Ulcerative colitis neoplasia is not associated with common inflammatory bowel disease single-nucleotide polymorphisms

Association of inflammatory bowel disease in first-degree relatives with risk of colorectal cancer: A nationwide case-control study in Sweden

This study aims to assess the association between inflammatory bowel disease (IBD) history in first-degree relatives (FDRs) and colorectal cancer (CRC) risk. We conducted a nationwide case-control study in Sweden among 69 659 CRC cases and 343 032 non-CRC controls matched on age, sex, birth year and residence county. Through linkage of multi-generation register and the nationwide ESPRESSO (Epidemiology Strengthened by histoPathology Reports in Sweden) cohort, we ascertained IBD diagnoses among parents, full siblings and offspring of the index individuals. Odds ratios (ORs) of CRC associated with IBD family history were calculated using conditional logistic regression. 2.2% of both CRC cases (1566/69659) and controls (7676/343027) had ≥1 FDR with IBD history. After adjusting for family history of CRC, we observed no increased risk of CRC in FDRs of IBD patients (OR, 0.96; 95%CI, 0.91-1.02). The null association was consistent according to IBD subtype (Crohn's disease or ulcerative colitis), number of FDRs with IBD (1 or ≥ 2), age at first IBD diagnosis in FDRs (<18, 18-39, 40-59 or ≥60 years), maximum location/extent of IBD or FDR relation (parent, sibling or offspring). The null association remained for early-onset CRC (diagnosed at age <50 years). In conclusion, IBD history in FDRs was not associated with an increased risk of CRC. Our findings suggest that extra screening for CRC may not be needed in the offspring, siblings or parents of IBD patients, and strengthen the theory that it is the actual inflammation or atypia of the colon in IBD patients that confers the increased CRC risk.

Association between Taxonomic Composition of Gut Microbiota and Host Single Nucleotide Polymorphisms in Crohn's Disease Patients from Russia

Crohn's disease (CD) is a chronic relapsing inflammatory bowel disease of unknown etiology. Genetic predisposition and dysbiotic gut microbiota are important factors in the pathogenesis of CD. In this study, we analyzed the taxonomic composition of the gut microbiota and genotypes of 24 single nucleotide polymorphisms (SNP) associated with the risk of CD. The studied cohorts included 96 CD patients and 24 healthy volunteers from Russia. Statistically significant differences were found in the allele frequencies for 8 SNPs and taxonomic composition of the gut microbiota in CD patients compared with controls. In addition, two types of gut microbiota communities were identified in CD patients. The main distinguishing driver of bacterial families for the first community type are Bacteroidaceae and unclassified members of the Clostridiales order, and the second type is characterized by increased abundance of Streptococcaceae and Enterobacteriaceae. Differences in the allele frequencies of the rs9858542 (BSN), rs3816769 (STAT3), and rs1793004 (NELL1) were also found between groups of CD patients with different types of microbiota communities. These findings confirm the complex multifactorial nature of CD.

A Systematic Review and Meta-Analysis on the Association between Inflammatory Bowel Disease Family History and Colorectal Cancer

BACKGROUND

Colorectal cancer (CRC) and inflammatory bowel disease (IBD) are closely interrelated. However, the effect of having a family history of one disease on the risk of another remains undetermined.

AIM

The purpose of this meta-analysis was to estimate the prevalence of a family history of CRC among patients with IBD, as well as the prevalence of a family history of IBD among patients with CRC.

METHODS

PubMed, Scopus, Embase, Web of Science, and Google Scholar were searched to identify studies reporting the prevalence of family history of IBD among patients with CRC, in addition to the prevalence of family history of CRC among IBD patients. Criteria for study inclusion consisted of the following: (1) studies that evaluated either IBD or CRC and dysplasia, (2) included all age groups, and (3) evaluated the family history effects for IBD or CRC. The total number of IBD patients and IBD patients with a family history of CRC and the total number of CRC patients and CRC patients with a family history of IBD were reviewed. The pooled prevalence of diseases was also estimated according to degree of relatives and geographical area. Random-effects models were used for estimating pooled prevalence.

RESULTS

A total of 27 studies were included with 26,576 IBD and 9,181 CRC or dysplasia patients. Eligible studies included 13 case-control, 10 cohort, and 4 cross-sectional types. The pooled prevalence of a family history of CRC among patients with IBD was 6% (95% CI: 4-9%). The pooled prevalence for first- and second-degree relatives (11%, 95% CI: 0-37%) was more than that for the other relative subgroups of relatedness degree. The prevalence in the American regions (8% (95% CI: 5-13%)) was higher than that in the others. The pooled prevalence for a family history of IBD among CRC or dysplasia patients was 11% (95% CI: 6-16%). The pooled prevalence for first-degree relatives (13% (95% CI: 3-28%) was higher than that for the other relative subgroups of relatedness degree; it was also greater in American countries (15%, 95% CI: 8-23%).

CONCLUSION

This study emphasizes the relationship between a family history of IBD and CRC development. Additionally, there was notable prevalence for a family history of CRC among IBD patients. American countries and first-degree relatives were identified to have a higher prevalence for both disease processes.

A case-control study examining the association of smad7 and TLR single nucleotide polymorphisms on the risk of colorectal cancer in ulcerative colitis

AIM

Ulcerative colitis (UC) is characterized by chronic mucosal inflammation and an increased risk of colorectal cancer. smad7, TLR2 and TLR4 modulate intestinal inflammation and their polymorphisms affect the risk of development of sporadic colorectal cancer. The aim of the current study was to examine the association between single nucleotide polymorphisms (SNPs) in smad7, TLR2 and TLR4 and the development of colorectal cancer in patients with UC.

METHOD

DNA was extracted from formalin-fixed, paraffin-embedded tissue from 90 patients with UC who had undergone panproctocolectomy between 1985 and 2013 (30 with UC-associated colorectal cancer and 60 control UC patients). Control cases were matched 2:1 for age at diagnosis of colitis, duration of disease and gender. Genotyping was performed for the smad7 rs4464148, rs11874392, rs12953717 and rs4939827 SNPs, the TLR2 rs5743704 and rs5743708 SNPs and the TLR4 rs4986790 and rs4986791 SNPs.

RESULTS

Sixty three of the 90 patients (70%) were men and the mean age at diagnosis of UC was 38.6 ± 1.6 years. The mean time to the diagnosis of UC-associated colorectal cancer was 13.5 ± 1.9 years. The 5-year recurrence-free and cancer-specific survival rates were 76% and 88%, respectively. All eight SNPs were in Hardy-Weinberg equilibrium. None of the eight SNPs assessed in smad7, TLR2 or TLR4 were associated with the development of UC-associated colorectal cancer at an allelic or genotypic level.

CONCLUSIONS

These data do not support an association between polymorphisms in smad7, TLR2 or TLR4 and the development of UC-associated colorectal cancer.

Single Nucleotide Polymorphisms in Colitis-Associated Colorectal Cancer: A Current Overview with Emphasis on the Role of the Associated Genes Products

Colitis-Associated Colorectal Cancer (CA-CRC) is one of the most severe complications of Inflammatory Bowel Disease (IBD) and constitutes the cause of death in 10-15% of patients. The risk ratio for carcinogenesis depends on numerous factors, such as the extent of intestinal inflammatory lesions and the duration of the disease. CA-CRC is a major problem of today's gastroenterology and colorectal surgery due to the fact that the incidence and prevalence of IBD are increasing. In this review, we discussed the current state of knowledge regarding genetic differences between sporadic CRC and CA-CRC, especially pertaining to the chromosomal instability mechanism (CIN). In order to explain CA-CRC molecular basis, we have analyzed the data from studies regarding the correlations between CA-CRC and the presence of Single Nucleotide Polymorphisms (SNPs). Further focus on the role of associated proteins has emphasized the role of NF-κB signaling as the main link between inflammation and carcinogenesis during the course of IBD.

Colonic microbiota is associated with inflammation and host epigenomic alterations in inflammatory bowel disease

Studies of inflammatory bowel disease (IBD) have been inconclusive in relating microbiota with distribution of inflammation. We report microbiota, host transcriptomics, epigenomics and genetics from matched inflamed and non-inflamed colonic mucosa [50 Crohn's disease (CD); 80 ulcerative colitis (UC); 31 controls]. Changes in community-wide and within-patient microbiota are linked with inflammation, but we find no evidence for a distinct microbial diagnostic signature, probably due to heterogeneous host-microbe interactions, and show only marginal microbiota associations with habitual diet. Epithelial DNA methylation improves disease classification and is associated with both inflammation and microbiota composition. Microbiota sub-groups are driven by dominant Enterbacteriaceae and Bacteroides species, representative strains of which are pro-inflammatory in vitro, are also associated with immune-related epigenetic markers. In conclusion, inflamed and non-inflamed colonic segments in both CD and UC differ in microbiota composition and epigenetic profiles.

Weak Cytotoxic T Cells Activation Predicts Low-Grade Dysplasia Persistence in Ulcerative Colitis

In patients with ulcerative colitis (UC), dysplasia develops in 10%–20% of cases. The persistence of low-grade dysplasia (LGD) in UC in 2 consecutive observations is still an indication for restorative proctocolectomy. Our hypothesis is that in the case of weak cytotoxic activation, dysplasia persists. We aimed to identify possible immunological markers of LGD presence and persistence.

Fascin protein stabilization by miR-146a implicated in the process of a chronic inflammation-related colon carcinogenesis model

OBJECTIVE

In sporadic colon tumors, multistep process of well-known genetic alterations accelerates carcinogenesis; however, this does not appear to be the case in inflammation-related ones. We previously established a model of inflammation-related colon carcinogenesis using human colonic adenoma cells, and identified fascin as a driver gene of this process. We analyzed the microRNAs involved in the stable fascin expression in colon adenocarcinoma cells.

MATERIALS AND METHODS

miRNA microarray analysis was performed using FPCK-1-1 adenoma cells and its-derived FPCKpP₁-4 adenocarcinoma cells through chronic inflammation. To assess the involvement of miRNA in the inflammation-related carcinogenesis, sphere-forming ability, expression of colon cancer stemness markers, and stability of fascin protein via the proteasome using tough decoy RNA technique.

RESULTS

We found that 17 miRNAs including miR-146a were upregulated and 16 miRNAs were downregulated in FPCKpP₁-4 adenocarcinoma cells. We revealed that miR-146a in the adenocarcinoma cells brought about acquisition of sphere formation, cancer stemness, and inhibition of proteasomal degradation of the fascin protein.

CONCLUSIONS

We found that stable fascin expression is brought about via the inhibition of proteasome degradation by miR-146a in the process of a chronic inflammation-related colon carcinogenesis.

Early detection of ulcerative colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CACC) is one of the most serious complications of inflammatory bowel disease (IBD), particularly in ulcerative colitis (UC); it accounts for approximately 15% of all-causes mortality among IBD patients. Because CACC shows a worse prognosis and higher mortality than sporadic colorectal cancer, early detection is critical. Colonoscopy is primarily recommended for surveillance and several advanced endoscopic imaging techniques are emerging. In addition, recent studies have reported on attempts to develop clinically relevant biomarkers for surveillance using various biosamples, which may become high-performance screening tools in the future, so the best approach and technique for cancer surveillance in long-standing UC patients remain under debate. This review gives a comprehensive description and summary about what progress has been made in terms of early CACC detection.

Impact of mucosal inflammation on risk of colorectal neoplasia in patients with ulcerative colitis: a systematic review and meta-analysis

BACKGROUND AND AIMS

Long-standing ulcerative colitis is an established risk factor for colorectal neoplasia. A number of observational studies have suggested that evidence of mucosal inflammation (endoscopic or histologic) is associated with a greater risk for colorectal neoplasia than is mucosal healing. Our goal was to systematically analyze the risk of colorectal neoplasia in patients with ulcerative colitis who have ongoing mucosal inflammation to better inform surveillance strategies.

METHODS

We performed a systematic review and meta-analysis of the effect of endoscopic and/or histologic inflammation on the risk of colorectal neoplasia in cohort and case-control studies. Sensitivity analyses for study setting and case definition were performed.

RESULTS

Six studies met the inclusion criteria, incorporating outcomes in 1443 patients. No study used a single validated measure for mucosal inflammation. The pooled odds ratio for colorectal neoplasia was 3.5 (95% confidence interval [CI], 2.6-4.8; P < .001) in those with any mucosal inflammation and 2.6 (95% CI, 1.5-4.5; P = .01) in those with histologic inflammation, when compared with those with mucosal healing. The overall quality of the studies was good.

CONCLUSION

The presence of objective evidence of mucosal inflammation during follow-up in patients with ulcerative colitis is associated with a greater risk of subsequent colorectal neoplasia than in those with mucosal healing. This risk factor should be considered in guidelines on surveillance intervals for these patients.

Associations between single-nucleotide polymorphisms and inflammatory bowel disease-associated colorectal cancers in inflammatory bowel disease patients: a meta-analysis

PURPOSE

To assess the correlation between single-nucleotide polymorphisms (SNPs) and inflammatory bowel disease (IBD)-associated colorectal cancer (CRC) in IBD patients.

METHODS

A systematic search of PubMed, EmBase, and Cochrane databases was performed. Five genetic models (allelic, dominant, recessive, heterozygous and homozygous models) were used to analyze the associations, and trial sequential analysis was used to analyze the robustness of the results.

RESULTS

We collected and analyzed the results of seven trials including a total of 2287 patients in our meta-analysis. A total of 8 SNPs were tested in IBD patients. For rs1800629 of TNF-α, the allelic model showed that polymorphism at this locus significantly increased the risk of IBD-associated CRC in IBD patients (OR 4.45, 95% CI 3.18-6.21, P < 0.001). The results also showed a significant association between rs1800629 and an IBD-associated CRC population (heterozygous model: OR 4.335, 95% CI 2.329-8.069, P < 0.001; homozygous model: OR 11.5, 95% CI 2.498-52.592, P = 0.002; dominant model: OR 4.986, 95% CI 2.754-9.026, P < 0.001; recessive model: OR 7.208, 95% CI 1.588-32.72, P = 0.01). Other studies have found that mutation of rs1143627 of IL1B (allelic model: OR 2.97; 95% CI 1.74-5.05, P < 0.001) and rs1050152 of OCTN1 (allelic model: OR 1.637, 95% CI 1.078-2.485, P = 0.021) increased the proportion of IBD-associated CRC in the population. Moreover, there were significant associations between IBD-associated CRC and ITLN rs2274910, gene desert rs1551398 and rs4871611, FCGR2A rs1801274, and S100-Z rs7712957 in the allelic model.

CONCLUSION

Associations between SNPs and the proportion of IBD-associated CRC in IBD patients were examined, and further investigation of additional SNPs and their association with the risk of morbidity is needed.

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.

Mapping hyper-susceptibility to colitis-associated colorectal cancer in FVB/NJ mice

Inbred strains of mice differ in susceptibility to colitis-associated colorectal cancer (CA-CRC). We tested 10 inbred strains of mice for their response to azoxymethane/dextran sulfate sodium-induced CA-CRC and identified a bimodal inter-strain distribution pattern when tumor multiplicity was used as a phenotypic marker of susceptibility. The FVB/NJ strain was particularly susceptible showing a higher tumor burden than any other susceptible strains (12.5-week post-treatment initiation). FVB/NJ hyper-susceptibility was detected as early as 8-week post-treatment initiation with FVB/NJ mice developing 5.5-fold more tumors than susceptible A/J or resistant B6 control mice. Linkage analysis by whole genome scan in informative (FVB/NJ×C3H/HeJ)F2 mice identified a novel susceptibility locus designated as C olon c ancer s usceptibility 6 (Ccs6) on proximal mouse chromosome 6. When gender was used as a covariate, a LOD score of 5.4 was computed with the peak marker being positioned at rs13478727, 43.8 Mbp. Mice homozygous for FVB/NJ alleles at this locus had increased tumor multiplicity compared to homozygous C3H/HeJ mice. Positional candidates in this region of chromosome 6 were analyzed with respect to a possible role in carcinogenesis and a role in inflammatory response using a new epigenetic gene scoring tool (Myeloid Inflammation Score).

Cancer surveillance in ulcerative colitis and Crohn's disease: new strategies

PURPOSE OF REVIEW

Inflammatory bowel disease (IBD) patients have a higher incidence of colon cancer than the general population. Colon cancer surveillance has traditionally involved taking numerous random biopsies to provide sufficient yield to detect dysplasia. Recently, consensus guidelines have been published which promote the use of chromoendoscopy for IBD colon cancer surveillance. This presents a new set of opportunities and challenges in the evaluation and management of dysplasia in IBD.

RECENT FINDINGS

Dysplasia, previously thought to be 'invisible' to the endoscopist, is now considered to be 'visible' in the majority of cases with the advent of the use of high-definition endoscopy and chromoendoscopy. This changes how we manage dysplastic lesions, providing the patient options for endoscopic resection rather than promoting total proctocolectomy.

SUMMARY

Implemention of chromoendoscopy may require additional training for endoscopists unfamiliar with the technique. However, if this proves to be cost-effective and provides a higher sensitivity in dysplasia detection, then widespread education and implementation will be well worth the efforts. To do so, future studies will need to prove its benefits in preventing or reducing colon cancer morbidity and mortality in this high-risk patient population.

Colitis-associated colon cancer: Is it in your genes?

Colitis-associated colorectal cancer (CA-CRC) is the cause of death in 10%-15% of inflammatory bowel disease (IBD) patients. CA-CRC results from the accumulation of mutations in intestinal epithelial cells and progresses through a well-characterized inflammation to dysplasia to carcinoma sequence. Quantitative estimates of overall CA-CRC risks are highly variable ranging from 2% to 40% depending on IBD severity, duration and location, with IBD duration being the most significant risk factor associated with CA-CRC development. Recently, studies have identified IBD patients with similar patterns of colonic inflammation, but that differ with respect to CA-CRC development, suggesting a role for additional non-inflammatory risk factors in CA-CRC development. One suggestion is that select IBD patients carry polymorphisms in various low penetrance disease susceptibility genes, which pre-dispose them to CA-CRC development, although these loci have proven difficult to identify in human genome-wide association studies. Mouse models of CA-CRC have provided a viable alternative for the discovery, validation and study of individual genes in CA-CRC pathology. In this review, we summarize the current CA-CRC literature with a strong focus on genetic pre-disposition and highlight an emerging role for mouse models in the search for CA-CRC risk alleles.