The minimal incubation period from the onset of Barrett's oesophagus to symptomatic adenocarcinoma

Background:The interval between the onset of Barrett's oesophagus (BO) and oesophageal adenocarcinoma (OAC) can be termed the incubation period. However, the unrecorded onset of BO precludes its direct observation.Methods:Determining the range of intervals between BO diagnosis and OAC within the longest observational BO follow-up study. Exclusion criteria were presence of high-grade dysplasia (HGD) or OAC at baseline, death within <2 years of BO diagnosis, oesophagectomy without HGD/OAC and loss to follow-up. A total of 133 patients (M/F 73/60) were taken into account.Results:In 1967 person years of follow-up there were 13 cases of HGD/OAC, (0.66% p.a.; 95% CI 0.58-0.74), 96 patients died without HGD/OAC and 24 survived without HGD/OAC. The mean intervals between BO diagnosis and either HGD/OAC, death or end of follow-up were 10.8, 12.6 and 25.5 years, respectively, and the mean ages at endpoint were 72.5, 80.0 and 68.3 years, respectively. The survivors without HGD/OAC had a lower age at BO diagnosis (mean 42.8 vs 61.2 and 67.4 years, P=0.001). Baseline presence of low-grade dysplasia was associated with progression to HGD/OAC (log rank P=0.001).Conclusion:The Rotterdam BO follow-up cohort revealed a long incubation period between onset of BO and development of HGD/OAC, in patients without HGD/OAC at baseline as illustrated by 24 patients diagnosed with BO at a young age and followed for a mean period of 25.5 years. Their tumour-free survival established a minimum incubation period, suggesting a true incubation period of three decades or more

Transcriptional profiling of Helicobacter pylori Fur- and iron-regulated gene expression

Intracellular iron homeostasis is a necessity for almost all living organisms, since both iron restriction and iron overload can result in cell death. The ferric uptake regulator protein, Fur, controls iron homeostasis in most Gram-negative bacteria. In the human gastric pathogen Helicobacter pylori, Fur is thought to have acquired extra functions to compensate for the relative paucity of regulatory genes. To identify H. pylori genes regulated by iron and Fur, we used DNA array-based transcriptional profiling with RNA isolated from H. pylori 26695 wild-type and fur mutant cells grown in iron-restricted and iron-replete conditions. Sixteen genes encoding proteins involved in metal metabolism, nitrogen metabolism, motility, cell wall synthesis and cofactor synthesis displayed iron-dependent Fur-repressed expression. Conversely, 16 genes encoding proteins involved in iron storage, respiration, energy metabolism, chemotaxis, and oxygen scavenging displayed iron-induced Fur-dependent expression. Several Fur-regulated genes have been previously shown to be essential for acid resistance or gastric colonization in animal models, such as those encoding the hydrogenase and superoxide dismutase enzymes. Overall, there was a partial overlap between the sets of genes regulated by Fur and those previously identified as growth-phase, iron or acid regulated. Regulatory patterns were confirmed for five selected genes using Northern hybridization. In conclusion, H. pylori Fur is a versatile regulator involved in many pathways essential for gastric colonization. These findings further delineate the central role of Fur in regulating the unique capacity of H. pylori to colonize the human stomach

Face-to-face vs telephone pre-colonoscopy consultation in colorectal cancer screening; A randomised trial

Background: A pre-colonoscopy consultation in colorectal cancer (CRC) screening is necessary to assess a screenees general health status and to explain benefits and risks of screening. The first option allows for personal attention, whereas a telephone consultation does not require travelling. We hypothesised that a telephone consultation would lead to higher response and participation in CRC screening compared with a face-to-face consultation. Methods:A total of 6600 persons (50-75 years) were 1: 1 randomised for primary colonoscopy screening with a pre-colonoscopy consultation either face-to-face or by telephone. In both arms, we counted the number of invitees who attended a pre-colonoscopy consultation (response) and the number of those who subsequently attended colonoscopy (participation), relative to the number invited for screening. A questionnaire regarding satisfaction with the consultation and expected burden of the colonoscopy (scored on five-point rating scales) was sent to invitees. Besides, a questionnaire to assess the perceived burden of colonoscopy was sent to participants, 14 days after the procedure.Results:In all, 3302 invitees were allocated to the telephone group and 3298 to the face-to-face group, of which 794 (24%) attended a telephone consultation and 822 (25%) a face-to-face consultation (P=0.41). Subsequently, 674 (20%) participants in the telephone group and 752 (23%) in the face-to-face group attended colonoscopy (P=0.018). Invitees and responders in the telephone group expected the bowel preparation to be more painful than those in the face-to-face group while perceived burden scores for the full screening procedure were comparable. More subjects in the face-to-face group than in the telephone group were satisfied by the consultation in general: (99.8% vs 98.5%, P=0.014).Conclusion:Using a telephone rather than a face-to-face consultation in a population-based CRC colonoscopy screening progr

Cure of Helicobacter pylori infection in patients with reflux oesophagitis treated with long term omeprazole reverses gastritis without exacerbation of reflux disease: results of a randomised controlled trial

BACKGROUND: Helicobacter pylori gastritis may progress to glandular atrophy and intestinal metaplasia, conditions that predispose to gastric cancer. Profound suppression of gastric acid is associated with increased severity of H pylori gastritis. This prospective randomised study aimed to investigate whether H pylori eradication can influence gastritis and its sequelae during long term omeprazole therapy for gastro-oesophageal reflux disease (GORD). METHODS: A total of 231 H pylori positive GORD patients who had been treated for > or =12 months with omeprazole maintenance therapy (OM) were randomised to either continuation of OM (OM only; n = 120) or OM plus a one week course of omeprazole, amoxycillin, and clarithromycin (OM triple; n = 111). Endoscopy with standardised biopsy sampling as well as symptom evaluation were performed at baseline and after one and two years. Gastritis was assessed according to the Sydney classification system for activity, inflammation, atrophy, intestinal metaplasia, and H pylori density. RESULTS: Corpus gastritis activity at entry was moderate or severe in 50% and 55% of the OM only and OM triple groups, respectively. In the OM triple group, H pylori was eradicated in 90 (88%) patients, and activity and inflammation decreased substantially in both the antrum and corpus (p<0.001, baseline v two years). Atrophic gastritis also improved in the corpus (p<0.001) but not in the antrum. In the 83 OM only patients with continuing infection, there was no change in antral and corpus gastritis activity or atrophy, but inflammation increased (p<0.01). H pylori eradication did not alter the dose of omeprazole required, or reflux symptoms. CONCLUSIONS: Most H pylori positive GORD patients have a corpus predominant pangastritis during omeprazole maintenance therapy. Eradication of H pylori eliminates gastric mucosal inflammation and induces regression of corpus glandular atrophy. H pylori eradication did not worsen reflux disease or lead to a need for increased omeprazole maintenance dose. We therefore recommend eradication of H pylori in GORD patients receiving long term acid suppression

NikR mediates nickel-responsive transcriptional induction of urease expression in Helicobacter pylori

The important human pathogen Helicobacter pylori requires the abundant expression and activity of its urease enzyme for colonization of the gastric mucosa. The transcription, expression, and activity of H. pylori urease were previously demonstrated to be induced by nickel supplementation of growth media. Here it is demonstrated that the HP1338 protein, an ortholog of the Escherichia coli nickel regulatory protein NikR, mediates nickel-responsive induction of urease expression in H. pylori. Mutation of the HP1338 gene (nikR) of H. pylori strain 26695 resulted in significant growth inhibition of the nikR mutant in the presence of supplementation with NiCl(2) at > or =100 microM, whereas the wild-type strain tolerated more than 10-fold-higher levels of NiCl(2). Mutation of nikR did not affect urease subunit expression or urease enzyme activity in unsupplemented growth media. However, the nickel-induced increase in urease subunit expression and urease enzyme activity observed in wild-type H. pylori was absent in the H. pylori nikR mutant. A similar lack of nickel responsiveness was observed upon removal of a 19-bp palindromic sequence in the ureA promoter, as demonstrated by using a genomic ureA::lacZ reporter gene fusion. In conclusion, the H. pylori NikR protein and a 19-bp operator sequence in the ureA promoter are both essential for nickel-responsive induction of urease expression in H. pylori

Leadership training to improve adenoma detection rate in screening colonoscopy: A randomised trial

Objective Suboptimal adenoma detection rate (ADR) at colonoscopy is associated with increased risk of interval colorectal cancer. It is uncertain how ADR might be improved. We compared t

Helicobacter pylori colonization and obesity - A Mendelian randomization study

Obesity is associated with substantial morbidity, costs, and decreased life expectancy, and continues to rise worldwide. While etiological understanding is needed for prevention, epidemiological studies indicated that colonization with Helicobacter pylori (H. pylori) may affect body mass index (BMI), but with inconsistent results. Here, we examine the relationship between H. pylori colonization and BMI/obesity. Cross-sectional analyses were performed in two independent population-based cohorts of elderly from the Netherlands and Germany (n = 13,044). Genetic risk scores were conducted based on genetic loci associated with either H. pylori colonization or BMI/obesity. We performed a bi-directional Mendelian randomization. Meta-analysis of cross-sectional data revealed no association between anti-H. pylori IgG titer and BMI, nor of H. pylori positivity and BMI. Anti-H. pylori IgG titer was negatively associated with obesity (OR 0.99972; 95% CI 0.99946-0.99997, p = 0.03) and with obesity classes (Beta -6.91 •10-5; 95% CI -1.38•10-4, -5.49•10-7, p = 0.048), but the magnitude of these effects was limited. Mendelian randomization showed no causal relation between H. pylori genetic risk score and BMI/obesity, nor between BMI or obesity genetic risk scores and H. pylori positivity. This study provides no evidence for a clinically relevant association between H. pylori and BMI/obesity

The role of the ferric uptake regulator (Fur) in regulation of Helicobacter pylori iron uptake

Background. Availability of the essential nutrient iron is thought to vary greatly in the gastric mucosa, and thus the human gastric pathogen Helicobacter pylori requires regulatory responses to these environmental changes. Bacterial iron-responsive regulation is often mediated by Ferric Uptake Regulator (Fur) homologs, and in this study we have determined the role of H. pylori Fur in regulation of H. pylori iron uptake. Methods. Wild-type H. pylori and fur mutant derivatives were compared after growth in ironrestricted and iron-replete conditions. Iron-uptake was measured using 55Fe-labeled iron, whereas gene expression was mon

Burden of waiting for surveillance CT colonography in patients with screen-detected 6–9 mm polyps

Purpose: We assessed the burden of waiting for surveillance CT colonography (CTC) performed in patients having 6–9 mm colorectal polyps on primary screening CTC. Additionally, we compared the burden of primary and surveillance CTC. Materials and methods: In an invitational population-based CTC screening trial, 101 persons were diagnosed with <3 polyps 6–9 mm, for which surveillance CTC after 3 years was advised. Validated questionnaires regarding expected and perceived burden (5-point Likert scales) were completed before and after index and surveillance CTC, also including items on burden of waiting for surveillance CTC. McNemar’s test was used for comparison after dichotomization. Results: Seventy-eight (77 %) of 101 invitees underwent surveillance CTC, of which 66 (85 %) completed the expected and 62 (79 %) the perceived burden questionnaire. The majority of participants (73 %) reported the experience of waiting for surveillance CTC as ‘never’ or ‘only sometimes’ burdensome. There was almost no difference in expected and perceived burden between surveillance and index CTC. Waiting for the results after the procedure was significantly more burdensome for surveillance CTC than for index CTC (23 vs. 8 %; p = 0.012). Conclusion: Waiting for surveillance CTC after primary CTC screening caused little or no burden for surveillance participants. In general, the burden of surveillance and index CTC were comparable. Key points: • Waiting for surveillance CTC withi

Computer tomography colonography participation and yield in patients under surveillance for 6-9 mm polyps in a population-based screening trial

Purpose: Surveillance CT colonography (CTC) is a viable option for 6-9 mm polyps at CTC screening for colorectal cancer. We established participation and diagnostic yield of surveillance and determined overall yield of CTC screening. Material and methods: In an invitational CTC screening trial 82 of 982 participants harboured 6-9 mm polyps as the largest lesion(s) for which surveillance CTC was advised. Only participants with one or more lesion(s) ≥6 mm at surveillance CTC were offered colonoscopy (OC); 13 had undergone preliminary OC. The surveillance CTC yield was defined as the number of participants with advanced neoplasia in the 82 surveillance participants, and was added to the primary screening yield. Results: Sixty-five of 82 participants were eligible for surveillance CTC of which 56 (86.2 %) participated. Advanced neoplasia was diagnosed in 15/56 participants (26.8 %) and 9/13 (69.2 %) with preliminary OC. Total surveillance yield was 24/82 (29.3 %). No carcinomas were detected. Adding surveillance results to initial screening CTC yield significantly increased the advanced neoplasia yield per 100 CTC participants (6.1 to 8.6; p < 0.001) and per 100 invitees (2.1 to 2.9; p < 0.001). Conclusion: Surveillance CTC for 6-9 mm polyps has a substantial yield of advanced adenomas and significantly increased the CTC yield in population screening. Key Points: • The participation rate in surveillance CT colonography (CTC) is 86 %. • Advanced adenoma prevalence in a 6-9 mm CTC surveillance population is high. • Surveillance CTC significantly increases the yield of population screening by CTC. • Surveillance CTC for 6-9 mm polyps is a safe strategy. • Sur