Are PPIs effective in prevention of esophageal carcinoma in individuals with Barrett's esophagus? The evidence is conflicting; I listed it from yes to no.
Acid-suppressive medications and risk of oesophageal adenocarcinoma in patients with Barrett's oesophagus: a systematic review and meta-analysis (Gut, 2014):
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.
GERD and Peptic Ulcers (Indian Health Service, 2018):
...observational data suggest that PPIs are most effective for
preventing progression of Barrett’s to cancer
Esomeprazole and aspirin in Barrett's oesophagus (AspECT): a randomised factorial trial (The Lancet, 2018):
Our data indicate that high-dose PPI (40 mg twice-daily) is better
than low-dose (20 mg once-daily) for patients with Barrett's
oesophagus in terms of delaying death, cancer, and dysplasia.
Chemoprevention of Barrett’s oesophagus: a step closer with PPIs and aspirin (Clinical Oncology, 2018):
On the basis of the findings from AspECT and the evidence from
observational studies, we believe that PPI use in clinical practice
for chemoprevention in patients with Barrett’s oesophagus is
justified...The finding that aspirin was beneficial moves us one step
closer to broader recommendations for aspirin use in patient with
Barrett’s oesophagus and for prevention of chronic diseases in
Aspirin Plus PPI Prevents Esophageal Cancer (Medscape, 2018):
Combined use of aspirin and a high-dose proton pump inhibitor (PPI)
protects against the development of esophageal cancer in people who
are at elevated risk for the malignancy, according to the results of a
major phase 3 chemoprevention trial from the United Kingdom, the
Aspirin and Esomeprazole Chemoprevention in Barrett's Metaplasia
Will a Proton Pump Inhibitor and an Aspirin Keep the Doctor Away for Patients With Barrett’s Esophagus? (Gastroenterology, 2019):
Most patients with known Barrett’s esophagus have symptomatic
gastroesophageal reflux disease. The study would support using a PPI
for acid suppression for such patients. Some patients lack
gastroesophageal reflux disease by symptoms, endoscopic findings, or
even pH testing; for these patients, the benefit is uncertain or
Proton Pump Inhibitors Do Not Reduce the Risk of Esophageal Adenocarcinoma in Patients with Barrett's Esophagus: A Systematic Review and Meta-Analysis (PLosOne, 2017):
No dysplasia- or cancer-protective effects of PPIs usage in patients
with BE were identified by our analysis.
Maintenance proton pump inhibition therapy and risk of oesophageal cancer (Cancer Epidemiology, 2018):
In conclusion, the long term use of PPIs is associated with increased
risk of oesophageal adenocarcinoma in the absence of other risk
factors. Long term use of PPIs should be addressed with caution.