheumatoid arthritis (n = 5). 33% were on biologics, 77% on antimetabolites and 79% on multiple medications. Mean cyst size increased from 12.6 mm to 17.8 mm over a median of 16.5 months. 6 patients elected for surgical resection, and none ultimately developed malignancy. 26 cases with follow-up were matched to control subjects, with no significant differences among cases and controls in initial cyst size (12.8 mm vs 11.9 mm, P = 0.69), mean size increase (6.9 mm vs 5 mm, P = 0.47), follow-up interval (24.3 months vs 21.5 months, P = 0.44). No significant differences in the rate of worrisome features, malignancy, or surgical resection.

CONCLUSIONS

Patients with mPCLs exposed to immunosuppressive medications did not have higher rates of malignancy or development worrisome features in the short term. This suggests that patients with mPCLs can be initiated or maintained on these agents without changes to surveillance practices.

Risk of cancer in inflammatory bowel disease: going up, going down, or still the same?

PURPOSE OF REVIEW

There has been increasing use of immunosuppressive medications as well as better surveillance techniques in inflammatory bowel disease (IBD), which is associated with an increased risk of intestinal and extraintestinal malignancies. We assessed the temporal trends of cancer incidence in IBD patients by reviewing the biomedical literature, performing meta-regression of existing studies, and examining trends in hospitalizations for cancer in IBD patients using a national hospitalization database.

RECENT FINDINGS

The overall risk of colorectal cancer in ulcerative colitis has decreased in the last 3 decades. The risk of small bowel cancer is significantly elevated among Crohn's disease patients, but there has been no change in incidence rates. The overall risk of non-Hodgkin lymphoma has increased over the last 16 years, and IBD patients on thiopurines and antitumor necrosis factor agents are at increased risk of non-Hodgkin lymphoma. The risk of melanoma in IBD patients is increased, with no significant change over time. The risk of nonmelanoma skin cancer is higher in patients using thiopurines compared with the non-IBD background population, with no significant change over time.

SUMMARY

This study points toward a decrease in the incidence of colorectal cancer in ulcerative colitis patients, but an increase in the incidence of lymphoproliferative disorders and nonmelanoma skin cancers with the use of immunosuppressive medications in IBD.

Stem cell-based therapies in inflammatory bowel disease: promises and pitfalls

Inflammatory bowel disease (IBD) is a chronic, often relapsing, condition that deeply impacts the quality of life for many patients. Although there have been significant advances in medical treatments, a large proportion of patients become refractory to available therapeutic options. Stem-cell therapy through hematopoietic stem cells (HSCs) or mesenchymal stem (stromal) cells (MSCs) is a promising therapeutic option for severe refractory cases especially when surgery is not feasible. In HSC transplantation, the objective is to destroy the 'autoreactive' immune cells responsible for disease chronicity, and to re-establish gut tolerance to gut microbes. In perianal Crohn's disease (CD), the objective is to deposit MSCs locally in fistulizing tracts to down-regulate the local immune response and induce wound healing. Results from upcoming and ongoing clinical trials will set the path of these novel therapeutic options that have the capability to successfully treat severe refractory Crohn's patients.

Diffusion-weighted MRI in Crohn's disease: Current status and recommendations

Over the past years, technological improvements and refinements in magnetic resonance imaging (MRI) hardware have made high-quality diffusion-weighted imaging (DWI) routinely possible for the bowel. DWI is promising for the detection and characterization of lesions in Crohn's disease (CD) and has been advocated as an alternative to intravenous gadolinium-based contrast agents. Furthermore, quantification using the apparent diffusion coefficient may have value as a biomarker of CD activity and has shown promise. In this article we critically review the literature pertaining to the value of DWI in CD for detection, characterization, and quantification of disease activity and complications. Although the body of supportive evidence is growing, it is clear that well-designed, multicenter studies are required before the role of DWI in clinical practice can be fully established. J. Magn. Reson. Imaging 2016;44:1381-1396.

Controversies in Pouch Surveillance for Patients with Inflammatory Bowel Disease

CASE 1

Following 2 years of rectal blood loss, a 31-year-old male was diagnosed with ulcerative pancolitis in 1978. Initial treatment consisted of both topical and systemic 5-aminosalicylic acids [5-ASAs], and remission was achieved. In both 1984 and 1986 he was hospitalised due to exacerbations necessitating treatment with intravenous corticosteroids. The following years went well, without disease activity, under treatment with 5-ASA. In 1997, at the age of 50 years, a surveillance colonoscopy showed a stenotic process with a macroscopic irregularity in the sigmoid region. Histology revealed at least high-grade dysplasia [HGD] and signs of an invasive growth pattern which could indicate colorectal cancer [CRC]. The patient underwent restorative proctocolectomy with ileal pouch-anal anastomosis [IPAA]. Histology of the resection specimen confirmed active inflammation in the colon and rectum and a carcinoma in situ was identified in the sigmoid colon without invasive growth. This patient did not have significant comorbidities-for example primary sclerosing cholangitis [PSC]-and the CRC family history was negative. What pouch surveillance strategy should be recommended?

CASE 2

A 34-year-old man presented at our inflammatory bowel disease [IBD] centre with ulcerative proctitis. Ten years later, after an initially mild disease course, his disease progressed to a pancolitis. An 11-year period with multiple exacerbations [on average every 2 year, including hospitalisation] followed and treatment consisted of topical and systemic 5-ASAs with intermittent corticosteroids. In 1998, at the age of 65 years, a two-stage restorative proctocolectomy with IPAA was performed due to disease activity refractory to systemic corticosteroids. The colectomy specimen confirmed the diagnosis of ulcerative pancolitis without evidence for colorectal dysplasia or carcinoma. Other than steroid-induced diabetes mellitus, this patient had no comorbidities. His father died from CRC at unknown age. What pouch surveillance strategy should be recommended?

Inflammatory bowel disease and cancer: The role of inflammation, immunosuppression, and cancer treatment

In patients with inflammatory bowel disease (IBD), chronic inflammation is a major risk factor for the development of gastrointestinal malignancies. The pathogenesis of colitis-associated cancer is distinct from sporadic colorectal carcinoma and the critical molecular mechanisms underlying this process have yet to be elucidated. Patients with IBD have also been shown to be at increased risk of developing extra-intestinal malignancies. Medical therapies that diminish the mucosal inflammatory response represent the foundation of treatment in IBD, and recent evidence supports their introduction earlier in the disease course. However, therapies that alter the immune system, often used for long durations, may also promote carcinogenesis. As the population of patients with IBD grows older, with longer duration of chronic inflammation and longer exposure to immunosuppression, there is an increasing risk of cancer development. Many of these patients will require cancer treatment, including chemotherapy, radiation, hormonal therapy, and surgery. Many patients will require further treatment for their IBD. This review seeks to explore the characteristics and risks of cancer in patients with IBD, and to evaluate the limited data on patients with IBD and cancer, including management of IBD after a diagnosis of cancer, the effects of cancer treatment on IBD, and the effect of IBD and medications for IBD on cancer outcomes.

Growth hormone is permissive for neoplastic colon growth

Growth hormone (GH) excess in acromegaly is associated with increased precancerous colon polyps and soft tissue adenomas, whereas short-stature humans harboring an inactivating GH receptor mutation do not develop cancer. We show that locally expressed colon GH is abundant in conditions predisposing to colon cancer and in colon adenocarcinoma-associated stromal fibroblasts. Administration of a GH receptor (GHR) blocker in acromegaly patients induced colon p53 and adenomatous polyposis coli (APC), reversing progrowth GH signals. p53 was also induced in skin fibroblasts derived from short-statured humans with mutant GHR. GH-deficient prophet of pituitary-specific positive transcription factor 1 (Prop1)(-/-) mice exhibited induced colon p53 levels, and cross-breeding them with Apc(min+/-) mice that normally develop intestinal and colon tumors resulted in GH-deficient double mutants with markedly decreased tumor number and size. We also demonstrate that GH suppresses p53 and reduces apoptosis in human colon cell lines as well as in induced human pluripotent stem cell-derived intestinal organoids, and confirm in vivo that GH suppresses colon mucosal p53/p21. GH excess leads to decreased colon cell phosphatase and tensin homolog deleted on chromosome 10 (PTEN), increased cell survival with down-regulated APC, nuclear β-catenin accumulation, and increased epithelial-mesenchymal transition factors and colon cell motility. We propose that GH is a molecular component of the "field change" milieu permissive for neoplastic colon growth.

Oral health and risk of colorectal cancer: results from three cohort studies and a meta-analysis

BACKGROUND

While studies have shown that poor oral health status may increase the risk of cancer, evidence of a specific association with the risk of colorectal cancer (CRC) is inconclusive. We evaluated the association between oral health and CRC risk using data from three large cohorts: the Shanghai Men's Health Study (SMHS), the Shanghai Women's Health Study (SWHS), and the Southern Community Cohort Study (SCCS), and carried out a meta-analysis of results from other relevant published studies.

PATIENTS AND METHODS

This study applied a nested case-control study design and included 825 cases/3298 controls from the SMHS/SWHS and 238 cases/2258 controls from the SCCS. The association between oral health status (i.e. tooth loss/tooth decay) and CRC risk was assessed using conditional logistic regression models. A meta-analysis was carried out based on results from the present study and three published studies.

RESULTS

We found that tooth loss was not associated with increased risk of CRC. ORs and respective 95% CIs associated with loss of 1-5, 6-10, and >10 teeth compared with those with full teeth are 0.87 (0.69-1.10), 0.93 (0.70-1.24), and 0.85 (0.66-1.11) among SMHS/SWHS participants; and 1.13 (0.72-1.79), 0.87 (0.52-1.43), and 1.00 (0.63-1.58) for those with loss of 1-4, 5-10, and >10 teeth among SCCS participants. Data regarding tooth decay were available in the SCCS, but were not associated with CRC risk. Meta-analysis confirmed the null association between tooth loss/periodontal disease and CRC risk (OR 1.05, 95% CI 0.86-1.29).

CONCLUSION

In this analysis of three cohorts and a meta-analysis, we found no evidence supporting an association between oral health and CRC risk.

How to Optimize Colon Cancer Surveillance in Inflammatory Bowel Disease Patients

Colitis-associated colorectal neoplasia (CRN) is a well-known complication of chronic inflammation of the colon either with ulcerative colitis (UC) or colonic Crohn's disease (CD). Studies have shown that inflammatory bowel disease (IBD) patients have an overall higher risk for colorectal dysplasia and cancer compared to the general population and this risk is further increased by certain associated factors, including extent of disease, duration of disease, and age at onset. In addition, other risk factors not related to IBD can also further increase the risk for CRN, such as a family history of sporadic colon cancer and a concomitant diagnosis of primary sclerosing cholangitis. The society guidelines mostly agree on the appropriate time to begin CRN surveillance but vary somewhat on the appropriate intervals between surveillance colonoscopies. In addition, there is not yet a consensus on the appropriate method for surveillance. In this review, we discuss the risk for CRN in colonic IBD, the associated factors that further increase the risk for CRN, the current surveillance guidelines and the current methods available for CRN surveillance.