Colorectal neoplasia in long-standing ulcerative colitis - a prospective study from a low-prevalence area

Colorectal cancer risk of flat low-grade dysplasia in inflammatory bowel disease: a systematic review and proportion meta-analysis

BACKGROUND

To date, the optimal management of patients with inflammatory bowel disease (IBD) and flat low-grade dysplasia (fLGD) of the colon or rectum remains controversial.

METHODS

A systematic review was reported in accordance with PRISMA 2020 (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). Patients diagnosed with fLGD on surveillance endoscopy were pooled from studies published between 2000 and 2020. Advanced neoplasia was defined by the presence of HGD, CRC or small bowel adenocarcinoma detected on subsequent surveillance endoscopy or from examination of resection specimens. We estimated the pooled annual incidence rate of colorectal cancer (CRC) and advanced neoplasia, and the risk factors associated with neoplastic progression.

RESULTS

We identified 24 articles and 738 IBD patients were diagnosed with fLGD on endoscopy. Two hundred thirty-six patients (32%) underwent immediate surgery with surgical specimens demonstrating CRC in 8 patients (pooled prevalence, 8.66%; 95% CI 3.58-19.46) and HGD (high grade dysplasia) in 11 patients (pooled prevalence, 13.97%; 95% CI 5.65-30.65). Five hundred-two patients (68%) underwent endoscopic surveillance with 63 patients with fLGD progressing to advanced neoplasia during endoscopic surveillance (38 HGD, 24 CRC and one patient developing small bowel adenocarcinoma). The mean duration of follow-up after fLGD diagnosis was 71 months (10.9-212). The pooled incidence of CRC and advanced neoplasia was 0.5 (95% CI 0.23-0.77) and 1.71 per 100 patient-year (95% CI 0.88-2.54) respectively. The use of corticosteroids and location of fLGD in the distal colon were significantly associated with neoplastic progression.

CONCLUSIONS

This study provides a summary incidence rate of CRC and advanced neoplasia in patients with IBD and fLGD to inform surgeons' and endoscopists' decision-making thus reducing potential ineffective treatments.

Ulcerative Colitis-Induced Colorectal Carcinoma: A Deleterious Concatenation

Inflammatory bowel disease (IBD) is a chronic inflammatory gastrointestinal ailment that encompasses Crohn's disease (CD) and ulcerative colitis (UC). UC is an idiopathic, chronic inflammatory condition of the colonic mucosa that begins in the rectum and progresses proximally in a continuous way over a portion of the entire colon. Chronic inflammation is linked to cancer, and IBD-related chronic colonic inflammation raises the risk of colorectal cancer. Chronic inflammation has been linked to cancer, and chronic colonic inflammation caused by IBD increases the risk of colorectal cancer (CRC). When CRC arises in people with IBD, unlike sporadic CRC, the lesions are difficult to identify due to mucosal alterations produced by inflammation. The total prevalence of IBD-associated CRC is increasing due to the rapidly increasing frequency of IBD. Screening and surveillance colonoscopy in IBD patients is considered to allow for the early diagnosis of dysplasia and cancer, improving the prognosis of IBD-related CRC by giving patients proactive therapy. This article has reviewed literature pertaining to the mechanisms related to CRC development in UC and its clinical and therapeutic implications.

Correlation of ulcerative colitis and colorectal cancer: a systematic review and meta-analysis

BACKGROUND

A large number of studies have shown that ulcerative colitis (UC) can increase the risk of colorectal cancer (CRC). The purpose of the present study was to explore the specific mechanism of UC influence on CRC.

METHODS

We searched PubMed for articles related to CRC and colitis since the establishment of the database until April 2021. Keywords, such as ulcerative colitis, colorectal cancer, and relevance, were used for the article search. Two investigators read through the full text according to the inclusion and exclusion criteria to screen the articles. Cochrane system review manual (version 5.3) was adopted to evaluate the quality of the selected articles. Then, data was extracted, and the overall risk of UC patients into CRC, the course of the disease, and the region were systematically analyzed.

RESULTS

A total of 11 studies involving 26,765 patients with UC were included. The results showed that UC is one of the risk factors for CRC. we also found that geographical location also had an impact on the transition from UC to CRC, but the impact was not significant. Patients with colitis had a significantly higher rate of conversion to CRC after 10 to 20 years of disease.

DISCUSSION

A total of 11 articles were included to analyze the association between UC and CRC. The studies found that the location, duration, and geographical location of patients with UC directly affected the occurrence of CRC and are independent risk factors for the transformation of UC into CRC.

Colorectal dysplasia and adenocarcinoma in patients with ulcerative colitis: an experience from a tertiary care hospital

Background

The rationale behind this study was to find out the frequency of dysplasia and colorectal cancer (CRC) in young patients with ulcerative colitis (UC) using histopathological examination. This facilitated early detection of dysplasia and CRC by regular endoscopic biopsies and also guided physicians on appropriate surveillance and management, thus improved outcome.

Methods

It was a prospective cross-sectional study conducted at the Department of Pathology, PIMS, Islamabad. Seventy-six biopsies of already diagnosed cases of UC of young patients aged between 15 and 40 years of either gender were included. Specimens were fixed in 10% buffer formalin, paraffin embedded followed by cutting, slide preparation, and staining with hematoxylin and eosin (H&E) stain, and examined under light microscope. Statistical package for social sciences (SPSS 21) was used for data compilation and analysis. Mean and standard deviation were calculated for quantitative variables. Frequency and percentage were calculated for qualitative variables.

Results

There were 13 (17.2%) patients who were diagnosed with colorectal dysplasia, 3 (4.0%) with indefinite for dysplasia, 8 (10.5%) with low-grade dysplasia, and 2 (2.6%) with high-grade dysplasia. There were three (3.9%) patients who were diagnosed for colorectal carcinoma, one (1.3%) with grade 1, one (1.3%) with grade 2, and one (1.3%) with grade 3 CRC.

Conclusion

Routine biopsies can identify dysplastic epithelium, which is an established sign for synchronized carcinoma with ulcerative colitis, and give the rationale for surveillance of the patients.

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.

Risk of colorectal cancer in Asian patients with ulcerative colitis: a systematic review and meta-analysis

BACKGROUND

The increased risk of colorectal cancer in ulcerative colitis is well known. The risk of sporadic colorectal cancer in Asian populations is considered low and risk estimates of colorectal cancer related to ulcerative colitis from Asia vary. This meta-analysis is an Asian perspective on the risk of colorectal cancer related to ulcerative colitis.

METHODS

We searched PubMed and Embase for terms related to colorectal cancer in ulcerative colitis from inception to July 1, 2016. The search for published articles was done by country for all countries in Asia. We included studies with information on the prevalence and cumulative risk of colorectal cancer at various timepoints. A random-effects meta-analysis was done to calculate the pooled prevalence as well as a cumulative risk at 10 years, 20 years, and 30 years of disease.

FINDINGS

Our search identified 2575 articles; of which 44 were eligible for inclusion. Our analysis included a total of 31 287 patients with ulcerative colitis with a total of 293 reported colorectal cancers. Using pooled prevalence estimates from various studies, the overall prevalence was 0·85% (95% CI 0·65-1·04). The risks for colorectal cancer were 0·02% (95% CI 0·00-0·04) at 10 years, 4·81% (3·26-6·36) at 20 years, and 13·91% (7·09-20·72) at 30 years. Subgroup analysis by stratifying the studies according to region or period of the study did not reveal any significant differences.

INTERPRETATION

We found the risk of colorectal cancer in Asian patients with ulcerative colitis was similar to recent estimates in Europe and North America. Adherence to screening is therefore necessary. Larger population-based, prospective studies are required for better estimates of the risk.

FUNDING

Indo-US Science and Technology Forum.

Inflammatory bowel disease in India - Past, present and future

There is rising incidence and prevalence of inflammatory bowel disease (IBD) in India topping the Southeast Asian (SEA) countries. The common genes implicated in disease pathogenesis in the West are not causal in Indian patients and the role of "hygiene hypothesis" is unclear. There appears to be a North-South divide with more ulcerative colitis (UC) in north and Crohn's disease (CD) in south India. IBD in second generation Indian migrants to the West takes the early onset and more severe form of the West whereas it retains the nature of its country of origin in migrants to SEA countries. The clinical presentation is much like other SEA countries (similar age and sex profile, low positive family history and effect of smoking, roughly similar disease location, use of aminosalicylates for CD, low use of biologics and similar surgical rates) with some differences (higher incidence of inflammatory CD, lower perianal disease, higher use of aminosalicylates and azathioprine and lower current use of corticosteroids). UC presents more with extensive disease not paralleled in severity clinically or histologically, follows benign course with easy medical control and low incidence of fulminant disease, cancer, complications, and surgery. UC related colorectal cancer develop in an unpredictable manner with respect to disease duration and site questioning the validity of strict screening protocol. About a third of CD patients get antituberculosis drugs and a significant number presents with small intestinal bleed which is predominantly afflicted by aggressive inflammation. Biomarkers have inadequate diagnostic sensitivity and specificity for both. Pediatric IBD tends to be more severe than adult. Population based studies are needed to address the lacunae in epidemiology and definition of etiological factors. Newer biomarkers and advanced diagnostic techniques (in the field of gastrointestinal endoscopy, molecular pathology and genetics) needs to be developed for proper disease definition and treatment.

Comparative analysis of copy number variations in ulcerative colitis associated and sporadic colorectal neoplasia

Background

The incidence of and mortality from colorectal cancers (CRC) can be reduced by early detection. Currently there is a lack of established markers to detect early neoplastic changes. We aimed to identify the copy number variations (CNVs) and the associated genes which could be potential markers for the detection of neoplasia in both ulcerative colitis-associated neoplasia (UC-CRN) and sporadic colorectal neoplasia (S-CRN).

Methods

We employed array comparative genome hybridization (aCGH) to identify CNVs in tissue samples of UC nonprogressor, progressor and sporadic CRC. Select genes within these CNV regions as a panel of markers were validated using quantitative real time PCR (qRT-PCR) method along with the microsatellite instability (MSI) in an independent cohort of samples. Immunohistochemistry (IHC) analysis was also performed.

Results

Integrated analysis showed 10 overlapping CNV regions between UC-Progressor and S-CRN, with the 8q and 12p regions showing greater overlap. The qRT-PCR based panel of MYC, MYCN, CCND1, CCND2, EGFR and FNDC3A was successful in detecting neoplasia with an overall accuracy of 54 % in S-CRN compared to that of 29 % in UC neoplastic samples. IHC study showed that p53 and CCND1 were significantly overexpressed with an increasing frequency from pre-neoplastic to neoplastic stages. EGFR and AMACR were expressed only in the neoplastic conditions.

Conclusion

CNVs that are common and unique to both UC-associated and sporadic colorectal neoplasm could be the key players driving carcinogenesis. Comparative analysis of CNVs provides testable driver aberrations but needs further evaluation in larger cohorts of samples. These markers may help in developing more effective neoplasia-detection strategies during screening and surveillance programs.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2303-4) contains supplementary material, which is available to authorized users.

Copy number variations are progressively associated with the pathogenesis of colorectal cancer in ulcerative colitis

AIM: To evaluate the association of known copy number variations (CNVs) in ulcerative colitis (UC) progressing to colorectal cancer.

METHODS: Microsatellite instability analysis using the National Cancer Institute’s panel of markers, and CNV association studies using Agilent 2 × 105 k arrays were done in tissue samples from four patient groups with UC: those at low risk (LR) or high risk of developing colorectal cancer, those with premalignant dysplastic lesions, and those with colitis-associated colorectal cancer (CAC). DNA from tissue samples of these groups were independently hybridized on arrays and analyzed. The data obtained were further subjected to downstream bioinformatics enrichment analysis to examine the correlation with CAC progression.

RESULTS: Microarray analysis highlighted a progressive increase in the total number of CNVs [LR (n = 178) vs CAC (n = 958), 5.3-fold], gains and losses [LR (n = 37 and 141) vs CAC (n = 495 and 463), 13.4- and 3.3-fold, respectively], size [LR (964.2 kb) vs CAC (10540 kb), 10.9-fold] and the number of genes in such regions [LR (n = 119) vs CAC (n = 455), 3.8-fold]. Chromosome-wise analysis of CNVs also showed an increase in the number of CNVs across each chromosome. There were 38 genes common to all four groups in the study; 13 of these were common to cancer genes from the Genetic Disease Association dataset. The gene set enrichment analysis and ontology analysis highlighted many cancer-associated genes. All the samples in the different groups were microsatellite stable.

CONCLUSION: Increasing numbers of CNVs are associated with the progression of UC to CAC, and warrant further detailed exploration.

Systematic review with meta-analysis: the declining risk of colorectal cancer in ulcerative colitis

BACKGROUND

Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer (CRC); however, the magnitude of this effect is open to debate.

AIM

To assess the risk of CRC in UC patients by systematic review and meta-analysis.

METHODS

A systematic literature search was performed up to November 2013. We selected studies describing the incidence and prevalence of CRC in patients with UC. Articles were assessed for quality using the Newcastle-Ottawa Scale. Cumulative incidence and incidence rates of CRC were combined and analysed using the generic inverse variance method. Sub-analyses were performed to identify factors associated with an increased risk of developing CRC.

RESULTS

A total of 81 studies (181 923 patients) met the inclusion criteria. The incidence rate of CRC in patients with UC was 1.58 per 1000 patient-years (py) [95% confidence interval (CI), 1.39–1.76]. Results were heterogeneous (I2 = 81–89%). The incidence rate was 4.02/1000 py (95%CI = 2.74–5.31) in studies that only included patients with extensive colitis, and 1.24/1000 py (95%CI = 1.01–1.47) in population-based studies. The incidence rate was 0.91/1000 py (95%CI = 0.61–1.2) in the first decade of disease, 4.07/1000 py (95%CI = 2.58–5.56) in the second, and 4.55/1000 py (95%CI = 2.64–6.46) in the third. The incidence rate decreased from 4.29/1000 py in the studies published in the 1950s to 1.21/1000 py in studies published in the last decade.

CONCLUSIONS

The risk of patients with ulcerative colitis developing colorectal cancer has decreased steadily over the last six decades, but the extent and duration of the disease increase this risk.