Early measles virus infection is associated with the development of inflammatory bowel disease

OBJECTIVE: The measles virus has been implicated as a possible etiological agent in the development of inflammatory bowel disease (IBD). Measles infection at an early age is associated with subacute sclerosing panencephalitis, a degenerative neurological condition caused by persistent measles infection of the central nervous system. We sought to determine whether infection with measles virus at an early age was also associated with an increased risk of developing IBD. METHODS: Patients with measles infection diagnosed before the age of 5 yr were identified through the diagnostic indices of the Mayo Clinic and the Rochester Epidemiology Project. A questionnaire was used to ascertain a subsequent history of IBD, which was confirmed by records from the subjects' physicians. The risks of developing Crohn's disease and ulcerative colitis were calculated relative to expected rates for these conditions in the Olmsted County, Minnesota population. RESULTS: Of 1164 eligible cases, 662 (57%) completed the questionnaire. There were six confirmed cases of Crohn's disease and six of ulcerative colitis. The expected number of cases was 1.9 for Crohn's disease (standardized incidence ratio [SIR] 3.1, 95% confidence interval [CI] 1.1-6.8) and 2.0 for ulcerative colitis (SIR 3.0, CI 1.1-6.5). There was a trend towards a higher risk of developing IBD with an earlier age of infection. CONCLUSIONS: Early measles infection is associated with an increased risk of developing Crohn's disease and ulcerative colitis. The risk may be higher with earlier infection.     

Survival and cause-specific mortality in ulcerative colitis: follow-up of a population-based cohort in Copenhagen County

BACKGROUND & AIMS: A population-based cohort from Copenhagen County comprising 1160 patients diagnosed with ulcerative colitis between 1962 and 1987 was followed-up until 1997 to describe survival and cause-specific mortality. METHODS: Observed vs. expected deaths were presented as standardized mortality ratio (SMR) with exact 95% confidence intervals (CI) calculated by using individually registered person-years at risk and Danish 1995 mortality rates. Cumulative survival curves were calculated. RESULTS: A total of 261 deaths occurred, not significantly different from the expected number of 249 (SMR, 1.05; 95% CI, 0.92-1.19). The median age at death among men was 70 years (range, 6-96 years) and among women 74 years (range, 25-96 years). Twenty-five deaths (9.6%) were caused by complications to ulcerative colitis, mostly infectious and cardiovascular postoperative complications. Patients older than 50 years of age at diagnosis and with extensive colitis showed an increased mortality within the first 2 years because of ulcerative colitis-associated causes. The mortality from colorectal cancer was not increased and that of cancer in general was significantly lower than expected: 50 vs. 71 (SMR, 0.70; 95% CI, 0.52-0.93). A significantly increased mortality from pulmonary embolism and pneumonia was found. Among women only, death from genitourinary tract diseases and suicide was significantly increased. CONCLUSIONS: Despite an overall normal life expectancy for patients with ulcerative colitis, patients >50 years of age and with extensive colitis at diagnosis had increased mortality within the first 2 years after diagnosis, owing to colitis-associated postoperative complications and comorbidity.     

Non-calculus suppurative cholangitis in Danish patients with inflammatory bowel disease

BACKGROUND/AIMS: We examined the risk of non-calculus suppurative cholangitis in patients with inflammatory bowel disease in the entire Danish population. METHODOLOGY: The study included all patients discharged from Danish hospitals with a diagnosis of Crohn's disease or ulcerative colitis as registered in the Danish National Registry of Patients from January 1, 1977 to December 31, 1992. We compared the observed number of patients hospitalized with suppurative cholangitis with expected numbers on the basis of age, gender, and calendar-specific incidence rates in the general population. RESULTS: Overall, 15,317 eligible patients with inflammatory bowel disease were discharged during the study period. Among these were 52 cases of non-calculus suppurative cholangitis. The incidence rate of non-calculus suppurative cholangitis in the cohort with inflammatory bowel disease was 46.1 per 100,000 person-years. The standardized incidence ratio (SIR) for suppurative cholangitis was increased similarly for patients with Crohn's disease [SIR=6.7, 95% confidence interval (CI): 3.1-12.7] and for patients with ulcerative colitis (SIR=6.6, 95% CI: 4.7-9.1). The highest relative risk was found in male patients younger than 40 years of age, for both Crohn's disease and ulcerative colitis (SIR=70.5 and 78.7, respectively). CONCLUSIONS: Patients with inflammatory bowel disease have an increased risk of non-calculus suppurative cholangitis.     

Risk of acute pancreatitis in patients with chronic inflammatory bowel disease. A Danish 16-year nationwide follow-up study

BACKGROUND: There are few epidemiologic data about the risk of acute pancreatitis in chronic inflammatory bowel diseases; we therefore wanted to estimate the risk of a first episode of acute pancreatitis in patients with Crohn's disease and ulcerative colitis in the total Danish population. METHODS: The study included all patients discharged from Danish hospitals with a diagnosis of Crohn's disease or ulcerative colitis registered in the Danish National Registry of Patients in the period from 1977 to 1992. The first episode of acute pancreatitis was identified in the cohort. The observed number of patients with acute pancreatitis was compared with expected numbers on the basis of age, sex, and calendar-specific incidence rates in the general population. RESULTS: Overall, 15,526 patients were discharged and followed up for 112,824 person-years. The standardized incidence ratio (SIR) for acute pancreatitis was increased both in patients with Crohn's disease (SIR = 4.3; 95% confidence interval (CI), 2.9-6.1) and in those with ulcerative colitis (SIR= 2.1; 95% CI, 1.6-2.8). CONCLUSION: Patients with chronic inflammatory bowel disease seem to be at increased risk of acute pancreatitis. Further validation and refinement of this registration-based study are needed.     

Survival and cause specific mortality in patients with inflammatory bowel disease: a long term outcome study in Olmsted County, Minnesota, 1940-2004

BACKGROUND AND AIMS: We followed a population based cohort of patients with inflammatory bowel disease (IBD) from Olmsted County, Minnesota, in order to analyse long term survival and cause specific mortality. Material and METHODS: A total of 692 patients were followed for a median of 14 years. Standardised mortality ratios (SMRs, observed/expected deaths) were calculated for specific causes of death. Cox proportional hazards regression was used to determine if clinical variables were independently associated with mortality. RESULTS: Fifty six of 314 Crohn's disease patients died compared with 46.0 expected (SMR 1.2 (95% confidence interval (CI) 0.9-1.6)), and 62 of 378 ulcerative colitis (UC) patients died compared with 79.2 expected (SMR 0.8 (95% CI 0.6-1.0)). Eighteen patients with Crohn's disease (32%) died from disease related complications, and 12 patients (19%) died from causes related to UC. In Crohn's disease, an increased risk of dying from non-malignant gastrointestinal causes (SMR 6.4 (95% CI 3.2-11.5)), gastrointestinal malignancies (SMR 4.7 (95% CI 1.7-10.2)), and chronic obstructive pulmonary disease (COPD) (SMR 3.5 (95% CI 1.3-7.5)) was observed. In UC, cardiovascular death was reduced (SMR 0.6 (95% CI 0.4-0.9)). Increased age at diagnosis and male sex were associated with mortality in both subtypes. In UC but not Crohn's disease, a diagnosis after 1980 was associated with decreased mortality. CONCLUSIONS: In this population based study of IBD patients from North America, overall survival was similar to that expected in the US White population. Crohn's disease patients were at increased risk of dying from gastrointestinal disease and COPD whereas UC patients had a decreased risk of cardiovascular death.     

Prognosis of chronic ulcerative colitis in a community.

Utilising the population based data resources of the Rochester Epidemiology Project, we estimated survival and risk of subsequent colon cancer in the 182 residents of Rochester, Minnesota, initially diagnosed with chronic ulcerative colitis (CUC) between 1985 and 1979. Twenty five (13.7%) had a proctocolectomy during the course of follow up. Three patients developed colorectal adenocarcinoma after the initial diagnosis of CUC (relative risk = 1.9, 95% CI 0.4-5.4). Excluding proctitis cases, the relative risk of cancer was 2.4 (95% CI 0.3-8.7). At last follow up, 37 (20.3%) were dead; only 10 patients had chronic ulcerative colitis mentioned on the death certificate. Overall survival was similar to that expected for the general population of like age and sex. Our results suggest that chronic ulcerative colitis in the community is typically a milder disease than would appear from hospital or referral centre series.     

Cancer in patients with ulcerative colitis, Crohn's disease and coeliac disease: record linkage study

OBJECTIVE: The objective of this study was to determine the risk of cancers in cohorts of patients with ulcerative colitis, Crohn's disease, or coeliac disease, compared with the risk in a control cohort. METHOD: The method used was the analysis of a linked statistical database of hospital and mortality data in an area in southern England. RESULTS: Rate ratios for cancer (excluding cases occurring within the first year of follow-up), compared with the value of 1 in the control cohort, were 1.25 [95% confidence interval (CI), 1.13-1.39] in patients with ulcerative colitis, 1.27 (95% CI, 1.11-1.45) with Crohn's disease, and 1.16 (95% CI, 0.94-1.43) with coeliac disease. In patients with ulcerative colitis or Crohn's disease, there was a significantly high risk of cancer of the colon [2.22 (95% CI, 1.71-2.83) and 1.64 (95% CI, 1.09-2.39), respectively]. In patients with ulcerative colitis there was a significantly high risk of cancer of the rectum [1.84 (95% CI, 1.27-2.58)]. In patients with ulcerative colitis or Crohn's disease, who did not undergo partial or total colectomy for it, the rate ratios for colon cancer were, respectively, 5.52 (95% CI, 4.39-6.71) and 4.81 (95% CI, 3.52-6.47). In ulcerative colitis, there was an elevated risk of cancer of the rectum, liver and ovary. The rate ratio for lung cancer was low, but of borderline significance [0.72 (95% CI, 0.50-0.98)]. In Crohn's disease, the rate ratio was high for cancer of the cervix [2.63 (95% CI, 1.12-5.29)]. In patients with coeliac disease, the high-risk cancer was non-Hodgkin's lymphoma [rate ratio 3.28 (95% CI, 1.49-6.28)]. CONCLUSION: All three diseases carry an increased risk of cancer overall when the first year cases are included, though fairly modest in scale, and the increased risk seen in coeliac disease reduces when first year cases are excluded. Each has a distinctive pattern of individual high-risk cancers.     

Ulcerative colitis and Crohn's disease: a comparison of the colorectal cancer risk in extensive colitis.

The risk of developing colorectal cancer has been compared in two identically selected cohorts of patients with extensive Crohn's colitis (n = 125) and extensive ulcerative colitis (n = 486). In both groups the effects of selection bias have been reduced wherever possible. There was an 18-fold increase in the risk of developing colorectal cancer in extensive Crohn's colitis and a 19-fold increase in risk in extensive ulcerative colitis when compared with the general population, matched for age, sex, and years at risk. The absolute cumulative frequency of risk for developing colorectal cancer in extensive colitis was 8% at 22 years from onset of symptoms in the Crohn's disease group and 7% at 20 years from onset in the ulcerative colitis group. The relative risk of colorectal cancer was increased in both ulcerative colitis and Crohn's disease among those patients whose colitis started before the age of 25 years. Whether the absolute risk is greater in the younger age group or merely reflects that the expected number of carcinomas increases with age is uncertain. While there is an increased risk of developing colorectal cancer in extensive colitis the number of patients with Crohn's disease who actually develop colorectal cancer is small because many patients with extensive Crohn's colitis undergo colectomy early in the course of their disease to relieve persistent symptoms unresponsive to medical treatment.     

Fracture risk is increased in Crohn's disease, but not in ulcerative colitis

AIMS: To study fracture rates and risk factors for fractures in patients with Crohn's disease and ulcerative colitis. METHODS: 998 self administered questionnaires were issued to members of the Danish Colitis/Crohn Association, and 1000 questionnaires were issued to randomly selected control subjects. 845 patients (84.5%) and 645 controls (65.4%) returned the questionnaire (p<0.01). 817 patients and 635 controls could be analysed. RESULTS: Analysis was performed on 383 patients with Crohn's disease (median age 39, range 8-82 years; median age at diagnosis 26, range 1-75 years), 434 patients with ulcerative colitis (median age 39, range 11-86 years; median age at diagnosis 29, range 10-78 years), and 635 controls (median age 43, range 19-93 years, p<0.01). The fracture risk was increased in female patients with Crohn's disease (relative risk (RR) = 2.5, 95% confidence interval (CI) 1.7-3.6), but not in male patients with Crohn's disease (RR = 0.6, 95% CI 0.3-1.3) or in patients with ulcerative colitis (RR = 1.1, 95% CI 0.8-1.6). An increased proportion of low energy fractures was observed in patients with Crohn's disease (15.7% versus 1.4 % in controls, 2p<0. 01), but not in patients with ulcerative colitis (5.4%, 2p=0.30). The increased fracture frequency in Crohn's disease was present for fractures of the spine, feet, and toes and fractures of the ribs and pelvis. Fracture risk increased with increasing duration of systemic corticosteroid use in Crohn's disease (2p=0.028), but not in ulcerative colitis (2p=0.50). CONCLUSIONS: An increased risk of low energy fractures was observed in female patients with Crohn's disease, but not in male patients with Crohn's disease or in patients with ulcerative colitis.     

Increased risk of cancer in ulcerative colitis: a population-based cohort study

OBJECTIVE: There is an increased risk of colorectal cancer among patients with ulcerative colitis (UC). However, the overall and site specific cancer risks in these patients have been investigated to a limited extent. To study the association between UC and cancer, a population-based study of 1547 patients with UC in Stockholm diagnosed between 1955 and 1984 was carried out. METHODS: The patients were followed in both the National Cancer Register and the National Cause of Death Register until 1989. For comparisons, regional cancer incidence rates in Stockholm County were used together with individually computed person-years at risk in the UC disease cohort. RESULTS: A total of 121 malignancies occurred among 97 individuals as compared with 89.8 expected (standardized morbidity ratio [SMR] = 1.4; 95% confidence interval (CI), 1.1-1.6). Overall, an excess number of colorectal cancers (SMR, 4.1; 95% CI, 2.7-5.8), and hepatobiliary cancers in men (SMR = 6.0; 95% CI, 2.8-11.1) associated with primary sclerosing cholangitis, was observed. The risk of pulmonary cancer was decreased (SMR = 0.3; 95% CI, 0.1-0.9). In all, 91 extracolonic malignancies were observed, compared with the 82.3 expected (SMR = 1.11; 95% CI, 0.9-1.3). CONCLUSIONS: In UC patients, the overall cancer incidence is increased mainly because of an increased incidence of colorectal and hepatobiliary cancer. This increase is partly counterbalanced by a decreased risk of pulmonary cancer compared with that in the general population.     

Increase in incidence and prevalence of inflammatory bowel disease in northern Denmark: a population-based study, 1978-2002

OBJECTIVES: Although incidence rates of inflammatory bowel disease have been reported worldwide, few long-term population-based studies with current time-trend analyses exist. We therefore examined time trends in the incidence rate of inflammatory bowel disease in a 25-year study period, and estimated the prevalence in 2002. All patients diagnosed between 1978 and 2002 were included as incident cases (n=2,326) and all patients living in North Jutland County on 31 December 2002 were used to estimate prevalent cases (n=2,205). METHODS: Medical records of all patients diagnosed with ulcerative colitis and Crohn's disease in the North Jutland County Hospital Discharge Registry were reviewed to examine if the diagnostic criteria were fulfilled. Age-specific and gender-specific standardized incidence rates were calculated. RESULTS: For ulcerative colitis, incidence rates in women increased from 8.3 (95% confidence interval (CI): 6.7-9.9) in 1978-1982 to 17.0 (95% CI: 14.7-19.3) per 100,000 person-years in 1998-2002. The corresponding figures for men were 7.7 (95% CI: 6.1-9.3) and 16.7 (95% CI: 14.4-18.8) per 100,000 person-years. For Crohn's disease, the incidence rates in women increased from 4.1 (95% CI: 3.0-5.2) in 1978-1982 to 10.7 (95% CI: 8.8-12.5) per 100,000 person-years in 1998-2002. The corresponding figures for men were 3.2 (95% CI: 2.1-4.2) and 8.5 (95% CI: 6.9-10.2) per 100,000 person-years. The prevalence of ulcerative colitis and Crohn's disease was 294 and 151 per 100,000 inhabitants, respectively. CONCLUSIONS: A marked and parallel increase was seen in both ulcerative colitis and Crohn's disease in both genders during the last 25 years, with a corresponding high prevalence of both diseases.     

Appendectomy is followed by increased risk of Crohn's disease

BACKGROUND & AIMS: Appendectomy is associated with a low risk of subsequent ulcerative colitis. This study analyzes the risk of Crohn's disease after appendectomy. METHODS: We followed-up 212,218 patients with appendectomy before age 50 years and a cohort of matched controls, identified from the Swedish Inpatient Register and the nationwide Census, for any subsequent diagnosis of Crohn's disease. RESULTS: An increased risk of Crohn's disease was found for more than 20 years after appendectomy, with incidence rate ratio 2.11 (95% confidence interval [CI], 1.21-3.79) after perforated appendicitis, 1.85 (95% CI, 1.10-3.18) after nonspecific abdominal pain, 2.15 (95% CI, 1.25-3.80) after mesenteric lymphadenitis, 2.52 (95% CI, 1.43-4.63) after other diagnoses. After nonperforated appendicitis, there was an increased risk among women but not among men (incidence rate ratio 1.37; 95% CI, 1.03-1.85, respectively, 0.89, 95% CI, 0.64-1.24). Patients operated on before age 10 years had a low risk (incidence rate ratio 0.48, 95% CI, 0.23-0.97). Crohn's disease patients with a history of perforated appendicitis had a worse prognosis. CONCLUSIONS: Appendectomy is associated with an increased risk of Crohn's disease that is dependent on the patient's sex, age, and the diagnosis at operation. The pattern of associations suggests a biologic cause.     

Risk factors for colorectal cancer in Crohn's colitis: a case-control study

BACKGROUND: Few data exist regarding exposures associated with colorectal cancer (CRC) in patients with Crohn's colitis. The aim of this study was to identify exposures that alter the risk of CRC in patients with Crohn's colitis. METHODS: The Research Patient Database Registry at Massachusetts General Hospital was searched to identify cases and controls. Cases had a confirmed diagnosis of Crohn's disease involving at least one third of the colon and a confirmed diagnosis of colorectal adenocarcinoma. Matched controls were randomly chosen from the same source population. Paired univariate analysis was performed to develop an odds ratio (OR) for each exposure. RESULTS: Twenty-seven patients were found to have Crohn's colitis and CRC. Colonoscopy performed for screening or surveillance was associated with an OR of 0.21 (95% CI 0.04-0.77; P=0.02). Nonsignificant trends for a protective effect included prior appendectomy (OR 0.30; 95% CI 0.05-1.17; P=0.10) and regular 5-aminosalicylate use (OR 0.30; 95% CI 0.05-1.17; P=0.10). Smoking history was associated with a 4-fold-increased risk for CRC, but this was not statistically significant (OR 4.00; 95% CI 0.80-38.67; P=0.11). CONCLUSIONS: We found that having a colonoscopy for an indication of surveillance or screening is associated with decreased risk of CRC in the setting of Crohn's colitis. These data underscore the importance of CRC surveillance for Crohn's colitis in addition to ulcerative colitis and should prompt further study in this area.     

Divergent patterns of total and cancer mortality in ulcerative colitis and Crohn's disease patients: the Florence IBD study 1978-2001

BACKGROUND AND AIMS: Two divergent patterns of mortality for smoking related diseases in ulcerative colitis and Crohn's disease patients were suggested in a previous population based study in Florence, Italy. Long term follow up (median 15 years) was completed to re-evaluate mortality in this Mediterranean cohort. PATIENTS AND METHODS: Overall, 920 patients with inflammatory bowel disease were followed until December 2001 or death, with seven patients (0.8%) lost to follow up. A total of 14 040 person years were available for analysis; 118 deaths were observed (81/689 in ulcerative colitis and 37/231 in Crohn's disease). Expected deaths were estimated using age, sex, and calendar specific national and local mortality rates; standardised mortality ratios (SMR) and 95% confidence interval (CI) were calculated. RESULTS: Among Crohn's disease patients, mortality was strongly increased for gastrointestinal diseases (SMR 4.49 (95% CI 1.80-9.25)), all cancers (SMR 2.10 (95% CI 1.22-3.36)), and lung cancer (SMR 4.00 (95% CI 1.60-8.24)), leading to a significant 50% excess total mortality. Ulcerative colitis patients showed a significantly reduced total mortality because of lower cardiovascular (SMR 0.67 (95% CI 0.45-0.95)) and lung cancer (SMR 0.32 (95% CI 0.07-0.95)) mortality. No significant excess for colorectal cancer mortality was evident in this extended follow up. CONCLUSIONS: These clearly divergent patterns of mortality correlate with documented differences in smoking habits between Crohn's disease and ulcerative colitis patients. Family doctors and gastroenterologists should consider stopping cigarette smoking a specific priority for Crohn's disease patients; the latter should be offered free participation in structured programmes for smoking cessation, with the aim of reducing smoking related excess mortality. Overall, no evidence of an increased mortality for large bowel cancer emerged in this series.     

Predictive and protective factors associated with colorectal cancer in ulcerative colitis: A case-control study

BACKGROUND & AIMS: Predictive and protective factors associated with colorectal cancer in chronic ulcerative colitis are not well described. Surveillance colonoscopy and 5-aminosalicylic acid therapy may mitigate cancer risk, but there is debate because these variables have not been evaluated in the same study. The presence of postinflammatory pseudopolyps and use of other anti-inflammatory medications may be important variables that influence risk, but data are sparse. METHODS: Variables associated with colorectal cancer were registered in 188 patients with ulcerative colitis-related cancer and matched controls. Conditional logistic regression, adjusted for age at colitis diagnosis and colitis duration, identified a final set of variables independently associated with colorectal cancer. RESULTS: In the final multiple variable model, the most important factors associated with colorectal cancer were a history of pseudopolyps (OR, 2.5; 95% CI: 1.4-4.6), 1 or 2 surveillance colonoscopies (OR, 0.4; 95% CI: 0.2-0.7), smoking (OR, 0.5; 95% CI: 0.2-0.9) and use of corticosteroids (OR, 0.4; 95% CI: 0.2-0.8), aspirin (OR, 0.3; 95% CI: 0.1-0.8), nonsteroidal anti-inflammatory drugs (OR, 0.1; 95% CI: 0.03-0.5), and 5-aminosalicylic acid agents (OR, 0.4; 95% CI: 0.2-0.9), although the latter was not statistically significant after 5 years. Primary sclerosing cholangitis and immunosuppressive use were not statistically significant. CONCLUSIONS: These results suggest that, in a population matched for extent and duration of chronic ulcerative colitis, surveillance colonoscopy and use of anti-inflammatory medications may reduce the risk of colorectal cancer. A history of postinflammatory pseudopolyps appears to be a predictive factor for cancer.     

Incidence of juvenile-onset Crohn's disease in Scotland: association with northern latitude and affluence

BACKGROUND & AIMS: The incidence of Crohn's disease in Scottish children has increased steadily over 30 years. Many studies have investigated genetic influence or possible links with childhood events. We aimed to study sociodemographic and/or geographic distribution of juvenile=onset Crohn's disease in Scotland. METHODS: Using a previously established and validated database covering the entire Scottish population, 580 Scottish children (<16 years of age at symptom onset) with inflammatory bowel disease incident between 1981 and 1995 were identified. Postcodes of incident cases were classed for geographic location and material deprivation. Incidence rates (/100,000/year) were sex standardized to the 1991 census population. The effects of sex, geographic location, time, and deprivation category were estimated from a multifactorial Poisson regression model. RESULTS: The incidence of juvenile-onset Crohn's disease was 2.3 (95% CI: 2.0-2.5) for the time period 1981 to 1995 and was significantly higher in northern (3.1, 95% CI: 2.6-3.8) than in southern Scotland (2.1, 95% CI: 1.9-2.4, P < 0.001). The incidence of juvenile-onset ulcerative colitis did not show north/south variation ( P = 0.677). The relative risks of developing CD were significantly lower in postcode areas with deprivation categories 2-7 as compared with deprivation score 1 (most affluent, P = 0.033). This pattern was not seen for UC. CONCLUSIONS: There was an increased incidence of juvenile-onset Crohn's disease in northern compared with southern Scotland. Children from more affluent areas had a higher relative risk of developing Crohn's disease. Juvenile onset ulcerative colitis did not show north/south variation in incidence or association with affluence.     

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.     

Ulcerative colitis in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival

BACKGROUND: There is significant geographic variation in the reported incidence of ulcerative colitis. AIMS: To update the incidence and prevalence of ulcerative colitis in Olmsted County, Minnesota, examine temporal trends, and determine overall survival. PATIENTS: All Olmsted County residents diagnosed with ulcerative colitis between 1940 and 1993 (incidence cases), and all residents with ulcerative colitis alive on 1 January 1991 (prevalence cases). METHODS: Incidence and prevalence rates were adjusted using 1990 US census figures for whites. The effects of age, sex, and calendar year on incidence rates were evaluated using Poisson regression. Survival from diagnosis was compared with that expected for US north-central whites. RESULTS: Between 1940 and 1993, 278 incidence cases were identified, for an adjusted incidence rate of 7.6 cases per 100 000 person years (95% confidence interval (CI), 6.7 to 8.5). On 1 January 1991, there were 218 residents with definite or probable ulcerative colitis, for an adjusted prevalence rate of 229 cases per 100 000 (95% CI, 198 to 260). Increased incidence rates were associated with later calendar years (p<0.002), younger age (p<0.0001), urban residence (p<0.0001), and male sex (p<0.003). Overall survival was similar to that expected (p>0.2). CONCLUSIONS: The overall incidence rate of ulcerative colitis in Olmsted County increased until the 1970s, and remained stable thereafter. Incidence rates among men and urban residents were significantly higher. The prevalence rate in Rochester in 1991 was 19% higher than that in 1980. Overall survival was similar to that of the general population.     

The risk of developing Crohn's disease after an appendectomy: a population-based cohort study in Sweden and Denmark

BACKGROUND: The relationship between appendectomy and Crohn's disease is controversial. A Swedish-Danish cohort study was conducted to assess the risk of developing Crohn's disease after an appendectomy. METHODS: 709 353 appendectomy patients in Sweden (since 1964) and Denmark (since 1977) were followed for first hospitalisations for Crohn's disease to 2004. Standardised incidence ratios (SIR) served as relative risks. RESULTS: Overall, 1655 Crohn's disease cases were observed during 11.1 million person-years of follow-up. Whereas appendectomy before the age of 10 years was not associated with the risk of Crohn's disease (SIR 1.00; 95% CI 0.80-1.25), the overall SIR of developing Crohn's disease was 1.52 (95% CI 1.45-1.59), being highest in the first 6 months (SIR 8.69; 95% CI 7.68-9.84). SIR diminished rapidly thereafter, with the risk of Crohn's disease reaching background levels after 5-10 years for Crohn's disease overall, as well as for Crohn's ileitis, ileocolonic Crohn's disease, Crohn's colitis and other/unspecified Crohn's disease. A long-term increased risk of Crohn's disease up to 20 years after the appendectomy was seen only in appendectomy patients without appendicitis or mesenteric lymphadenitis. CONCLUSION: The transient increased risk of Crohn's disease after an appendectomy is probably explained by diagnostic bias.     

Microsatellite Instability Is Uncommon in Intestinal Mucosa of Patients with Crohn's Disease

Patients with long-standing inflammatory bowel disease have an increased risk for colorectal carcinoma. Microsatellite instability occurs in colonic neoplasms and has been reported in colonic tissues from patients with ulcerative colitis. Patients with Crohn's disease also have an increased risk for colorectal cancer, although it is lower than that associated with ulcerative colitis. This study was designed to determine whether microsatellite instability occurs in Crohn's disease, and whether it occurs with similar frequency to that observed in ulcerative colitis. In all, 177 tissue samples from 33 patients with Crohn's disease were evaluated for microsatellite alterations. Microsatellite instability occurred in five different tissue samples from one of 33 Crohn's disease patients. Four of the five tissue samples showed microsatellite instability at more than one locus. We conclude that microsatellite instability is less common in Crohn's disease than ulcerative colitis and may reflect differences in cancer risk between these two forms of inflammatory bowel disease.