Volume 68 - 2005 - Fasc.3 - Original articles
Primary antibiotic resistance and effectiveness of helicobacter pylori triple therapy in ulcero-inflammatory pathologies of the upper digestive tract
Objectives : To determine firstly, the rates of primary antimi- crobial resistance for Helicobacter pylori - associated upper - diges- tive lesions in relation to the success rate of triple therapy ; and secondly, the performance of HpSA stool antigen detection test for control of eradication after treatment.
Methods : Prospective open study of 436 patients who under- went upper - digestive tract endoscopy with biopsies for histologi- cal examination and culture between January 1 and July 31, 2002 at a University hospital in Brussels, Belgium. The primary resis- tance to antibiotics of H. pylori isolates was determined by disc diffusion method. Seventy of 164 infected patients agreed to be included in the treatment study with standard triple therapy with amoxicillin + clarithromycin + omeprazole adjusted on the basis of antibiogram results. Control of eradication was tested by 14C-Urea breath test and H. pylori Stool Antigen test (HpSA test).
Results : Primary resistance to clarithromycin and metronida- zole was observed in 3% and 31% of the isolates, respectively. No primary resistance to amoxicillin and tetracycline was observed. By intention to treat analysis, H. pylori was eradicated in 56 (80%) patients included in the therapeutic study. Three (4%) patients were lost to follow-up. The rate of eradication failure was 20% (14/70), included 11 cases documented by a positive control test (14C-Urea breath test). In comparison with 14C-Urea breath test, the H. pylori Stool Antigen test showed a sensitivity of 100%, a specificity of 91%, PPV of 69%, and NPV of 100%.
Conclusion : Standard triple therapy achieved 80% bacterial eradication in this patient population with a low prevalence of H. pylori primary antibiotic resistance. Our data confirm that the H. pylori Stool Antigen test displays a diagnostic performance similar to the breath test for control of eradication. (Acta gastro- enterol. belg., 2005, 68, 287-293).
Microsatellite instability in sporadic and inherited colon adenocarcinomas from Greek patients : correlation with several clinicopathological characteristics
Background and aims : Microsatellite instability seems to play a significant role in colorectal carcinogenesis, as it is reported to occur in HNPCC patients as well as in a proportion of sporadic cases. The aim of this study was to examine the presence of microsatellite instability in relation to other commonly observed genetic abnormalities and clinicopathological characteristics of sporadic and inherited colorectal cancers.
Methodology : One hundred and three sporadic colorectal ade- nocarcinomas and 9 adenocarcinomas from HNPCC patients were histologically evaluated. The presence of microsatellite instability was investigated at six loci. K-ras and p53 mutations, p53 LOH, hMLH1 expression and methylation status were examined as well. Statistical analysis was performed to define possible correlations of the observed genetic alterations with the clinicopathological characteristics of the analysed tumors.
Results : High-grade microsatellite instability was found in 14% of sporadic adenocarcinomas and in 78% of adenocarcinomas from HNPCC patients. K-ras and p53 mutations were found in 29% and 28% of sporadic adenocarcinomas respectively and in 0% and 22% of the 9 HNPCC cases. A statistically significant cor- relation was noticed in sporadic tumors between the presence of MSI-H and tumor location at the proximal colon, as well as with the female gender.
Conclusions : Sporadic MSI+ colon adenocarcinomas seem to represent a distinct entity with a unique profile of genetic changes, different from those observed in HNPCC or MSI negative spo- radic tumors. (Acta gastroenterol. belg., 2005, 68, 294-301).
oesophageal intraepithelial and invasive neoplasia of squamous cell type : epi- demiology and outcome in Luxembourg, 1980-2001
Background and study aims : oesophageal intraepithelial neo- plasia of squamous cell type (INSC) and invasive oesophageal squamous cell carcinoma (IOSCC) are infrequent diseases in Western Europe. The aim of the present study was to collect pop- ulation-based data of both entities over a 20 year-period and to look for concomitant neoplastic affections in order to define an adequate diagnostic strategy.
Patients and methods: The National Morphologic Tumour Registry allowed to review the data of all patients with INSC and IOSCC diagnosed between 1980 and 2001 and to record the time trends in incidence, the oncologic co-morbidity and the outcome of the patients.
Results : 29 patients with INSC and 363 cases of IOSCC were identified. The overall age-standardized (world) incidence rate of intraepithelial neoplasia and invasive squamous cell carcinoma were 0.2 and 4.2 per 105, respectively, the M/F-ratio for both 3:1. During the study period, the incidence rate of invasive cancer remained stable in males but showed a 3-fold increase in females. There was a 2-fold increase of the intraepithelial neoplasia inci- dence in the last decade. The precancerous/cancerous-ratio increased slightly over the last 5 years. 31% of the patients with an INSC and 17.6% of those with IOSCC had concomitant precan- cerous and cancerous lesions especially of head and neck (laryngo- pharyngeal) or pulmonary origin. The observed 5-year survival rate was 8.8 +/- 3% (95% confidence interval) for IOSCC and 27.6% +/- 17% for INSC.
Conclusions : The incidence of invasive oesophageal squamous cell carcinomas remains stable whereas that of detected intraep- ithelial squamous cell neoplasias is remarkably low, indicating potential underdiagnosis. Considering the overall low incidence rates, mass screening for oesophageal cancer does not seem rea- sonable in Luxembourg. Nevertheless, patients at high-risk for oesophageal or head and neck or broncho-pulmonary cancer should be identified and surveilled by endoscopy, possibly with vital staining. (Acta gastroenterol. belg., 2005, 68, 302-307).