Crohn's disease and cancer risk (Denmark)

The 2023 Impact of Inflammatory Bowel Disease in Canada: Cancer and IBD

Cancer is a major cause of morbidity and mortality among people with inflammatory bowel disease (IBD). Intestinal cancers may arise as a complication of IBD itself, while extra-intestinal cancers may arise due to some of the immunosuppressive therapies used to treat IBD. Colorectal cancer (CRC) and small bowel cancer risks remain elevated among persons with IBD as compared to age-and sex-matched members of the general population, and the lifetime risk of these cancers is strongly correlated to cumulative intestinal inflammatory burden. However, the cumulative risk of cancer, even among those with IBD is still low. Some studies suggest that IBD-CRC incidence has declined over the years, possibly owing to improved treatment standards and improved detection and management of early neoplastic lesions. Across studies of extra-intestinal cancers, there are generally higher incidences of melanoma, hepatobiliary cancer, and lung cancer and no higher incidences of breast cancer or prostate cancer, with equivocal risk of cervical cancer, among persons with IBD. While the relative risks of some extra-intestinal cancers are increased with treatment, the absolute risks of these cancers remain low and the decision to forego treatment in light of these risks should be carefully weighed against the increased risks of intestinal cancers and other disease-related complications with undertreated inflammatory disease. Quality improvement efforts should focus on optimized surveillance of cancers for which surveillance strategies exist (colorectal cancer, hepatobiliary cancer, cervical cancers, and skin cancers) and the development of cost-effective surveillance strategies for less common cancers associated with IBD.

Risk of uterine cervical cancer in inflammatory bowel disease: a systematic review and meta-analysis

BACKGROUND AND AIMS

There are limited data on the association between uterine cervical cancer (UCC) and inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

This systematic review and meta-analysis assessed the risk of UCC in patients with IBD. We searched MEDLINE, Embase, Cochrane Library, Scopus, Web of Science, ClinicalTrials.gov, gray literature and conference proceedings for studies published before 21 January 2022. Two reviewers independently screened studies, extracted data and assessed quality using the Newcastle-Ottawa Scale. Subgroup analyses were based on IBD type, biologic era, immunosuppression status, study location and design, and publication status. Fifteen studies were included.

RESULTS

The pooled relative risk (RR) of UCC in IBD was 1.34 (95% confidence interval [CI], 1.07-1.69; I2 = 53.4%). In subgroup analyses, the pooled RRs of UCC in CD and UC were 1.18 (95% CI, 0.97-1.42) and 1.50 (95% CI, 1.01-12.21), respectively. The pooled RRs of UCC in pre-biologic and biologic eras were 1.36 (95% CI, 0.83-2.23) and 1.99 (95% CI, 1.03-3.86), respectively. The pooled RR of UCC in immunomodulator users was 2.18 (95% CI, 0.81-5.87). The pooled RRs of UCC in Asia, Europe and North America were 5.65 (95% CI, 2.65-12.07), 1.13 (95% CI, 0.96-1.34) and 1.38 (95% CI, 1.10-1.73), respectively.

CONCLUSIONS

The risk of UCC was significantly increased in IBD, particularly in UC but not in CD, suggesting that women with IBD should undergo regular UCC screening and consider vaccination.

Incidence of lymphomas in inflammatory bowel disease: report of an emblematic case, systematic review, and meta-analysis

Introduction

Over the past 20 years, the increasing use of combined therapy with immunosuppressants and biologic agents has markedly reduced the use of steroids in the management of inflammatory bowel diseases (IBD). However, medical therapy seems to promote, in the long run, carcinogenesis resulting in an increased risk of developing different types of malignancies, including lymphomas. The aim of this study was to systematically review the current incidence and prognosis of lymphoid neoplasms occurring in patients with IBD.

Methods

Studies analyzing the incidence of lymphomas in subjects of age >18 years affected by IBD were included in this systematic review and meta-analysis. Studies focusing on pediatric populations, not reporting person-years of follow-up, or with a duration < 1 year were excluded. PubMed, Embase, Web of Science Core Collection, and Cochrane Central Register were searched from inception through January 2022. Publication bias within studies was assessed using Begg's and Egger's tests and random effects model. Quantitative results were synthesized using relative-risk meta-analysis. PRISMA guidelines were used to carry out this systematic review (PROSPERO Registration Number: CRD42023398348).

Results

A total of 345 studies published between 1985 and 2022, with a total of 6,17,386 patients were included in the meta-analysis. Substantial heterogeneity between studies prevented the pooling of estimates (I² = 97.19%). Evidence of publication bias was overall low (p = 0.1941). Patients affected by Crohn's disease (CD) were 1,86,074 (30.13%), while 2,78,876 (46.17%) were diagnosed with UC. The remaining 23.7% of cases were diagnosed with indeterminate colitis. Immunomodulators and biologic therapy were used in 24,520 (5.27%), and 17,972 (3.86%) patients, respectively. Reported incidence rates for lymphoma in IBD ranged from 0.0/100,000 person/years (py) (95% CI 0.0-3.7/100,000) to 89/100,000 py (95% CI 36-160/100,000). Reported incidence rates of lymphoma in CD ranged from 0.0/100,000 py (95% CI 0.0-3.7/100,000) to 91/100,000 py (95% CI 18-164/100,000). For UC, the incidence rate ranged from 0.0/100,000 py (95% CI 0.0-3.7/100,000) to 95/100,000 py (95% CI 0-226/100,000). Male-to-female ratio was ~4:1. Therapy with immunomodulators was directly associated with an increased incidence of lymphoma (p < 0.0001). Evidence of publication bias was overall low (p = 0 .1941).

Conclusions

The evidence arising from this study highlights a correlation between the use of immunomodulators and subsequent lymphoma development. Combined multidisciplinary approach and long-term follow-up are warranted in order to decrease mortality deriving from the coexistence of both conditions.

Systematic review registration

Identifier: CRD42023398348.

Solid extraintestinal malignancies in patients with inflammatory bowel disease

Malignancies constitute the second cause of death in patients with inflammatory bowel diseases (IBD), after cardiovascular diseases. Although it has been postulated that IBD patients are at greater risk of colorectal cancer compared to the general population, lately there has been evidence supporting that this risk is diminishing over time as a result of better surveillance, while the incidence of extraintestinal cancers (EICs) is increasing. This could be attributed either to systemic inflammation caused by IBD or to long-lasting immunosuppression due to IBD treatments. It seems that the overall risk of EICs is higher for Crohn’s disease patients and it is mainly driven by skin cancers, and liver-biliary cancers in patients with IBD and primary sclerosing cholangitis. The aims of this review were first to evaluate the prevalence, characteristics, and risk factors of EICs in patients with IBD and second to raise awareness regarding a proper surveillance program resulting in early diagnosis, better prognosis and survival, especially in the era of new IBD treatments that are on the way.

Inflammatory bowel disease and risk of small bowel cancer: a binational population-based cohort study from Denmark and Sweden

OBJECTIVE

Crohn's disease (CD) is associated with increased risk of small bowel cancer (SBC), but previous studies have been small. We aimed to examine the risk of incident SBC and death from SBC in patients with inflammatory bowel disease (IBD).

DESIGN

In a binational, population-based cohort study from Sweden and Denmark of patients with IBD during 1969-2017 and matched reference individuals from the general population, we evaluated the risk of incident SBC and death from SBC. Cox regression was used to estimate adjusted hazard ratios (aHRs).

RESULTS

We identified 161 896 individuals with IBD (CD: 47 370; UC: 97 515; unclassified IBD: 17 011). During follow-up, 237 cases of SBC were diagnosed in patients with IBD (CD: 24.4/100 000 person-years; UC: 5.88/100 000 person-years), compared with 640 cases in reference individuals (2.81/100 000 person-years and 3.32/100 000 person-years, respectively). This corresponded to one extra case of SBC in 385 patients with CD and one extra case in 500 patients with UC, followed up for 10 years. The aHR for incident SBC was 9.09 (95% CI 7.34 to 11.3) in CD and 1.85 (95% CI 1.43 to 2.39) in UC. Excluding the first year after an IBD diagnosis, the aHRs for incident SBC decreased to 4.96 in CD and 1.69 in UC. Among patients with CD, HRs were independently highest for recently diagnosed, childhood-onset, ileal and stricturing CD. The relative hazard of SBC-related death was increased in both patients with CD (aHR 6.59, 95% CI 4.74 to 9.15) and patients with UC (aHR 1.57; 95% CI 1.07 to 2.32).

CONCLUSION

SBC and death from SBC were more common in patients with IBD, particularly among patients with CD, although absolute risks were low.

Clinical and Histopathologic Features of Colorectal Adenocarcinoma in Crohn's Disease

GOALS

The aim of this study was to assess the histopathologic characteristics of colorectal carcinomas (CRC) in patients with Crohn's disease (CD).

BACKGROUND

A higher frequency of microsatellite instability (MSI) is seen in mucinous compared with nonmucinous CRC which suggests that its pathogenesis involves distinct molecular pathways. Several publications reported a higher percentage of mucinous adenocarcinoma in CD patients with CRC. So far, there has been no investigation of MSI in CD patients with mucinous CRC.

STUDY

The medical records of patients who underwent surgery for CRC were reviewed and those with a history of CD identified. The data of histologic classification and MSI status of the tumor were investigated.

RESULTS

Fourteen patients with CD-associated CRC were identified (5 female, 9 male) resulting in 20 CRC in total. Histologic investigation revealed 7 adenocarcinomas without a mucinous or signet ring cell component. All other CRCs harbored a mucinous (n=11) and/or signet ring cell (n=6) component. All tumors assessed for MSI were found to be microsatellite stable.

CONCLUSIONS

Our data indicate that CRCs with signet ring cell and mucinous components were much more common in patients with CD than in patients with sporadic CRC. This observation suggests that CRC in CD represent an own entity with distinct histopathologic and molecular features. This may implicate potential consequences for diagnosis and therapy of CRC in CD in the future as well as new factors to identify patients with an increased risk for developing CRC in CD.

Inflammatory Bowel Disease and Small Bowel Cancer Risk, Clinical Characteristics, and Histopathology: A Population-Based Study

BACKGROUND & AIMS

Inflammatory bowel disease (IBD) may increase risk of small bowel cancer (SBC). However, little is known of the characteristics and features of IBD-SBC, due to a low number of cases worldwide. We performed a population-based study of IBD and SBC to calculate risk and increase our understanding of clinical characteristics and histopathological and molecular features.

METHODS

The study population consisted of all individuals aged 16 years or older living in Denmark during 1978-2010. Through linkage between national registers and subsequent scrutiny of medical records and pathology descriptions, we identified 40 cases of IBD-SBC. Risk was calculated by standardized incidence ratio (SIR) (observed/expected); patient characteristics were derived from medical files, and surgery specimens were obtained from hospitals nationwide for histopathological and molecular analyses.

RESULTS

During 241,620 person-years of follow-up, 23 patients with Crohn's disease developed small bowel adenocarcinoma (SIR, 14.38; 95% confidence interval, 8.78-22.20) and 9 developed neuroendocrine tumors (SIR, 6.83; 95% confidence interval, 3.13-12.97). No significantly increased risk of SBC was found among patients with ulcerative colitis. Most patients with SBC had moderate-to-severe Crohn's disease with small bowel and upper gastrointestinal involvement. Assessment of surgical specimens of small bowel adenocarcinomas revealed a clear transition from inflammation to dysplasia and cancer, whereas no tumors had evidence of microsatellite instability.

CONCLUSIONS

In a population-based study of patients in Denmark with IBD and SBC, we found risk of adenocarcinomas and neuroendocrine tumors to be increased among persons with Crohn's disease. Most patients with IBD-SBC had extensive IBD of moderate-to-severe activity. Adenocarcinomas appeared to develop via an inflammation-dysplasia-carcinoma pathway, but differed from IBD-related colorectal adenocarcinomas in their molecular features.

Intestinal and Nonintestinal Cancer Risks for Patients with Crohn's Disease

Crohn's disease (CD) is a chronic inflammatory disease that confers a higher risk of cancer than in the general population. New, large, population-based studies in the past decade show that patients with CD are at higher risk of colorectal, small bowel, melanoma, and cervical cancer. Patients who use thiopurines are at additional risk of development of lymphoma and nonmelanoma skin cancer. Preventive surveillance for cancers of the colorectum, skin, and uterine cervix is advised.

Chronic exposure to endosulfan induces inflammation in murine colon via β-catenin expression and IL-6 production

Endosulfan (ENDO) is a widely used organochlorine (OC) pesticide and persistent organo-pollutant. Epidemiological studies have shown that high levels of OC exposure were related to colorectal cancer (CRC) incidence. The objectives of the present study were to evaluate histological changes in the colon, as well as in in situ expression of β-catenin and P-selectin, and serum levels of select pro-inflammatory cytokines in mice administered ENDO; there is a relationship between increased serum IL-6 and P-selectin levels in CRC patients and aberrant β-catenin signaling is important in initiation/maintenance of most CRCs. Mice were exposed to ENDO (at dose < LD₅₀) orally once a week for up to 24 weeks, and monitored (inclusive) for a total of 42 weeks. The experiment was comprised of three groups, one that did not receive ENDO (olive oil vehicle), one administered 2 mg ENDO/kg/week and a positive control (for induction of CRC) given a weekly 20 mg 1,2-dimethylhydrazine (DMH)/kg injection. The results indicated that oral administration of ENDO provoked moderate inflammation starting at six weeks, and severe colonic inflammation with an appearance of dysplastic formations (aberrant crypts) in mice treated with ENDO (or DMH) for 12 weeks or longer. Serum IL-6 levels significantly increased starting at six weeks and rose to a peak of 15-fold higher than in controls at 42 weeks; TNFα levels likewise significantly increased, with a later peak (≈four-fold higher than controls) at 30-42 weeks. Immunohistochemical analysis of the colon also showed that expression of β-catenin and P-selectin increased with length of exposure to ENDO. Taken together, the results indicate that continued repeated oral exposure to ENDO induces increased expression of β-catenin and P-selectin, inflammation in the colon, and, ultimately, local tissue dysplasia.

Worldwide Incidence of Colorectal Cancer, Leukemia, and Lymphoma in Inflammatory Bowel Disease: An Updated Systematic Review and Meta-Analysis

Background/Aims. Inflammatory bowel disease (IBD) is associated with an increased risk of colorectal cancer (CRC). In addition, there may be an association between leukemia and lymphoma and IBD. We conducted a systematic review and meta-analysis of the IBD literature to estimate the incidence of CRC, leukemia, and lymphoma in adult IBD patients. Methods. Studies were identified by a literature search of PubMed, Cochrane Library, Medline, Web of Science, Scopus, EMBASE, and ProQuest Dissertations and Theses. Pooled incidence rates (per 100,000 person-years [py]) were calculated through use of a random effects model, unless substantial heterogeneity prevented pooling of estimates. Several stratified analyses and metaregression were performed to explore potential study heterogeneity and bias. Results. Thirty-six articles fulfilled the inclusion criteria. For CRC, the pooled incidence rate in CD was 53.3/100,000 py (95% CI 46.3–60.3/100,000). The incidence of leukemia was 1.5/100,000 py (95% CI −0.06–3.0/100,000) in IBD, 0.3/100,000 py (95% CI −1.0–1.6/100,000) in CD, and 13.0/100,000 py (95% CI 5.8–20.3/100,000) in UC. For lymphoma, the pooled incidence rate in CD was 0.8/100,000 py (95% CI −0.4–2.1/100,000). Substantial heterogeneity prevented the pooling of other incidence estimates. Conclusion. The incidence of CRC, leukemia, and lymphoma in IBD is low.

Who and how to screen for cancer in at-risk inflammatory bowel disease patients

Inflammatory bowel diseases (IBDs) include both Crohn's disease and ulcerative colitis and both diseases are marked by inflammation within the gastrointestinal tract. Due to long-standing inflammation, IBD patients are at increased risk of colorectal cancer, especially patients with chronic inflammation, pancolitis, co-diagnosis of primary sclerosing cholangitis and a longer duration of disease. Small bowel inflammation places Crohn's patients at an increased risk of small bowel cancer. A higher risk of skin cancers, lymphomas and cervical abnormalities is also seen in IBD patients; this is likely related to both disease factors and the presence of immunosuppressive medication. This article reviews which patients are at an increased risk of IBD-associated or IBD treatment-associated cancers, when to begin screening and which screening methods are recommended.

Ulcerative colitis-associated colorectal cancer

The association between ulcerative colitis (UC) and colorectal cancer (CRC) has been acknowledged. One of the most serious and life threatening consequences of UC is the development of CRC (UC-CRC). UC-CRC patients are younger, more frequently have multiple cancerous lesions, and histologically show mucinous or signet ring cell carcinomas. The risk of CRC begins to increase 8 or 10 years after the diagnosis of UC. Risk factors for CRC with UC patients include young age at diagnosis, longer duration, greater anatomical extent of colonic involvement, the degree of inflammation, family history of CRC, and presence of primary sclerosing cholangitis. CRC on the ground of UC develop from non-dysplastic mucosa to indefinite dysplasia, low-grade dysplasia, high-grade dysplasia and finally to invasive adenocarcinoma. Colonoscopy surveillance programs are recommended to reduce the risk of CRC and mortality in UC. Genetic alterations might play a role in the development of UC-CRC. 5-aminosalicylates might represent a favorable therapeutic option for chemoprevention of CRC.

Small bowel adenocarcinoma and Crohn's disease: Any further ahead than 50 years ago?

This review of the literature on small bowel carcinoma associated with Crohn’s disease specifically addresses the incidence, risk factors, and protective factors which have been identified. It also reviews the clinical presentation, the current modalities of diagnosis, the pathology, treatment, and surveillance. Finally, the prognosis and future direction are addressed. Our experience with small bowel adenocarcinoma in Crohn’s disease is reported. Readers will be provided with a better understanding of this rare and often poorly recognized complication of Crohn’s disease.

A novel shift in estrogen receptor expression occurs as estradiol suppresses inflammation-associated colon tumor formation

Postmenopausal women on estrogen replacement therapy (ERT) have a reduced risk of developing colon cancer compared with postmenopausal women not on ERT, suggesting a role for estradiol (E2) in protection against this disease. To determine whether E2 protects against inflammation-associated colon cancer when administered following the initiation of colonic DNA damage, in this study, we implanted E2-containing pellets into mice after co-treatment with azoxymethane and two rounds of dextran sulfate sodium (DSS). Wild-type (WT) E2-treated mice had reduced numbers and average area of adenocarcinomas compared with the control mice. These effects were lost in estrogen receptor-β (Erβ (Esr2)) knockout mice. Surprisingly, apoptosis was reduced and cell proliferation was increased in sections from tumors of the WT E2 mice compared with the WT control mice. These findings are probably due, in part, to a reduction in ERβ expression in colonic epithelial cells as the cells progressed from a non-malignant to a cancerous state as enhanced apoptosis was observed in normal colonocytes expressing higher levels of ERβ. Furthermore, epithelial cells within the tumors had dramatically increased ERα mRNA and protein expression compared with the non-diseased mice. We conclude that while E2 treatment resulted in an overall suppression of colonic adenocarcinoma formation, reduced ERβ expression accompanied by enhanced ERα expression caused an altered colonocyte response to E2 treatment compared with the earlier stages of colon cancer development. These data are the first examples of decreased ERβ expression concurrent with increased ERα expression as a disease develops and highlight the importance of understanding the timing of E2 exposure with regard to the prevention of inflammation-associated colon cancer.

Cancer risk in Japanese Crohn's disease patients: investigation of the standardized incidence ratio

BACKGROUND AND AIM

There have been very few reported investigations on the standardized incidence ratio (SIR) of intestinal cancer and all cancers other than intestinal cancer with Crohn's disease (CD) by organ in Japan. This study examined the risk of developing cancer (i.e. SIR) that occurs in association with CD.

METHODS

The subjects were 770 CD patients managed at our hospital department, which specializes in inflammatory bowel disease, during the approximately 25 years from July 1985 to August 2010. The number of expected cancer patients in a healthy population matched for sex and age with the CD patients in our hospital was then calculated. The relative risk, or SIR, was also calculated.

RESULTS

The total observation period was 10,552 person-years, during which 19 cases (2.5%) of cancer were discovered in 770 subjects. The cancer cases included nine cases of colorectal cancer (CRC), one case of small bowel cancer, one case of stomach cancer, three cases of acute myeloid leukemia, two cases of endometrial cancer, one case of lung cancer, one case of skin cancer, and one case of thyroid cancer. The SIR for cancers in Japan in 2003 was 0.87 (95% confidence interval [CI] 0.52-1.35) for all cancers, 2.79 (95% CI 1.28-5.29) for CRC, and 6.94 (95% CI 1.43-20.3) for leukemia.

CONCLUSIONS

Among the cancers in CD patients in our hospital, no significant difference was seen in the risk for all cancers in comparison with the standard population. However, the risks for CRC and leukemia were significantly higher than in the standard population.

Immunosuppression and risk of cervical cancer

A markedly increased risk of cervical cancer is known in women immunosuppressed due to AIDS or therapy following organ transplantation. The aim of this review is to determine the association between other conditions affecting the immune system and the risk of cervical cancer. Patients with end-stage renal disease seem to be at an increased risk of cervical cancer. A higher risk of cervical precancerous lesions was found in patients with some autoimmune diseases; particularly if treated with immunosuppressants. Among behavioral factors weakening the immune system, smoking appeared to strongly increase the risk of cervical cancer, while poor diet only moderately increased the risk. It is difficult to determine whether sexually transmitted infections other than human papillomavirus infection are independent risk factors. Identifying those groups of women likely to fail in clearing persistent human papillomavirus infections would help individualize screening guidelines and target immune-associated factors in the cervical cancer etiology.

New trends in inflammatory bowel disease epidemiology and disease course in Eastern Europe

Trends in current epidemiological data suggest that the incidence of inflammatory bowel diseases is changing. Eastern Europe previously was seen as a low incidence area; however, new data confirm that incidence and prevalence are quickly increasing in some countries, reaching moderate-to-high incidence as reported in Western European countries. The quality of the studies also improved. Recently, data became available on the natural history of the disease from Eastern European countries. Current trends are similar to those reported from Western Europe and North America, including less complicated disease at diagnosis, accelerated use of immunomodulators and decreased need for surgery in Crohn's disease, more cases of proctitis and relatively low colorectal cancer risk in ulcerative colitis. In addition, in-depth analysis of disease course enabled the identification of possible predictive factors leading to some novel findings, such as the association between the decline in surgery risk and early treatment strategy. In contrast, some unexplained differences exist, such as the low overall colectomy risk in ulcerative colitis.

Declining risk of colorectal cancer in inflammatory bowel disease: an updated meta-analysis of population-based cohort studies

BACKGROUND

Recently reported risks of colorectal cancer (CRC) in inflammatory bowel disease (IBD) have been lower than those reported before 2000. The aim of this meta-analysis was to update the CRC risk of ulcerative and Crohn's colitis, investigate time trends, and identify high-risk modifiers.

METHODS

The MEDLINE search engine was used to identify all published cohort studies on CRC risk in IBD. Publications were critically appraised for study population, Crohn's disease localization, censoring for colectomy, and patient inclusion methods. The following data were extracted: total and stratified person-years at risk, number of observed CRC, number of expected CRC in background population, time period of inclusion, and geographical location. Pooled standardized incidence ratios and cumulative risks for 10-year disease intervals were calculated. Results were corrected for colectomy and isolated small bowel Crohn's disease.

RESULTS

The pooled standardized incidence ratio of CRC in all patients with IBD in population-based studies was 1.7 (95% confidence interval [CI], 1.2-2.2 ). High-risk groups were patients with extensive colitis and an IBD diagnosis before age 30 with standardized incidence ratios of 6.4 (95% confidence interval, 2.4-17.5) and 7.2 (95% confidence interval, 2.9-17.8), respectively. Cumulative risks of CRC were 1%, 2%, and 5% after 10, 20, and >20 years of disease duration, respectively.

CONCLUSIONS

The risk of CRC is increased in patients with IBD but not as high as previously reported and not in all patients. This decline could be the result of aged cohorts. The risk of CRC is significantly higher in patients with longer disease duration, extensive disease, and IBD diagnosis at young age.

Risk of colorectal cancer and small bowel adenocarcinoma in Crohn's disease: a population-based study from western Hungary 1977-2008

BACKGROUND AND AIMS

Limited data are available on the incidence and predictors of colorectal (CRC) and small bowel adenocarcinoma (SBA) in patients with Crohn's disease (CD) from population-based cohorts. Since data are completely missing from Eastern Europe, our aim was to analyze the incidence and risk factors of CD associated CRC and SBA in the population-based, Veszprem province database, which included incident patients diagnosed between January 1, 1977 and December 31, 2008.

METHODS

The data of 506 incident CD patients were analyzed (age-at-diagnosis: 31.5, SD: 13.8 years). Both hospital and outpatient records were collected and comprehensively reviewed.

RESULTS

CRC was diagnosed in five patients (5/5758 person-year-duration) during follow-up, while no patients developed SBA in this cohort. Standardized incidence ratio (SIR) of CRC was not increased overall with five cases observed vs. 5.02 expected (SIR: 0.99, 95% CI: 0.41-2.39); however, there was a tendency for increased incidence in males (five cases observed vs. 2.56 expected; SIR: 1.95, 95% CI: 0.81-4.70). Age at onset of CD (p<0.001), male gender (p=0.022) and stenosing disease behavior at diagnosis (p<0.001) but not disease location were identified as risk factors for developing CRC in univariate analysis and Kaplan-Meier analysis. The cumulative risk for developing CRC after a disease duration of 20 years was 1.1% (95% CI: 0.6-1.7%).

CONCLUSIONS

The incidence of CRC and SBA was not increased in this population-based CD cohort. Age at onset of CD, male gender and stenosing disease behavior at diagnosis were identified as risk factors of CRC.

Mortality in inflammatory bowel disease in the Netherlands 1991-2002: results of a population-based study: the IBD South-Limburg cohort

BACKGROUND

The aim was to evaluate overall and disease-specific mortality in a population-based inflammatory bowel disease (IBD) cohort in the Netherlands, as well as risk factors for mortality.

METHODS

IBD patients diagnosed between 1 January 1991 and 1 January 2003 were included. Standardized mortality ratios (SMRs) were calculated overall and with regard to causes of death, gender, as well as age, phenotype, smoking status at diagnosis, and medication use.

RESULTS

At the censoring date, 72 out of 1187 patients had died (21 Crohn's disease [CD], 47 ulcerative colitis [UC], and 4 indeterminate colitis [IC] patients). The SMR (95% confidence interval [CI]) was 1.1 (0.7-1.6) for CD, 0.9 (0.7-1.2) for UC and 0.7 (0.2-1.7) for IC. Disease-specific mortality risk was significantly increased for gastrointestinal (GI) causes of death both in CD (SMR 7.5, 95% CI: 2.8-16.4) and UC (SMR 3.4, 95% CI: 1.4-7.0); in CD patients, especially in patients <40 years of age at diagnosis. For UC, an increased SMR was noted in female patients and in patients <19 years and >80 years at diagnosis. In contrast, UC patients had a decreased mortality risk from cancer (SMR 0.5, 95% CI; 0.2-0.9).

CONCLUSIONS

In this population-based IBD study, mortality in CD, UC, and IC was comparable to the background population. The increased mortality risk for GI causes might reflect complicated disease course, with young and elderly patients at diagnosis needing intensive follow-up. Caution in interpreting the finding on mortality risk from cancer is needed as follow-up was probably to short to observe IBD-related cancers.

Adverse effects of biologics used for treating IBD

In the last decade, biologic agents, in particular anti-TNF agents such as infliximab, adalimumab, and certolizumab have substantially extended the therapeutic armamentarium of inflammatory bowel disease (IBD). Additional approaches include biologicals, such as natalizumab, that block leucocyte adhesion; those that target cytokines, such as interleukin-12/23 antibodies; or those that inhibit T-cell signaling, such as interleukin-6 receptor antibodies. However, these drugs have a number of contraindications and side effects, especially when used in combination with classical immunosuppressive agents or corticosteroids. Areas of concern include opportunistic infections, malignancies, and miscellaneous complications such as injection/infusion reactions and autoimmunity and contraindications, such as heart failure and acute infectious diseases. In this review, the indications of biologicals in IBD treatment are briefly reported, and the potential disadvantages of a more active therapeutic approach in IBD are discussed. We have learned in the last decade that anti-TNF-alpha therapy is an effective and relatively safe treatment option for selected patients that changes the natural course of severe IBD. However, despite these changed therapeutic paradigms and goals in IBD, clinicians should be aware that the powerful immunosuppressive capacity of biologicals necessitates a rigorous long-term safety follow-up.

Current trends in inflammatory bowel disease: the natural history

The description of the prognosis of inflammatory bowel disease (IBD) is based on systematic follow-up of population-based cohorts. A steady increase in incidence of IBD has occurred. The distribution of ulcerative colitis (UC) is fairly uniform with a preponderance of left-sided disease. One-third of Crohn's disease (CD) patients present with colonic disease, one-third with ileocolonic disease and one-third with small bowel disease. IBD is associated with extra-intestinal manifestations (EIMs) in up to 36% of patients. Uveitis and episcleritis are the most common. The cumulative probability of a relapsing course in UC is 90% after 25 years. In CD disease behaviour varies substantially with time. At diagnosis behaviour is inflammatory in 70% of patients. At follow-up there is a change to either stricturing or penetrating disease. Most patients with CD will eventually require surgery. Risk factors for CD recurrence after surgery include penetrating/fistulizing disease behaviour, young age, short duration of disease before first surgery and ileocolonic disease. The incidence of colorectal cancer (CRC) in UC seems to be decreasing. The risk of CRC in CD seems to be equivalent to the risk in UC. Patients with small bowel CD are also at increased risk of small bowel adenocarcinoma. CD is associated with a mortality rate 20-70% higher than expected, whereas mortality in UC is equivalent to that of the general population. The improved prognosis of IBD, especially UC, could be due to a chemopreventive effect of the medications used. Further studies are needed to develop the best strategy for the reduction of mortality and cancer risk in IBD.

Safety profile of IBD: lymphoma risks

This article describes the cancer risks of commonly used inflammatory bowel disease (IBD) medications, with an emphasis on hematologic malignancy risks. The increasing use of immunosuppressant therapies in the treatment of IBD has raised this question to an even greater importance. Studies evaluating these medications are complicated due to varying disease severity and concomitant use of other immunosuppressant medication. The potential risks of all therapies must be weighed against the benefits these therapies can offer these patients.

Safety profile of IBD: lymphoma risks

This article describes the cancer risks of commonly used inflammatory bowel disease (IBD) medications, with an emphasis on hematologic malignancy risks. The increasing use of immunosuppressant therapies in the treatment of IBD has raised this question to an even greater importance. Studies evaluating these medications are complicated due to varying disease severity and concomitant use of other immunosuppressant medication. The potential risks of all therapies must be weighed against the benefits these therapies can offer these patients.

Incidence and prognosis of cholangiocarcinoma in Danish patients with and without inflammatory bowel disease: a national cohort study, 1978-2003

Patients with inflammatory bowel disease (IBD) are at increased risk of cholangiocarcinoma (CC), but quantitative data are scant. Furthermore, little is known about the impact of IBD on CC occurrence and prognosis. Based on nationwide population-based registries we compared the incidence and survival of CC patients with and without IBD from 1978 to 2003. We used the National Registry of Patients and the Danish Cancer Registry to identify patients with IBD and CC. From the Civil Registration System we identified population controls. We calculated incidence rates, incidence rate ratios (compared with population controls), and absolute cumulative risks. We also computed median survival in CC patients with and without IBD. 2,725 CC patients were identified. The incidence of CC among the 41,280 IBD patients was 7.6 per 100,000 person years compared with 1.9 per 100,000 among the 412,796 population controls (four-fold increased risk). The 10 year cumulative risk of CC in IBD patients was 0.07%. Sub analyses showed that the increased risk of CC was more pronounced in male IBD patients and in patients with ulcerative colitis. We found a decreasing CC incidence in IBD patients over calendar time. CC patients with IBD were, on average, 15 years younger at cancer diagnosis than IBD-free CC patients, and median survival was 1 month in both groups. In conclusion, the absolute risk of CC in IBD patients was low and the CC incidence decreased over calendar time. The prognosis was equally grave, regardless of the presence of IBD.

The epidemiology and pathogenesis of neoplasia in the small intestine

PURPOSE

The mucosa of the small intestine encompasses about 90% of the luminal surface area of the digestive system, but only 2% of the total annual gastrointestinal cancer incidence in the United States.

METHODS

The remarkable contrast in age-standardized cancer incidence between the small and large intestine has been reviewed with respect to the cell type patterns, demographic features, and molecular characteristics of neoplasms.

RESULTS

Particularly noteworthy is the predominance of adenocarcinoma in the colon, which exceeds 98% of the total incidence by cell type, in contrast to that of 30% to 40% in the small intestine, resulting in an age-standardized ratio of rates exceeding 50-fold. The prevalence of adenomas and carcinomas is most prominent in the duodenum and proximal jejunum. The positive correlation in global incidence rates of small and large intestinal neoplasms and the reciprocal increases in risk of second primary adenocarcinomas suggest that there are common environmental risk factors. The pathophysiology of Crohn inflammatory bowel disease and the elevated risk of adenocarcinoma demonstrate the significance of the impaired integrity of the mucosal barrier and of aberrant immune responses to luminal indigenous and potentially pathogenic microorganisms.

CONCLUSION

In advancing a putative mechanism for the contrasting mucosal susceptibilities of the small and large intestine, substantial differences are underscored in the diverse taxonomy, concentration and metabolic activity of anaerobic organisms, rate of intestinal transit, changing pH, and the enterohepatic recycling and metabolism of bile acids. Experimental and epidemiologic studies are cited that suggest that the changing microecology, particularly in the colon, is associated with enhanced metabolic activation of ingested and endogenously formed procarcinogenic substrates.

Concomitant carcinoid tumor and papillary urothelial neoplasm of low malignant potential in a patient with Crohn's disease: a case report

Patients with a long-term history of inflammatory bowel diseases show an increased risk of developing colorectal cancers. In the case of Crohn's disease, such an increased risk is also associated with other malignant tumors. The report presents a very rare case of a concomitant carcinoid tumor and papillary urothelial neoplasm of low malignant potential in a 35-year-old patient with diagnosed Crohn's disease complicated by an enterovesical fistula. The carcinoid tumor and papillary urothelial neoplasm of low malignant potential were diagnosed by postoperative histopathology. In patients with Crohn's disease, concomitant occurrence of various malignancies may be observed even earlier in life.

Risks and clinical features of colorectal cancer complicating Crohn's disease in Japanese patients

BACKGROUND AND AIM

No reports on the relative risk of development of colorectal cancer (CRC) in Japanese patients with Crohn's disease (CD) have been published. The present study aimed to investigate the relative risk and the clinical features of CRC complicating CD among patients managed at Fukuoka University Chikushi Hospital, Fukuoka, Japan (a tertiary referral center for inflammatory bowel diseases).

METHODS

The clinical backgrounds were analyzed of 512 patients with CD who have been treated by our department during the last 20-year period (1985-2005) (total 6212.6 person years at risk). The standardized incidence ratio (SIR) refers to the relative risk of CRC in the subjects as compared with that in a sex- and age-matched healthy population.

RESULTS

There were six cases with CRC. The SIR was significantly higher (3.2-fold higher; 95% confidence interval, 1.2-6.9 P < 0.05) in the CD group than in the healthy population. The significant risk factors identified were female sex, mixed small and large bowel type, observation period over 20 years, onset of CD at less than 25 years of age, presence of anal disease, and positive history of surgery. The prognosis for the six cases with CRC was very poor (five cases died within 1.5 years).

CONCLUSION

The risk of CRC in longstanding CD in Japan was similar to that in Western countries. The necessity of surveillance in the management of CD would also need to be discussed in the near future, especially in CD patients with anal lesions or fistulae, and are particularly important in patients with a 20-year or more history of CD.

Screening and surveillance colonoscopy in chronic Crohn's colitis: results of a surveillance program spanning 25 years

BACKGROUND & AIMS

Since 1980, we have followed 259 patients with chronic Crohn's colitis in a prospective colonoscopic surveillance program. Our initial results through August 1998 showed a 22% chance of developing definite dysplasia or cancer by the fourth surveillance examination. We now update the results of all examinations since September 1998 until April 2005.

METHODS

All patients had at least 7 years of Crohn's colitis affecting at least one third of the colon. Patients were recalled every 1 to 2 years or sooner if dysplasia was found. Pathology was classified as normal, dysplasia (indefinite, low-grade [LGD], or high-grade [HGD]), or carcinoma. Lesions were classified as flat, polyp, or mass.

RESULTS

A total of 1424 examinations were performed on 259 patients. Ninety percent had extensive colitis. The median age at diagnosis was 22 years (range, 2-61 y), and the median disease duration was 18 years (range, 7-49 y). On screening examination, definite dysplasia or cancer was found in 18 patients (7%). Thirteen had LGD, 2 had HGD, and 3 had cancer. On surveillance examinations, a first finding of definite dysplasia or cancer was found in an additional 30 patients (14%). Twenty-two had LGD, 4 had HGD, and 4 had cancer. The cumulative risk of detecting an initial finding of any definite dysplasia or cancer after a negative screening colonoscopy was 25% by the 10th surveillance examination. The cumulative risk of detecting an initial finding of flat HGD or cancer after a negative screening colonoscopy was 7% by the ninth surveillance examination.

CONCLUSIONS

Periodic surveillance colonoscopy should be part of the routine management of chronic extensive Crohn's colitis.

Small Bowel Adenocarcinoma Complicating Crohn's Disease: Case Series and Review of the Literature

Colonic adenocarcinoma frequently complicates inflammatory bowel disease of the colon, but small bowel adenocarcinoma (SBA) is a rare complication of Crohn's disease (CD). We present two patients with SBA in CD and review the literature with regards to CD-related SBA. A 45-year-old male with a 17-year history of ileal CD presented with obstructive symptoms but no radiographic evidence of a mass. After laparoscopic ileocolectomy and repair of incidental ileosigmoid fistula, pathology showed a T3N0 adenocarcinoma within the ileal CD. Two years after his resection he was without evidence of disease. A 59-year-old male with a 15-year history of CD presented with an acute exacerbation. Small bowel follow through demonstrated a long ileal stricture for which he underwent an ileocolic resection. Postoperative pathology confirmed a T3N1 CD-related SBA. He died from metastatic cancer 3 months later. Review of the literature identified 154 cases of SBA complicating CD with several distinguishing features from de novo SBA. Patients with SBA and CD are, as a group, younger and more likely to be male. SBA is rarely diagnosed preoperatively in these patients, and has a poor prognosis due to its advanced stage at diagnosis.

The risk of cancer in patients with Crohn's disease

PURPOSE

The risk of cancer in patients with Crohn's disease is not well defined. Using meta-analytical techniques, the present study was designed to quantify the risk of intestinal, extraintestinal, and hemopoietic malignancies in such patients.

METHODS

A literature search identified 34 studies of 60,122 patients with Crohn's disease. The incidence and relative risk of cancer were calculated for patients with Crohn's disease and compared with the baseline population of patients without Crohn's disease. Overall pooled estimates, with 95 percent confidence intervals, were obtained, using a random-effects model.

RESULTS

The relative risk of small bowel, colorectal, extraintestinal cancer, and lymphoma compared with the baseline population was 28.4 (95 percent confidence interval, 14.46-55.66), 2.4 (95 percent confidence interval, 1.56-4.36), 1.27 (95 percent confidence interval, 1.1-1.47), and 1.42 (95 percent confidence interval, 1.16-1.73), respectively. On subgroup analysis, patients with Crohn's disease had an increased risk of colon cancer (relative risk, 2.59; 95 percent confidence interval, 1.54-4.36) but not of rectal cancer (relative risk, 1.46; 95 percent confidence interval, 0.8-2.55). There was significant association between the anatomic location of the diseased bowel and the risk of cancer in that segment. The risk of small bowel cancer and colorectal cancer was found to be higher in North America and the United Kingdom than in Scandinavian countries with no evidence of temporal changes in the cancer incidence.

CONCLUSIONS

The present meta-analysis demonstrated an increased risk of small bowel, colon, extraintestinal cancers, and lymphoma in patients with Crohn's disease. Patients with extensive colonic disease that has been present from a young age should be candidates for endoscopic surveillance; however, further data are required to evaluate the risk of neoplasia over time.

Associated Neoplastic Disease in Inflammatory Bowel Disease

The development of intestinal carcinoma in the setting of inflammatory bowel disease (IBD) has been recognized as an unsavory outcome of chronic inflammation of the bowel. Numerous studies have recently documented the clinical and morphologic features of malignant transformation in this closely-followed group of patients. This article highlights the recent findings of these population-based studies with specific attention to surgical concepts and frames these data in the context of surgical approaches to cancer arising in inflammatory disease. Specifically, the authors address the pathobiology of malignant transformation, the management of colorectal cancer in inflammatory bowel disease, the development of dysplasia in ulcerative colitis, surveillance of patients who have IBD, chemoprevention of cancer, and special features of surgical oncologic management.

Intestinal cancer in patients with Crohn's disease

BACKGROUND

Surveillance of intestinal cancer in Crohn's disease (CD) has often been advocated. To date, no clear evidence exists whether CD patients are at special risk for intestinal cancer. An increased incidence of small bowel adenocarcinoma is suggested. However, recent figures also suggest an increased risk of CD associated colorectal cancer. We report our experience with 10 cases of CD complicated by intestinal adenocarcinoma.

MATERIALS AND METHODS

Our institutional database included 330 patients treated for CD between 1988-2005. Data of patients that developed carcinoma within Crohn's lesions of either small or large bowel were analyzed.

RESULTS

Ten patients were diagnosed with CD complicated by carcinoma. In nine patients, cancer was present in the colorectum and in one, in Crohn's ileitis. Tumors were in conjunction with fistulae in three and developed within strictures in five patients. Mean age at the time of diagnosis of CD was 43 years. Mean duration of CD until diagnosis of cancer was 14 years. Only five patients were diagnosed for cancer preoperatively. Staging revealed advanced tumors in almost all patients. Mean survival after surgery was 29 months (2-149 months).

CONCLUSIONS

Cancer risk in CD and especially in Crohn's colitis may still be underestimated. Delayed diagnosis resulted in a poor prognosis. The value of colonoscopy as surveillance tool is questioned by the fact that in our patients, carcinoma was diagnosed in some patients preoperatively by routine colonoscopy. Therefore, additional markers should be identified to detect CD patients at risk.

Survival after colorectal cancer in patients with Crohn's disease: A nationwide population-based Danish follow-up study

BACKGROUND AND AIMS

Patients with Crohn's disease (CD) are at increased risk of colorectal cancer (CRC), but little is known about the impact of CD on CRC prognosis. Based on nationwide population-based registries, we compared survival among CRC patients with CD and CRC patients without CD.

METHODS

We used the Danish Cancer Registry and the Danish Hospital Discharge Registry to identify all patients diagnosed with CRC, with and without CD, in Denmark between 1977 and 1999. We ascertained the stage distribution at the time of CRC diagnosis and 1- and 5-yr survival both for patients with Crohn-associated CRC and patients with non-Crohn CRC. Cox regression was used to compute hazard ratios (HRs), adjusting for gender, age, calendar year, and stage.

RESULTS

We identified 100 CRC patients with CD and 71,438 CRC patients without CD. At the time of diagnosis, patients with CD were younger, but stage distributions were similar in the two groups. The overall HR for CRC with CD compared to CRC without CD was 1.82 (95% CI 1.36-2.43) after 1 yr of follow-up, and 1.57 (95% CI 1.24-1.99) after 5 yr of follow-up. Subanalyses showed that the effect of CD on CRC survival was more pronounced in the youngest patients (0-59 yr), in men, and in patients whose tumors had regional spread.

CONCLUSIONS

We found that CD worsens the prognosis of CRC, particularly CRC with regional spread.

Malignant lymphomas in autoimmunity and inflammation: a review of risks, risk factors, and lymphoma characteristics

Certain autoimmune and chronic inflammatory conditions, such as Sjögren's syndrome and rheumatoid arthritis (RA), have consistently been associated with an increased risk of malignant lymphomas, but it is unclear whether elevated lymphoma risk is a phenomenon that accompanies inflammatory conditions in general. Likewise, it is debated whether the increased risk identified in association with some disorders pertains equally to all individuals or whether it varies among groups of patients with different phenotypic or treatment-related characteristics. It is similarly unclear to what extent the increased lymphoma occurrence is mediated through specific lymphoma subtypes. This update reviews the many findings on risks, risk levels, and lymphoma characteristics that have been presented recently in relation to a broad range of chronic inflammatory, including autoimmune, conditions. Recent results clearly indicate an association between severity of chronic inflammation and lymphoma risk in RA and Sjögren's syndrome. Thus, the average risk of lymphoma in RA may be composed of a markedly increased risk in those with most severe disease and little or no increase in those with mild or moderate disease. The roles of immunosuppressive therapy and EBV infection seem to be limited. Furthermore, RA, Sjögren's syndrome, systemic lupus erythematosus, and possibly celiac disease may share an association with risk of diffuse large B-cell lymphoma, in addition to well-established links of Sjögren's syndrome with risk of mucosa-associated lymphoid tissue lymphoma and of celiac disease with risk of small intestinal lymphoma. However, there is also obvious heterogeneity in risk and risk mediators among different inflammatory diseases.

Cancer in Crohn's disease

There has been a multitude of case reports, case series, hospital-based, and population-based studies that link CD to various types of cancers. When each of these studies is scrutinized, however, there is only enough evidence to support a link between colorectal adenocarcinoma, SBA, and squamous and adenocarcinomas that are associated with perianal fistulizing disease. All of the studies of large bowel adenocarcinoma or SBA follow patients in an era during which there were far fewer effective medicines to treat CD and surgery was more commonplace. The only surveillance study of patients who had extensive, long-duration Crohn's colitis showed a 22% risk for developing neoplasia (low-grade, high-grade, or cancer) after four surveillance examinations. Overall results from this study and the multitude of the other studies show that the risk for cancer in Crohn's colitis is equal to that in UC given equal extent and duration of disease. Patients who have Crohn's colitis that affects at least one third of the colon and with at least 8 years of disease should undergo screening and surveillance, just as in UC. Although the absolute risk for SBA in CD is low (2.2% at 25 years in one study), we should not rule out screening and surveying for this complication that is associated with significant morbidity and mortality in patients who have long-standing, extensive, small bowel disease. The risk for lymphoma and leukemia in CD is low, but immunomodulators and biologics may increase this risk. The evidence that links carcinoid tumors to CD is weak, and population-based studies need to be done. The study of cancers that are associated with CD is an evolving field that surely will change given that immunomodulators and biologics are being used with greater frequency.

Two synchronous adenocarcinomas of the small bowel in a patient with undiagnosed Crohn's disease of the terminal ileum

A small but significant excess of deaths for tumors of the digestive system has been described in Crohn's disease. In a study analyzing all cancers of the small intestine within a defined population, Crohn's disease was the major underlying factor for cancer of the small intestine. Areas of the small intestine containing strictures are unusually prone to malignant transformation. We report the rare case of a patient in whom surgery for intestinal occlusion disclosed Crohn's disease of the distal ileum complicated by two adenocarcinomas arising within distinct areas of the inflamed bowel.

Meta-analysis: colorectal and small bowel cancer risk in patients with Crohn's disease

BACKGROUND

Crohn's disease is associated with small bowel cancer whilst risk of colorectal cancer is less clear.

AIM

To ascertain the combined estimates of relative risk of these cancers in Crohn's disease.

METHODS

MEDLINE was searched to identify relevant papers. Exploding references identified additional publications. When two papers reviewed the same cohort, the later study was used.

RESULTS

Meta-analysis showed overall colorectal cancer relative risk in Crohn's disease as 2.5 (1.3-4.7), 4.5 (1.3-14.9) for patients with colonic disease and 1.1 (0.8-1.5) in ileal disease. Meta-regression showed reduction in relative risk over the past 30 years. Subgroup analysis showed Scandinavia had significantly lower colorectal cancer relative risk than the UK and North America. Cumulative risk analysis showed 10 years following diagnosis of Crohn's disease relative risk of colorectal cancer is 2.9% (1.5%-5.3%). Meta-analysis showed small bowel cancer relative risk in Crohn's disease is 33.2 (15.9-60.9). Small bowel cancer relative risk has not significantly reduced over the last 30 years.

CONCLUSION

Relative risk of colorectal and small bowel cancers are significantly raised in Crohn's disease. Cumulative risk of colorectal cancer of 2.9% at 10 years suggests a potential benefit from routine screening. However, the value of screening requires rigorous appraisal.

Synchronous adenocarcinoma and carcinoid tumor of the terminal ileum in a Crohn's disease patient

Background

Several malignancies have been described in association with inflammatory bowel diseases, the most common being adenocarcinoma. Carcinoid tumor and Crohn disease has also been previously reported, however the coexistence of both neoplasms is quite rare and the clinical diagnosis is very difficult. Here we report what we believe to be the fourth case of a mixed adenocarcinoid tumor coexisting with Crohn's disease.

Case report

The patient presented with clinical and radiological features of intestinal obstruction. Laparotomy showed a stricturing lesion in the last 6 cm of the terminal ileum with proximal dilation. Only the histology of the resected surgical specimen proved the presence of a mixed adenocarcinoid tumor involving the terminal ileum.

Conclusion

Carcinoid tumor should be suspected in elderly patients with Crohn's disease presenting with intestinal obstruction and laparotomy should be considered to exclude malignancy.

Increased risk of intestinal cancer in Crohn's disease: a meta-analysis of population-based cohort studies

OBJECTIVES

The risk of intestinal malignancy in Crohn's disease (CD) remains uncertain since risk estimates vary worldwide. The global CD population is growing and there is a demand for better knowledge of prognosis of this disease. Hence, the aim of the present study was to conduct a meta-analysis of population-based data on intestinal cancer risk in CD.

METHODS

The MEDLINE search engine and abstracts from international conferences were searched for the relevant literature by use of explicit search criteria. All papers fulfilling the strict inclusion criteria were scrutinized for data on population size, time of follow-up, and observed to expected cancer rates. STATA meta-analysis software was used to perform overall pooled risk estimates (standardized incidence ratio (SIR), observed/expected) and meta-regression analyses of the influence of specific variables on SIR.

RESULTS

Six papers fulfilled the inclusion criteria and reported SIRs of colorectal cancer (CRC) in CD varying from 0.9 to 2.2. The pooled SIR for CRC was significantly increased (SIR, 1.9; 95% CI 1.4-2.5), as was the risk for colon cancer separately (SIR, 2.5; 95% CI 1.7-3.5). Regarding small bowel cancer, five studies reported SIRs ranging from 3.4 to 66.7, and the overall pooled estimate was 27.1 (95% CI 14.9-49.2).

CONCLUSIONS

The present meta-analysis of intestinal cancer risk in CD, based on population-based studies only, revealed an overall increased risk of both CRC and small bowel cancer among patients with CD. However, some of the available data were several decades old, and future studies taking new treatment strategies into account are required.

The risk of lymphoma in the treatment of inflammatory bowel disease with immunosuppressive agents

Immunosuppressive agents have become an established part of the therapeutic armamentarium for inflammatory bowel disease (IBD). However, when used in transplant recipients or for other indications, agents that suppress or modulate the immune system (immunomodulators) have been associated with an increased risk of lymphoma. Fortunately, in part because of the lower doses used in IBD patients, the risk of lymphoma in IBD patients appears to be significantly less than that associated with renal and hepatic transplant-related immunosuppression. Whether the risk of azathioprine or 6-mercaptopurine associated lymphoma in IBD is real or relates to the underlying disease remains unclear. The results of several recent large well designed population-based studies suggest that the lymphoma risk associated with azathioprine and 6-mercaptopurine therapy is likely to be of minimal clinical significance compared to the established and more frequent risks of myelosuppression and infection, and is far outweighed by the clinical benefit of immunomodulator therapy in IBD. While the issue of lymphoma risk is likely to become more relevant with the growing number of biologic and immunomodulators being tested in clinical trials for IBD, early post-marketing surveillance data on infliximab suggests that the lymphoma risk may not be any greater than that associated with azathioprine and 6-mercaptopurine.

[Contraction of the hip and fecal drainage via a fistula tract 30 years after "appendectomy"]

A 46-year-old female was admitted with increasing fecal drainage via a fistula tract in the right inguinal region. She had a history of surgery for appendicitis 30 years previously, from which there was disturbed wound healing resulting in a blunt fistula, and the patient suffered from contraction of the right hip. Computed tomographic scan and ultrasound demonstrated an inflammatory mass in the right inguinal region. Colonoscopy demonstrated a stenosis of the rectosigmoid junction but did not provide any further specific information. Surgery revealed the presumed diagnosis of complicated Crohn's disease, but an advanced squamous cell carcinoma was also identified. The patient died 23 months later due to generalized tumor. Although malignant transformation of a fistula tract is rare, this case demonstrates that long-standing fistulas should be cured as far as possible without significant morbidity. In the case of incurable fistulas, malignancy must definitely be excluded if the clinical appearance of the fistula changes.

Anal and rectal cancer in Crohn's disease

Several epidemiological studies have been published regarding the risk of Crohn's disease- associated colorectal cancer. The findings are, however, contradictory and it has been particularly difficult to obtain indisputable information on the incidence of cancer limited to the rectum and the anus. During 1987-2000 rectal or anal cancer was diagnosed in 335 patients in Sweden (153 males, 182 females). In other words, approximately 3 Crohn patients per million inhabitants were diagnosed with rectal or anal cancer every year during that time period which is 1% of the total number of cases. At diagnosis of cancer 36% were aged below 50 years and 58% below 60 years. Corresponding figures for all cases of anal and rectal cancer were 5% and 18%, respectively. Present knowledge from the literature implies that there is an increased risk of rectal and anal cancer only in Crohn's disease patients with severe proctitis or severe chronic perianal disease. However, the rectal remnant must also be considered a risk factor. Multimodal treatment is similar to that in sporadic cancer but proctectomy and total or partial colectomy is added depending on the extent of the Crohn's disease. The outcome is the same as in sporadic cancer at a corresponding stage but the prognosis is often poor due to the advanced stage of cancer at diagnosis. We suggest that six high-risk groups should be recommended annual surveillance after a duration of Crohn's disease of 15 years including extensive colitis, chronic severe anorectal disease, rectal remnant, strictures, bypassed segments and sclerosing cholangitis.