The frequency of advanced adenoma in consulting patients: a nationwide survey in Iceland (2003-2006).

AIM: To assess the frequency of advanced colorectal adenomas in consulting patients in Iceland. METHOD: The histological configuration of colorectal adenomas (CRA) found in 3603 patients was classified into tubular (TA), villous (VA) and serrated (SA) and the degree of neoplastic severity into low-grade dysplasia (LGD), high-grade dysplasia (HGD), carcinoma in situ (CIS), intramucosal carcinoma (IMC) and submucosal carcinoma (SMC). Advanced CRA were those showing HGD, CIS, IMC and/or SMCs. In patients with two or more adenomas, the adenoma with the highest degree of epithelial neoplasia was selected to record cases. RESULTS: Between 2003 and 2006 a total of 19424 endoscopic examinations (13572 colonoscopies and 5852 sigmoidoscopies) were performed in Iceland (mean, 4856 endoscopies per year). At histology a mean of 759.3 CRA per year were found. Thus, CRA were found in 15.6% of the colorectal endoscopies performed per year. Out of the 3037 CRA studied, 67% were TA, 29% VA and the remaining 4% SA. LGD was present in 79%, HGD in 15%, CIS in 2.4%, IMC in 1.9% and SMC in 1.9%. Consequently, out of 3037 CRA investigated, 652 (21.5%) were advanced CRA; 71% of these showed HGD, 11% CIS, 9% IMC and 9% SMC. Two-thirds of the 652 advanced CRA were advanced VA, and more than three-quarters of 58 advanced CRA with SMC, were advanced VA. CONCLUSION: Advanced VA displaying intraepithelial neoplasia (HGD and CIS) showed a propensity to evolve into invasive carcinoma. Accordingly, VA displaying HGD and CIS might be regarded as biological markers for predicting colorectal cancer risk. This is the first study in which the frequency of CRA and advanced CRA detected in consulting patients is reported on a nationwide basis.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results.

INTRODUCTION: Esomeprazole, the first proton pump inhibitor to be developed as an optical isomer, has demonstrated more effective healing vs. omeprazole and lansoprazole in patients with reflux oesophagitis (RO). However, RO recurs in a high proportion (approximately 80%) of these patients within 12 months of initial therapy, highlighting the importance of maintenance treatment. Previous studies have shown esomeprazole to be effective as maintenance therapy in healed RO patients. AIM: This study was conducted to compare esomeprazole 20 mg once daily (o.d.) with lansoprazole 15 mg o.d. for the prevention of recurrence of RO. METHODS: 1391 patients with endoscopically verified RO (LA classification) were enrolled in this randomized, double-blind, parallel-group, multicentre trial. During the initial healing phase of the study, all patients received 4-8 weeks' open treatment with esomeprazole 40 mg: 1236 healed (identified by endoscopy at 4 and 8 weeks) and symptom-free (i.e. no heartburn or acid regurgitation) patients were randomized to 6 months' maintenance treatment with esomeprazole 20 mg o.d. or lansoprazole 15 mg o.d. Time to relapse (relapse of RO and/or discontinuation due to symptom recurrence) was analysed using a log-rank test. RESULTS: Esomeprazole maintained a significantly higher proportion of patients in remission than lansoprazole over the 6-month course of treatment (P < 0.0001, intention-to-treat analysis). After 6 months' treatment, 83% of esomeprazole recipients were in remission compared with 74% of lansoprazole recipients (life-table estimates). Esomeprazole gave a longer time to relapse than lansoprazole irrespective of baseline LA Grade, significantly so for baseline LA Grades B, C and D (P < 0.05 for each comparison). Significantly more patients were free from heartburn in the esomeprazole group compared with the lansoprazole group at 1, 3 and 6 months (P < 0.05). Significant differences at 6 months between esomeprazole 20 mg o.d. and lansoprazole 15 mg o.d. were also observed for control of epigastric pain and acid regurgitation (P < 0.05 and P < 0.001, respectively). Both treatment regimens were well tolerated. CONCLUSION: Esomeprazole 20 mg o.d. is a more effective maintenance treatment than lansoprazole 15 mg o.d. for symptom-free patients with healed RO.

Esomeprazole 20 mg and lansoprazole 15 mg in maintaining healed reflux oesophagitis: Metropole study results.

AIM: To compare the efficacy of esomeprazole, 20 mg once daily, vs. lansoprazole, 15 mg once daily, for the maintenance treatment of patients with healed reflux oesophagitis. METHODS: During the initial open healing phase, 1391 patients with endoscopically verified reflux oesophagitis and a history of heartburn, with or without acid regurgitation, received esomeprazole 40 mg for 4-8 weeks. Patients who were healed (identified by endoscopy at 4 or 8 weeks) and symptom free were then randomized to receive 6 months of treatment with esomeprazole, 20 mg once daily, or lansoprazole, 15 mg once daily. RESULTS: Esomeprazole, 20 mg once daily, maintained a significantly higher proportion of patients in remission than lansoprazole, 15 mg once daily, over 6 months [83% (95% CI, 80-86%) of esomeprazole recipients compared with 74% (95% CI, 70-78%) of lansoprazole recipients; P < 0.0001; life table estimates]. When data were analysed according to baseline Los Angeles grade classification, esomeprazole, 20 mg once daily, achieved consistently higher remission rates across all grades of disease severity, whereas the efficacy of lansoprazole decreased to a greater extent with increasing severity of reflux oesophagitis. CONCLUSION: Esomeprazole, 20 mg once daily, is more effective than lansoprazole, 15 mg once daily, in maintaining remission in patients with healed reflux oesophagitis.

High frequency of LOH, MSI and abnormal expression of FHIT in gastric cancer.

The FHIT gene is a putative tumour suppressor gene. In this study, we analysed a set of 50 gastric tumours for alterations of FHIT, and found 38 of 45 tumours (84%) exhibiting loss of heterozygosity (LOH) within the FHIT gene. We used both nested Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and single step RT-PCR to analyse the FHIT transcripts and found 34 of 39 (87%) tumours and seven of the 11 (64%) corresponding non-cancerous tissues showed low or aberrant expression of FHIT mRNA and the appearance of the aberrant FHIT transcripts depended on the conditions of the RT-PCR. In these aberrant transcripts, frequent deletions and/or insertions were detected by direct sequencing. All breakpoints for deletions and insertions were at splicing sites. All insertions came from the adjacent introns, whose appearance was completely in accordance with the 'GU-AG' rule for pre-mRNA splicing. It may be suggested that an alternative splicing mechanism functions in the formation of these aberrant transcripts. The fragile nature of FRA3B within the FHIT gene could be responsible for the formation of the aberrant mRNA. Negative or reduced Fhit expression was detected in 39 of 50 tumours (78%). Moreover, an association was found between abnormal Fhit expression and positive node status (P=0.012). Thirteen of 48 tumours (27%) displayed microsatellite instability (MSI), among which 10 tumours also showed MSI within the FHIT gene. Furthermore, we detected an association between MSI and negative node status (P=0.02). We conclude that the abnormalities of FHIT, presumably associated with the unstable nature of FRA3B within the FHIT gene, are involved in the carcinogenesis of gastric cancer, and lack of mismatch repair (MMR) could possibly promote its alteration in a subset of gastric tumours.

Alterations of E-cadherin and beta-catenin in gastric cancer.

BACKGROUND: The E-cadherin-catenin complex plays a crucial role in epithelial cell-cell adhesion and in the maintenance of tissue architecture. Perturbation in the expression or function of this complex results in loss of intercellular adhesion, with possible consequent cell transformation and tumour progression. METHODS: We studied the alterations of E-cadherin and beta-catenin in a set of 50 primary gastric tumours by using loss of heterozygosity (LOH) analysis, gene mutation screening, detection of aberrant transcripts and immunohistochemistry (IHC). RESULTS: A high frequency (75%) of LOH was detected at 16q22.1 containing E-cadherin locus. Three cases (6%) showed the identical missense mutation, A592T. This mutation is not likely to contribute strongly to the carcinogenesis of gastric cancer, because a low frequency (1.6%) of this mutation was also found in 187 normal individuals. We also detected a low frequency (0.36%, 0%) of this mutation in 280 breast tumours and 444 other tumours, including colon and rectum, lung, endometrium, ovary, testis, kidney, thyroid carcinomas and sarcomas, respectively. We also analyzed the aberrant E-cadherin mRNAs in the gastric tumours and found that 7 tumours (18%) had aberrant mRNAs in addition to the normal mRNA. These aberrant mRNAs may produce abnormal E-cadherin molecules, resulting in weak cell-cell adhesion and invasive behaviour of carcinoma cells. Reduced expression of E-cadherin and beta-catenin was identified at the frequency of 42% and 28%, respectively. Specially, 11 tumours (22%) exhibited positive cytoplasmic staining for beta-catenin IHC. An association was found between reduced expression of E-cadherin and beta-catenin. Moreover, an association was detected between reduced expression of E-cadherin and diffuse histotype. CONCLUSION: Our results support the hypothesis that alterations of E-cadherin and beta-catenin play a role in the initiation and progression of gastric cancer.

Increasing the thermal stability of euphauserase. A cold-active and multifunctional serine protease from Antarctic krill.

A molecular model of Antarctic krill euphauserase based on the known crystal structure of its fiddler crab analog, collagenase I, indicates that the core structure of these enzymes is almost identical. Euphauserase is a cold-active and thermally sensitive enzyme with a high affinity for Lys, Arg and large hydrophobic amino acids. Residue Phe137 in euphauserase, localized in loop D (autolysis loop), is highly exposed on the surface of the molecule. Therefore, it appeared to be an easy target for autolysis. The broadly specific euphauserase has a low affinity for negatively charged residues. In order to increase the stability of the enzyme, two mutants were created in which residue Phe137 was replaced by a Glu and an Asp residue. Both mutations resulted in increased stability of the recombinant euphauserase towards thermal inactivation.

Propeptide dependent activation of the Antarctic krill euphauserase precursor produced in yeast.

Euphauserase is a brachyurin type digestive enzyme isolated from Antarctic krill. The brachyurins belong to clan SA of the S1 family of serine endopeptidases. In this study, we demonstrate that the precursor form of recombinant euphauserase, termed pro-r-euphauserase, can be successfully expressed in Pichia pastoris. The presence of most of the 51-residue euphauserase propeptide is essential during expression, under the growth conditions of Pichia. The propeptide may be required either for correct folding or processing of the enzyme. Cod trypsin generates a fully active r-euphauserase from its precursor, which appears to be identical to the native enzyme. The mature r-euphauserase sequence contains 250 amino-acid residues including a 13-residue activation peptide, which seems to be attached to the molecule by a disulfide bond. Euphauserase shares an average sequence identity of 62% with its type I brachyurin analogue, crab collagenase I. However, the identity between these two sequences is much higher in the regions shown to be important for the broad substrate specificity and collagen binding of crab collagenase I. The type I brachyurins share only 30-40% identities with the type II brachyurins and trypsins. The low isoelectric point of euphauserase, with a calculated pI value of 3.9, is typical for the type I brachyurins.

[Flow cytometric analysis of human malignancies.].

In this article recent advances in the flow cytometric analysis of human tumors are reviewed with regard to both DNA ploidy analysis and the estimation of S-phase fraction (SPF). The technique and background principles of flow cytometry are described and its clinical usefulness is discussed. Special consideration is given to malignancies of the breast, urinary bladder, prostate gland, ovaries, endometrium, skin, colorectum and the thyroid gland. Finally the usefulness of flow cytometry in the diagnosis of partial and complete hydatidiform moles is described.

[DNA flow cytometry is a useful prognostic guide in the treatment of breast cancer.].

It is widely agreed that the presence or absence of axillary lymph-node involvement (N) is the most reliable predictor of relapse or survival in breast cancer, together with tumor size (T) and the presence or absence of distant metastasis (M). These prognostic factors are the cornerstones of the TNM staging system. The aim of the present study was to ascertain, in all patients diagnosed with invasive primary breast cancer in Iceland during the years 1981-84 (n=347), whether flow cytometric DNA analysis of ploidy status and fraction of cells in the S-phase contribute prognostic information, addi nottional to that obtained with TNM staging variables. Paraffin fixed tumor material was available from 340 patients (98%) and DNA ploidy and S-phase fraction was assessed with flow cytometry. DNA ploidy could be analysed in 98% of tumor samples (n=334), of which 114 (34%) were diploid and 220 (66%) non-diploid. S-phase fraction could be analysed in 97% of the tumor samples (n=329), the median S-phase value was 7.0%, and was higher in non-diploid than diploid tumors (p<0.0001, 9.3% vs. 2.7%). Median duration of patient follow-up was 7.5 years. The disease-free survival at that point of time was 15% higher in patients with diploid tumors than non-diploid ones (p=0.004, 69% vs 54%). Similar survival comparison in relation to S-phase fraction was 30% when the median S-phase value was used as cut-off point (p<0.0001, S-phase<7.0% being 74% vs. S-phase ;7.0% being 44%). Multivariate analyses with regard to breast cancer survival and disease-free survival, which included both ploidy status and S-phase categories adjusting for age, tumor size and lymph node involvement, showed the S-phase value categories to be independent prognostic variables (p<0.0001). Patients with high S-phase tumors had a three-fold higher risk of recurrence than patients with low S-phase tumors. Ploidy status was not an independent prognostic variable, if however the S-phase categories were excluded from analysis, ploidy status was on the borderline of being an independent variable (p=0.09). In node-negative patients the S-phase fraction was the only useful variable in determining prognosis. We conclude that the S-phase value is a useful prognostic guide for the clinician and will be used for this purpose in the treatment of breast cancer in Iceland.