SAN DIEGO – In patients with Barrett’s esophagus (BE), acid suppression with proton pump inhibitors (PPIs) and, to a lesser extent, histamine2 receptor antagonists (H2RA) reduced the risk of progression to esophageal adenocarcinoma (EAC), according to the findings from a study reported at the annual Digestive Disease Week.
Both treatments were independently associated with reduced risk of progression to cancer in the nested, case-control study. Taking PPIs reduced the risk of developing EAC by 69% and taking H2RAs reduced the risk by 45%.
“There are no concrete guidelines regarding use of PPIs for patients with Barrett’s esophagus,” said presenting author Dr Mimi C. Tan, a postdoctoral research fellow at Baylor College of Medicine in Houston. “The guidelines for these agents are based on symptoms of reflux. Although this study does not tell us for sure, it looks like taking these medications [in Barrett’s esophagus] prevents cancer. The effect is stronger with PPIs, but H2RAs still have an effect.”
Alice Goodman
Dr. Mimi Tan
The incidence of BE is increasing in the United States, and BE is the only known risk factor for EAC.
“There is a knowledge gap, with a deficiency of studies of cases with longitudinal follow-up in a cohort of BE patients examining the effects of PPIs and H2RAs on progression to EAC,” Dr. Tan explained. “We conducted this study in a large cohort of BE patients and hypothesized that acid suppression with PPIs and H2RAs would decrease the risk of EAC.”
The study included a cohort of 29,536 male veterans diagnosed with BE between 2004 and 2009 identified in the national Veterans Affairs Corporate Data Warehouse. Of those, 760 had an ICD-9 diagnosis of EAC. Cases of incident BE (in patients who developed EAC) were matched with controls with BE who did not develop cancer by the time of each EAC diagnosis in the corresponding case. Cases were followed until 2011.
After exclusions, the final analysis was based on 311 cases with EAC after BE and 856 matched controls with no EAC. Use of acid suppression was based on reports of medications dispensed at a Veteran’s Affairs pharmacy.
In general, patients with EAC were significantly more overweight and obese than controls (86.8% versus 80.6%, respectively, P = .04) and were more often cigarette smokers than controls (19% versus 13%, respectively, P = .02).
Cases were less likely than controls to fill at least one prescription for a PPI: 65% of cases versus 83% of controls. Dr Tan said the number of H2RA users was much smaller; 8% of cases had at least one prescription for an H2RA, compared with 14% of controls.
For PPIs, duration of use was not associated with risk, whereas the opposite was true for H2RA users.
“This was an observational study, not a randomized trial, so we can’t say with certainty that PPI and H2RA use reduce the risk of cancer,” Dr. Tan cautioned. “But the study suggests that there may be a role for these medications. Further study is needed.”
In a separate interview, Dr Tan noted that the risk of developing EAC in people with BE is low – 0.5% per year.
During the question and answer session following her presentation, an audience member said that it is interesting and disturbing that so many BE patients are not on acid suppression.
“There are no clear cut guidelines that state that BE patients should be on a PPI,” Dr Tan noted. “Maybe that’s why primary care doctors are not prescribing them.”
In a talk after Dr Tan’s presentation, Dr Stuart Spechler of UT Southwestern Medical Center, Dallas, noted that it appears that clonal diversity at diagnosis of BE identifies patients likely to develop EAC.
“This raises a concern: If these cells are predestined to become cancer, can they achieve salvation through good acts?” Dr. Spechler asked. “Dr Tan’s study suggests that they can. The malignant potential of BE may be predetermined, and acid suppression therapy reduces the risk of progression to EAC.”
Dr. Tan had no financial disclosures to report.