Use of proton pump inhibitors and risk of progression of Barrett's esophagus to neoplastic lesions

Barrett's Esophagus and Intestinal Metaplasia

Intestinal metaplasia refers to the replacement of the differentiated and mature normal mucosal epithelium outside the intestinal tract by the intestinal epithelium. This paper briefly describes the etiology and clinical significance of intestinal metaplasia in Barrett’s esophagus. This article summarizes the impact of intestinal metaplasia on the diagnosis, monitoring, and treatment of Barrett’s esophagus according to different guidelines. We also briefly explore the basis for the endoscopic diagnosis of intestinal metaplasia in Barrett’s esophagus. The identification techniques of goblet cells in Barrett’s esophagus are also elucidated by some scholars. Additionally, we further elaborate on the current treatment methods related to Barrett’s esophagus.

Barrett’s esophagus in 2016: From pathophysiology to treatment

Esophageal complications caused by gastroesophageal reflux disease (GERD) include reflux esophagitis and Barrett’s esophagus (BE). BE is a premalignant condition with an increased risk of developing esophageal adenocarcinoma (EAC). The carcinogenic sequence may progress through several steps, from normal esophageal mucosa through BE to EAC. A recent advent of functional esophageal testing (particularly multichannel intraluminal impedance and pH monitoring) has helped to improve our knowledge about GERD pathophysiology, including its complications. Those findings (when properly confirmed) might help to predict BE neoplastic progression. Over the last few decades, the incidence of EAC has continued to rise in Western populations. However, only a minority of BE patients develop EAC, opening the debate regarding the cost-effectiveness of current screening/surveillance strategies. Thus, major efforts in clinical and research practice are focused on new methods for optimal risk assessment that can stratify BE patients at low or high risk of developing EAC, which should improve the cost effectiveness of screening/surveillance programs and consequently significantly affect health-care costs. Furthermore, the area of BE therapeutic management is rapidly evolving. Endoscopic eradication therapies have been shown to be effective, and new therapeutic options for BE and EAC have emerged. The aim of the present review article is to highlight the status of screening/surveillance programs and the current progress of BE therapy. Moreover, we discuss the recent introduction of novel esophageal pathophysiological exams that have improved the knowledge of the mechanisms linking GERD to BE.

Role of nitric oxide in the pathogenesis of Barrett’s-associated carcinogenesis

Barrett’s esophagus (BE), a premalignant condition to Barrett’s adenocarcinoma (BAC), is closely associated with chronic inflammation due to gastro-esophageal reflux. Caudal type homeobox 2 (CDX2), a representative marker of BE, is increased during the metaplastic and neoplastic transformation of BE. Nitric oxide (NO) has been proposed to be a crucial mediator of Barrett’s carcinogenesis. We previously demonstrated that CDX2 might be induced directly under stimulation of large amounts of NO generated around the gastro-esophageal junction (GEJ) by activating epithelial growth factor receptor in a ligand-independent manner. Thus, we reviewed recent developments on the role of NO in Barrett’s carcinogenesis. Notably, recent studies have reported that microbial communities in the distal esophagus are significantly different among groups with a normal esophagus, reflux esophagitis, BE or BAC, despite there being no difference in the bacterial quantity. Considering that microorganism components can be one of the major sources of large amounts of NO, these studies suggest that the bacterial composition in the distal esophagus might play an important role in regulating NO production during the carcinogenic process. Controlling an inflammatory reaction due to gastro-esophageal reflux or bacterial composition around the GEJ might help prevent the progression of Barrett’s carcinogenesis by inhibiting NO production.

BOB CAT: A Large-Scale Review and Delphi Consensus for Management of Barrett's Esophagus With No Dysplasia, Indefinite for, or Low-Grade Dysplasia

OBJECTIVES

Barrett's esophagus (BE) is a common premalignant lesion for which surveillance is recommended. This strategy is limited by considerable variations in clinical practice. We conducted an international, multidisciplinary, systematic search and evidence-based review of BE and provided consensus recommendations for clinical use in patients with nondysplastic, indefinite, and low-grade dysplasia (LGD).

METHODS

We defined the scope, proposed statements, and searched electronic databases, yielding 20,558 publications that were screened, selected online, and formed the evidence base. We used a Delphi consensus process, with an 80% agreement threshold, using GRADE (Grading of Recommendations Assessment, Development and Evaluation) to categorize the quality of evidence and strength of recommendations.

RESULTS

In total, 80% of respondents agreed with 55 of 127 statements in the final voting rounds. Population endoscopic screening is not recommended and screening should target only very high-risk cases of males aged over 60 years with chronic uncontrolled reflux. A new international definition of BE was agreed upon. For any degree of dysplasia, at least two specialist gastrointestinal (GI) pathologists are required. Risk factors for cancer include male gender, length of BE, and central obesity. Endoscopic resection should be used for visible, nodular areas. Surveillance is not recommended for <5 years of life expectancy. Management strategies for indefinite dysplasia (IND) and LGD were identified, including a de-escalation strategy for lower-risk patients and escalation to intervention with follow-up for higher-risk patients.

CONCLUSIONS

In this uniquely large consensus process in gastroenterology, we made key clinical recommendations for the escalation/de-escalation of BE in clinical practice. We made strong recommendations for the prioritization of future research.

Acid-suppressive medications and risk of oesophageal adenocarcinoma in patients with Barrett's oesophagus: a systematic review and meta-analysis

BACKGROUND AND AIMS

Acid-suppressive medications, particularly proton pump inhibitors (PPIs), may decrease the risk of oesophageal adenocarcinoma (OAC) in patients with Barrett's oesophagus (BO). We performed a systematic review with meta-analysis of studies evaluating the association between acid-suppressive medications (PPIs and histamine receptor antagonists (H2RAs)) and risk of OAC or high-grade dysplasia (BO-HGD) in patients with BO.

METHODS

We performed a systematic search of multiple electronic databases and conference proceedings up to June 2013 to identify studies reporting the association between use of acid-suppressive medications and risk of OAC and/or BO-HGD in patients with BO. Summary ORs with 95% CIs were estimated.

RESULTS

We identified seven observational studies (2813 patients with BO, 317 cases of OAC or BO-HGD, 84.4% PPI users). On meta-analysis, PPI use was associated with a 71% reduction in risk of OAC and/or BO-HGD in patients with BO (adjusted OR 0.29; 95% CI 0.12 to 0.79). There was a trend towards a dose-response relationship with PPI use for >2-3 years protective against OAC or BO-HGD (three studies; PPI use >2-3 years vs <2-3 years: OR 0.45 (95% CI 0.19 to 1.06) vs 1.09 (0.47 to 2.56)). Considerable heterogeneity was observed. Two studies reported the association between H2RA use and risk of OAC and/or BO-HGD (1352 patients with BO, 156 cases of OAC, 25.4% on H2RAs), and both studies did not show a significant effect.

CONCLUSIONS

Based on meta-analysis of observational studies, the use of PPIs is associated with a decreased risk of OAC and/or BO-HGD in patients with BO. None of the studies showed an increased risk of OAC. PPI use should be considered in BO, and chemopreventive trials of PPIs in patients with BO are warranted.

Carcinogenesis of Barrett's esophagus: a review of the clinical literature

Barrett's esophagus (BE) is a premalignant condition of esophageal adenocarcinoma (EAC). Although the incidence of BE has risen rapidly in the West, it is rare in Asia despite a recent increase in the prevalence of gastroesophageal reflux disease. Controversies over the definition of BE are presented because most cases show short-segment BE, especially ultra-short BE, in Asia. Here we review possible risk factors for the development of EAC, particularly possible roles of ethnicity, specialized intestinal metaplasia (SIM), BE length, and environmental factors, such as Helicobacter pylori infection and obesity. Additionally, we summarize recent studies on the effect of chemoprevention including proton pump inhibitors, nonsteroidal anti-inflammatory drugs or aspirin in order to reduce the risk of neoplastic progression in BE patients. Although substantial knowledge of risk factors of dysplasia/EAC in BE is shown, the risk for neoplastic development may be influenced by geographic variation, study population, the presence or absence of SIM or dysplasia at baseline, and the small number of BE patients investigated. Recently, the efficiency of surveillance for BE patients has been discussed from the standpoint of cost-effectiveness. It may be too difficult to draw conclusions because no randomized clinical trials of BE surveillance have been performed.

Exposure to gastric juice may not cause adenocarcinogenesis of the esophagus

AIM: To determine the effects of gastric juice on the development of esophageal adenocarcinoma (EAC).

METHODS: A animal model of duodenogastroesophageal reflux was established in Sprague-Dawley rats undergoing esophagoduodenostomy. The development of EAC and forestomach adenocarcinoma was investigated 40 wk after the treatment. Intraluminal pH and bile of the forestomach were measured.

RESULTS: There were no significant differences in pH (t = 0.117, P = 0.925) or bile (χ² = 0.036, P = 0.85) in the forestomach before and 40 wk after esophagoduodenostomy. There were also no significant differences between the model and controls during esophagoduodenostomy or 40 wk after esophagoduodenostomy. The incidence of intestinal metaplasia (88%) and intestinal metaplasia with dysplasia and adenocarcinoma (28%) in the esophagus in the model was higher than in the controls 40 wk after surgery (χ² = 43.06, P < 0.001 and χ² = 9.33, P = 0.002, respectively) and in the forestomach in the model (χ² = 32.05, P < 0.001 and χ² = 8.14, P = 0.004, respectively). The incidence rates of inflammation in the esophagus and forestomach were 100% and 96%, respectively (χ² = 1.02, P = 0.31) in the model, which was higher than in the esophageal control (6.8%) (χ² = 42.70, P < 0.001).

CONCLUSION: Gastric juice exposure may not cause intestinal metaplasia with dysplasia or adenocarcinoma of the forestomach and may not be related to EAC.

[Newly recognized side-effects of proton pump inhibitors. Arguments in favour of fundoplication for GERD?]

Among other indications proton pump inhibitors (PPIs) are used as medical treatment of gastroesophageal reflux disease (GERD) and are the most frequently prescribed and most frequently used drugs in gastroenterology. Until recently PPIs were regarded as very safe and associated with very few side-effects. However, during recent years study results have revealed many severe adverse events associated especially with long-term PPI use. We review the currently available evidence, regarding the side-effects of PPIs and discuss the potential impact on treatment strategies for GERD (conservative treatment vs. antireflux surgery). Currently available data suggest that PPIs are associated with osteoporosis-related fractures, Clostridium difficile associated diarrhea (CDAD), community and hospital-acquired pneumonia, pharmacologic interaction with clopidogrel and acetylsalicylic acid with subsequent increased rate of cardiovascular events, refractory hypomagnesemia and rebound reflux symptoms etc. The risk-benefit ratio of PPIs is increasingly recognized as being less favourable. This leads to a more critical viewpoint and raises the question whether the side-effects of PPIs may outweigh the benefits, especially with long-term use. The side-effects of PPIs seem to make a strong argument in favour of laparoscopic fundoplication in the treatment of GERD.

Risk factors and chemoprevention in Barrett's esophagus--an update

OBJECTIVE

Barrett's esophagus (BO) is a precursor of esophageal adenocarcinoma (OAC), a cancer with a poor prognosis and an increasing incidence. Hence there is an interest in mapping causal factors underlying BO and finding strategies to reduce the risk of dysplasia progression in patients with BO. Here we review current knowledge on established as well as less risk factors for the development of BO. Additionally, we summarize today's status on the use of chemoprevention aiming to reduce the risk of cancer progression in BO patients.

METHODS

We searched Medline and the Cochrane Library using the MeSH terms "Barrett's esophagus" and "Barrett esophagus," both alone and combined with the terms "risk factor," "aetiology," "diet," or "prevention." Focus was on original contributions, systematic reviews, and meta-analyses.

RESULTS

Established risk factors for the development of BO include gastro-esophageal reflux, obesity, male gender, Caucasian ethnicity, and increasing age. Smoking might increase the risk of BO, while aspirin/NSAIDs, Helicobacter pylori infection, and specific "healthy" dietary factors may lower the risk. The potential value of using chemoprevention with proton pump inhibitors, aspirin/NSAIDs, or statins is still uncertain.

CONCLUSIONS

There is today a substantial knowledge of risk factors of BO. Certain diet may be protective of BO, albeit yet to be proven. The efficiency of chemoprevention in BO is currently addressed further in randomized clinical trials.

[Adverse effects of proton pump inhibitors: should we worry about long-term exposure?]

Long-term treatment with proton pump inhibitors (PPI) is becoming more prevalent. Although they are well tolerated in the short term, serious concerns about long-term use have arisen. Recent data suggest that the latter is associated with an increased risk for osteoporotic fracture (especially vertebral), Clostridium difficile infection and rebound acid hypersecretion after treatment discontinuation. Acute interstitial nephritis is rare but may progress to chronic renal failure. An increased risk of community-acquired pneumonia has not been established in the general population and seems limited to the most vulnerable patients. Consistent data are still missing to correctly assess the risk of iron deficiency, vitamin B12 deficiency or hypomagnesaemia and the risk of digestive malignant diseases, despite the pathophysiological basis that exists concerning gastric malignancy. Many drug interactions can occur on long-term treatment, including some that imply the cytochrome P450 enzymes. Finally, the risk-benefit balance for a chronic PPI use in children seems unfavorable in most cases.

Risk factors for neoplastic progression in Barrett’s esophagus

Barrett’s esophagus (BE) confers a significant increased risk for development of esophageal adenocarcinoma (EAC), with the pathogenesis appearing to progress through a “metaplasia-dysplasia-carcinoma” (MDC) sequence. Many of the genetic insults driving this MDC sequence have recently been characterized, providing targets for candidate biomarkers with potential clinical utility to stratify risk in individual patients. Many clinical risk factors have been investigated, and associations with a variety of genetic, specific gastrointestinal and other modifiable factors have been proposed in the literature. This review summarizes the current understanding of the mechanisms involved in neoplastic progression of BE to EAC and critically appraises the relative roles and contributions of these putative risk factors from the published evidence currently available.

Outcomes of Barrett's oesophagus related to systemic sclerosis: a 3-year EULAR Scleroderma Trials and Research prospective follow-up study

OBJECTIVE

Barrett's oesophagus (BE) is the major risk factor for oesophageal adenocarcinoma (EAC). SSc is associated with an increased risk of BE related to chronic reflux. The aim of this study is to determine the outcomes of BE and estimate the EAC risk in SSc patients over a 3-year prospective study.

METHODS

SSc patients were recruited through EUSTAR network centres. Inclusion criterion was a recent histological finding of BE. The patients were then prospectively followed and, as recommended, a second oesophageal endoscopy was performed according to the presence of BE-related dysplasia at baseline.

RESULTS

A total of 50 SSc patients with BE (40 without and 10 with dysplasia) were included and 46 completed the follow-up (138 patient-years). During the 3-year follow-up, 4 of the 46 BE patients (3% per year) were diagnosed with high-grade dysplasia/EAC, of which one developed cardial EAC. EAC incidence in the BE subgroup with dysplasia increased to 4% per year compared with the absence of EAC cases in the BE subgroup without dysplasia at baseline.

CONCLUSION

Our results, in accordance with previous published data suggesting an increased risk of EAC or cardial adenocarcinoma in SSc, highlight the need for accurate follow-up of BE SSc patients at risk of developing adenocarcinoma.

Barrett's esophagus: A historical perspective, an update on core practicalities and predictions on future evolutions of management

Interpretation of exploding knowledge about Barrett's esophagus is impaired by use of several conflicting definitions. Because any histological type of esophageal columnar metaplasia carries risk for esophageal adenocarcinoma, the diagnosis of Barrett's esophagus should no longer require demonstration of intestinal-type metaplasia. Endoscopic recognition and grading of Barrett's esophagus remains a significant source of ambiguity. Reflux disease is a key factor for development of Barrett's esophagus, but other factors must underlie its development, since it occurs in only a minority of reflux disease patients. Neither antireflux surgery nor proton pump inhibitor (PPI) therapy has major impacts on cancer risk. Within a year, a major trial should indicate whether low-dose aspirin usefully reduces cancer risk. The best referral centers have transformed the accuracy of screening and surveillance for early curable esophageal adenocarcinoma by use of enhanced and novel endoscopic imaging, visually-guided, rather than blind biopsies and by partnership with expert pathologists. General endoscopists now need to upgrade their skills and equipment so that they can rely mainly on visual targeting of biopsies on mucosal areas of concern in their surveillance practice. General pathologists need to greatly improve their interpretation of biopsies. Endoscopic therapy now achieves very high rates of cure of high-grade dysplasia and esophageal adenocarcinoma with minimal morbidity and risk. Such results will only be achieved by skilled interventional endoscopists. Esophagectomy should now be mainly restricted to patients whose cancer has extended into and beyond the submucosa. Weighing risks and benefits in the management of Barrett's esophagus is difficult, as is the process of adequately informing patients about their specific cancer risk.

Safety of proton pump inhibitor exposure

Proton pump (H(+)/K(+)-adenosine triphosphatase) inhibitors (PPIs) are widely used to treat patients with acid-related disorders because they are generally perceived to be safe and effective. However, as with any pharmacologic agent, they have the potential for side effects. Many studies have examined the side effects of long-term or short-term PPI exposure. We review the mechanism of action of PPIs, focusing on recently released products that might have greater risks of adverse effects than older products because of increased potency and/or duration of action. We summarize the data available on the putative adverse effects of PPI therapy and propose guidelines for clinicians who prescribe these agents to limit the potential for adverse outcomes in users of these effective therapeutic agents.