Intestinal cancer in patients with Crohn's disease. A population study in central Israel

Inflammatory bowel disease among first generation immigrants in Israel: A nationwide epi-Israeli Inflammatory Bowel Disease Research Nucleus study

BACKGROUND

Israel has a high rate of Jewish immigration and a high prevalence of inflammatory bowel disease (IBD).

AIM

To compare IBD prevalence in first-generation immigrants vs Israel-born Jews.

METHODS

Patients with a diagnosis of IBD as of June 2020 were included from the validated epi-IIRN (Israeli IBD Research Nucleus) cohort that includes 98% of the Israeli population. We stratified the immigration cohort by IBD risk according to country of origin, time period of immigration, and age group as of June 2020.

RESULTS

A total of 33544 patients were ascertained, of whom 18524 (55%) had Crohn's disease (CD) and 15020 (45%) had ulcerative colitis (UC); 28394 (85%) were Israel-born and 5150 (15%) were immigrants. UC was more prevalent in immigrants (2717; 53%) than in non-immigrants (12303, 43%, P < 0.001), especially in the < 1990 immigration period. After adjusting for age, longer duration in Israel was associated with a higher point prevalence rate in June 2020 (high-risk origin: Immigration < 1990: 645.9/100000, ≥ 1990: 613.2/100000, P = 0.043; intermediate/low-risk origin: < 1990: 540.5/100000, ≥ 1990: 192.0/100000, P < 0.001). The prevalence was higher in patients immigrating from countries with high risk for IBD (561.4/100000) than those originating from intermediate-/low-risk countries (514.3/100000; P < 0.001); non-immigrant prevalence was 528.9/100000.

CONCLUSION

Lending support to the environmental effect on IBD etiology, we found that among immigrants to Israel, the prevalence of IBD increased with longer time since immigration, and was related to the risk of IBD in the country of origin. The UC rate was higher than that of CD only in those immigrating in earlier time periods.

Small bowel adenocarcinoma in Crohn's disease: a systematic review and meta-analysis of the prevalence, manifestation, histopathology, and outcomes

BACKGROUND AND AIMS

Small bowel adenocarcinoma (SBA) is a rare neoplasm that is associated with Crohn's disease (CD). This study aims to quantify the prevalence of CD-SBA, review the current evidence of histopathology and molecular analysis findings, and identify the clinical presentation and outcomes of CD-SBA.

METHODS

Electronic databases Medline and Embase were searched for articles describing SBA in inflammatory bowel disease patients. The histopathology, molecular analysis findings, clinical presentation, prevalence, and outcomes of CD-SBA were extracted, and results were pooled with random effects.

RESULTS

In total, 33 articles were included in the analysis. Prevalence of SBA was 1.15 (CI: 0.31-2.33) per 1000 CD patients. Only 11% (CI: 0.04-0.21) of CD-SBA patients had observable radiological features. CD-SBA was most commonly found in the ileum (84%), diagnosed at stage 2 (36%), with main presenting complaints including obstruction, weight loss, and abdominal pain. Significant histopathological findings included adjacent epithelial dysplasia, and an equal distribution of well-differentiated (49%) and poorly differentiated subtypes (46%). Most prevalent genetic mutation was KRAS mutation (18%), followed by mismatch repair deficiency (9.7%). The 5-year overall survival for CD-SBA patients was 29% (CI: 0.18-0.41), and 33% (CI: 0.26-0.41) for de novo SBA. No statistically significant increase in risk for CD-SBA was noted for treatment with thiopurines, steroids, and 5-ASA.

CONCLUSION

Our meta-analysis found the prevalence of CD-SBA to be 1.15 per 1000 CD patients. The 5-year overall survival for CD-SBA was poor. The presenting symptoms were non-specific, and therefore the diagnosis requires a high index of suspicion.

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

BACKGROUND AND AIM

Although surveillance colonoscopy is recommended by several guidelines for Crohn's disease (CD), the evidence is insufficient to support the validity of this recommendation. Moreover, the efficacy of surveillance colonoscopy for anorectal cancer remains unclear. Therefore, we performed a systematic review of cancer in patients with CD before considering the proper surveillance methods.

METHODS

We conducted a systematic review and meta-analysis examining the incidence of intestinal cancer and a literature review to clarify the characteristic features of cancer in CD. We performed the systematic literature review of studies published up to May 2019.

RESULTS

Overall, 7344 patients were included in eight studies. The standardized incidence ratios (95% confidence intervals) of colorectal cancer (CRC) and small bowel cancer (SBC) were 2.08 (1.43-3.02) and 22.01 (9.10-53.25), respectively. The prevalence of CRC and SBC was 57/7344 (0.77%) and 17/7344 (0.23%), respectively, during a median follow-up of 12.55 years. Additionally, 54 studies reporting 208 anorectal cancer cases were identified. In patients with anorectal cancer, the prognosis for survival was 2.1 ± 2.3 years, and advanced cancer greater than stage T3 occurred in 46/74 patients (62.1%). Many more reports of anorectal cancer were published in Asia than in Western countries.

CONCLUSION

Although we were unable to state a recommendation for surveillance for SBC, we should perform cancer surveillance for CRC in patients with CD. However, the characteristics of cancer may differ according to geography or race. We must establish proper and effective surveillance methods that are independently suitable to detect these differences.

Colorectal Malignancy in a Prospective Irish Inflammatory Bowel Disease Population 15 Years Since Diagnosis: Comparison with the EC-IBD Cohort

BACKGROUND AND AIM

As part of the EC-IBD prospective inception cohort study, we had unique opportunity to follow up our patients since diagnosis in the early 1990s.

PATIENTS AND METHODS

All patients from the greater Dublin area (n = 192) were followed up from inception between 1991 and 1993 until the 30 September 2009. Patients who developed malignancies were logged electronically with verification of the site and histology.

RESULTS

Of the initial 192 patients, 133 were included in the 15-year follow-up. Of those, 80 (60.2%) had UC and 53 (39.8%) had CD. There were 82 (61.7%) males and 51 (38.3%) females. Six patients had extraintestinal malignancy; however, there was no CRC related to IBD noted in our cohort. Four of the 6 identified cases had UC (64%) with a mean age of 54.25 years at the time of cancer diagnosis, whereas the two CD patients had a mean age of 51.5 years at the time of cancer diagnosis.

CONCLUSION

CRC was not observed in our cohort. The six extraintestinal malignancies did not show significant relation to IBD. The high total colectomy rate (in the prebiological therapy era) may have contributed to low malignancy rate.

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.

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.

Colorectal cancer and Crohn's colitis: clinical implications from 313 surgical patients

BACKGROUND

The relation between Crohn's colitis (CC) and colorectal cancer is still controversial. Several case reports and retrospective studies have shown that patients with Crohn's disease (CD) have a 6- to 20-fold higher risk to develop CRC than does the normal population. The extent of disease (extensive colitis), presence of anal fistula, age > 40 years, strictures, and length of disease >10 years may be important determinants for increasing risk. Despite this evidence, other population-based studies have shown no increased risk of colon or rectal cancer. The aim of this study was to investigate retrospectively factors that may predict the development of cancer.

METHODS

We searched the histopathologic database of the Digestive Surgery Unit at Careggi University Hospital for CC patients (January 1987 to September 2011) and identified 313 patients with CC who underwent surgery.

RESULTS

There are 11 (3.5 %) of adenocarcinomas. Multivariate analysis showed disease duration (p = 0.001), age at CD diagnosis (p = 0.002), distal localization (p = 0.045), and penetrating disease (p = 0.041) to be risk factors. Multivariate analysis showed that 40 patients who had undergone previous immunosuppressive therapy had a significant risk of developing CRC (p = 0.026).

CONCLUSIONS

Crohn's colitis patients who require surgery are at higher risk for developing CRC, particularly those whose disease duration is >10 years, have distal localization, age at diagnosis was <40 years, and have penetrating disease. Previous immunosuppressive therapy should be better investigated. We recommend surgery for any patient presenting with colonic strictures.

Incidence, presentation, and prognosis of small bowel adenocarcinoma in patients with small bowel Crohn's disease: a prospective observational study

BACKGROUND

Patients with Crohn's disease (CD) of the colon are at risk for colorectal cancer and should be screened for dysplasia and cancer of the colon. Small bowel adenocarcinoma (SBA) is a complication of small bowel CD and carries a poor prognosis. However, there is no screening test for SBA in patients with small bowel CD. The aim of this study was to assess the risk and incidence of SBA in a large prospective cohort of patients with small bowel CD and to compare it with the risk of colorectal cancer in patients with CD involving the colon, recruited in the same cohort.

METHODS

In a nationwide French cohort, 11,759 patients with CD were enrolled by 680 gastroenterologists. The SBA risk was obtained by dividing the observed cases in our cohort to the expected cases in the general population.

RESULTS

At baseline, 8222 (69.9%) patients had small bowel CD (either alone or associated with colonic CD); their median follow-up was 35 months (interquartile range, 29-40). Five new cases of SBA were diagnosed, all in patients with small bowel CD, within inflamed areas. Among the 5 patients with incident SBA, 4 died of SBA and 1 is in remission 7 years after the diagnosis of SBA. The incidence rates of SBA were 0.235 per 1000 patient-years (95% confidence interval [CI], 0.076-0.547) among patients with small bowel CD and 0.464 per 1000 patient-years (95% CI, 0.127-1.190) among those with small bowel CD for >8 years. This accounted for approximately 30% of the risk of colorectal cancer in patients with CD of the colon. Patients with small bowel CD and small bowel CD for >8 years had an SBA standardized incidence ratio of 34.9 (95% CI, 11.3-81.5) and 46.0 (95% CI, 12.5-117.8), respectively.

CONCLUSIONS

SBA in patients with small bowel CD carries a poor prognosis, and its risk is approximately 30% of colorectal cancer risk in patients with CD of the colon. Further studies should determine if small bowel endoscopic screening in high-risk patients is feasible and effective.

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.

Small bowel adenocarcinoma in Crohn disease: CT-enterography features with pathological correlation

PURPOSE

The aim of this study was to analyze the clinical, pathological, and CT-enterography findings of small bowel adenocarcinomas in Crohn disease patients.

MATERIALS AND METHODS

Clinical, histopathological, and imaging findings were retrospectively evaluated in seven Crohn disease patients with small bowel adenocarcinoma. CT-enterography examinations were reviewed for morphologic features and location of tumor, presence of stratification, luminal stenosis, proximal dilatation, adjacent lymph nodes, and correlated with findings at histological examination.

RESULTS

The tumor was located in the terminal (n = 6) or distal (n = 1) ileum. On CT-enterography, the tumor was visible in five patients, whereas two patients had no visible tumor. Four different patterns were individualized including small bowel mass (n = 2), long stenosis with heterogeneous submucosal layer (n = 2), short and severe stenosis with proximal small bowel dilatation (n = 2), and sacculated small bowel loop with irregular and asymmetric circumferential thickening (n = 1). Stratification, fat stranding, and comb sign were present in two, two, and one patients, respectively.

CONCLUSION

Identification of a mass being clearly visible suggests strongly the presence of small bowel adenocarcinoma in Crohn disease patients but adenocarcinoma may be completely indistinguishable from benign fibrotic or acute inflammatory stricture. Knowledge of these findings is critical to help suggest the diagnosis of this rare but severe complication of Crohn disease.

Health supervision in the management of children and adolescents with IBD: NASPGHAN recommendations

Ulcerative colitis (UC) and Crohn disease (CD), collectively referred to as inflammatory bowel disease (IBD), are chronic inflammatory disorders that can affect the gastrointestinal tract of children and adults. Like other autoimmune processes, the cause(s) of these disorders remain unknown but likely involves some interplay between genetic vulnerability and environmental factors. Children, in particular with UC or CD, can present to their primary care providers with similar symptoms, including abdominal pain, diarrhea, weight loss, and bloody stool. Although UC and CD are more predominant in adults, epidemiologic studies have demonstrated that a significant percentage of these patients were diagnosed during childhood. The chronic nature of the inflammatory process observed in these children and the waxing and waning nature of their clinical symptoms can be especially disruptive to their physical, social, and academic development. As such, physicians caring for children must consider these diseases when evaluating patients with compatible symptoms. Recent research efforts have made available a variety of more specific and effective pharmacologic agents and improved endoscopic and radiologic assessment tools to assist clinicians in the diagnosis and interval assessment of their patients with IBD; however, as the level of complexity of these interventions has increased, so too has the need for practitioners to become familiar with a wider array of treatments and the risks and benefits of particular diagnostic testing. Nonetheless, in most cases, and especially when frequent visits to subspecialty referral centers are not geographically feasible, primary care providers can be active participants in the management of their pediatric patients with IBD. The goal of this article is to educate and assist pediatricians and adult gastroenterology physicians caring for children with IBD, and in doing so, help to develop more collaborative care plans between primary care and subspecialty providers.

Small bowel carcinoma mimicking a relapse of Crohn's disease: a case series

We describe three patients diagnosed and treated for presumed (relapsing) Crohn's disease, but who were subsequently diagnosed with a small bowel carcinoma. This case series underlines the necessity of performing a full work up in the diagnosis of CD and to consider small bowel carcinoma in patients with small bowel CD failing medical therapy.

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.

Long-term complications, extraintestinal manifestations, and mortality in adult Crohn's disease in population-based cohorts

BACKGROUND

Crohn's disease (CD) is a chronic, progressive, destructive disease. Numerous intestinal and extraintestinal complications and manifestations can occur during its clinical course. This literature review summarizes our current knowledge of the long-term complications, extraintestinal complications, and mortality in CD in adults as reported in population-based studies that include long-term follow-up results.

METHODS

A literature search of English and non-English language publications listed in the electronic databases of Medline (source PubMed, 1935 to July, 2009).

RESULTS

The relative risk of incident fractures is increased in CD patients by ≈30%-40%. These patients have also have a 3-fold increased risk of deep venous thrombosis and pulmonary embolism. A variety of extraintestinal manifestations (primary sclerosing cholangitis, ankylosing spondylitis, iritis/uveitis, pyoderma gangrenosum, erythema nodosum) and diseases (asthma, bronchitis, pericarditis, psoriasis, rheumatoid arthritis, and multiple sclerosis) are associated with CD. The risks of colorectal and small bowel cancers relative to the general population are 1.4-1.9 and 21.1-27.1, respectively. A slightly increased risk of lymphoma, irrespective of medication use, has been reported in a recent meta-analysis of population-based studies. Overall mortality is slightly increased in CD, with a standardized mortality ratio of 1.4.

CONCLUSIONS

CD is frequently associated with disease complications and extraintestinal conditions. Whether the impact of changing treatment paradigms with increased use of immunosuppressives and biologic agents can reduce disease complications and associated conditions is unknown.

Risk of colorectal cancer in self-reported inflammatory bowel disease and modification of risk by statin and NSAID use

BACKGROUND

Statins and nonsteroidal anti-inflammatory drugs (NSAIDs) are associated with reduced risk of colorectal cancer (CRC) in some studies. The objective of this study was to quantify the relative risk of inflammatory bowel disease (IBD) as a risk factor for CRC and to estimate whether this risk may be modified by long-term use of NSAIDs or statins.

METHODS

The Molecular Epidemiology of Colorectal Cancer study is a population-based, case-control study of incident colorectal cancer in northern Israel and controls matched by age, sex, clinic, and ethnicity. Personal histories of IBD and medication use were measured by structured, in-person interview. The relative risk of IBD and effect modification by statins and NSAIDs were quantified by conditional and unconditional logistic regression.

RESULTS

Among 1921 matched pairs of CRC cases and controls, a self-reported history of IBD was associated with a 1.9-fold increased risk of CRC (95% confidence interval [CI], 1.12-3.26). Long-term statin use was associated with a reduced risk of both IBD-associated CRC (odds ratio [OR] = 0.07; 95% CI, 0.01-0.78) and non-IBD CRC (OR = 0.49; 95% CI, 0.39-0.62). Stratified analysis suggested that statins may be more protective among those with IBD (ratio of OR = 0.14; 95% CI, 0.01-1.31; P = .51), although not statistically significant. NSAID use in patients with a history of IBD was suggestive of reduced risk of CRC but did not reach statistical significance (OR = 0.47; 95% CI, 0.12-1.86).

CONCLUSIONS

The risk of CRC was elevated 1.9-fold in patients with IBD. Long-term statin use was associated with reduced risk of CRC in patients with IBD.

Fistula-associated anal adenocarcinoma in Crohn's disease

BACKGROUND

Adenocarcinoma arising from perianal fistulae in patients with Crohn's disease (CD) is rare. The literature consists mainly of case reports and small series making characterization of this clinical entity difficult. We present 6 patients with CD and fistula-associated anal adenocarcinoma (FAAA) and a systematic review of published series.

METHODS

Retrospective charts were reviewed of 6 consecutive patients with FAAA in CD treated from 1992 through 2007. All available variables of our patients and of all available published cases were included for statistical analysis.

RESULTS

All patients treated at our institution had severe perianal CD at presentation. The average age at time of diagnosis was 45.5 years. All patients underwent abdominoperineal resection (APR) and 4 received chemoradiation. Four patients died with metastatic disease, 1 is alive with pelvic recurrence at 55 months, and 1 is alive without evidence of disease at 19 months follow-up. A total of 23 publications including 65 patients (37 female, mean age 53 years) with FAAA were reviewed in our systematic review. The average fistula duration was 14 years. Mean delay of cancer diagnosis was 11 months. APR was performed in 56 patients with an overall 3-year survival rate of 54%. Thirteen of 15 patients with node-positive tumors died with recurrent disease following surgery.

CONCLUSIONS

Adenocarcinoma arising from long-standing perianal CD fistulae is being increasingly reported. The outcome is poor following operative treatment, especially if perirectal lymph nodes are involved. Periodical cancer surveillance should be performed in all patients with long-standing perianal CD fistulae.

Mechanisms by which inflammation may increase intestinal cancer risk in inflammatory bowel disease

Patients with ulcerative colitis and Crohn's disease are at increased risk of developing intestinal cancers via mechanisms that remain incompletely understood. However, chronic inflammation and repeated events of inflammatory relapse in inflammatory bowel disease (IBD) expose these patients to a number of signals known to have tumorigenic effects including persistent activation of the nuclear factor-kappaB and cyclooxygenase-2/prostaglandin pathways, release of proinflammatory mediators such as tumor necrosis factor-alpha and interleukin-6, and enhanced local levels of reactive oxygen and nitrogen species. These inflammatory signals can contribute to carcinogenesis via 3 major processes: 1) by increasing oxidative stress, which promotes DNA mutagenesis thus contributing to tumor initiation; 2) by activating prosurvival and antiapoptotic pathways in epithelial cells, thereby contributing to tumor promotion; and 3) by creating an environment that supports sustained growth, angiogenesis, migration, and invasion of tumor cells, thus supporting tumor progression and metastasis. The present review integrates clinical and basic research observations in an attempt to provide a comprehensive understanding of how inflammatory processes may contribute to intestinal cancer development in IBD patients.

Colonic Crohn's disease

Crohn's disease is an inflammatory disease of the gastrointestinal (GI) tract of uncertain etiology. It can affect any portion of the GI tract, involving the colon in approximately 60% of cases. Diagnosis can be unclear, but suspicion can be raised based upon clinical, endoscopic, and pathologic findings. Initial management is often medical, with surgery reserved for patients with colonic complications of Crohn's disease, such as hemorrhage, fulminant colitis, abscess or fistula, stricture, and malignant transformation. The operative choice and conduct depends upon the clinical presentation and intraoperative findings. The extent of resection is controversial, but segmental resection is appropriate in selected cases.

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.

Jumbo forceps are superior to standard large-capacity forceps in obtaining diagnostically adequate inflammatory bowel disease surveillance biopsy specimens

BACKGROUND

In inflammatory bowel disease (IBD) surveillance colonoscopy, an increased number of biopsy specimens correlates with a higher dysplasia detection rate. Larger biopsy specimens may also increase the diagnostic yield.

OBJECTIVE

To compare a new jumbo forceps with a standard large-capacity forceps in obtaining diagnostically adequate IBD surveillance biopsy specimens.

DESIGN

Prospective single-center study.

PATIENTS AND METHODS

Twenty-four patients who were undergoing an IBD surveillance colonoscopy were enrolled. As part of standard IBD surveillance, 8 paired biopsy specimens were obtained from the rectosigmoid by using the jumbo forceps and a standard large-capacity forceps.

OUTCOME MEASUREMENTS

Biopsy specimens were deemed adequate if they met all 3 of the following criteria: (1) length > or =3 mm, (2) penetration into the muscularis mucosa, and (3) < 20% crush artifact.

RESULTS

The proportion of adequate biopsy specimens obtained with the jumbo forceps was significantly higher than that obtained with the large-capacity control forceps (67% vs 48%, P < .0001). The average length of the biopsy specimen obtained with the jumbo forceps was 4.00 mm (95% CI, 3.81-4.20 mm) compared with 3.19 mm (95% CI, 2.99-3.38 mm) with the large-capacity (control) forceps.

LIMITATIONS

(1) No validated outcome measurement for the quality of GI biopsy specimens exists and (2) in this study, interobserver variability between pathologists was high.

CONCLUSIONS

The jumbo forceps was superior to a standard large-capacity forceps in obtaining diagnostically adequate IBD surveillance biopsy specimens. Because biopsy specimens obtained with the jumbo forceps were larger, the use of this forceps for IBD surveillance will allow the endoscopist to sample a larger colonic mucosal surface area, potentially resulting in an increased dysplasia detection rate.

Cancer in inflammatory bowel disease

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn's disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal-anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.

Cancer in inflammatory bowel disease

Patients with long-standing inflammatory bowel disease (IBD) have an increased risk of developing colorectal cancer (CRC). Many of the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability, and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Colon cancer risk in inflammatory bowel disease increases with longer duration of colitis, greater anatomic extent of colitis, the presence of primary sclerosing cholangitis, family history of CRC and degree of inflammation of the bowel. Chemoprevention includes aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins. To reduce CRC mortality in IBD, colonoscopic surveillance with random biopsies remains the major way to detect early mucosal dysplasia. When dysplasia is confirmed, proctocolectomy is considered for these patients. Patients with small intestinal Crohn’s disease are at increased risk of small bowel adenocarcinoma. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal-anastomosis have a rather low risk of dysplasia in the ileal pouch, but the anal transition zone should be monitored periodically. Other extra intestinal cancers, such as hepatobiliary and hematopoietic cancer, have shown variable incidence rates. New endoscopic and molecular screening approaches may further refine our current surveillance guidelines and our understanding of the natural history of dysplasia.

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.

Meta-analysis of risk of malignancy with immunosuppressive drugs in inflammatory bowel disease

BACKGROUND

There is a concern as to whether long-term administration of immunosuppressants in patients with inflammatory bowel disease (IBD) would increase the risk of malignancy.

OBJECTIVE

To compare the risks of developing malignancy between patients with IBD treated with immunosuppressive agents and patients with IBD not receiving these agents.

METHODS

A systematic literature review was conducted, and a meta-analysis was performed on data retrieved from cohort studies that followed patients with IBD who received immunosuppressive agents for more than a year and documented the incidence of newly developed malignancy. An electronic search was conducted using MEDLINE (1966-September 2006), the Cochrane Library (issue 3, 2006), and Japana Centra Revuo Medicina (1981-September 2006). Medical subject headings used in the searches were azathioprine, 6-mercaptopurine, cyclosporine, methotrexate, tacrolimus, inflammatory bowel disease, and neoplasms. We imposed no language limitation in the searches. Additionally, a manual search of reference listings from all articles retrieved from the electronic databases was performed. Using data obtained from control groups or population-based studies, the incidence of newly developed malignancy in patients with IBD treated with immunosuppressive agents was compared with that of patients with IBD who were not receiving immunosuppressive agents. Statistical analysis for the change in risk of developing malignancy was performed using the weighted mean difference (WMD) normalized to per person-year and its 95% confidence interval.

RESULTS

Nine cohort studies met the inclusion criteria for this meta-analysis. Analysis of these studies showed no discernible difference (WMD -0.3 x 10(-3)/person-year; 95% CI -1.2 x 10(-3) to 0.7 x 10(-3)) in the incidence of any kind of malignancy in patients with IBD who received immunosuppressants compared with those who did not receive immunosuppressants. No significant difference in WMD was observed when the data from patients with either Crohn's disease (CD) or ulcerative colitis (UC) were analyzed separately.

CONCLUSIONS

Our findings suggest that the administration of immunosuppressive agents in patients with either CD or UC probably does not confer a significantly increased risk of malignancy compared with patients with IBD who are not receiving these agents.

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.

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.

Crohn's colitis: the incidence of dysplasia and adenocarcinoma in surgical patients

PURPOSE

Data supporting an increased risk of colorectal cancer in patients with Crohn's colitis are inconsistent. Despite this, clinical recommendations regarding colonoscopic screening and surveillance for patients with Crohn's colitis are extrapolated from chronic ulcerative colitis protocols. The primary aim of our study was to determine the incidence of dysplasia and carcinoma in pathology specimens of patients undergoing segmental or total colectomy for Crohn's disease of the large bowel. In addition, we sought to identify risk factors associated with the development of dysplasia and carcinoma.

METHODS

We performed a retrospective review of all patients operated on at our institution for Crohn's colitis between January 1992 and May 2004. Data were retrieved from patient charts, operative notes, and pathology reports. Logistic regression was used to model the probability of having dysplasia or adenocarcinoma.

RESULTS

Two hundred twenty-two patients (138 females) who underwent surgical resection for the treatment of Crohn's colitis were included in the study. Mean age at surgery was 41 (range, 15-82) years and the mean duration of disease was 10 (range, 0-53) years. There were five cases of dysplasia (2.3 percent) and six cases of adenocarcinoma (2.7 percent). Three patients with dysplasia and one with adenocarcinoma were diagnosed on preoperative colonoscopy; while the other cases were discovered incidentally on pathologic examination of resected specimens. Factors associated with the presence of dysplasia or adenocarcinoma included older age at diagnosis (38.2 vs. 30.3 years, P = 0.02), longer disease duration (16.0 vs. 10.1 years, P = 0.05), and disease extent (90 percent extensive vs. 59 percent limited, P = 0.05).

CONCLUSIONS

Patients with severe Crohn's colitis requiring surgery are at significant risk for developing dysplasia and adenocarcinoma, particularly when diagnosed at an older age, after longer disease duration, and with more extensive colon involvement.

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease

BACKGROUND

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia, in patients with inflammatory bowel disease.

OBJECTIVES

To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease.

SEARCH STRATEGY

The following strategies were used to identify relevant studies:1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to August 2005. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases.2. Hand searching of reference lists from papers.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors.

DATA COLLECTION AND ANALYSIS

Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a P value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present, the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel.

MAIN RESULTS

Karlen 1998a in a nested case-control study comprising 142 patients from a study population of 4664 UC patients, found that 2/40 patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 controls (RR 0.28, 95% CI 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% CI 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% CI 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveilled patients; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P = 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P = 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in a surveillance group died from colorectal cancer compared to 2 of 95 patients in a non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (P < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83).

AUTHORS' CONCLUSIONS

There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance, and these patients have a correspondingly better prognosis, but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it may be acceptably cost-effective.

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.

Risk of intestinal cancer in inflammatory bowel disease: a population-based study from olmsted county, Minnesota

BACKGROUND & AIMS

The risk for colorectal cancer in Crohn's disease and ulcerative colitis patients from the United States currently is unknown. We estimated the risk for small-bowel and colorectal cancer in a population-based cohort of 692 inflammatory bowel disease patients from Olmsted County, Minnesota, from 1940 to 2001.

METHODS

The Rochester Epidemiology Project was used to identify cohort patients with colorectal and small-bowel cancer. The cumulative probability of cancer and standardized incidence ratios (SIR) were estimated using expected rates from Surveillance, Epidemiology, and End Results, white patients from Iowa, from 1973 to 2000, and Olmsted County, from 1980 to 1999.

RESULTS

Colorectal cancer was observed in 6 ulcerative colitis patients vs 5.38 expected (SIR, 1.1; 95% confidence interval [CI], 0.4-2.4), but 4 of these occurred among those with extensive colitis or pancolitis (SIR, 2.4; 95% CI, 0.6-6.0). Six Crohn's disease patients (vs 3.2 expected) developed colorectal cancer (SIR, 1.9; 95% CI, 0.7-4.1). Three Crohn's disease patients developed small-bowel cancer vs 0.07 expected (SIR, 40.6; 95% CI, 8.4-118).

CONCLUSIONS

The risk for colorectal cancer was not increased among ulcerative colitis patients overall, but appeared to be increased among those with extensive colitis. The colorectal cancer risk was increased slightly among Crohn's disease patients, who also had a 40-fold excess risk for small-bowel cancer.

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.

[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.

Review article: colorectal carcinoma and inflammatory bowel disease

The risk of colorectal cancer for any patient with ulcerative colitis is estimated to be 2% after 10 years, 8% after 20 years and 18% after 30 years of disease. The relative risk of colorectal cancer in Crohn's colitis is approximately 5.6 and should raise the same concerns as in ulcerative colitis. Risk factors for colorectal cancer include disease duration, early onset, extensive disease, primary sclerosing cholangitis and a family history of sporadic colorectal cancer. All patients should have a review colonoscopy 8-10 years after diagnosis to establish the extent of the disease. Surveillance should begin 8-10 years after disease onset for pancolitis and 15-20 years after disease onset for left-sided disease. Regular surveillance is recommended, with a screening interval every 3 years in the second decade of disease and annually by the fourth decade. Random biopsies should be taken at regular intervals with attention paid to dysplasia-associated lesions or masses, irregular plaques, villiform elevations, ulcers and strictures. Dysplasia is recognized as a premalignant condition, but the likelihood of progression to cancer is difficult to predict. High-grade dysplasia, confirmed by two expert gastrointestinal pathologists, is a strong indication for colectomy, as is low-grade dysplasia, although the diagnosis of low-grade dysplasia is unreliable. Surveillance programmes indicate that the overall 5-year survival rate is higher in surveyed patients, although patients still present with Dukes C cancers or disseminated malignancy. Surveillance has huge socioeconomic implications. As surveillance is not 100% effective, alternative ways of reducing the cancer risk with chemopreventive agents, such as aminosalicylates, are being considered.

Systematic review: has disease outcome in Crohn's disease changed during the last four decades?

BACKGROUND

Disease outcome in Crohn's disease might have changed during the last four decades. Disease outcome measurement in Crohn's disease has methodological difficulties because of patient selection and lack of proper definition of diagnostic and outcome measurement criteria.

AIM

To assess possible changes in disease outcome in Crohn's disease during the last four decades.

METHODS

A systematic literature search was performed using the MEDLINE search engine and major international conference libraries. Articles and abstracts were selected according to stringent inclusion criteria.

RESULTS

Forty articles and nine abstracts complied with the inclusion criteria. Seven studies with a median follow-up time between 11.1 and 17 years showed standard mortality ratios in Crohn's disease ranging between 2.16 and 0.72 with a tendency of decline during the last four decades. One study with 11.4 years mean follow-up time showed a statistically significant increased relative risk for colorectal cancer that was not confirmed by three others. Sixteen publications applied in the disease recurrence category. Probability of first resective surgery ranged between 38 and 96% during the first 15 years after diagnosis. The overall recurrence and surgical recurrence rates after first resective surgery ranged between 50 and 60, and 28 and 45% respectively during the following 15 years without an apparent time trend.

CONCLUSION

This structured literature review provides no hard evidence for change in disease outcome in Crohn's disease during the last four decades.

Intestinal and extra-intestinal cancer in Crohn's disease: follow-up of a population-based cohort in Copenhagen County, Denmark

AIM

To determine the long-term risk of intestinal and extra-intestinal malignancies in Crohn's disease patients in Copenhagen County, Denmark.

METHODS

In Copenhagen County, a strictly population-based cohort of 374 patients with Crohn's disease diagnosed between 1962 and 1987 was followed until 1997 in order to determine the long-term risk of intestinal and extra-intestinal malignancies. Information on cancer occurrence was provided by the Danish National Cancer Registry and confirmed by the examination of hospital files. The observed number of cases was compared with the expected number, calculated from individually computed person-years at risk and 1995 cancer incidence rates for the background population.

RESULTS

The risk of small bowel adenocarcinoma was significantly increased, independent of age and gender (standardized morbidity ratio, 66.7; 95% confidence interval, 18.1-170.7). The risk of colorectal cancer was not increased, either in the total group of patients or in patients with colonic Crohn's disease exclusively (standardized morbidity ratio, 1.64; 95% confidence interval, 0.20-5.92). Extra-intestinal cancer did not occur more frequently than expected.

CONCLUSIONS

This population-based study of patients with Crohn's disease revealed no increase in colorectal cancer risk, possibly due to maintenance treatment with 5-aminosalicylic acid preparations and surgery in treatment failure. In contrast, the risk of small bowel cancer was increased more than 60-fold, but the numbers were small. The risk of extra-intestinal cancer was not increased and no lymphomas were observed.

Strategies for detecting colon cancer and/or dysplasia in patients with inflammatory bowel disease

BACKGROUND

Patients with longstanding ulcerative colitis and colonic Crohn's disease have an increased risk of colorectal cancer compared with the general population. This review assesses the evidence that endoscopic surveillance may prolong life by allowing earlier detection of colon cancer or its pre-cursor lesion, dysplasia in patients with inflammatory bowel disease.

OBJECTIVES

To assess the effectiveness of cancer surveillance programs in reducing the death rate from colorectal cancer in patients with ulcerative colitis and colonic Crohn's disease.

SEARCH STRATEGY

The following strategies were used to identify relevant studies: 1. MEDLINE and the Cochrane Central Register of Controlled Trials were searched from 1966 to December 2002. The medical subject headings "Ulcerative Colitis", "Crohn Disease" or "Inflammatory Bowel Disease" and "Surveillance" or "Cancer" were used to perform key-word searches of the databases. 2. Hand searching of reference lists from papers.

SELECTION CRITERIA

Potentially relevant articles were reviewed independently and unblinded by three authors to determine if they fulfilled the selection criteria. Each article was rated as being eligible, ineligible, or without sufficient information to determine eligibility. Any disagreement between reviewers was resolved by consensus. Any trials published in abstract form were only considered if it was possible to obtain full details of the protocol and results from the authors.

DATA COLLECTION AND ANALYSIS

Eligible articles were reviewed in duplicate and the results of the primary research trials were abstracted onto specially designed data extraction forms. The proportion of patients dying from bowel cancer or other causes in the control and surveillance groups of each study was derived from life tables, survival curves or where possible, by calculating life tables from the data provided. Data from the original research articles were converted into 2x2 tables (survival versus death x surveillance versus control) for each of the individual studies for comparable follow-up intervals. The presence of significant heterogeneity among studies was tested by the chi-square test. Because this is a relatively insensitive test, a p value of less than 0.1 was considered statistically significant. Provided statistical heterogeneity was not present (p>0.10), the fixed effects model was used for the pooling of data. The 2x2 tables were combined into a summary test statistic using the pooled relative risk (RR) and 95% confidence intervals as described by Cochrane and Mantel and Haenszel.

MAIN RESULTS

Karlen 1998a found that 2/40 of the patients dying of colorectal cancer had undergone surveillance colonoscopy on at least one occasion compared with 18/102 of the controls (RR 0.28, 95% confidence interval 0.07 to 1.17). One of 40 patients who died from colorectal cancer had undergone surveillance colonoscopies on two or more occasions compared with 12/102 controls (RR 0.22, 95% confidence interval 0.03 to 1.74) in contrast to a more modest effect observed for patients who had only one colonoscopy (RR 0.43, 95% confidence intervals 0.05 to 3.76). Choi 1993 found that carcinoma was detected at a significantly earlier stage in the surveillance group; 15/19 had Duke's A or B carcinoma in the surveilled group compared to 9/22 in the non-surveilled group (P= 0.039). The 5-year survival rate was 77.2% for cancers occurring in the surveillance group and 36.3% for the no-surveillance group (P= 0.026). Four of 19 patients in the surveillance group died from colorectal cancer compared to 11 of 22 patients in the non-surveillance group (RR 0.42, 95% CI 0.16 to 1.11). Lashner 1990 found that four of 91 patients in the surveillance group died from colorectal cancer compared to 2 of 95 patients in the non-surveilled group (RR 2.09, 95% CI 0.39 to 11.12). Colectomy was less common in the surveillance group, 33 compared to 51 (p < 0.05) and was performed four years later (after 10 years of disease) in the surveillance group. For the pooled data analysis 8/110 patients in the surveillance group died from colorectal cancer compared to 13/117 patients in the non-surveillance group (RR 0.81, 95% CI 0.17 to 3.83).

REVIEWERS' CONCLUSIONS

There is no clear evidence that surveillance colonoscopy prolongs survival in patients with extensive colitis. There is evidence that cancers tend to be detected at an earlier stage in patients who are undergoing surveillance and these patients have a correspondingly better prognosis but lead-time bias could contribute substantially to this apparent benefit. There is indirect evidence that surveillance is likely to be effective at reducing the risk of death from IBD-associated colorectal cancer and indirect evidence that it is acceptably cost-effective.

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.

Review article: the incidence and prevalence of colorectal cancer in inflammatory bowel disease

Although colorectal cancer (CRC), complicating ulcerative colitis and Crohn's disease, only accounts for 1-2% of all cases of CRC in the general population, it is considered a serious complication of the disease and accounts for approximately 15% of all deaths in inflammatory bowel disease (IBD) patients. The magnitude of the risk was found to differ, even in population-based studies. Recent figures suggest that the risk of colon cancer for people with IBD increases by 0.5-1.0% yearly, 8-10 years after diagnosis. The magnitude of CRC risk increases with early age at IBD diagnosis, longer duration of symptoms, and extent of the disease, with pancolitis having a more severe inflammation burden and risk of the dysplasia-carcinoma cascade. Considering the chronic nature of the disease, it is remarkable that there is such a low incidence of CRC in some of the population-based studies, and possible explanations have to be investigated. One possible cancer-protective factor could be treatment with 5-aminosalicylic acid preparations (5-ASAs). Adenocarcinoma of the small bowel is extremely rare, compared with adenocarcinoma of the large bowel. Although only few small bowel cancers have been reported in Crohn's disease, the number was significantly increased in relation to the expected number.

Aminosalicylates and colorectal cancer in IBD: a not-so bitter pill to swallow

Inflammatory bowel disease (IBD) is associated with an increased risk of developing intestinal cancer at sites of chronic inflammation. Aminosalicylates, including both sulfasalazine and mesalamine, are the most commonly prescribed anti-inflammatory agents prescribed in IBD. On balance, the body of literature to date suggests that aminosalicylates confer some protection against the development of colonic neoplasia in patients with IBD and in a variety of models, including in the noninflamed gut. This latter observation implies that aminosalicylates may be of chemopreventive value in normal as well as IBD individuals. The current review examines and gives an overview of the evidence from a variety of sources, including epidemiological, in vivo and in vitro studies that have investigated the potential anticancer effects of aminosalicylates.

Colonic dysplasia and cancer in inflammatory bowel disease

Extracolonic malignancies are a relatively rare complication of inflammatory bowel disease. In contrast, colorectal cancer remains a major concern for patients with long-standing UC. The best available evidence suggests that patients with long-standing Crohn's colitis are at similar risk for colorectal cancer as those patients with long-standing UC. In patients with UC, the magnitude of this increased risk appears to be greater in patients with more extensive colonic involvement. It appears that the magnitude of this risk increases with increasing duration of disease, at least in UC. Whether this reflects the increased risk of cancer that occurs with the aging process or a separate phenomena distinct to UC is unclear. To date, the methods available to reduce the risk of cancer are less than optimal. Although surgical procedures eliminate the risk, the mental and physical sequelae of these procedures can be substantial. Surveillance with colonoscopic biopsies is likely effective in reducing although not eliminating the risk of colorectal cancer. Efforts to develop chemopreventative agents and improved surveillance methods remain areas of active investigation.