Characterisation of the Timing and Prevalence of Receptor Tyrosine Kinase Expression Changes in Esophageal Carcinogenesis

Despite being common in epithelial malignancies, the timing of receptor tyrosine kinase (RTK) up-regulation is poorly understood and therefore hampers the identification of the receptor to target for effective treatment. We aimed to determine if RTK expression changes were early events in carcinogenesis. Esophageal adenocarcinoma and its pre-invasive lesion, Barrett's esophagus, were used for immunohistochemical analysis of the RTK panel, EGFR, ErbB2, ErbB3, Met and FGFR2, by utilising a cohort of patients with invasive disease (n = 367) and two cohorts with pre-invasive disease, one cross-sectional (n = 110) and one longitudinal in time (n = 91). The results demonstrated that 51% of esophageal adenocarcinomas over-expressed at least one of the RTK panel; with 21% of these over-expressing multiple receptors. Up-regulation of RTK expression was an early event corresponding with low grade dysplasia development (25% in areas without dysplasia vs. 63% in low grade dysplasia, p

Risk of Barrett's oesophagus, oesophageal adenocarcinoma and reflux oesophagitis and the use of nitrates and asthma medications

To investigate the relationship between use of asthma medication and nitrates and risk of reflux oesophagitis, Barrett's oesophagus and oesophageal adenocarcinoma.

Nonsteroidal anti-inflammatory drugs and the esophageal inflammation-metaplasia-adenocarcinoma sequence

Observational studies suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the risk of esophageal adenocarcinoma, but it is not known at what stage they may act in the esophageal inflammation-metaplasia-adenocarcinoma sequence. In an all-Ireland case-control study, we investigated the relationship between the use of NSAIDs and risk of reflux esophagitis, Barrett's esophagus, and esophageal adenocarcinoma. Patients with esophageal adenocarcinoma, long-segment Barrett's esophagus and population controls were recruited from throughout Ireland. Esophagitis patients were recruited from Northern Ireland only. Data were collected on known and potential risk factors for esophageal adenocarcinoma and on the use of NSAIDs, including aspirin, at least 1 year before interview. Associations between use of NSAIDs and the stages of the esophageal inflammation-metaplasia-adenocarcinoma sequence were estimated by multiple logistic regression. In total, 230 reflux esophagitis, 224 Barrett's esophagus, and 227 esophageal adenocarcinoma and 260 population controls were recruited. Use of aspirin and NSAIDs was associated with a reduced risk of Barrett's esophagus [odds ratio [OR; 95% confidence interval (95% CI)], 0.53 (0.31-0.90) and 0.40 (0.19-0.81), respectively] and esophageal adenocarcinoma [OR (95% CI), 0.57 (0.36-0.93) and 0.58 (0.31-1.08), respectively]. Barrett's esophagus and esophageal adenocarcinoma patients were less likely than controls to have used NSAIDs. Selection or recall bias may explain these results and the results of previous observational studies indicating a protective effect of NSAIDs against esophageal adenocarcinoma. If NSAIDs have a true protective effect on the esophageal inflammation-metaplasia-adenocarcinoma sequence, they may act early in the sequence.

Have patients with esophagitis got an increased risk of adenocarcinoma?:Results from a population-based study

To examine an increased risk of esophageal adenocarcinoma is restricted to patients who develop Barrett's esophagus or whether esophagitis per se is a risk factor for adenocarcinoma.

Mortality in Barrett's oesophagus:Results from a population based study

Background: Patients with Barrett's oesophagus have an increased risk of oesophageal adenocarcinoma but this cancer only accounts for a small proportion of deaths in these patients. Other causes of death are reportedly raised in this group. We examined cause specific mortality among individuals in a population based Barrett's oesophagus register. Methods: We constructed a register of all patients diagnosed with columnar mucosa (including specialised intestinal metaplasia) of the oesophagus within Northern Ireland between 1993 and 1999. Deaths occurring within this cohort until 31 December 2000 were identified and mortality rates were compared with the general population. Results: Overall mortality was not raised in Barrett's patients. During 7413 person years of follow up in 2373 patients there were 253 deaths (standardised mortality ratio (SMR) 96 (95% confidence interval (CI) 84-107)). Mortality from oesophageal cancer was raised in patients with specialised intestinal metaplasia (SMR 774 (95% CI 317-1231 )) but only 4.7% of patients died from this cancer. Mortality from stroke (SMR 65 (95% CI 37-93)) was significantly lower than the general population while mortality from non-cancerous digestive system diseases was significantly higher (SMR 211 (95% CI 111-311)). Mortality rates from all other causes were similar to those of the general population. Conclusions: This study demonstrates that the overall mortality rate in patients with Barrett's oesophagus is closely similar to that of the general population. Oesophageal cancer mortality was raised but is an uncommon cause of death in these patients who also appear to have a reduced risk of death from stroke.

Incidence of colorectal cancer in a population-based cohort of patients with Barrett's oesophagus

Objective. Previous studies have shown a positive association between colorectal cancer and Barrett's oesophagus, but this association is disputed. No population-based studies have examined the incidence of this cancer in patients with Barrett's oesophagus. Material and methods. The present study comprised a population-based cohort of patients with Barrett's oesophagus (constructed using pathology reports of all oesophageal biopsies in Northern Ireland 1993-99; cohort subclassified according to whether specialized intestinal metaplasia (SIM) was present, absent, or not commented on in biopsies). Cases of colorectal cancer were identified by linking with the Northern Ireland Cancer Registry. The comparison group used was the general population in Northern Ireland. Results. A total of 2969 patients with Barrett's oesophagus were followed for a total of 14,014 person-years (mean 4.7 years). SIM was present in 1670 patients (56.2%), absent in 545 (18.4%) and not commented on in 754 (25.4%). Colorectal cancer was diagnosed in 39 patients; 22 patients had cancer diagnosed at least 6 months after diagnosis of Barrett's oesophagus. There was no increased risk of colorectal cancer: the standardized incidence ratio (SIR) for cancer diagnosed at least 6 months after entry into the cohort was 0.82 (95% CI, 0.48-1.17); this risk did not alter with SIM status or gender. To assess a possible effect of diagnostic bias, we calculated SIRs for cancers occurring after at least 3 months, after at least 1 month and at any time after diagnosis of Barrett's oesophagus. These were 0.94 (0.57-1.30), 1.09 (0.69-1.48) and 1.46 (1.00-1.92), respectively. Conclusions. The incidence of colorectal cancer was not elevated in patients with Barrett's oesophagus. Diagnostic bias may explain why previous studies have found an association. © 2005 Taylor & Francis.

Oesophageal adenocarcinoma and prior diagnosis of Barrett's oesophagus: a population-based study

Objective: Endoscopic surveillance of Barrett's oesophagus (BO) provides an opportunity to detect early stage oesophageal adenocarcinoma (OAC). We sought to determine the proportion of OAC patients with a prior diagnosis of BO on a population basis and to evaluate the influence of a prior diagnosis of BO on survival, taking into account lead and length time biases.

Design: A retrospective population-based study of all OAC patients in Northern Ireland between 2003 and 2008. A prior BO diagnosis was determined by linkage to the Northern Ireland BO register. Stage distribution at diagnosis and histological grade were compared between patients with and without a prior BO diagnosis. Overall survival, using Cox models, was compared between patients with and without a prior BO diagnosis. The effect of adjusting the survival differences for histological grade and estimates of lead and length time bias was assessed.

Results: There were 716 OAC cases, 52 (7.3%) of whom had a prior BO diagnosis. Patients with a prior BO diagnosis had significantly lower tumour stage (44.2% vs 11.1% had stage 1 or 2 disease; p<0.001), a higher rate of surgical resection (50.0% vs 25.5%; p<0.001) and had a higher proportion of low/intermediate grade tumours (46.2% vs 26.5%; p=0.011). A prior BO diagnosis was associated with significantly better survival (HR for death 0.39; 95% CI 0.27 to 0.58), which was minimally influenced by adjustment for age, sex and tumour grade (adjusted HR 0.44; 95% CI 0.30 to 0.64). Correction for lead time bias attenuated but did not abolish the survival benefit (HR 0.65; 95% CI 0.45 to 0.95) and further adjustment for length time bias had little effect.

Conclusions: The proportion of OAC patients with a prior diagnosis of BO is low; however, prior identification of BO is associated with an improvement in survival in OAC patients.