For patients with advanced urothelial cancer treated with atezolizumab, proton pump inhibitor (PPI) use is a negative prognostic marker, according to a study published online Sept. 15 in Clinical Cancer Research.
Ashley M. Hopkins, Ph.D., from Flinders University in Adelaide, Australia, and colleagues pooled data from two advanced urothelial cancer trials (IMvigor210 and IMvigor211) to examine the association between PPI use and overall survival (OS) and progression-free survival (PFS).
The researchers found that 35 percent of the 1,360 participants received a PPI within the 60-day window (between 30 days prior and 30 days after treatment initiation). There was an association noted for PPI use with significantly worse OS and PFS (hazard ratios, 1.52 [95 percent confidence interval, 1.27 to 1.83] and 1.38 [95 percent confidence interval, 1.18 to 1.62], respectively) with atezolizumab but not chemotherapy. In IMvigor211, PPI users had an OS treatment effect of atezolizumab versus chemotherapy of 1.04 (95 percent confidence interval, 0.81 to 1.34) compared with 0.69 (95 percent confidence interval, 0.56 to 0.84) for PPI nonusers.
“PPIs are overused, or inappropriately used, in patients with cancer by up to 50 percent, seemingly from a perspective that they will cause no harm,” Hopkins said in a statement. “The findings from this study suggest that noncritical PPI use needs to be approached very cautiously, particularly when an immune checkpoint inhibitor is being used to treat urothelial cancer.”
Several authors disclosed financial ties to the pharmaceutical industry.