According to a real-world evidence dataset at the 2023 ASCO Annual Meeting, proton pump inhibitor (PPI) use among patients with glioblastoma was found to be detrimental to survival. 

PPI use is known to increase activity of ALDH1A1, an enzyme which mediates therapy resistance and poor prognosis in many cancers, including glioblastoma. While this interaction suggests a potentially hazardous effect on tumor biology and survival, there are no existing prospective randomized data to establish

Using XCELSIOR, a nationwide observational research protocol that uses patient e-consent to gather medical records from all sites of care, this study included 320 patients with glioblastoma from 222 treatment sites. Patients were stratified based on exposure to PPI, extent of surgical resection, and MGMT methylation status. Investigators then calculated the overall survival.

For the entire patient population, mOS measured substantially better for patients who were not receiving PPI. The 5-year survival rate for patients not receiving PPI was 29.9% vs 6.6% for those receiving PPI.

In a multivariate analysis considering the extent of surgical resection and MGMT methylation, PPI exposure yielded a hazard ratio (HR) of 1.57 (P = .009). For the interaction of MGMT methylation and PPI exposure together, the HR was 2.63 (P = .043), which was significant as the HR of MGMT methylation alone was  0.40 (P = .0028).

According to Michael Castro, MD, Beverly Hills Cancer Center, Beverly Hills, California, and coauthors,, “ PPI use in [glioblastoma] appeared detrimental to survival … Additionally, the use of PPI appeared to completely abrogate the survival benefit of chemotherapy associated with methylated-MGMT.” They concluded, “these data suggest avoiding PPIs in [glioblastoma] patients.”

Source:

Castro MP, Quinn J, Wasserman A, et al. Use of proton pump inhibitors (PPI) in glioblastoma (GBM) and relationship to overall survival in a national real-world evidence (RWE) database. Presented at 2023 ASCO Annual Meeting; June 2-6, 2023; Chicago, IL. Abstract e14027