Clinical puzzle: Barrett's oesophagus

Diagnostic Inaccuracies of Barrett's Oesophagus on Gastroscopy: Are We Performing Unnecessary Surveillance?

Background It is common for patients to enter Barrett's oesophagus (BO) surveillance based on endoscopic appearances before the diagnosis is histologically confirmed. We set out to review this practice by establishing the accuracy of endoscopic diagnoses of BO. Methods All gastroscopy reports in which a diagnosis of BO was recorded were reviewed over one year. These were compared to the histopathological reports to assess diagnostic accuracy. Results BO was diagnosed in 84 procedures. This diagnosis was incorrect according to histology in 42.9% (n=36) of cases. Diagnostic accuracy was higher with gastroenterologists (38.8% incorrect, n=21) compared to surgeons (50% incorrect, n=15). Diagnostic accuracy was higher with consultants (34.9% incorrect, n=22) compared to registrars (66.7% incorrect, n=14). The dose of sedation used had no impact on accuracy. Unnecessary surveillance was booked in 36.1% (n=13) of cases. Conclusion It is insufficient to rely on endoscopic appearances alone to diagnose BO, irrespective of speciality or experience. The diagnosis should only be made after reviewing the histopathology report. This can eliminate unnecessary repeat endoscopy procedures, sparing patients from unjustifiable risk and helping to cut down on long waiting lists in endoscopy departments. The implementation of the Prague classification and Seattle protocol can improve diagnostic accuracy.

A prospective cohort study of obesity and risk of oesophageal and gastric adenocarcinoma in the NIH-AARP Diet and Health Study

OBJECTIVE

The incidence of oesophageal adenocarcinoma (EAC) has increased rapidly over the past 40 years and accumulating evidence suggests that obesity, as measured by body mass index (BMI), is a major risk factor. It remains unclear whether abdominal obesity is associated with EAC and gastric adenocarcinoma.

DESIGN

Cox proportional hazards regression was used to examine associations between overall and abdominal obesity with EAC and gastric adenocarcinoma among 218 854 participants in the prospective NIH-AARP cohort.

RESULTS

253 incident EAC, 191 gastric cardia adenocarcinomas and 125 gastric non-cardia adenocarcinomas accrued to the cohort. Overall obesity (BMI) was positively associated with EAC and gastric cardia adenocarcinoma risk (highest (≥35 kg/m(2)) vs referent (18.5-<25 kg/m(2)); HR 2.11, 95% CI 1.09 to 4.09 and HR 3.67, 95% CI 2.00 to 6.71, respectively). Waist circumference was also positively associated with EAC and gastric cardia adenocarcinoma risk (highest vs referent; HR 2.01, 95% CI 1.35 to 3.00 and HR 2.22, 95% CI 1.43 to 3.47, respectively), whereas waist-to-hip ratio (WHR) was positively associated with EAC risk only (highest vs referent; HR 1.81, 95% CI 1.24 to 2.64) and persisted in patients with normal BMI (18.5-<25 kg/m(2)). Mutual adjustment of WHR and BMI attenuated both, but did not eliminate the positive associations for either with risk of EAC. In contrast, the majority of the anthropometric variables were not associated with adenocarcinomas of the gastric non-cardia.

CONCLUSION

Overall obesity was associated with a higher risk of EAC and gastric cardia adenocarcinoma, whereas abdominal obesity was found to be associated with increased EAC risk; even in people with normal BMI.

Expression, localization and polymorphisms of the nuclear receptor PXR in Barrett's esophagus and esophageal adenocarcinoma

BACKGROUND

The continuous exposure of esophageal epithelium to refluxate may induce ectopic expression of bile-responsive genes and contribute to the development of Barrett's esophagus (BE) and esophageal adenocarcinoma. In normal physiology of the gut and liver, the nuclear receptor Pregnane × Receptor (PXR) is an important factor in the detoxification of xenobiotics and bile acid homeostasis. This study aimed to investigate the expression and genetic variation of PXR in reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma.

METHODS

PXR mRNA levels and protein expression were determined in biopsies from patients with adenocarcinoma, BE, or RE, and healthy controls. Esophageal cell lines were stimulated with lithocholic acid and rifampicin. PXR polymorphisms 25385C/T, 7635A/G, and 8055C/T were genotyped in 249 BE patients, 233 RE patients, and 201 controls matched for age and gender.

RESULTS

PXR mRNA levels were significantly higher in adenocarcinoma tissue and columnar Barrett's epithelium, compared to squamous epithelium of these BE patients (P<0.001), and RE patients (P=0.003). Immunohistochemical staining of PXR showed predominantly cytoplasmic expression in BE tissue, whereas nuclear expression was found in adenocarcinoma tissue. In cell lines, stimulation with lithocholic acid did not increase PXR mRNA levels, but did induce nuclear translocation of PXR protein. Genotyping of the PXR 7635A/G polymorphism revealed that the G allele was significantly more prevalent in BE than in RE or controls (P=0.037).

CONCLUSIONS

PXR expresses in BE and adenocarcinoma tissue, and showed nuclear localization in adenocarcinoma tissue. Upon stimulation with lithocholic acid, PXR translocates to the nuclei of OE19 adenocarcinoma cells. Together with the observed association of a PXR polymorphism and BE, this data implies that PXR may have a function in prediction and treatment of esophageal disease.

Dietary fat and meat intakes and risk of reflux esophagitis, Barrett's esophagus and esophageal adenocarcinoma

The aim of our study was to investigate whether dietary fat and meat intakes are associated with reflux esophagitis (RE), Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). In this all-Ireland case-control study, dietary intake data were collected using a food frequency questionnaire in 219 RE patients, 220 BE patients, 224 EAC patients and 256 frequency-matched controls between 2002 and 2005. Unconditional multiple logistic regression analysis was used to examine the association between dietary variables and disease risk using quartiles of intake, to attain odds ratios (ORs) and 95% confidence intervals (95% CIs), while adjusting for potential confounders. Patients in the highest quartile of total fat intake had a higher risk of RE (OR = 3.54; 95% CI = 1.32-9.46) and EAC (OR = 5.44; 95% CI = 2.08-14.27). A higher risk of RE and EAC was also reported for patients in the highest quartile of saturated fat intake (OR = 2.79; 95% CI = 1.11-7.04; OR = 2.41; 95% CI = 1.14-5.08, respectively) and monounsaturated fat intake (OR = 2.63; 95% CI = 1.01-6.86; OR = 5.35; 95% CI = 2.14-13.34, respectively). Patients in the highest quartile of fresh red meat intake had a higher risk of EAC (OR = 3.15; 95% CI = 1.38-7.20). Patients in the highest category of processed meat intake had a higher risk of RE (OR = 4.67; 95% CI = 1.71-12.74). No consistent associations were seen for BE with either fat or meat intakes. Further studies investigating the association between dietary fat and food sources of fat are needed to confirm these results.

Differential expression of the nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) for grading dysplasia in patients with Barrett's oesophagus

AIMS

To investigate expression of nuclear receptors farnesoid X receptor (FXR) and pregnane X receptor (PXR) as a diagnostic tool to improve grading of dysplasia in Barrett's oesophagus patients.

METHODS AND RESULTS

Immunostaining was analysed on a total of 192 biopsy samples of 22 Barrett's patients with no dysplasia (ND), 17 with low-grade dysplasia (LGD), 20 high-grade dysplasia (HGD) and 24 with adenocarcinoma (AC). Nuclear FXR expression was observed in 15 of 22 (68%) ND cases versus none of 19 HGD; 3 of 17 (18%); LGD; 5 of 60 (8%) patients with AC (P<0.001). FXR expression was highly specific for non-dysplastic tissue. Nuclear PXR was expressed in 16 of 20 (80%) HGD cases versus two of 16 (13%) LGD cases (PPV 89%). Upon examining adjacent tissue taken from HGD and AC patients, PXR expression was high in samples of all tissue types.

CONCLUSIONS

Nuclear receptors are expressed differentially during neoplastic progression, with FXR positivity being useful to distinguish ND from dysplasia and AC. PXR nuclear expression is able to separate HGD from LGD and ND. The combination of FXR and PXR also appears to have diagnostic and possibly prognostic value, but future prospective studies are required to investigate their predictive power for neoplastic progression in Barret's oesophagus.

Secretory phospholipase A2 inhibition attenuates intercellular adhesion molecule-1 expression in human esophageal adenocarcinoma cells

BACKGROUND

Esophageal adenocarcinoma is an aggressive malignancy, with most patients succumbing to metastatic disease. The presence of intercellular adhesion molecule-1 (ICAM-1) in these cancer cells contributes to their metastatic potential. The ICAM-1 production in other cell types is stimulated by the actions of phospholipase enzymes. We hypothesize that inhibition of the enzyme secretory phospholipase A2 (sPLA2), which contributes to the growth potential of normal esophageal mucosa and esophageal cancer cells, may attenuate ICAM-1 production and nuclear factor-kappa beta activation in human esophageal adenocarcinoma cells.

METHODS

The FLO-1 verified human esophageal adenocarcinoma cells were treated with 5-(4-benzyloxyphenyl)-4S-(7-phenylheptanoylamino) pentanoic acid, a specific inhibitor of group IIa sPLA2 (5 μM, 10 μM, and 15 μM doses), followed by tumor necrosis factor-alpha stimulation (20 ng/mL). Cells and medium were collected and analyzed by immunoblotting, flow cytometry, and enzyme-linked immunosorbent assay. Statistical analysis was performed using analysis of variance with the Fisher's least significant difference post-hoc test.

RESULTS

Treatment with sPLA2 inhibitor attenuated total cellular ICAM-1 expression in a dose-dependent manner (p<0.005). Cell-surface and secreted ICAM-1 expression decreased significantly with sPLA2 inhibitor treatment (p<0.001 and p<0.05, respectively). sPLA2 inhibition attenuated nuclear factor-kappa beta activation dose-dependently (p<0.05).

CONCLUSIONS

Esophageal adenocarcinoma has significant metastatic potential, and inhibiting its metastasis would significantly advance the treatment of this disease. We demonstrate here that treatment of human esophageal adenocarcinoma cells with sPLA2 inhibitor attenuates the expression of ICAM-1, a marker of metastatic potential, and nuclear factor-kappa beta activation, suggesting a common pathway between the two. These findings identify inhibition of sPLA2 as a potential therapeutic target for esophageal adenocarcinoma.

Iron intake and markers of iron status and risk of Barrett's esophagus and esophageal adenocarcinoma

OBJECTIVE

To investigate the association between iron intake and iron status with Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC).

METHODS

A total of 220 BE patients, 224 EAC patients, and 256 frequency-matched controls completed a lifestyle and food frequency questionnaire and provided serum and toenail samples between 2002 and 2005. Using multiple logistic regression, odds ratios (OR) and 95% confidence intervals (95% CI) were calculated within quartiles of intake/status.

RESULTS

Comparing the fourth to the first quartile, ferritin (OR 0.47; 95% CI: 0.23, 0.97) and transferrin saturation (OR 0.41; 95% CI: 0.20, 0.82) were negatively associated with BE; while total iron binding capacity was positively associated per 50 μg/dl increment (OR 1.47; 95% CI: 1.12, 1.92). Comparing the fourth to the first quartile, iron intake (OR 0.50; 95% CI: 0.25, 0.98), non-heme iron intake per 10 mg/day increment (OR 0.29; 95% CI: 0.08, 0.99), and toenail iron (OR 0.40; 95% CI: 0.17, 0.93) were negatively associated with EAC; while heme iron intake was positively associated (OR 3.11 95% CI: 1.46, 6.61).

PRINCIPAL CONCLUSION

In contrast to the hypothesis that increased iron intakes and higher iron stores are a risk factor for BE and EAC, this study suggests that higher iron intakes and stores may have a protective association with BE and EAC, with the exception of what was found for heme iron intake.