biostudies-literatureUnknown30(10)Chen BFMelissa Lee Cancer Foundation<h4>Importance</h4>This study highlights the potential negative impact of the co-administration of proton pump inhibitors (PPI) on treatment outcomes in patients with hormone receptor-positive (HR+) metastatic and recurrent breast cancer who were receiving CDK4/6 inhibitor (CDK4/6i) treatment, providing real-world evidence to guide treatment strategies.<h4>Objective</h4>To determine whether the co-administration of proton pump inhibitors (PPI) affects treatment outcomes, including progression-free survival (PFS) and overall survival (OS), in patients with HR+ metastatic and recurrent breast cancer receiving CDK4/6i treatment.<h4>Results</h4>There were 55.7% patients in the no-antacid group, 33.1% in the PPI group, and 11.1% in the H2-blocker only group. Patients receiving PPI in combinatioThe oncologistoyaf268https://www.ebi.ac.uk/biostudies/studies/S-EPMC12505142biostudies-literatureReal-world evaluation of CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer: prognostic effect of proton pump inhibitor use.PMC12505142Huang CCLin YSLiu CYFeng CJTseng LMChen YJCheng HFTsai YFLai JILien PJChen BFChao TCfalseReal-world evaluation of CDK4/6 inhibitors in hormone receptor-positive metastatic breast cancer: prognostic effect of proton pump inhibitor use.<h4>Importance</h4>This study highlights the potential negative impact of the co-administration of proton pump inhibitors (PPI) on treatment outcomes in patients with hormone receptor-positive (HR+) metastatic and recurrent breast cancer who were receiving CDK4/6 inhibitor (CDK4/6i) treatment, providing real-world evidence to guide treatment strategies.<h4>Objective</h4>To determine whether the co-administration of proton pump inhibitors (PPI) affects treatment outcomes, including progression-free survival (PFS) and overall survival (OS), in patients with HR+ metastatic and recurrent breast cancer receiving CDK4/6i treatment.<h4>Results</h4>There were 55.7% patients in the no-antacid group, 33.1% in the PPI group, and 11.1% in the H2-blocker only group. Patients receiving PPI in combinatio2025-01-01T00:00:00Z2025 Oct2026-05-06T03:18:14.823Z2026-05-06T03:12:20.181ZS-EPMC125051424089187510.1093/oncolo/oyaf268