New research suggests that commonly prescribed medications for heartburn and high blood pressure may raise the risk of severe side effects for breast cancer patients. Proton pump inhibitors (PPIs), widely used to treat heartburn and indigestion, showed the strongest link to these complications. The findings were published in Cancer Medicine.
The study analyzed data from approximately 23,000 participants in clinical trials for early-stage and advanced breast cancer. Most were receiving anti-HER2 therapies, while others were undergoing CDK4/6 inhibitors, hormonal therapy, or chemotherapy.
Researchers examined the effects of concurrent use of medications for high blood pressure, high cholesterol, Type 2 diabetes, and heartburn. Participants taking proton pump inhibitors experienced shorter survival times and a 36% higher risk of severe treatment-related side effects—events that, while not life-threatening, often require hospitalization.
High blood pressure medications, including beta-blockers, ACE inhibitors, and calcium-channel blockers, were also associated with an increased risk of severe side effects. In contrast, cholesterol-lowering drugs such as statins and the diabetes medication metformin did not appear to affect treatment outcomes or survival.
“This research highlights the importance of regularly reviewing patient medications, as people are living longer and managing multiple health conditions,” said Natansh Modi, PhD, a lecturer in pharmacology at the University of South Australia and one of the study’s authors.
Doctors can use these findings to guide treatment decisions and minimize complications. Patients taking these medications during cancer therapy are encouraged to discuss potential risks and benefits with their healthcare providers.
