In the Meta analysis of 7053 patients, the use of PPIs to reduce the risk of HGD and / or EAC in BE has not been confirmed, despite significant heterogeneity in the study. Our results are consistent with previous system assessments18. In our analysis, we added additional research to provide a more reliable and comprehensive estimate of the impact of EC risk. With the increase of the number of participants, TSA were conducted to evaluate the statistical value of the statistical results and guide further research.
Barrett's esophagus (BE) is one of the complications of gastroesophageal reflux disease (GERD). Therefore, it is generally used to reduce gastric acid to treat patients with BE or GERD. Acid exposure has also been shown to up-regulate the expression of cyclooxygenase-2 (COX-2) in Barrett's esophagus (acid). COX-2 expression is increased during the early development of many tumors, including EAC, and is closely related to the development of BE into esophageal adenocarcinoma19, 20. Meta-analysis showed that the use of COX inhibitors was negatively correlated with the risk of tumor progression in patients with BE21. But the protective effect has been controversial. Some studies shown that there are contradictory results between the use of H2RA and the development of HGD or EAC. Even a lot of studies reported that it increases the risk of HGD or EAC4, 22. Bile exposure has also been shown to up-regulate the expression of COX-2 in BE23. The main preventive mechanism of PPIs is to promote the healing of esophageal mucosa by reducing esophageal acid and bile exposure.
The results of this study suggest that there was no definite evidence that PPIs intervention improved the incidence of esophageal cancer in patients with BE. The results of cohort study are different from case-control study. One potential explanation for this result is immortal time bias24. It can be produced in cohort studies. When it occurs, there may be an illusion of therapeutic effect in some studies. PPIs has been shown to improve GERD in patients25. But whether the treatment of Barrett's esophagus with PPIs reduces the risk of cancer is worth considering. Endoscopic therapy has been shown to effectively eliminate dysplasia and metaplastic epithelium and greatly reduce the incidence of cancer in a number of randomized controlled trials. There are many treatments for BE, such as radiofrequency ablation, argon plasma coagulation, photodynamic therapy, endoscopic mucosal resection and so on. The presence of nodules, ulcers or strictures in the esophageal segment of Barrett is thought to be associated with an increased risk of EAC26. Once it happens, the adverse effect on patients may be minimized by choosing to remove the lesion rather than medication.
There are limitations in this paper. First, the relationship between PPIs dose, the time of PPIs use and the occurrence of adverse events are not conducted. Second, due to the limited number of studies we analyzed, publication bias assessment was not conducted27. However, we conducted TSA to show more intuitively that the treatment of BE by PPIs is still controversial and worthy of further exploration.