The prevention and treatment of dysplasia in gastroesophageal reflux disease: The results and the challenges ahead

Barrett's Epithelium to Esophageal Adenocarcinoma: Is There a "Point of No Return"?

Background: Esophageal adenocarcinoma (EA) arises from Barrett's epithelium (BE), and chronic gastroesophageal reflux disease is considered the strongest risk factor for disease progression. All BE patients undergo acid suppressive therapy, surveillance, and BE removal by surgery or endoscopic ablation, yet the incidence of EAC continues to increase. Despite the known side effects and mortality, the one-size-fits-all approach is the standard clinical management as there are no reliable methods for risk stratification. Methods: Paired-end Illumina NextSeq500 RNA sequencing was performed on total RNA extracted from 20-week intervals (0, 20, 40, and 60 W) of an in vitro BE carcinogenesis (BEC) model to construct time series global gene expression patterns (GEPs). The cells from two strategic time points (20 and 40 W) based on the GEPs were grown for another 20 weeks, with and without further acid and bile salt (ABS) stimulation, and the recurrent neoplastic cell phenotypes were evaluated. Results: Hierarchical clustering of 866 genes with ≥ twofold change in transcript levels across the four time points revealed maximum variation between the BEC20W and BEC40W cells. Enrichment analysis confirmed that the genes altered ≥ twofold during this window period associated with carcinogenesis and malignancy. Intriguingly, the BEC20W cells required further ABS exposure to gain neoplastic changes, but the BEC40W cells progressed to malignant transformation after 20 weeks even in the absence of additional ABS. Discussion: The transcriptomic gene expression patterns in the BEC model demonstrate evidence of a clear threshold in the progression of BE to malignancy. Catastrophic transcriptomic changes during a window period culminate in the commitment of the BE cells to a "point of no return," and removal of ABS is not effective in preventing their malignant transformation. Discerning this "point of no return" during BE surveillance by tracking the GEPs has the potential to evaluate risk of BE progression and enable personalized clinical management.

Proton Pump Inhibitors Diminish Barrett's Esophagus Length: Our Experience

AIM

Our main objectives were to evaluate the influence of two-year proton pump inhibitors (PPI) therapy in patients with Barrett's oesophagus on its length, in both types, short and long segment.

METHODS

In this single-centre, prospective interventional controlled study were analysed data collected prospectively over two years from patients with Barrett's oesophagus diagnosed by endoscopy. Patients who received continuous proton pump inhibitors (PPI) for 2 years were included. At each patient visit symptoms were recorded, and at each endoscopy, the length of Barrett's oesophagus (BE) was measured. Biopsies were taken along the length of the oesophagus at intervals of 1 cm. In total, 50 patients with Barrett's oesophagus were included in the study: 10 of whom had long-segment Barrett's oesophagus, and 40 patients had short-segment Barrett's oesophagus. The mean number of endoscopies performed was 3 per patient.

RESULTS

The length of Barrett's esophagus (BE) was influenced by PPI therapy: Circumferential extension in BE patients short-segment Barrett's esophagus (SSBE) (before treatment was 1.5 cm and after treatment was 0.8 cm Maximum proximal extension in SSBE group before treatment was 2.3 cm (SD ± 1.1 cm), and 1.1 cm (SD ± 0.9 cm), respectively. Squamous islands were detected in 25% of patients examined after 2 years on PPIs.

CONCLUSIONS

PPIs achieve a reduction to the length of Barrett's oesophagus, in both types, and the development of squamous islands is commonly associated with their use.

Effect of proton pump inhibitors on markers of risk for high-grade dysplasia and oesophageal cancer in Barrett's oesophagus

BACKGROUND

It has been shown that the presence on diagnosis of endoscopic macroscopic markers indicates a high-risk group for Barrett's oesophagus.

AIM

To determine whether proton pump inhibitor therapy prior to diagnosis of Barrett's oesophagus influences markers for risk development of subsequent high-grade dysplasia/adenocarcinoma.

METHODS

A review of all patients with Barrett's oesophagus entering a surveillance programme was undertaken. Five hundred and two patients diagnosed with Barrett's oesophagus were assessed on diagnosis for endoscopic macroscopic markers or low-grade dysplasia. Subsequent development of high-grade dysplasia/adenocarcinoma was documented. The relationship between the initiation of proton pump inhibitor therapy prior to the diagnosis of BE and the presence of macroscopic markers or low-grade dysplasia at entry was determined.

RESULTS

Fourteen patients developed high-grade dysplasia/adenocarcinoma during surveillance. Patients who entered without prior proton pump inhibitor therapy were 3.4 times (95% CI: 1.98-5.85) more likely to have a macroscopic marker or low-grade dysplasia than those patients already on a proton pump inhibitor.

CONCLUSIONS

Use of proton pump inhibitor therapy prior to diagnosis of Barrett's oesophagus significantly reduced the presence of markers used to stratify patient risk. Widespread use of proton pump inhibitors will confound surveillance strategies for patients with Barrett's oesophagus based on entry characteristics but is justified because of the lower risk of neoplastic progression.

Proton-pump inhibitor therapy and the development of dysplasia in patients with Barrett's oesophagus

OBJECTIVE

To examine whether proton-pump inhibitor (PPI) therapy influences the incidence and progression of dysplasia in patients with Barrett's oesophagus.

DESIGN AND SETTING

Review of prospective data on patients undergoing surveillance with regular endoscopy and biopsy at a private endoscopy centre in Canberra, ACT, between 1981 and 2001.

PATIENTS

350 patients diagnosed with Barrett's oesophagus.

INTERVENTIONS

PPI therapy was progressively introduced into clinical practice from late 1989. Once begun, PPI therapy was ongoing, with no attempt to reduce the dose.

MAIN OUTCOME MEASURES

Relationship between development of dysplasia or adenocarcinoma and delay between diagnosis with Barrett's oesophagus and starting PPI therapy was determined by Cox regression analyses, stratified by year of enrollment. Age, sex, presence of macroscopic markers (severe oesophagitis, nodularity, Barrett's ulcer, stricture) and use of aspirin or non-steroidal anti-inflammatory drugs were considered as confounding factors in the regression analyses.

RESULTS

The 350 patients had 1422 surveillance endoscopies, with a median follow-up of 4.7 years. Patients who delayed using a PPI for 2 years or more after diagnosis with Barrett's oesophagus had 5.6 times (95% CI, 2.0-15.7) the risk of developing low-grade dysplasia at any given time as those who used a PPI in the first year. Similar results were found for the risk of developing high-grade dysplasia or adenocarcinoma (hazard ratio, 20.9; 95% CI, 2.8-158).

CONCLUSIONS

Use of ongoing PPI therapy appeared beneficial in the prevention of dysplasia and adenocarcinoma in patients with Barrett's oesophagus. We suggest that all patients with this condition, even those with no oesophagitis or symptoms, should be encouraged to continue long term PPI therapy.