Johan Offerhaus

Sulindac induced regression of colorectal adenomas in familial adenomatous polyposis: evaluation of predictive factors.

BACKGROUND--Sulindac, a non-steroidal anti-inflammatory drug, causes regression of colorectal adenomas in patients with familial adenomatous polyposis (FAP) but the response is variable. Specific clinical factors predictive of sulindac induced regression have not been studied. METHODS--22 patients with FAP were given sulindac 150 mg orally twice a day. Polyp number and size were determined before treatment and at three months. The relation of nine clinical factors to polyp regression (per cent of baseline polyp number after treatment) was evaluated by univariate and multivariate analysis. RESULTS--After three months of sulindac, polyp number had decreased to 45 per cent of baseline and polyp size to 50 per cent of baseline (p < 0.001 and p < 0.01, respectively). Univariate analysis showed greater polyp regression in older patients (p = 0.004), those with previous colectomy and ileorectal anastomosis (p = 0.001), and patients without identifiable mutation of the APC gene responsible for FAP (p = 0.05). With multivariate regression analysis, response to sulindac treatment was associated with previous subtotal colectomy. CONCLUSIONS--Sulindac treatment seems effective in producing regression of colorectal adenomas of FAP patients with previous subtotal colectomy regardless of baseline polyp number and size. Changed sulindac metabolism, reduced area of the target mucosa, or changed epithelial characteristics after ileorectal anastomosis may explain these findings.

Nasopharyngeal angiofibroma in patients with familial adenomatous polyposis.

Four patients with nasopharyngeal angiofibroma and familial adenomatous polyposis are reported here. Nasopharyngeal angiofibroma was 25 times more frequent in our patient population with familial adenomatous polyposis than in an age-matched hospital population. The association of these two rare conditions suggests that nasopharyngeal angiofibroma is an extracolonic manifestation of adenomatous polyposis. In addition, somatic mutation of the adenomatous polyposis coli gene, which causes adenomatous polyposis when mutated in the germline, could play a role in the pathogenesis of sporadic nasopharyngeal angiofibroma.

The role of bile salt composition in liver pathology of mdr2 (-/-) mice: differences between males and females.

BACKGROUND/AIMS The mouse mdr2 gene encodes a P-glycoprotein expressed in the canalicular membrane of the hepatocyte. Mice in which this gene has been inactivated (mdr2 -/-) show a defect in biliary phospholipid and cholesterol secretion and develop non-suppurative cholangitis. We hypothesized that secretion of bile salts without lipids initiates this liver disease. METHODS To delineate the pathologic process, mdr2 (-/-) mice were fed different bile salt-supplemented diets for 22 weeks after weaning. Aspects of liver pathology including eosinophilic bodies, portal inflammation, ductular proliferation, mitotic activity and fibrosis were semi-quantitatively scored. RESULTS It was observed that liver pathology was more severe in female than in male mice when fed a purified control diet. This correlated with a more hydrophobic bile salt composition of female vs. male bile. When increasing amounts of cholate were added to the diet (0.01% and 0.1%), the secretion of taurocholate increased and this was accompanied by a more severe liver pathology. At the high dose of cholate (0.1%), the bile salt compositions of male and female mice became similar, as did the severity of the histological score. Addition of cholate to the diet did not induce liver pathology in (+/+) mice. Addition of ursodeoxycholate to the diet (0.5%) led to a near complete replacement of biliary bile salts by tauroursodeoxycholate and this reduced pathology and dissipated the difference between males and females. CONCLUSIONS These observations support our hypothesis that liver pathology in the mdr2 (-/-) mouse is caused by bile salts and depends on the hydrophobicity c.q. cytotoxicity of biliary bile salts.

Polymorphisms in metabolic genes related to tobacco smoke and the risk of gastric cancer in the European prospective investigation into cancer and nutrition.

Metabolizing enzymes, which often display genetic polymorphisms, are involved in the activation of compounds present in tobacco smoke that may be relevant to gastric carcinogenesis. We report the results of a study looking at the association between risk of gastric adenocarcinoma and polymorphisms in genes CYP1A1, CYP1A2, EPHX1, and GSTT1. A nested case-control study was carried out within the European Prospective Investigation into Cancer and Nutrition, developed in 10 European countries. The study includes 243 newly diagnosed cases of histologically confirmed gastric adenocarcinoma and 946 controls matched by center, age, sex, and date of blood collection. Genotypes were determined in nuclear DNA from WBCs. We found an increased risk of gastric cancer for homozygotes for C (histidine) variant in Y113H of EPHX1 (odds ratio, 1.91; 95% confidence interval, 1.19-3.07) compared with subjects with TC/TT. There was also a significant increased risk for smokers carrying at least one variant allele A in Ex7+129C>A (m4) of CYP1A1 and never smokers with null GSTT1 and allele A in the locus −3859G>A of CYP1A2. Most of these genes are involved in the activation and detoxification of polycyclic aromatic hydrocarbons, suggesting a potential role of these compounds in gastric carcinogenesis. (Cancer Epidemiol Biomarkers Prev 2006;15(12):2427–34)

Pathology findings and validation of gastric and esophageal cancer cases in a European cohort (EPIC/EUR-GAST)

Objective. Cardia, non-cardia and intestinal and diffuse subtypes of gastric cancer may have different trends and etiological factors. However, the available information is not always collected in population cancer registries, and heterogeneous criteria have been applied for the histopathological classification of tumors. We describe the pathological features of incident gastric and esophageal cancers identified within the European Prospective Investigation into Cancer and Nutrition (EPIC). Material and methods. In an investigation on gastric and esophageal cancer (EUR-GAST) in the EPIC project, a validation study of diagnoses reported by EPIC centers was conducted by a European panel of pathologists. Original pathology reports, stained slides of tumors and the respective paraffin blocks were requested from the centers. Results. The whole series encompassed 467 cancer cases (gastric and esophageal cancers). Material was available for histopathological validation in 263 cases (56%); in the remaining cases, information was retrieved from the original reports (n=110; 24%) or codes provided by the EPIC centers (n=94; 20%). Among cases submitted to histopathological validation reported originally as unknown histotype or unknown site, a specific diagnosis was made in 95% and 74% of the cases, respectively. In cases for which only the original reports were available, the respective percentages were 46% and 67%. Gastric adenocarcinomas were classified according to site (cardia (29.4%), non-cardia (48.2%) and unknown (22.4%)) and histological type (intestinal (33.4%), diffuse (33.7%) and mixed, unclassified or unknown (32.9%)). Frequency of cardia was higher in Northern countries (35%) than in Mediterranean countries (18%). Conclusions. In addition to providing epidemiological data within the EPIC cohort on gastric and esophageal adenocarcinomas, the results reported here confirm the relevance of a validation study, notably for multicenter studies.

Barrett's adenocarcinomas resemble adenocarcinomas of the gastric cardia in terms of chromosomal copy number changes, but relate to squamous cell carcinomas of the distal oesophagus with respect to the presence of high-level amplifications

Three different cancers predominantly occur at the gastro‐oesophageal junction: squamous cell carcinomas of the distal oesophagus, adenocarcinomas of the distal oesophagus (Barretts carcinomas), and adenocarcinomas of the gastric cardia. The aim of the present study was to investigate how, and to what extent, Barretts carcinoma differs from adenocarcinoma of the gastric cardia on the one hand and squamous cell carcinoma of the distal oesophagus on the other, with respect to chromosomal aberrations and related gene expression. The present study analysed 14 squamous cell carcinomas, 24 Barretts carcinomas, and 16 carcinomas of the gastric cardia. Comparative genomic hybridization revealed chromosomal abnormalities in all cases. Typical chromosomal aberrations for the squamous cell carcinoma type were gains at 3q and 11q13, and losses at 3p, 4q, 9p, 11q, and 13q. In contrast, typical copy number changes for both cardiac and Barretts adenocarcinomas were gains at 2q, 7p, and 13q, and losses at 17p. High‐level amplification occurred in all three groups, but its frequency in the cardiac carcinomas was lower than in the other two groups. In conclusion, squamous cell carcinomas are characterized by chromosomal aberrations which are distinct from those seen in carcinomas of the gastric cardia and in Barretts adenocarcinomas. With respect to Barretts cancer, the chromosomal aberrations more closely reflect the adenocarcinoma phenotype than the squamous origin of the epithelium. Copyright

Serrated polyps of the colon: how reproducible is their classification?

For several years, the lack of consensus on definition, nomenclature, natural history, and biology of serrated polyps (SPs) of the colon has created considerable confusion among pathologists. According to the latest WHO classification, the family of SPs comprises hyperplastic polyps (HPs), sessile serrated adenomas/polyps (SSA/Ps), and traditional serrated adenomas (TSAs). The term SSA/P with dysplasia has replaced the category of mixed hyperplastic/adenomatous polyps (MPs). The present study aimed to evaluate the reproducibility of the diagnosis of SPs based on currently available diagnostic criteria and interactive consensus development. In an initial round, H&E slides of 70 cases of SPs were circulated among participating pathologists across Europe. This round was followed by a consensus discussion on diagnostic criteria. A second round was performed on the same 70 cases using the revised criteria and definitions according to the recent WHO classification. Data were evaluated for inter-observer agreement using Kappa statistics. In the initial round, for the total of 70 cases, a fair overall kappa value of 0.318 was reached, while in the second round overall kappa value improved to moderate (kappa = 0.557; p < 0.001). Overall kappa values for each diagnostic category also significantly improved in the final round, reaching 0.977 for HP, 0.912 for SSA/P, and 0.845 for TSA (p < 0.001). The diagnostic reproducibility of SPs improves when strictly defined, standardized diagnostic criteria adopted by consensus are applied.

Gene expression profiling identifies markers of ampullary adenocarcinoma

Ampullary adenocarcinoma is an aggressive cancer with a poor prognosis. Without surgical resection, ampullary adenocarcinomas can be difficult to distinguish from ampullary adenomas. The aim of this study was to identify differentially expressed genes in ampullary adenocarcinoma in order to identify candidate markers of the disease. The Affymetrix Human Genome U133 GeneChip set (HG-U133A and HG-U133B) was used to obtain gene expression profiles of 5 ampullary adenocarcinomas and 10 normal duodenal samples. Using fold change analysis we identified 235 fragments expressed at least fivefold higher in ampullary cancers than in normal duodenum. The expression profiles of eight candidate overexpressed genes (osteopontin, mesothelin, tissue inhibitor of metalloproteinases 1, mucin-1, mucin-5, fascin, heat shock protein 47, fibronectin 1) were confirmed by immunohistochemistry or in situ hybridization on tissue microarrays (TMA) containing 54 ampullary adenocarcinomas. One of these genes, osteopontin, was expressed 27-fold higher levels in ampullary adenocarcinomas compared to normal duodenum by genechip analysis. We therefore determined serum osteopontin levels in patients with ampullary neoplasms, patients with other periampullary diseases and in normal controls. Mean pre-operative serum osteopontin levels as measured by competitive ELISA were 906 ± 268 ng/ml in patients with ampullary cancer, 867 ± 160 ng/ml in patients with an ampullary adenoma, 327.1±195.6 ng/ml in patients with non-malignant periampullary diseases and 204 ± 65 ng/ml in age-matched healthy controls (P

Sulindac Inhibits β-Catenin Expression in Normal-Appearing Colon of Hereditary Nonpolyposis Colorectal Cancer and Familial Adenomatous Polyposis Patients

Sulindac reduces colorectal cancer risk in genetically susceptible humans and animals. The molecular mechanisms underlying these effects are incompletely understood. Many studies suggest an important role for induction of apoptosis involving the mitochondrial pathway and the death receptor pathway. Alternatively, mechanisms involving the APC-β-catenin-Wnt pathway have been suggested, possibly mediated by p21. We determined the effects of sulindac on apoptosis and expression of death receptor (DR)-4 and DR5, β-catenin, and p21 in normal-appearing colorectal epithelium. Biopsies were obtained before and after sulindac treatment during two chemoprevention studies. Patients (n = 18) with hereditary nonpolyposis colorectal cancer (HNPCC) received 150 mg sulindac bd for 4 weeks in a placebo-controlled crossover design. Patients (n = 6) with familial adenomatous polyposis (FAP) received 150 mg sulindac bd for 6 months. Apoptosis was assessed by M30 staining and expression patterns of DR4, DR5, β-catenin, and p21 were studied immunohistochemically. In HNPCC patients, apoptotic indices were similar following placebo and sulindac. Also in FAP patients, apoptotic indices were not different after sulindac compared with pretreatment values. Expression of DR4 and DR5 was observed in all samples with no consistent differences between placebo/baseline and sulindac. Intensity of membranous β-catenin staining was lower in HNPCC samples following sulindac compared with placebo (P < 0.001). Similar results were obtained in FAP samples (P < 0.01). p21 expressions before and after sulindac treatment were similar in both patient groups. In conclusion, sulindac inhibits β-catenin expression in normal colorectal epithelium from HNPCC and FAP patients without affecting apoptotic indices and DR4, DR5, and p21 expression.

Agenesis of the corpus callosum and gray matter heterotopia in three patients with constitutional mismatch repair deficiency syndrome

Constitutional mismatch repair deficiency (CMMR-D) syndrome is a rare inherited childhood cancer predisposition caused by biallelic germline mutations in one of the four mismatch repair (MMR)-genes, MLH1, MSH2, MSH6 or PMS2. Owing to a wide tumor spectrum, the lack of specific clinical features and the overlap with other cancer predisposing syndromes, diagnosis of CMMR-D is often delayed in pediatric cancer patients. Here, we report of three new CMMR-D patients all of whom developed more than one malignancy. The common finding in these three patients is agenesis of the corpus callosum (ACC). Gray matter heterotopia is present in two patients. One of the 57 previously reported CMMR-D patients with brain tumors (therefore all likely had cerebral imaging) also had ACC. With the present report the prevalence of cerebral malformations is at least 4/60 (6.6%). This number is well above the population birth prevalence of 0.09–0.36 live births with these cerebral malformations, suggesting that ACC and heterotopia are features of CMMR-D. Therefore, the presence of cerebral malformations in pediatric cancer patients should alert to the possible diagnosis of CMMR-D. ACC and gray matter heterotopia are the first congenital malformations described to occur at higher frequency in CMMR-D patients than in the general population. Further systematic evaluations of CMMR-D patients are needed to identify possible other malformations associated with this syndrome.