Embryological signaling pathways in Barrett's metaplasia development and malignant transformation; mechanisms and therapeutic opportunities

Barrett's metaplasia of the esophagus (BE) is the precursor lesion of esophageal adenocarcinoma (EAC), a deadly disease with a 5-year overall survival of less than 20%. The molecular mechanisms of BE development and its transformation to EAC are poorly understood and current surveillance and treatment strategies are of limited efficacy. Increasing evidence suggests that aberrant signaling through pathways active in the embryological development of the esophagus contributes to BE development and progression to EAC. We discuss the role that the Bone morphogenetic protein, Hedgehog, Wingless-Type MMTV Integration Site Family (WNT) and Retinoic acid signaling pathways play during embryological development of the esophagus and their contribution to BE development and malignant transformation. Modulation of these pathways provides new therapeutic opportunities. By integrating findings in developmental biology with those from translational research and clinical trials, this review provides a platform for future studies aimed at improving current management of BE and EAC.

Predictors of colorectal neoplasia after polypectomy: based on initial and consecutive findings

BACKGROUND

Colorectal adenoma patients are kept under surveillance because of the risk of developing metachronous neoplasia. The aim is to determine predictors of neoplasia development after polypectomy.

METHODS

It is an observational cohort study. 433 Patients who had ≥1 adenoma removed between 1988 and 2004 were included, with follow-up until 2010. Multivariate analysis of patient and adenoma characteristics was performed at initial colonoscopy and at consecutive positive examinations. The main outcome measured was the development of metachronous (advanced) adenomas during follow-up.

RESULTS

Median follow-up was 85 months. Multivariate analysis identified male sex, ≥3 adenomas, high-grade dysplasia and age ≥55 years as risk factors for metachronous lesions at first surveillance. Analysis using life expectancy as a timescale showed ≥3 adenomas to be the only predictive factor. The time to second or third metachronous adenoma did not depend on the number of adenomas. Patients with ≥3 adenomas were five years older at the time of their first polypectomy compared with those with fewer adenomas, but of the same age at the first recurrence. Prevalence of high-grade dysplasia was associated with age and high-grade dysplasia in the prior adenoma independent of time interval.

CONCLUSIONS

Adenoma development after polypectomy occurs in a regular and repetitive way. Our data suggest that only the interval between the initial colonoscopy and the first follow-up colonoscopy should be based on initial findings, i.e. number of adenomas, and that subsequent colonoscopies can be planned at predetermined intervals.

Regulation of TRAIL receptor expression by β-catenin in colorectal tumours

Tumour-necrosis-factor-related apoptosis-inducing ligand (TRAIL) is being investigated as a targeted cancer therapeutic and the expression of its pro-apoptotic receptors, DR4 and DR5, increases during colorectal carcinogenesis. This study investigated the role of β-catenin in the regulation of these receptors. In human colorectal adenoma and carcinoma cell lines, downregulation of β-catenin resulted in lower total DR4 and DR5 protein levels. Similarly, cell membrane expression of DR4 and DR5 was reduced after downregulation of β-catenin in colon carcinoma cells, whereas induction of β-catenin in HeLa cells led to increased cell membrane expression of DR4 and DR5. Downregulation of β-catenin decreased the recombinant human TRAIL sensitivity of human colon carcinoma cells. Activation of the transcription factor T-cell factor-4 (TCF-4) is an important function of β-catenin. Dominant-negative TCF-4 overexpression, however, did not significantly affect TRAIL receptor expression or recombinant human TRAIL sensitivity. Human colorectal adenomas (N = 158) with aberrant (cytoplasmic and nuclear) β-catenin expression had a higher percentage of immunohistochemical DR4 and DR5 staining per tumour (mean: 73 and 88%, respectively) than those with membranous β-catenin staining only (mean: 50 and 70%, respectively, P < 0.01 for both). Furthermore, aberrant β-catenin staining co-localized with DR4 and DR5 expression in 92% of adenomas. In 53 human colorectal carcinomas, aberrant β-catenin expression was present in most cases and DR4/5 expression was largely homogenous. Similarly, in adenomas from APC(min) mice, cytoplasmic β-catenin staining co-localized with staining for the murine TRAIL death receptor. In conclusion, the gradual increase in TRAIL receptor expression during colorectal carcinogenesis is at least partially mediated through increased β-catenin expression, independently of TCF-4-signalling.

Detection of infliximab levels and anti-infliximab antibodies: a comparison of three different assays

BACKGROUND

Formation of antibodies to infliximab (ATI) inversely correlates with functional drug levels and clinical outcome. Comparison of drug levels and anti-drug antibody monitoring is hampered by lack of standardisation.

AIM

To determine the correlation between three different assays for measuring infliximab and ATI.

METHODS

Serum samples and spiked controls (total 62) were evaluated in a blinded way in infliximab and ATI assays developed by Sanquin Amsterdam, Netherlands (A), Laboratory for Pharmaceutical Biology, KU Leuven, Belgium (B) and a commercially available kit from Biomedical Diagnostics (BMD), Paris, France (C) performed by the University Medical Center Groningen (UMCG), Netherlands.

RESULTS

All infliximab assays showed a linear quantitative correlation (Pearson r = 0.91 for A vs. B, 0.83 for A vs. C and 0.73 for B vs. C). Assay C detected infliximab in 11 samples (18%) not detected by A and B, including samples containing only ATI. All ATI assays showed a good linear correlation (Pearson r = 0.95 for A vs. B, 0.99 for A vs. C and 0.97 for B vs. C). Assay A detected ATI in five samples with low ATI that were not detected by assays B and C. Assay B did not detect ATI in three patient samples with low ATI according to assays A and C.

CONCLUSIONS

There is a good correlation of infliximab and antibodies to infliximab measurements between these assays. Nevertheless, the Biomedical Diagnostics kit detected false positive infliximab levels in 18% of the samples.

High detection rate of adenomas in familial colorectal cancer

BACKGROUND AND AIMS

Subjects with one first-degree relative (FDR) with colorectal cancer (CRC) <50 years old or two FDRs with CRC have an increased risk for CRC (RR 4-6). Current guidelines recommend colonoscopic surveillance of such families. However, information about the yield of surveillance is limited. The aim of the present study was to evaluate the outcome of surveillance and to identify risk factors for the development of adenomas.

PATIENTS AND METHODS

Subjects were included if they fulfilled the following criteria: asymptomatic subjects aged between 45 and 65 years, with one FDR with CRC <50 years old (group A) or two FDRs with CRC diagnosed at any age (group B). Subjects with a personal history of inflammatory bowel disease or colorectal surgery were excluded.

RESULTS

A total of 551 subjects (242 male) met the selection criteria. Ninety-five subjects with a previous colonoscopy were excluded. Two of 456 remaining subjects (0.4%) were found to have a colorectal tumour (one CRC and one carcinoid). Adenomas were detected in 85 (18.6%) and adenomas with advanced pathology in 37 subjects (8.1%). 30 subjects (6.6%) had multiple (>1) adenomas. Men were more often found to have an adenoma than women (24% vs 14.3%; p=0.01). Adenomas were more frequent in group B compared with group A (22.0% vs 15.6%; p=0.09).

CONCLUSION

The yield of colonoscopic surveillance in familial CRC is substantially higher than the yield of screening reported for the general population.

Deficiencies in fat-soluble vitamins in long-term users of somatostatin analogue

BACKGROUND

Somatostatin analogues are administered to control hormone hypersecretion in acromegaly and carcinoid patients. Somatostatin analogues can increase fat in the stools, which can lead to loss of fat-soluble vitamins. The effect of long-term somatostatin analogue use on vitamin levels remains unknown.

AIM

To investigate the prevalence of fat-soluble vitamin deficiencies in long-term somatostatin analogue users.

METHODS

All acromegaly and carcinoid patients using somatostatin analogues for ≥ 18 months visiting the University Medical Center Groningen between December 2008 and April 2009 were eligible. Vitamin levels of fat-soluble vitamins in blood, clinical and vitamin-dependent laboratory parameters were collected.

RESULTS

In all, 19 acromegaly and 35 carcinoid patients were included. Twelve patients experienced steatorrhoea; two carcinoid patients experienced night blindness. Forty-two (78%) were deficient for one or more vitamins, and 32% (n = 17) had multiple deficiencies. Deficiencies for vitamin A, D, E, K1 and E in erythrocytes occurred in 6%, 28%, 15%, 63% and 58% of the patients. Prevalence of vitamin D, E and K1 deficiencies was similar in both patient groups. Treatment duration did not influence vitamin levels. The length of intestinal resection and age correlated negatively with vitamin A levels.

CONCLUSIONS

Fat-soluble vitamin deficiencies are frequent during long-term somatostatin analogue treatment. Therefore, fat-soluble vitamins should be monitored in these patients.

Evaluation of management of desmoid tumours associated with familial adenomatous polyposis in Dutch patients

BACKGROUND

The optimal treatment of desmoid tumours is controversial. We evaluated desmoid management in Dutch familial adenomatous polyposis (FAP) patients.

METHODS

Seventy-eight FAP patients with desmoids were identified from the Dutch Polyposis Registry. Data on desmoid morphology, management, and outcome were analysed retrospectively. Progression-free survival (PFS) rates and final outcome were compared for surgical vs non-surgical treatment, for intra-abdominal and extra-abdominal desmoids separately. Also, pharmacological treatment was evaluated for all desmoids.

RESULTS

Median follow-up was 8 years. For intra-abdominal desmoids (n=62), PFS rates at 10 years of follow-up were comparable after surgical and non-surgical treatment (33% and 49%, respectively, P=0.163). None of these desmoids could be removed entirely. Eventually, one fifth died from desmoid disease. Most extra-abdominal and abdominal wall desmoids were treated surgically with a PFS rate of 63% and no deaths from desmoid disease. Comparison between NSAID and anti-estrogen treatment showed comparable outcomes. Four of the 10 patients who received chemotherapy had stabilisation of tumour growth, all after doxorubicin combination therapy.

CONCLUSION

For intra-abdominal desmoids, a conservative approach and surgery showed comparable outcomes. For extra-abdominal and abdominal wall desmoids, surgery seemed appropriate. Different pharmacological therapies showed comparable outcomes. If chemotherapy was given for progressively growing intra-abdominal desmoids, most favourable outcomes occurred after combinations including doxorubicin.

Hereditary non-polyposis colorectal cancer: identification of mutation carriers and assessing pathogenicity of mutations

Hereditary non-polyposis colorectal cancer (HNPCC), also referred to as Lynch syndrome, is an autosomal dominantly inherited disorder that is characterized by susceptibility to colorectal cancer and extracolonic malignancies, in particular endometrial cancer. HNPCC is caused by pathogenic mutations in the mismatch repair (MMR) genes, which play an important role in maintaining genomic stability during DNA replication. Identification of MMR gene mutation carriers is important as this enables them to enrol in surveillance programmes, thus reducing their risk of cancer and increasing survival. Clinical criteria as well as non-clinical criteria have been formulated to select patients for mutation analysis. In this paper we review the approaches used to select patients for mutation analysis. Mutation analysis in the MMR genes may yield mutations of which the pathogenic nature is unclear. Criteria to determine the pathogenicity of such variants are discussed, as well as differences in design of functional assays to assess pathogenicity.

Novel approaches in the outpatient care of patients with chronic inflammatory bowel disease

Treatment strategies for Crohn's disease are targeted toward lifelong management. Optimization of outpatient care is mandatory, because of many clinics facing capacity issues, and, along with routine follow-up of patients with inflammatory bowel disease, is putting increasing pressure on outpatient clinics. Recent studies demonstrate clearly that alternative management strategies are feasible and effective with a high rate of patient satisfaction. It is recommended that future research evaluates the way in which medical care is provided and explores the long-term effects of novel management strategies in IBD. This approach can then be extrapolated to other chronic conditions.

Symptom experience, nonadherence and quality of life in adult liver transplant recipients

Survival outcomes after liver transplantation in adult patients have gradually improved with a five-year survival of about 70% and a ten-year survival of about 60%. The present review focuses on relevant patient-reported outcomes such as self-perceived side effects of immunosuppressive drugs, medication nonadherence and long-term health-related quality of life after liver transplantation. These entities are interrelated but have often been studied separately. Self-perceived symptom experience in liver transplant recipients has not been studied extensively. Symptoms that cause distress differ between men and women, e.g. symptoms related to cosmetic side effects of drugs. Medication nonadherence seems to be infrequent, but if present may have serious consequences. Important risk factors were found to be the costs of drugs, age <40 years, psychiatric disorders, side effects of drugs, beliefs that drugs were harmful, and large influence of the liver transplant on the patient's life. Health-related quality of life is satisfactory, but below the level of the general population. Results, however, must be interpreted with caution as quality-of-life improvements may have been overstated due to variables such as selection bias (e.g. exclusion of severely ill and deceased patients), too many short-term studies, and suboptimal methodology. Presently we lack data on the influence of recurrence of disease, 'de novo' diseases and gender differences on health-related quality of life in liver transplanted patients.

Microscopic colitis: an unfamiliar but treatable disease

Chronic diarrhoea is a frequent complaint in clinical practice. Microscopic colitis is the cause of this symptom in 10% of these cases and the prevalence is rising. To exclude microscopic colitis a colonoscopy with multiple biopsies of different regions of the colon is mandatory. A sigmoidoscopy alone is insufficient. Two histopathological types of microscopic colitis can be distinguished: collagenous colitis and lymphocytic colitis. Nowadays, there is sufficient evidence to recommend budesonide as the first-choice treatment. Bismuth can also be recommended, but this drug is not easily available in the Netherlands. Evidence of efficacy of other drugs is scant.

Symptom experience associated with immunosuppressive drugs after liver transplantation in adults: possible relationship with medication non-compliance?

Symptom experience (occurrence and perceived distress) associated with side effects of immunosuppressive medications in organ transplant patients may well be associated with poorer quality of life and medication non-compliance. The aims of this study were: first, to assess symptom experience in clinically stable adult patients during long-term follow-up after liver transplantation; and second, to study the relationship between symptom experience and medication non-compliance. This cross-sectional study included 123 liver transplant patients. Symptom experience was assessed using the "Modified Transplant Symptom Occurrence and Symptom Distress Scale" (29-item version) at the annual evaluation. According to the duration of follow-up, patients were divided into a short-term (1-4 yr) and a long-term (5-18 yr) cohort. Medication non-compliance was measured using electronic monitoring. Results showed that increased hair growth was the most frequent symptom in both sexes. Symptom distress was more serious in women than in men. The most distressing symptom in women was excessive and/or painful periods, while in men this was impotence. Clear differences were revealed at item level between symptom occurrence and symptom distress in relationship with the two time cohorts and between sexes. No relationship was found between symptom experience and prednisolone non-compliance.

Independent induction of caspase-8 and cFLIP expression during colorectal carcinogenesis in sporadic and HNPCC adenomas and carcinomas

Background: TNF-Related Apoptosis Inducing Ligand (TRAIL) is a promising agent for the induction of apoptosis in neoplastic tissues. Important determinants of TRAIL sensitivity are two intracellular proteins of the TRAIL pathway, caspase-8 and its anti-apoptotic competitor cellular Flice-Like Inhibitory Protein (cFLIP). Methods: The aim of this study was to investigate basic expression of caspase-8 and cFLIP in normal colorectal epithelium (n = 20), colorectal adenomas (n = 66) and colorectal carcinomas (n = 44) using immunohistochemistry performed on both sporadic and Hereditary Non-Polyposis Colorectal Cancer (HNPCC or Lynch syndrome)-associated adenomas and carcinomas. Results: Expression of both caspase-8 and cFLIP was similar in cases with sporadic and hereditary origin. Expression of caspase-8 in colorectal adenomas and carcinomas was increased when compared to normal colon tissue (P = 0.02). Nuclear, paranuclear as well as cytoplasmic localizations of caspase-8 were detected. Immunohistochemistry revealed an upregulation of cFLIP in colorectal carcinomas in comparison to normal epithelium and colorectal adenomas (P < 0.001). A large variation in the caspase-8/cFLIP ratio was observed between the individual adenomas and carcinomas. Conclusion: Caspase-8 and cFLIP are upregulated during colorectal carcinogenesis. Upregulation of caspase-8 and/or downregulation of cFLIP may be interesting approaches to maximize TRAIL sensitivity in colorectal neoplasms.

Review article: Inflammatory bowel disease and genetics

INTRODUCTION

Inflammatory bowel disease (IBD) comprising ulcerative colitis (UC) and Crohn's disease (CD) is multigenic disorder. Tremendous progress has been achieved in unravelling the genetic background of IBD. It has led to the discovery of mutations in NOD2 associated with ileal CD and numerous other genes have been found to be associated with IBD susceptibility.

METHODS

A review of the literature on the genetic background of IBD was performed.

RESULTS

It is only partially understood how mutations in NOD2 lead to CD. Mouse models, in vitro data and studies in humans offer conflicting data as regards whether there is a loss or gain of function of NOD2 in CD. Several additional genes have been identified of which only a few are currently being recognized as potential disease causing or disease modifying genes. Promising candidate genes include TLR4, MDR1, NOD1 (CARD4), DLG5 as well as the IBD5 locus including SLC22A4/5.

CONCLUSIONS

Although genetic research has not yet led to a better prediction of the disease course or patient selection for medical therapy, remarkable progress has been made in the understanding of the pathogenesis of IBD. For future genetic research, accurate phenotyping of patients is very important and large population-based cohorts are needed. Eventually, genetic research may be able to classify different disease phenotypes on a more detailed molecular basis and may provide important contributions in the development of new therapeutic approaches.

Is surveillance of the small bowel indicated for Lynch syndrome families?

BACKGROUND

Small bowel cancer (SBC) is one of the tumours associated with Lynch syndrome (LS). To advise on screening for this tumour it is paramount to be informed about the lifetime risk. The aim of this study was to calculate the lifetime risk of SBC in LS and to identify possible risk factors.

METHODS

Clinical and pathological data were collected on 1496 proven or putative carriers of a mismatch repair gene mutation from 189 families. Kaplan-Meier survival analysis was used to calculate the lifetime risk and to assess potential risk factors.

RESULTS

28 (1.9%) of the 1496 (putative) mutation carriers were identified with SBC. The median age at diagnosis was 52 years (range 23-69 years). The lifetime risk of developing SBC was 4.2%. There was no difference in risk between males and females (log rank: p = 0.2470), or between MLH1 and MSH2 mutation carriers (log rank: p = 0.2754). SBC was not observed in MSH6 mutation carriers (n = 203). The previous occurrence of colorectal cancer and a family history of SBC did not increase the risk significantly.

CONCLUSIONS

Approximately, one out of 25 mutation carriers will develop SBC during life. No specific risk factors were identified. The risk appeared to be too low to advise screening by means of an invasive burdensome procedure like double balloon enteroscopy. However, screening by a non-invasive procedure (videocapsule endoscopy) might be considered if future studies will show its cost effectiveness. In patients with unexplained abdominal complaints and/or unexplained iron deficiency anaemia SBC should be considered.

Effects of different immunosuppressive regimens on regulatory T-cells in noninflamed colon of liver transplant recipients

BACKGROUND

Regulatory T-cells (Treg) are natural suppressors of autoimmunity. Previous studies indicate that immunosuppressive drugs, especially calcineurin-inhibitors, may interfere with Treg homeostasis. Inflammatory bowel disease (IBD) can relapse or develop de novo after liver transplantation. IBD is associated with a relative deficiency of Treg. The aim of this study was to determine the effect of long-term immunosuppression on the presence of Treg in the noninflamed colonic mucosa of liver transplant recipients.

METHODS

Colonic biopsies of normal mucosa of 36 liver transplant recipients on different types of immunosuppression and 11 controls were studied. Treg marker Foxp3 and Treg products transforming growth factor-beta (TGF-beta) and interleukin-10 (IL-10) were studied by quantitative polymerase chain reaction (Q-PCR) and immunohistochemistry. TGF-beta-induced Smad-protein 3 and 7 were studied by Q-PCR.

RESULTS

No significant differences between controls and patients were observed in IL-10, TGF-beta, and Smad expression. Mucosal Foxp3 mRNA levels and Foxp3+CD3+ cells were significantly reduced in transplant recipients using prednisone/azathioprine/tacrolimus compared with controls but no direct relationship between Foxp3 expression and 1 specific drug was detected.

CONCLUSIONS

These results challenge the hypothesis that calcineurin-induced reduction of Treg or TGF-beta expression predisposes nontransplanted tissue to inflammation, but indicate that combined immunosuppression hampers Treg development in the intestine.

[Screening the population for colorectal cancer: the background to a number of pilot studies in the Netherlands]

Colorectal cancer is one of the most common cancers in the Netherlands, where it is now the second most commonly-occurring cancer in terms of both incidence (10,000 new cases each year) and mortality rate (4,400 each year). - In 40% of all cases the disease is diagnosed at a late stage, which is associated with a poor outcome. - Research has shown that screening of the general population for colorectal cancer by means of the faecal occult blood test (FOBT) results in a reduction in mortality of approximately 16%. Whether endoscopic screening will result in a greater reduction in the mortality rate is currently under investigation. - This year, the first pilot study on implementation of screening for colorectal cancer using two different types of FOBT will start in the Netherlands.

Identification of mismatch repair gene mutations in young patients with colorectal cancer and in patients with multiple tumours associated with hereditary non-polyposis colorectal cancer

BACKGROUND

Patients with early-onset colorectal cancer (CRC) or those with multiple tumours associated with hereditary non-polyposis colorectal cancer (HNPCC) raise suspicion of the presence of germline DNA mismatch repair (MMR) gene mutations.

AIM

To analyse the value of family history, microsatellite instability (MSI) analysis and MMR protein staining in the tumour to predict the presence of an MMR gene mutation in such patients.

METHODS

In 281 patients diagnosed with CRC before the age of 50 years or with CRC and at least one additional HNPCC-associated cancer, germline mutation analysis in MLH1, MSH2 and MSH6 was carried out with denaturing gradient gel electrophoresis and multiplex ligation-dependent probe amplification. MSI analysis with five consensus markers and MMR protein staining for MLH1, MSH2 and MSH6 were carried out in the tumours.

RESULTS

25 pathogenic mutations (8 in MLH1, 9 in MSH2 and 8 in MSH6) were found. MSI analysis missed three and immunohistochemistry (IHC) missed two mutation carriers. Sensitivities of family history, MSI analysis and IHC for the presence of a mutation were 76%, 82% and 88%, specificities were 64%, 70% and 84%, and positive predictive values were 19%, 23% and 38%, respectively. Multivariate analysis showed the highest odds ratio for IHC (38.3, 95% confidence interval 9.0 to 184). Prevalence of pathogenic germline MMR gene mutations in patients with CRC before the age of 50 years was 6% and in those with > or =2 HNPCC-associated tumours was 22%. In the second group, no mutation carriers were found among the 29 patients who were diagnosed with their first tumour after the age of 60 years.

CONCLUSION

Family history, MSI analysis and IHC are indicative parameters to select patients with CRC for MMR gene mutation analysis. The data show that IHC is the best single selection criterion.

Increased risk of fundic gland polyps during long-term proton pump inhibitor therapy

BACKGROUND

It is controversial whether proton pump inhibitor use leads to fundic gland polyp development.

AIM

To determine whether fundic gland polyp development is due to proton pump inhibitor use and to investigate mechanisms involved.

METHODS

Proton pump inhibitor use and the presence of fundic gland polyps were assessed in consecutive patients undergoing oesophagogastroduodenoscopy. Biopsies from fundic gland polyps and gastric mucosa were taken. Dysplasia was graded as negative, low or high grade. Prevalence of parietal cell hyperplasia and parietal cell protrusions and the proportional cystic area were assessed.

RESULTS

599 patients participated, 322 used proton pump inhibitors, 107 had fundic gland polyps. Long-term proton pump inhibitor use was associated with an increased risk of fundic gland polyps (1-4.9 years use: OR 2.2, 95% CI: 1.3-3.8; > or =5 years: OR 3.8, 95% CI: 2.2-6.7) while short-term therapy (<1 year) was not (OR 1.0, 95% CI: 0.5-1.8). Low-grade dysplasia was found in one fundic gland polyp. Fundic gland polyps associated with long-term proton pump inhibitor use had a larger proportional cystic area and higher frequency of parietal cell hyperplasia and parietal cell protrusion.

CONCLUSIONS

Long-term proton pump inhibitor use is associated with an up to fourfold increase in the risk of fundic gland polyps. Risk of dysplasia is negligible. Aetiologically, these polyps seem to arise because of parietal cell hyperplasia and parietal cell protrusions resulting from acid suppression.

CARD15 in inflammatory bowel disease and Crohn's disease phenotypes: an association study and pooled analysis

BACKGROUND

Three major polymorphisms of the Caspase-Activation Recruitment Domain containing protein 15 gene have been described to be associated with Crohn's disease. Genotype-phenotype studies reported in literature provide conflicting data on disease localisation and behaviour. We investigated the relation of Caspase-Activation Recruitment Domain containing protein 15 with inflammatory bowel disease and Crohn's disease phenotypic characteristics in a large Dutch cohort and performed a pooled analysis on inflammatory bowel disease patients and Crohn's disease phenotypic characteristics reported in association studies.

METHODS

We genotyped 781 cases and 315 controls for the R702W, G908R and 1007fsinsC variants and for six microsatellite markers in and close to Caspase-Activation Recruitment Domain containing protein 15. In the pooled analysis data of 7201 inflammatory bowel disease patients and 3720 controls from 20 studies were included.

RESULTS

Association was found for Crohn's disease with R702W and 1007fsinsC, including several disease characteristics, and not for ulcerative colitis. In the pooled analysis all three common Caspase-Activation Recruitment Domain containing protein 15 variants showed strong association with Crohn's disease (p<0.00001; odds ratio varying from 3.0 for single heterozygotes to 14.7 for compound heterozygotes) and not with ulcerative colitis. Phenotype analysis showed association with small bowel involvement, stricturing and penetrating disease.

CONCLUSION

Caspase-Activation Recruitment Domain containing protein 15 is associated with Crohn's disease and not with ulcerative colitis. All three common Crohn's disease-associated variants are associated with small bowel involvement, the G908R and 1007fsinsC alleles also being associated with a complicated disease course.

What is the appropriate screening protocol in Lynch syndrome?

INTRODUCTION

Lynch syndrome families have a substantial risk of developing colorectal cancer (CRC). The recommended surveillance protocol includes colonoscopy every 2 years from age 20-25 years. It is yet unknown whether annual screening of patients aged 40-60 years is more effective than bi-annual screening, whether patients who had an adenoma removed should be re-examined after a year and whether surveillance of second-degree relatives is indicated. The aim of this study was to address these issues.

METHODS

All carriers of a mismatch repair gene mutation who participated in the surveillance program were selected from the Dutch Lynch syndrome registry. The results of colonoscopy were prospectively collected.

RESULTS

A total of 666 mutation carriers were identified in 110 families. Fourty-one CRCs were detected during endoscopic follow-up, of which 34 (83%) were diagnosed between age 40 and 60 years. In five of 34 patients, CRC was diagnosed within 1 year after colonoscopy, eight cancers were diagnosed between 1 and 2 years and the remaining tumors more than 2 years after colonoscopy. All eight CRCs detected between 1 and 2 years were at local stage. At least one adenoma was diagnosed at 141 examinations. The risk of developing CRC during follow-up in carriers with an adenoma was similar as in carriers without an adenoma at the previous colonoscopy. 280 parent-child couples with at least one Lynch syndrome-related carcinoma were identified in 110 families. In only 19 (6.8%) of these couples, CRC developed earlier in the child than an Lynch syndrome-associated cancer in the parent.

CONCLUSION

The current surveillance protocol, i.e., bi-annual colonoscopy in first-degree relatives independent of age and endoscopic findings, appears to be appropriate.

Inflammatory bowel disease after liver transplantation: risk factors for recurrence and de novo disease

Inflammatory bowel disease (IBD) is associated with primary sclerosing cholangitis (PSC) and autoimmune hepatitis (AIH) and can recur or develop de novo after orthotopic liver transplantation (OLT). The aim of this study was to investigate the incidence and severity of IBD after liver transplantation and to perform a multivariate analysis for possible risk factors. In this retrospective study, 91 patients transplanted for PSC or AIH, without prior colectomy, were included. Sixty patients were transplanted for PSC, 31 for AIH. IBD activity before and after OLT and other possible risk factors were analysed in a multivariate model. Forty-nine patients (54%) had IBD before OLT. Forty patients (44%) had active IBD after transplantation: recurrence in 32 and de novo in 8. Cumulative risk for IBD after OLT was 15, 39 and 54% after 1, 5 and 10 years, respectively. In 59% of patients with IBD prior to OLT the disease was more active after transplantation. Risk factors for recurrent disease were: symptoms at time of OLT, short interval of IBD before OLT and use of tacrolimus. 5-aminosalicylates were protective. A cytomegalovirus positive donor/negative recipient combination increased the risk for de novo IBD.

[Endoluminal treatment of gastro-oesophageal reflux disease: too early to determine a clear role]

Gastro-oesophageal reflux disease is a chronic disorder. The most important therapeutic measure is long-term pharmacological acid inhibition. Anti-reflux surgery plays a role in cases where pharmacological treatment fails. A new development is endoluminal treatment for reflux disorders. The various methods used are based on one of the following principles: radiofrequency ablation, gastroplication and implantation of a bulking agent. Short-term results with endoluminal treatment are not very positive and longer-term results have been disappointing so far. Results from randomised studies are still largely unavailable. Longer follow-up and controlled randomised studies are needed before a well-founded judgment can be made regarding the place of endoluminal treatment in the therapeutic armamentarium.

[Treatment of servere ulcerative colitis]

10-15% of patients with ulcerative colitis experience a severe episode of colonic inflammation that does not respond to mesalazine and oral corticosteroids. These patients require hospitalisation and treatment with intravenous corticosteroids. However, 25% of these patients do not respond to treatment. In these cases, intravenous cyclosporin is effective. Infliximab, an antibody against tumour necrosis factor alpha, is also beneficial. With these new treatment options, the colectomy rate in the acute phase has declined to about 35%. Other new therapies are under investigation in phase 2 and 3 trials. Surgery remains an important treatment option. Patients, gastroenterologists and surgeons should be involved in the clinical decision-making process.

[The Nobel Prize in Physiology or Medicine for 2005 for the discovery of the stomach bacterium Helicobacter pylori]

This year, the Nobel Prize in Physiology or Medicine was awarded to the Australian doctors Marshall and Warren for their discovery and further identification of the stomach bacterium Helicobacter pylori. Thanks to their confidence in their own observations, we are now able to cure people with peptic-ulcer disease and low-grade gastric lymphoma and are potentially able to prevent gastric cancer.

[Statins for the prevention of colorectal carcinoma: not yet recommended]

Statins are widely prescribed as lipid-lowering agents in the primary and secondary prevention of cardiovascular disease. They are increasingly associated with potential chemopreventive effects with respect to cancer. A recent case-control study reported a 47% relative reduction in the risk of colorectal cancer associated with statin use after adjustment for other known risk factors. There is evidence of an inhibitory effect of statins on colorectal carcinogenesis from in vitro studies, animal experiments, and observational and epidemiological reports in humans. Although statins seem promising as chemopreventive agents, it is still too early to recommend their use against colorectal cancer outside the context of clinical trials.

Expression of apoptosis related proteins during malignant progression in chronic ulcerative colitis

BACKGROUND

Chronic ulcerative colitis (CUC) is associated with increased risk of developing colon cancer through a dysplasia (intraepithelial neoplasia)-carcinoma sequence.

AIMS

To investigate the expression of apoptosis and inflammatory related proteins in CUC.

METHODS

The expression of proteins involved in apoptosis and inflammation (inducible nitric oxide synthase (iNOS), cyclooxygenase 2 (COX-2), Bcl-xl, Fas, and active caspase 3) was investigated and compared with that seen in sporadic colon carcinoma.

RESULTS

COX-2 was negative in the epithelium of all samples. iNOS was clearly present in inflammatory areas in CUC epithelium, weakly expressed in dysplasia, and absent or weakly expressed in tumour cells. Bcl-xl was absent in CUC, increased in dysplasia, and highly expressed in most carcinomas. Fas expression was positive in the surface epithelium of CUC, dysplasia, and most tumour cells. Activated caspase 3 was weakly positive in all samples, indicating limited apoptosis. Compared with CUC associated carcinoma, iNOS was consistently expressed in sporadic colon carcinoma cells, whereas Bcl-xl was almost absent in these tumour cells and Fas was only weakly expressed. Activated caspase 3 was present in normal mucosal samples and some tumour cells.

CONCLUSION

Apoptosis related proteins--particularly iNOS, Bcl-xl, and Fas-show a distinct pattern of expression in the CUC to carcinoma sequence, which differs from that seen in sporadic carcinoma, but bears a striking resemblance to that seen during neoplastic progression in Barrett's oesophagus. These results support a causal role for chronic inflammation in cancer development in CUC, and treatment of ulcerative colitis should aim to minimise inflammation.

The management of univestigated dyspepsia in primary care

Dyspepsia is very common in western countries, where 10-40% of the population experience upper abdominal pain or discomfort over the course of one year. Mostly it is a chronic relapsing problem. Prompt endoscopy is imperative in all patients with sinister symptoms (including the first appearance of symptoms after the age of 50-55). In other patients endoscopy is unlikely to contribute to medical management. In those a ''test and treat'' strategy implying non invasive testing for Helicobacter pylori (H. pylori) and treatment of the infection if present seems to be the best approach under current conditions (H. pylori prevalence among dyspeptics 28-61% in recent studies). If the patient is H. pylori-negative and in case of persisting symptoms after successful H. pylori eradication, empirical treatment with an antisecretory drug is justified. Endoscopy is reserved for those patients in whom this approach fails. With a continuing decrease in H. pylori prevalence the accuracy of the used non-invasive H. pylori test needs to be high and urea breath tests are to be preferred, the faecal antigen test being a reasonable alternative. At a very low prevalence of H. pylori in the dyspeptic population (below 10%) non invasive testing for H. pylori loses its significance and empirical treatment with an antisecretory drug becomes a rational first step. The physician involved in the care for dyspeptic patients needs to be aware of the current H. pylori prevalence.

[More hereditary intestinal cancer can be detected if patients with colorectal carcinoma that are selected by the pathologist are examined for microsatellite instability]

OBJECTIVE

To determine whether an investigation of microsatellite instability (MSI) in patients with colorectal carcinoma that have been selected by the pathologist could increase the number of detected families with hereditary non-polyposis colorectal carcinoma (HNPCC).

DESIGN

Prospective inventory.

METHOD

Pathologists selected patients with a newly diagnosed colorectal carcinoma for MSI analysis of their tumour tissue if they met one of the following four criteria: (a) colorectal carcinoma diagnosed below 50 years of age; (b) a second colorectal carcinoma; (c) a combination of colorectal carcinoma and another HNPCC-related cancer; (d) colorectal adenoma with high-grade dysplasia diagnosed below 40 years of age. Patients with a positive MSI-test were referred to a clinical geneticist. The new strategy was introduced and explored in 5 hospitals for a period of to months.

RESULTS

The new strategy was adopted and implemented successfully by pathologists and surgeons and accepted with satisfaction by the patients. Of the 55 patients included, 10 had a positive MSI-test. In 8/10 patients, DNA-mutation analysis was started by the clinical geneticist and 3 germline mutations in the MSH2-gene were detected. In 2 of 3 families with a pathogenic mutation, the family history alone did not fulfil the clinical criteria for HNPCC.

CONCLUSION

Selection by the pathologist for MSI investigation was feasible in daily practice and identified more HNPCC patients than selection based on family history alone.

[Screening for coeliac disease currently not indicated]

Coeliac disease is a common disorder, but most persons with coeliac disease remain undetected because they have only mild aspecific symptoms or are free of symptoms. For a definitive diagnosis small bowel biopsies showing partial or (sub)total villous atrophy are required. The presence of anti-endomysium and/or anti-tissue-transglutaminase antibodies in serum is strongly predictive for coeliac disease. In case of clear clinical suspicion the most straightforward way to diagnose or exclude coeliac disease is by taking endoscopic biopsies from the distal duodenum. When the suspicion is low, determination of the above mentioned antibodies as a first step suffices. At present there are insufficient reasons to initiate population-wide screening for coeliac disease by means of serological testing or individual screening by taking duodenal biopsies during each gastroscopy.

Microscopic colitis: prevalence and distribution throughout the colon in patients with chronic diarrhoea

BACKGROUND

Microscopic colitis presents with chronic diarrhoea with or without abdominal pain. Microscopic colitis is an important cause of chronic diarrhoea. It can be distributed throughout the colon, as well as limited to the right colon. Microscopic colitis is associated with coeliac disease. We studied the prevalence and distribution of microscopic colitis in patients with diarrhoea and normal colonoscopy and we studied the association with coeliac disease.

METHODS

Colonoscopy was performed. Biopsies were taken from every segment of the colon. Lymphocytic colitis was defined as the presence of more than 20 lymphocytes per 100 epithelial cells and collagenous colitis was defined as thickening of the basal membrane of more than 10 microm. Upper endoscopy was performed if upper intestinal symptoms were present. If this was the case, small bowel biopsies were taken.

RESULTS

Microscopic colitis was found in 13 out of 103 patients. The distribution was diffuse throughout the colon in ten and restricted to the right colon in three patients. In seven patients, upper endoscopy was performed. Marsh I/II lesions were found in six out of seven patients.

CONCLUSION

Microscopic colitis was limited to the right colon in 23% of patients. Biopsies of macroscopically normal colonic mucosa in patients with diarrhoea is mandatory.

Review article: the potential of combinational regimen with non-steroidal anti-inflammatory drugs in the chemoprevention of colorectal cancer

Non-steroidal anti-inflammatory drugs are chemopreventive agents in colorectal cancer. Non-steroidal anti-inflammatory drugs do not, however, offer complete protection against adenoma and carcinoma development. There is increasing interest in combining non-steroidal anti-inflammatory drugs with agents that target specific cell signalling pathways in malignant and premalignant cells. This review aims to describe the current knowledge regarding the efficacy of peroxisome proliferator-activated receptor-gamma ligands, cholesterol synthesis inhibitors (statins), epidermal growth factor signalling inhibitors and tumour necrosis factor-related apoptosis-inducing ligand against colorectal neoplasms and the rationale for combining these drugs with non-steroidal anti-inflammatory drugs to improve efficacy in the chemoprevention of colorectal cancer, a PUBMED computer search of the English language literature was conducted to identify relevant papers published before July 2004. Peroxisome proliferator-activated receptor-gamma ligands and statins, both in clinical use, reduce the growth rate of human colon cancer cells in vitro and in rodents models. In vitro, preclinical in vivo and clinical studies have shown efficacy of epidermal growth factor signalling inhibition in colorectal cancer. In vitro, tumour necrosis factor-related apoptosis-inducing ligand induces apoptosis in human colon cancer cells, but not in normal cells. These drugs have all been shown to interact with non-steroidal anti-inflammatory drugs in colorectal cancer cells and/or in rodent models. Combinational regimen are a promising strategy for the chemoprevention of colorectal cancer and should be further explored.

Chronic inflammation, apoptosis and (pre-)malignant lesions in the gastro-intestinal tract

Inflammatory conditions are characterized by activation of the transcription factor nuclear factor kappa B (NF-kappaB), resulting in the expression of NF-kappaB-regulated, inflammation-related genes, such as inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). Expression of these genes contributes to the survival of cells. Indeed, exposure to pro-inflammatory cytokines in the absence of NF-kappaB activation leads to apoptosis.(1,2) Chronic inflammatory conditions are accompanied by constitutive activation of NF-kappaB and hence, to the continuous expression of pro-survival genes, as has been observed in chronic gastritis.(3) Although beneficial for the survival of cells during exposure to inflammatory stress, the continuous activation of NF-kappaB may also pose a risk: cells with a pro-survival phenotype may give rise to continuously proliferating cells and may thus be tumorigenic. Progression to a malignant phenotype of these cells will most likely involve additional changes in the expression of non-NF-kappaB regulated genes e.g. a shift in the balance of pro- and anti-apoptotic genes towards a more anti-apoptotic phenotype. Literature on inflammation-related genes and the apoptotic balance in pre-malignant and malignant conditions in the gastro-intestinal tract is still scarce and conflicting. In this review, we aim to give an overview of the existing literature and we will focus on inflammation- and apoptosis-related genes in the sequence of normal epithelium-inflamed epithelium-metaplasia-dysplasia-cancer in the gastrointestinal tract, in particular esophagus (Barrett's esophagus: BE), stomach (gastritis) and colon (inflammatory bowel disease: IBD).

Chronic inflammation, apoptosis and (pre-)malignant lesions in the gastro-intestinal tract

Inflammatory conditions are characterized by activation of the transcription factor nuclear factor kappa B (NF-kappaB), resulting in the expression of NF-kappaB-regulated, inflammation-related genes, such as inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). Expression of these genes contributes to the survival of cells. Indeed, exposure to pro-inflammatory cytokines in the absence of NF-kappaB activation leads to apoptosis.(1,2) Chronic inflammatory conditions are accompanied by constitutive activation of NF-kappaB and hence, to the continuous expression of pro-survival genes, as has been observed in chronic gastritis.(3) Although beneficial for the survival of cells during exposure to inflammatory stress, the continuous activation of NF-kappaB may also pose a risk: cells with a pro-survival phenotype may give rise to continuously proliferating cells and may thus be tumorigenic. Progression to a malignant phenotype of these cells will most likely involve additional changes in the expression of non-NF-kappaB regulated genes e.g. a shift in the balance of pro- and anti-apoptotic genes towards a more anti-apoptotic phenotype. Literature on inflammation-related genes and the apoptotic balance in pre-malignant and malignant conditions in the gastro-intestinal tract is still scarce and conflicting. In this review, we aim to give an overview of the existing literature and we will focus on inflammation- and apoptosis-related genes in the sequence of normal epithelium-inflamed epithelium-metaplasia-dysplasia-cancer in the gastrointestinal tract, in particular esophagus (Barrett's esophagus: BE), stomach (gastritis) and colon (inflammatory bowel disease: IBD).

Chronic inflammation, apoptosis and (pre-)malignant lesions in the gastro-intestinal tract

Inflammatory conditions are characterized by activation of the transcription factor nuclear factor kappa B (NF-kappaB), resulting in the expression of NF-kappaB-regulated, inflammation-related genes, such as inducible nitric oxide synthase (iNOS) and cyclo-oxygenase-2 (COX-2). Expression of these genes contributes to the survival of cells. Indeed, exposure to pro-inflammatory cytokines in the absence of NF-kappaB activation leads to apoptosis.(1,2) Chronic inflammatory conditions are accompanied by constitutive activation of NF-kappaB and hence, to the continuous expression of pro-survival genes, as has been observed in chronic gastritis.(3) Although beneficial for the survival of cells during exposure to inflammatory stress, the continuous activation of NF-kappaB may also pose a risk: cells with a pro-survival phenotype may give rise to continuously proliferating cells and may thus be tumorigenic. Progression to a malignant phenotype of these cells will most likely involve additional changes in the expression of non-NF-kappaB regulated genes e.g. a shift in the balance of pro- and anti-apoptotic genes towards a more anti-apoptotic phenotype. Literature on inflammation-related genes and the apoptotic balance in pre-malignant and malignant conditions in the gastro-intestinal tract is still scarce and conflicting. In this review, we aim to give an overview of the existing literature and we will focus on inflammation- and apoptosis-related genes in the sequence of normal epithelium-inflamed epithelium-metaplasia-dysplasia-cancer in the gastrointestinal tract, in particular esophagus (Barrett's esophagus: BE), stomach (gastritis) and colon (inflammatory bowel disease: IBD).

Cost effectiveness of a new strategy to identify HNPCC patients

BACKGROUND

Distinguishing hereditary non-polyposis colorectal cancer (HNPCC) from non-hereditary colorectal cancer (CRC) can increase the life expectancy of HNPCC patients and their close relatives.

AIM

To determine the effectiveness, efficiency, and feasibility of a new strategy for the detection of HNPCC, using simple criteria for microsatellite instability (MSI) analysis of newly detected tumours that can be applied by pathologists. Criteria for MSI analysis are: (1) CRC before age 50 years; (2) second CRC; (3) CRC and HNPCC associated cancer; or (4) adenoma before age 40 years.

METHODS

The efficacy and cost effectiveness of the new strategy was evaluated against current practice. Decision analytic models were constructed to estimate the number of extra HNPCC mutation carriers and the costs of this strategy. The incremental costs and gain in life expectancy for a HNPCC mutation carrier were evaluated by Markov modelling. Feasibility was explored in five hospitals.

RESULTS

Using the new strategy, 2.2 times more HNPCC patients can be identified among a CRC population compared with current practice. This new strategy was found to be cost effective with an expected cost effectiveness ratio of 3801 per life year gained. When including the group of siblings and children, the cost effectiveness ratio became 2184 per life year gained. Sensitivity analysis showed these findings to be robust.

CONCLUSIONS

MSI testing in a selection of newly diagnosed CRC patients was shown to be cost effective and a feasible method to identify patients at risk for HNPCC who are not recognised by family history.

No association between the Arg201Gly polymorphism of the DCC gene and colorectal cancer

BACKGROUND AND AIMS

In one small study, the DCC Arg201Gly polymorphism has been observed more frequently in colorectal cancer cases compared with controls. We wondered whether these results could be replicated in a much larger study.

METHODOLOGY

The DCC Arg201 Gly polymorphism was genotyped in 625 unselected Caucasian colorectal cancer patients and 220 controls. Association analysis was used to search for a difference between patients and controls. Subgroup analyses were performed for site of tumour, gender, age at diagnosis, family history of colorectal cancer and modified Dukes classification.

RESULTS

The association analyses revealed no difference in Arg201Gly genotype frequency between patients and controls, neither overall nor for different subgroups according to site of tumour, gender, age at diagnosis, family history of colorectal cancer and modified Dukes classification.

CONCLUSION

No association was observed between the Arg201Gly polymorphism of DCC and colorectal cancer risk.

Duodenal versus jejunal biopsies in suspected celiac disease

BACKGROUND AND STUDY AIMS

In the past, small-bowel biopsies for diagnosis of celiac disease were taken from the jejunum with a suction capsule, but nowadays most physicians take endoscopic biopsies from the distal duodenum. To validate that practice we compared the diagnostic yield of endoscopic duodenal biopsies with that of endoscopic jejunal biopsies. In addition, we describe a method of orienting biopsy specimens optimally.

PATIENTS AND METHODS

Upper endoscopy was performed with a colonoscope. Four jejunal and four duodenal biopsies were taken and oriented immediately thereafter. The pathologist rated the orientation as poor, adequate, or good, and histopathological results were expressed according to the Marsh classification. Jejunal and duodenal biopsy results were compared.

RESULTS

146 patients were included. Jejunal biopsies were taken in 142 patients, and Marsh I-II lesions were found in 56 and Marsh III lesions in 15 patients. In three patients duodenal biopsies were normal while jejunal biopsies showed Marsh I-II lesions. No discrepancies were found in patients with Marsh III lesions. Orientation was good in all biopsies.

CONCLUSION

Duodenal biopsies are sufficient to diagnose full-blown celiac disease (Marsh III), but Marsh I-II lesions may be missed in some cases.

Assessment of apoptosis by M30 immunoreactivity and the correlation with morphological criteria in normal colorectal mucosa, adenomas and carcinomas

AIMS

To investigate the monoclonal antibody M30 for the assessment of apoptosis in colorectal tissues. Although Terminal deoxyribonucleotidyl transferase mediated nick end labelling (TUNEL) and in-situ end labelling (ISEL) are the methods most often used to demonstrate and quantify apoptosis in histological tissue sections, the interpretation and specificity of these techniques have been controversial. Immunohistochemistry using the monoclonal antibody M30 that recognizes caspase-cleaved cytokeratin 18 is considered to be a promising alternative but has yet to be validated against a generally accepted standard.

METHODS AND RESULTS

Paraffin sections of normal colonic mucosa (n = 30), normal mucosa obtained from resection margins from carcinomas (n = 30), colorectal adenomas (n = 84) and carcinomas (n = 40) were studied. Apoptosis of epithelial cells was assessed by M30 immunoreactivity and morphological criteria and expressed as a proportion of the total number of cells counted (apoptotic index). Mean apoptotic indices using M30 were 0.18 +/- 0.04% in normal mucosa, 0.42 +/- 0.04% in adenomas and 1.97 +/- 0.24% in carcinomas. Using morphological criteria, these indices were 0.23 +/- 0.03%, 0.62 +/- 0.06% and 1.78 +/- 0.19%, respectively. Apoptotic counts were higher in normal mucosa obtained from resection margins than in genuinely normal mucosa using the M30 antibody. Apoptotic indices obtained by M30 immunoreactivity and morphological criteria were positively correlated (r = 0.71, P < 0.01).

CONCLUSION

Assessment of apoptotic cells by M30 immunoreactivity correlates well with morphological criteria. Apoptotic indices increase in the course of the adenoma-carcinoma sequence. Apoptosis in normal mucosa obtained from resection margins differs from genuinely normal mucosa necessitating caution when interpreting studies of apoptosis in normal colonic mucosa. Our findings support the use of the M30 method in the study of apoptosis in colorectal tissues.

Dyspepsia management in primary care

BACKGROUND

Dyspepsia is common in western society. Prompt endoscopy is imperative in all patients with sinister symptoms or if symptoms first appear after the age of 50-55 years, but the optimal management of younger patients with uncomplicated dyspepsia is still open to debate.

METHODS

The literature on the management of uncomplicated dyspepsia is reviewed and a personal view is presented.

RESULTS

Strategies based on non-invasive detection of Helicobacter pylori are probably the most cost-effective. Currently (H. pylori prevalence 30%-40%), a 'test and treat' approach using a non-invasive test to detect H. pylori is likely to be the most efficient first step. If the patient is H. pylori-negative or if symptoms persist after successful H. pylori eradication, empirical treatment with an anti-secretory drug is justified. Endoscopy is reserved for those patients in whom this approach fails. If the prevalence of H. pylori decreases, the positive predictive value of any non-invasive H. pylori test will become too low. A 'test and scope' approach in which a positive test can be confirmed by two or more biopsy-based tests is then more appropriate. At a very low prevalence of H. pylori in the dyspeptic population, non-invasive testing for H. pylori loses its significance and empirical treatment with an antisecretory drug becomes a rational first step.

CONCLUSIONS

The optimal approach to management of uncomplicated dyspepsia is dependent on the prevalence of H. pylori among the dyspeptic population. At the current prevalence rate, 'test and treat', followed by acid suppressive treatment in the case of persisting symptoms, is the most appropriate strategy.

Decision analysis in the surgical treatment of colorectal cancer due to a mismatch repair gene defect

BACKGROUND

In view of the high risk of developing a new primary colorectal carcinoma (CRC), subtotal colectomy rather than segmental resection or hemicolectomy is the preferred treatment in hereditary non-polyposis colorectal cancer (HNPCC) patients. Subtotal colectomy however implies a substantial decrease in quality of life. To date, colonoscopic surveillance has been shown to reduce CRC occurrence.

AIMS

To compare the potential health effects in terms of life expectancy (LE) for patients undergoing subtotal colectomy or hemicolectomy for CRC.

METHODS

A decision analysis (Markov) model was created. Information on the 10 year risk of CRC after subtotal colectomy (4%) and hemicolectomy (16%) and stages of CRCs detected within a two year surveillance interval (32% Dukes' A, 54% Dukes' B, and 14% Dukes' C) were derived from two cohort studies. Five year survival rates used for the different Dukes stages (A, B, and C) were 98%, 80%, and 60%, respectively. Remaining LE values were calculated for hypothetical cohorts with an age at CRC diagnosis of 27, 47, and 67 years, respectively. Remaining LE values were also calculated for patients with CRC of Dukes' stage A.

RESULTS

The overall LE gain of subtotal colectomy compared with hemicolectomy at ages 27, 47, and 67 was 2.3, 1, and 0.3 years, respectively. Specifically for Dukes' stage A, this would be 3.4, 1.5, and 0.4 years.

CONCLUSIONS

Unless surveillance results improve, subtotal colectomy still seems the preferred treatment for CRC in HNPCC in view of the difference in LE. For older patients, hemicolectomy may be an option as there is no appreciable difference in LE.

[Prevention of colorectal cancer: acetylsalicyclic acid and cyclo-oxygenase-2 inhibitors are only partially effective]

Acetylsalicylic acid was recently shown to inhibit the development of colorectal adenomas in subjects with a moderately increased risk for colorectal cancer. The mechanisms by which acetylsalicylic acid and other NSAIDs, including COX-2 inhibitors, exert this effect include: inhibition of COX-2, induction of apoptosis and induction of the P21 protein that controls the development of crypt cells. For the majority of the population, a healthy lifestyle and healthy eating habits are the best means of preventing colorectal cancer. In addition, population-wide screening should be encouraged. For people with an increased risk of colorectal cancer, acetylsalicylic acid only has a partial effect and therefore endoscopic surveillance is still indicated. Sulindac or celecoxib may be useful for patients with familial adenomatous polyposis and in particular for inhibiting the development of rectal adenomas after subtotal colectomy with ileorectal anastomosis. However, in these cases endoscopic surveillance is also still necessary.

[Gene therapy with interleukin 10 in Crohn's disease: too early yet]

An improved understanding of the pathogenesis of inflammatory bowel disease (IBD) has led to the development of new drugs such as infliximab and insights into the modes of action of commonly used drugs such as azathioprine and methotrexate. These drugs act, at least in part, by inducing apoptosis of activated T-cells, which are an important phenomenon in the aberrant mucosal immune response in Crohn's disease. Gene therapy directed towards delivering anti-inflammatory proteins such as interleukin 10 (IL-10) to the inflamed mucosa is another new means of correcting the balance between the proinflammatory and anti-inflammatory cytokines in IBD. Gene-therapeutic manipulation of T-cells or bacteria to make them selectively deliver IL-10 to the gut mucosa has been successfully described in experimental models of IBD. Although interleukin-10-based gene therapy for Crohn's disease is an attractive option, safety aspects concerning the gene transfection method and questions about the efficacy of interleukin-10 in Crohn's disease in particular, prevent its application in the near future.

Dysplasia in fundic gland polyps is associated with nuclear beta-catenin expression and relatively high cell turnover rates

BACKGROUND

Fundic gland polyps (FGPs) occur in both syndromic and sporadic form. Syndromic FGPs arise through mutations in the adenomatous polyposis coli (APC) gene, whereas sporadic FGPs are caused by beta-catenin gene mutations. Dysplasia in sporadic FGPs, found less often than in syndromic FGPs, was recently associated with APC rather than beta-catenin mutations. These data suggest different functional consequences of APC and beta-catenin mutations. To investigate this hypothesis, we examined proliferative activity, degree of apoptosis, beta-catenin expression and p53 expression in syndromic and sporadic FGPs.

METHODS

Syndromic FGPs (n = 9) from familial adenomatous polyposis (FAP) patients and sporadic FGPs (n = 18) were studied. Proliferative activity, apoptotic cell death and expression of beta-catenin and p53 were examined by immunohistochemistry. In FGPs containing dysplasia, areas with and without dysplasia were compared.

RESULTS

Syndromic and sporadic FGPs without dysplasia exhibited similar proliferative activity, degree of apoptosis, beta-catenin and p53 expression. Dysplasia was observed more often in syndromic (4/9) than in sporadic FGPs (1/18). Within FGPs containing dysplasia, dysplastic areas showed abnormal nuclear beta-catenin staining in 3/5 cases and higher rates of cell proliferation and apoptosis than non-dysplastic areas. Overexpression of p53 was not observed.

CONCLUSION

The finding of similar rates of proliferation and apoptosis in syndromic and sporadic FGPs does not support the hypothesis that APC and beta-catenin gene mutations have different functional consequences in FGPs. The association of dysplasia with relatively high cell turnover rates and nuclear expression of beta-catenin indicates activation of the Wnt-APC-beta-catenin pathway in dysplasia. The finding of dysplasia in some but not all syndromic FGPs suggests the involvement of other genes in addition to the APC gene in the development of dysplasia in FGPs.

Diffuse and intestinal type gastric carcinomas differ in their expression of apoptosis related proteins

BACKGROUND

Gastric carcinomas can be divided into intestinal and diffuse types, with the last type having a worse prognosis.

AIMS

To investigate whether specific patterns in the expression of apoptosis related proteins correlate with carcinoma type and/or prognosis

METHODS

The expression of Fas, Bcl-2, Bax, Bcl-xl, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) was studied immunohistochemically and the extent of apoptosis and proliferation was investigated in 11 cases of intestinal type and in eight cases of diffuse type carcinoma.

RESULTS

Fas was expressed in all intestinal type and in one diffuse type carcinoma. Bcl-xl was expressed in 10 of 11 intestinal type and in one of eight diffuse type carcinomas. Bcl-2 was expressed in lamina propria immune cells. iNOS was expressed in six of 11 intestinal type and in four of eight diffuse type carcinomas, and COX-2 was expressed in eight of 11 intestinal type and in six of eight diffuse type carcinomas.

CONCLUSION

Fas and Bcl-xl expression can differentiate between intestinal type and diffuse type gastric carcinomas. No differences in apoptosis and proliferation between intestinal type and diffuse type gastric carcinomas were observed.

Inflammatory bowel disease after liver transplantation: the effect of different immunosuppressive regimens

BACKGROUND

Seemingly conflicting results have been reported on the prevalence and severity of inflammatory bowel disease after liver transplantation. Regimens with different combinations of drugs can be used for immunosuppression after transplantation.

AIM

To study retrospectively the prevalence of inflammatory bowel disease after liver transplantation, and the possible relationship with maintenance immunosuppressive regimens.

METHODS

All 78 patients with end-stage primary sclerosing cholangitis (48 patients) or autoimmune cirrhosis (30 patients), transplanted between 1979 and July 2001, and with a follow-up of at least 1 year, were eligible for this study. In addition to patient and transplant characteristics, data on inflammatory bowel disease and immunosuppression before and after transplantation were collected. The Kaplan-Meier method was used for survival analysis. Possible risk factors for inflammatory bowel disease after transplantation were analysed by Cox univariate and multivariate regression.

RESULTS

The median follow-up after transplantation was 7.2 years (range, 1.1-22.3 years). Nine of 25 patients with pre-transplant inflammatory bowel disease experienced flare-ups after transplantation. Six of 53 patients without pre-transplant inflammatory bowel disease developed de novo inflammatory bowel disease after transplantation. The cumulative risks (standard errors in parentheses) for inflammatory bowel disease were 6% (3%), 12% (4%) and 20% (5%) at 1, 3 and 5 years after transplantation, respectively. The inflammatory bowel disease-free survival was significantly higher in patients not receiving tacrolimus vs. those receiving tacrolimus, in patients receiving azathioprine vs. those not receiving azathioprine and in patients taking the regimen prednisolone-azathioprine-ciclosporin A vs. those taking tacrolimus-prednisolone. Pre-transplant inflammatory bowel disease and the use of tacrolimus were found to be independent predictors for inflammatory bowel disease after transplantation.

CONCLUSIONS

The prevalence of inflammatory bowel disease after liver transplantation is affected by the immunosuppression used. Azathioprine seems to have a protective effect and tacrolimus a promoting effect.

Rapidly progressive adenomatous polyposis in a patient with germline mutations in both the APC and MLH1 genes: the worst of two worlds

The two most common inherited forms of colorectal cancer are familial adenomatous polyposis and hereditary non-polyposis colorectal cancer. Simultaneous inheritance of both an APC gene mutation and a mismatch repair gene (for example, MLH1) mutation has never been described. In the present case report, we report rapidly progressive adenomatous polyposis in a 10 year old boy with a germline frame shift mutation in the APC gene and a germline splice site mutation in the MLH1 gene. Immunohistochemical investigations showed abnormal expression of beta-catenin in early adenomas with low grade dysplasia, attributed to the APC gene mutation. Subsequent loss of function of the MLH1 gene, as shown by absent immunostaining of its protein in adenomas with high grade dysplasia, may well have caused the rapid progression to high grade dysplasia in many of the adenomas.