Barrett's oesophagus: optimal strategies for prevention and treatment

Risk Prediction Models for Barrett's Esophagus Discriminate Well and Are Generalizable in an External Validation Study

BACKGROUND

Barrett's esophagus is the precursor to the highly lethal esophageal adenocarcinoma. Risk prediction models have been developed to assist in its detection, potentially improving early identification and treatment of esophageal adenocarcinoma. Six models have been developed.

AIMS

To externally validate three models (Rubenstein, Thrift, and Baldwin-Hunter models) and compare them to a fourth risk prediction model (Ireland model) for Barrett's esophagus.

METHODS

Data from 120 Barrett's cases and 235 population controls were available to externally validate the three models. Discriminatory ability of these models was assessed by the area under the receiver operating characteristic curve. Calibration was assessed with the calibration slope, Hosmer-Lemeshow test, and Lowess smoother calibration plot. Following external validation, diagnostic accuracy of the three models was compared to that of the Ireland model.

RESULTS

On external validation, the Rubenstein model had an area under the receiver operating characteristic curve of 0.71 and was well calibrated (Hosmer-Lemeshow test, p = 0.67). Likewise, the Thrift and Baldwin-Hunter models had similar discrimination (0.71 and 0.70, respectively) and were also well calibrated (p = 0.69 and p = 0.28). Our previous external validation of the Ireland model provided an area under the receiver operating characteristic curve of 0.83 and was well calibrated (p = 0.14). The Ireland model demonstrated a statistically significantly greater area under the receiver operating characteristic curve than the Rubenstein (p = 0.02), Thrift (p = 0.001), and Baldwin-Hunter (p = 0.002) models.

CONCLUSION

We externally validated the Rubenstein, Thrift, and Baldwin-Hunter risk prediction models and compared them to the Ireland model. The Ireland model demonstrated improved accuracy, albeit with slightly poorer calibration.

Proton pump inhibitor-refractory gastroesophageal reflux disease: challenges and solutions

A significant percentage of patients with gastroesophageal reflux disease (GERD) will not respond to proton pump inhibitor (PPI) therapy. The causes of PPI-refractory GERD are numerous and diverse, and include adherence, persistent acid, functional disorders, nonacid reflux, and PPI bioavailability. The evaluation should start with a symptom assessment and may progress to imaging, endoscopy, and monitoring of esophageal pH, impedance, and bilirubin. There are a variety of pharmacologic and procedural interventions that should be selected based on the underlying mechanism of PPI failure. Pharmacologic treatments can include antacids, prokinetics, alginates, bile acid binders, reflux inhibitors, and antidepressants. Procedural options include laparoscopic fundoplication and LINX as well as endoscopic procedures, such as transoral incisionless fundoplication and Stretta. Several alternative and complementary treatments of possible benefit also exist.

The Prevalence and Clinical Features of Non-responsive Gastroesophageal Reflux Disease to Practical Proton Pump Inhibitor Dose in Korea: A Multicenter Study

BACKGROUND/AIMS

In Korea, there are no available multicenter data concerning the prevalence of or diagnostic approaches for non-responsive gastroesophageal reflux disease (GERD) which does not respond to practical dose of proton pump inhibitor (PPI) in Korea. The purpose of this study is to evaluate the prevalence and the symptom pattern of non-responsive GERD.

METHODS

A total of 12 hospitals who were members of a Korean GERD research group joined this study. We used the composite score (CS) as a reflux symptom scale which is a standardized questionnaire based on the frequency and severity of typical symptoms of GERD. We defined "non-responsive GERD" as follows: a subject with the erosive reflux disease (ERD) whose CS was not decreased by at least 50% after standard-dose PPIs for 8 weeks or a subject with non-erosive reflux disease (NERD) whose CS was not decreased by at least 50% after half-dose PPIs for 4 weeks.

RESULTS

A total of 234 subjects were analyzed. Among them, 87 and 147 were confirmed to have ERD and NERD, respectively. The prevalence of non-responsive GERD was 26.9% (63/234). The rates of non-responsive GERD were not different between the ERD and NERD groups (25.3% vs. 27.9%, respectively, p=0.664). There were no differences between the non-responsive GERD and responsive GERD groups for sex (p=0.659), age (p=0.134), or BMI (p=0.209). However, the initial CS for epigastric pain and fullness were higher in the non-responsive GERD group (p=0.044, p=0.014, respectively).

CONCLUSIONS

In conclusion, this multicenter Korean study showed that the rate of non-responsive GERD was substantially high up to 26%. In addition, the patients with the non-responsive GERD frequently showed dyspeptic symptoms such as epigastric pain and fullness.

Chemokines and their receptors in esophageal cancer--the systematic review and future perspectives

Esophageal cancer (EC) is an aggressive malignant solid tumor with rapid progression and unfavorable prognosis. The 5-year survival rate for EC patients was estimated to be less than 10 %. Therefore, there is an urgent need to improve diagnostic tool and effective treatment therapies for EC patients. In our paper, the general structure and function of chemokines and their receptors as well as their role in cancer progression were shortly presented. Moreover, the aim of our paper was to summarize and refer the current findings concerning the role of selected chemokines and their receptors as candidates for tumor markers of EC. Some clinical investigations have proved the involvement of these proteins in proliferation, migration, invasiveness and metastasis of tumor cells. Increasing evidence from previous studies suggested that C-X-C motif chemokine 12 (CXCL12), also known as stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 may provide novel diagnostic and prognostic strategies to reduce the burden of EC. Moreover, therapy targeting the CXCL12/CXCR4 axis may open a new direction for treatment of EC patients. However, given their nonspecific nature, the diagnostic value of chemokines and their receptors may be limited. Therefore, future larger investigations, especially in the blood of EC patients, still need to be continued to further clarify the significance of these proteins as potential candidates for tumor markers in diagnosis and prognosis of EC patients.

Step-by-step management of refractory gastresophageal reflux disease

Up to a third of the patients who receive proton pump inhibitor (PPI) once daily will demonstrate lack or partial response to treatment. There are various mechanisms that contribute to PPI failure and they include residual acid reflux, weakly acidic and weakly alkaline reflux, esophageal hypersensitivity, and psychological comorbidity, among others. Some of these underlying mechanisms may coincide in the same patient. Evaluation for proper compliance and adequate dosing time of PPIs should be the first management step before ordering invasive diagnostic tests. Doubling the PPI dose or switching to another PPI is the second step of management. Upper endoscopy and pH testing appear to have limited diagnostic value in patients who failed PPI treatment. In contrast, esophageal impedance with pH testing (multichannel intraluminal impedance MII-pH) on therapy appears to provide the most insightful information about the subsequent management of these patients (step 3). In step 4, treatment should be tailored to the specific underlying mechanism of patient's PPI failure. For those who demonstrate weakly acidic or weakly alkaline reflux as the underlying cause of their residual symptoms, transient lower esophageal sphincter relaxation reducers, endoscopic treatment, antireflux surgery and pain modulators should be considered. In those with functional heartburn, pain modulators are the cornerstone of therapy.

An algorithm for diagnosis and treatment of refractory GERD

Patients with gastro-esophageal reflux disease (GERD) who are not responding to proton pump inhibitors (PPIs) given once daily are very common. These therapy-resistant patients have become the new face of GERD in clinical practice in the last decade. Upper endoscopy appears to have a limited diagnostic value. In contrast, esophageal impedance with pH testing on therapy appears to provide the most insightful information about the subsequent management of these patients. Commonly, doubling the PPI dose or switching to another PPI will be offered to patients who failed PPI once daily. Failure of such therapeutic strategies is commonly followed by assessment for weakly or residual acidic reflux. There is growing information about the potential value of compounds that can reduce transient lower esophageal sphincter relaxation rate. Esophageal pain modulators are commonly offered to patients with functional heartburn although supportive clinical studies are still missing.

The role of weakly acidic reflux in proton pump inhibitor failure, has dust settled?

Patients that do not respond satisfactorily to standard proton pump inhibitor (PPI) treatment have become the most common presentation of gastro-esophageal reflux disease (GERD) in third referral gastrointestinal practices. The causes of refractory GERD include lack of compliance with treatment, residual acid reflux and weakly acidic reflux, esophageal hypersensitivity and persistent symptoms not associated with reflux. A role for weakly acidic reflux in symptom generation has been proposed since the availability of impedance-pH monitoring. The possible mechanisms by which persistent weakly acidic reflux might contribute to persistent symptoms in patients under PPI treatment may include esophageal distension by increased reflux volume, persistent impaired mucosal integrity (ie, dilation of intercellular spaces) and/or esophageal hypersensitivity to weakly acidic reflux events. To establish a definite role of weakly acidic reflux in refractory GERD, outcome studies targeting this type of reflux are still lacking. Treatment strategies to reduce the number or effect of weakly acidic reflux could involve drugs that decrease transient lower esophageal sphincter relaxations (ie, baclofen or similar), improve oesophageal mucosa resistance or visceral pain modulators. Finally, anti-reflux surgery can be considered, only if a clear symptom-weakly acidic reflux association was demonstrated.

Management of gastroesophageal reflux disease that does not respond well to proton pump inhibitors

PURPOSE OF REVIEW

Patients with gastroesophageal reflux disease (GERD) who are not responding to proton pump inhibitors (PPIs) given once daily are very common. These therapy-resistant patients have become the new face of GERD in clinical practice in the last decade and presently pose a significant therapeutic challenge to the practicing physician. We reviewed newly accumulated information about the management of PPI failure that has been published over the past 2 years.

RECENT FINDINGS

There are diverse mechanisms that contribute to the failure of PPI treatment in GERD patients and they are not limited to residual reflux. Some of the causes of PPI failure may coincide in the same patient. Upper endoscopy appears to have limited diagnostic value. In contrast, esophageal impedance with pH testing on therapy appears to provide the most insightful information about the subsequent management of these patients. Commonly, doubling the PPI dose or switching to another PPI will be offered to patients who failed PPI once daily. Failure of such therapeutic strategies is commonly followed by assessment for residual reflux. There is growing information about the potential value of compounds that can reduce transient lower esophageal sphincter relaxations. Esophageal pain modulators are commonly offered to patients with functional heartburn, although supportive clinical studies are still missing.

SUMMARY

Management of refractory GERD patients remains an important clinical challenge. Recent studies have cemented the value of impedance-pH testing in pursuing proper treatment. Presently, the most promising therapeutic development for this patient population is transient lower esophageal sphincter relaxation reducers.

Proton pump inhibitor failure--what are the therapeutic options?

Proton pump inhibitor (PPI) failure is very common and may affect up to one-third of the PPI consumers. Identifying the underlying mechanisms for PPI failure in each individual patient is essential for treatment success. For residual acid reflux, increasing the PPI dose to twice daily; switching to another PPI, or adding an histamine 2 receptor antagonist could be a successful therapeutic strategy. In patients with duodenogastroesophageal reflux, weak acidic/alkaline reflux and hypersensitivity to acid reflux, therapeutic modalities that reduce transient lower esophageal sphincter relaxation or visceral pain could be entertained. Treatment of PPI failure due to delayed gastric emptying should be focused on improving gastric motor activity. Psychological management may supplement any medical or surgical approach toward PPI failure.

The effect of antireflux surgery on esophageal carcinogenesis in patients with barrett esophagus: a systematic review

OBJECTIVE

To determine whether patients with Barrett esophagus who undergo antireflux surgery differ from medically treated patients in incidence of esophageal adenocarcinoma and probability of disease regression/progression.

SUMMARY BACKGROUND DATA

Barrett esophagus is a risk factor for the development of esophageal adenocarcinoma. A question exists as to whether antireflux surgery reduces this risk.

METHODS

Query of PubMed (1966 through October 2005) using predetermined search terms revealed 2011 abstracts, of which 100 full-text articles were reviewed. Twenty-five articles met selection criteria. A review of article references and consultation with experts revealed additional articles for inclusion. Studies that enrolled adults with biopsy-proven Barrett esophagus, specified treatment-type rendered, followed up patients with endoscopic biopsies no less than12 months of instituting therapy, and provided adequate extractable data. The incidence of adenocarcinoma and the proportion of patients developing progression or regression of Barrett esophagus and/or dysplasia were extracted.

RESULTS

In surgical and medical groups, 700 and 996 patients were followed for a total of 2939 and 3711 patient-years, respectively. The incidence rate of esophageal adenocarcinoma was 2.8 (95% confidence interval, 1.2-5.3) per 1000 patient-years among surgically treated patients and 6.3 (3.6-10.1) among medically treated patients (P = 0.034). Heterogeneity in incidence rates in surgically treated patients was observed between controlled studies and case series (P = 0.014). Among controlled studies, incidence rates were 4.8 (1.7-11.1) and 6.5 (2.6-13.8) per 1000 patient-years in surgical and medical patients, respectively (P = 0.320). Probability of progression was 2.9% (1.2-5.5) in surgical patients and 6.8% (2.6-12.1) in medical patients (P = 0.054). Probability of regression was 15.4% (6.1-31.4) in surgical patients and 1.9% (0.4-7.3) in medical patients (P = 0.004).

CONCLUSIONS

Antireflux surgery is associated with regression of Barrett esophagus and/or dysplasia. However, evidence suggesting that surgery reduces the incidence of adenocarcinoma is largely driven by uncontrolled studies.

Systematic review: proton-pump inhibitor failure in gastro-oesophageal reflux disease--where next?

Proton-pump inhibitor failure has become a common clinical dilemma in gastrointestinal clinics and has been increasingly encountered at the primary care level as well. Underlying mechanisms are diverse and may overlap. Most patients who have proton-pump inhibitor failure are likely to originate from the non-erosive reflux disease phenotype. Currently, available diagnostic modalities provide limited clues to the exact underlying cause. Treatment relies primarily on escalating dosing of proton-pump inhibitors. However, new insights into the pathophysiology of proton-pump inhibitor failure are likely to provide alternative therapeutic options.

Immunonutrition and cancer

The immune system is the body's primary defence against invading pathogens, non-self components and cancer cells. Inflammatory processes, including the release of pro-inflammatory cytokines and formation of reactive oxygen and nitrogen species, are an essential part of these processes. Although such actions are usually followed rapidly by anti-inflammatory effects, excessive production of pro-inflammatory cytokines, or their production in the wrong biological context may lead to situations of chronic inflammation. Whether such conditions arise as a result of exogenous chemicals, invading pathogens or disease processes, the long-term implications include an increased risk of cancer. A number of nutrients have the ability to modulate immune response and counter inflammatory processes. Zinc, epigallocatechin galate (EGCG), omega-3 polyunsaturated fatty acids and probiotics all act differently to modulate immune response, but all appear to have the potential to protect against cancer development and progression. We suggest that immunonutrition may provide a less invasive alternative to immunotherapy in protection against cancers associated with chronic inflammation.