Intestinal cancer in patients with Crohn's disease: A systematic review and meta-analysis

Global patterns in the epidemiology, cancer risk, and surgical implications of inflammatory bowel disease

Inflammatory bowel disease (IBD), mainly including ulcerative colitis and Crohn's disease, imposes a huge medical and economic burden worldwide. Recently, the diagnosis, treatment, and surveillance of IBD have advanced rapidly, which has changed the epidemiology, cancer risk, and surgery risk of IBD. Here, we reviewed the recent literature on the epidemiology, IBD-related cancer, and IBD-related surgery. We created a choropleth map to show the worldwide incidence trend for Crohn's disease and ulcerative colitis. We also found that the cancer risk and surgery risk of IBD are declining and discussed some risk factors associated with them. Based on the recent trend, we proposed several suggestions and hoped to reduce the global burden of IBD as far as possible.

Possible poor prognosis in younger-onset Crohn's disease-associated anorectal cancer: A subanalysis of the Nationwide Japanese study

Background and aims

Crohn's disease (CD)-associated intestinal cancers are characterized by their high incidence, particularly at the anorectal site in the Japanese population. Accumulating evidence revealed that younger-onset sporadic colorectal cancer may exhibit unique biological features. To the best of our knowledge, few previous articles reported clinicopathological features in patients with CD-associated anorectal cancer (CDAAC). Therefore, we aimed to clarify the relationship between the younger onset of cancer and clinicopathological characteristics and prognosis, and the efficacy of cancer surveillance in patients with CDAAC.

Methods

CD patients who had been diagnosed with intestinal cancers from 1983 to 2020 were collected from 39 Japanese institutions in this study. Of 316 patients with CD-associated intestinal cancers, we analyzed 211 patients with CDAAC. We divided the patients into two groups according to the median age at cancer diagnosis (45 years old).

Results

Younger-onset CDAAC (YO-CDAAC) patients were significantly more likely to have a poor outcome than those with older-onset CDAAC (OO-CDAAC) in terms of both disease-free survival (DFS) (p = 0.0014) and overall survival (OS) (p = 0.023). Multivariate analysis showed that age under 45 years old at diagnosis of cancer was one of the independent factors for poor DFS and OS (hazard ratios: 2.15, 95% confidence interval: 1.09-4.26, p = 0.028, hazard ratios: 1.95, 95% confidence interval: 1.05-3.60, p = 0.033, respectively). Patients detected via surveillance showed significantly better DFS and OS rates than symptomatic patients in YO-CDAAC (p = 0.012 and 0.0031, respectively).

Conclusions

YO-CDAAC may have a poorer prognosis compared with OO-CDAAC. Surveillance could be important to improve cancer prognosis, especially in young CD patients with anorectal disease.

Multimodality imaging features of small bowel cancers complicating Crohn's disease: a pictorial review

Patients with Crohn's disease (CD) are at increased risk of developing small bowel cancer, since chronic inflammation may trigger the histopathological sequence that begins from low-grade dysplasia of the intestinal epithelium and may eventually lead to malignant transformation. Owing to their location in a portion of the gastrointestinal tract which is not easily accessible to conventional endoscopic techniques, the detection of CD-related small bowel cancers is still a clinical challenge. The radiological features of CD-related small bowel adenocarcinoma (SBA) in patients with CD have been described in some previous studies, including its appearance in both CT and MRI examinations. Radiological signs of active or fibrostenotic CD may be intermixed with those suggesting the presence of CD-related SBA. In CT studies, the most relevant findings consistent with malignant transformation are the presence of a stricture with irregular asymmetric thickening of small bowel walls, loss of mural stratification, and moderate enhancement after intravenous administration of iodinated contrast media, in association with enlarged adjacent mesenteric lymph nodes. Many of the CD-related SBA features that can be observed on CT imaging are similar to those detectable by MRI. This latter modality provides the additional value of the functional characterization of small bowel strictures, thereby helping to distinguish between inflammatory, fibrotic, and malignant stenosis in the setting of active CD. Positron Emission Tomography (PET)/CT enables the metabolic assessment of enlarged mesenteric lymph nodes, and PET/MRI fusion imaging can incorporate morphological, functional and metabolic information into a single set of imaging data, thus overcoming the limitations of the separate assessment of each individual modality. Owing to the low incidence and prevalence of this long-term complication of CD, we believe that a detailed multimodality pictorial essay on this topic, also including the PET-CT and fusion imaging documentation of some cases, would be useful to the medical literature.

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

BACKGROUND AND AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Small Bowel Carcinoma in the Setting of Inflammatory Bowel Disease

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

Appendiceal Mucinous Neoplasms and Inflammatory Bowel Disease: Systematic Review of the Literature

There is no clear evidence on the prevalence and clinical presentation of appendiceal mucinous neoplasm (AMN) among patients with inflammatory bowel disease (IBD), so a systematic review was performed to investigate the diagnosis, management and treatment of AMN in these patients. PubMed, Medline, Scopus and the Cochrane Library were searched for articles published up to September 2023. Twenty-three studies reporting data about 34 AMN patients were included. UC patients had a median age of 52 years and a median length of disease of 10 years; CD patients had a median age of 40.5 years and a median length of disease of 5 years. A pre-operative diagnosis was achieved in 44% of patients. Most patients were symptomatic (82.6%) and showed moderate-severe disease activity (61%). Surgical procedures were performed: laparoscopic appendectomy, ileocecal resection, right hemicolectomy and colectomy/proctocolectomy. Of the patients, 73.5% were diagnosed with low-grade mucinous neoplasm (LAMN) and nine with adenocarcinoma. Synchronous colorectal dysplasia/carcinoma was present in 23.5% of patients. IBD patients with long-standing disease should be routinely screened, not only for colorectal cancer but also for AMN, during gastro-enterologic follow-up. Laparoscopic appendectomy of unruptured LAMN as well as right hemicolectomy of non-metastatic adenocarcinoma are safe procedures in IBD patients.

Crohn's Disease-Associated Anorectal Cancer Has a Poor Prognosis With High Local Recurrence: A Subanalysis of the Nationwide Japanese Study

INTRODUCTION

Colorectal cancer (CRC) is one of the major life-threatening complications in patients with Crohn's disease (CD). Previous studies of CD-associated CRC (CD-CRC) have involved only small numbers of patients, and no large series have been reported from Asia. The aim of this study was to clarify the prognosis and clinicopathological features of CD-CRC compared with sporadic CRC.

METHODS

A large nationwide database was used to identify patients with CD-CRC (n = 233) and sporadic CRC (n = 129,783) over a 40-year period, from 1980 to 2020. Five-year overall survival (OS), recurrence-free survival (RFS), and clinicopathological characteristics were investigated. The prognosis of CD-CRC was further evaluated in groups divided by colon cancer and anorectal cancer (RC). Multivariable Cox regression analysis was used to adjust for confounding by unbalanced covariables.

RESULTS

Compared with sporadic cases, patients with CD-CRC were younger; more often had RC, multiple lesions, and mucinous adenocarcinoma; and had lower R0 resection rates. Five-year OS was worse for CD-CRC than for sporadic CRC (53.99% vs 71.17%, P < 0.001). Multivariable Cox regression analysis revealed that CD was associated with significantly poorer survival (hazard ratio 2.36, 95% confidence interval: 1.54-3.62, P < 0.0001). Evaluation by tumor location showed significantly worse 5-year OS and RFS of CD-RC compared with sporadic RC. Recurrence was identified in 39.57% of CD-RC cases and was mostly local.

DISCUSSION

Poor prognosis of CD-CRC is attributable primarily to RC and high local recurrence. Local control is indispensable to improving prognosis.

Role of adherent invasive Escherichia coli in pathogenesis of inflammatory bowel disease

Gut microbiota imbalances play an important role in inflammatory bowel disease (IBD), but no single pathogenic microorganism critical to IBD that is specific to the IBD terminal ileum mucosa or can invade intestinal epithelial cells has been found. Invasive Escherichia coli (E. coli) adhesion to macrophages is considered to be closely related to the pathogenesis of inflammatory bowel disease. Further study of the specific biological characteristics of adherent invasive E. coli (AIEC) may contribute to a further understanding of IBD pathogenesis. This review explores the relationship between AIEC and the intestinal immune system, discusses the prevalence and relevance of AIEC in Crohn's disease and ulcerative colitis patients, and describes the relationship between AIEC and the disease site, activity, and postoperative recurrence. Finally, we highlight potential therapeutic strategies to attenuate AIEC colonization in the intestinal mucosa, including the use of phage therapy, antibiotics, and anti-adhesion molecules. These strategies may open up new avenues for the prevention and treatment of IBD in the future.

Perioperative optimization of Crohn's disease

Crohn's disease (CD) is a chronic inflammatory disease mainly affecting the gastrointestinal tract. With the increased availability of modalities in the last two decades, the treatment of CD has advanced remarkably. Although medical treatment is the mainstay of therapy, most patients require surgery during the course of their illness, especially those who experience complications. Nutritional optimization and ERAS implementation are crucial for patients with CD who require surgical intervention to reduce postoperative complications. The increased surgical risk was found to be associated with the use of corticosteroids, but the association of surgical risk with immunomodulators, biologic therapy, such as anti-TNF mediations, anti-integrin medications, and anti-IL 12/23 was low in certainty. Decisions about preoperative medication must be made on an individual case-dependent basis. Preoperative imaging studies can assist in the planning of appropriate surgical strategies and approaches. However, patients must be informed of any alterations to their treatment. In summary, the management of perioperative medications and surgery-related decision-making should be individualized and patient-centered based on a multidisciplinary approach.

Risk of Cancer in Inflammatory Bowel Diseases: Umbrella Review and Reanalysis of Meta-analyses

BACKGROUND & AIMS

To summarize the epidemiologic evidence and assess the validity of claimed associations of inflammatory bowel diseases (IBDs) with overall and site-specific cancer risk.

METHODS

We systematically searched PubMed, Embase, and Scopus from inception to May 10, 2021, to identify and comprehensively reanalyze the data of meta-analyses on associations between IBDs (ie, Crohn's disease [CD] and ulcerative colitis [UC]) and subsequent risk of cancer. The strength of epidemiologic evidence was graded as high, moderate, or weak, by applying prespecified criteria that included the random effects estimate, its 95% confidence interval, and P value, estimates of heterogeneity, small-study effects, and robustness to unmeasured confounding.

RESULTS

This study critically appraised 277 estimates derived from 24 published meta-analyses and our own meta-analyses. The association between pediatric-onset IBDs and overall risk of cancer showed high epidemiologic evidence. Twenty associations (15 cancer types) demonstrated moderate evidence: any cancer (pediatric-onset UC), mouth to terminal ileum (CD), small bowel (CD/UC), colon (CD), rectum (CD/UC), colon-rectum (IBDs, pediatric-onset CD/UC), bile ducts and liver (CD/UC), liver (CD), intrahepatic cholangiocarcinoma (IBDs), bile ducts (CD), skin (CD), squamous cell carcinoma of the skin (CD), nonmelanoma skin cancer (UC), kidney (CD), and thyroid cancer (IBDs). Another 40 associations (23 cancer types) showed statistical significance; however, our confidence in these effect estimates was weak. No statistical significance was found regarding further 47 associations.

CONCLUSIONS

Associations between IBDs and different types of malignancy showed varying levels of evidence and magnitude of risk. Further primary research investigating the impact of a consistent set of risk factors that are known to affect cancer risk is warranted.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021254996.

Intestinal Cancer and Dysplasia in Crohn's Disease

Crohn's disease is associated with an increased risk of adenocarcinoma of the involved portions of the small bowel and colorectum and has similar risk factors to those described in ulcerative colitis, most significantly, extent of bowel involvement, PSC, and duration of unresected disease. Prevention strategies include risk stratification and secondary prevention with colonoscopic screening and surveillance to identify dysplasia or early-stage cancers, with surgery when needed. There is emerging information to suggest that control of inflammation may provide primary prevention of neoplasia, but further studies are required to test this strategy.

Evidence-based clinical practice guidelines for inflammatory bowel disease 2020

Inflammatory bowel disease (IBD) is a general term for chronic or remitting/relapsing inflammatory diseases of the intestinal tract and generally refers to ulcerative colitis (UC) and Crohn's disease (CD). Since 1950, the number of patients with IBD in Japan has been increasing. The etiology of IBD remains unclear; however, recent research data indicate that the pathophysiology of IBD involves abnormalities in disease susceptibility genes, environmental factors and intestinal bacteria. The elucidation of the mechanism of IBD has facilitated therapeutic development. UC and CD display heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management depends on the understanding and tailoring of evidence-based interventions by physicians. In 2020, seventeen IBD experts of the Japanese Society of Gastroenterology revised the previous guidelines for IBD management published in 2016. This English version was produced and modified based on the existing updated guidelines in Japanese. The Clinical Questions (CQs) of the previous guidelines were completely revised and categorized as follows: Background Questions (BQs), CQs, and Future Research Questions (FRQs). The guideline was composed of a total of 69 questions: 39 BQs, 15 CQs, and 15 FRQs. The overall quality of the evidence for each CQ was determined by assessing it with reference to the Grading of Recommendations Assessment, Development and Evaluation approach, and the strength of the recommendation was determined by the Delphi consensus process. Comprehensive up-to-date guidance for on-site physicians is provided regarding indications for proceeding with the diagnosis and treatment.