Blood Pressure Medication Could Help Fight Cancer

A common blood pressure medication could improve chemotherapy's ability to fight off cancer by opening up blood vessels in solid tumors, a new study shows.

Published in the journal Nature Communications, the report looked at the effect of the angiotensin inhibitor losartan in mice with pancreatic and breast cancer.

The same researchers previously discovered that losartan improves the distribution of large molecules called nanomedicines within tumors by preventing the formation of collagen, a key ingredient of the extracellular matrix.

The current study focused on whether losartan and other drugs that block the hormone angiotensin, which has many purposes in the body, would affect blood vessels within tumors.

"Angiotensin inhibitors are safe blood pressure medications that have been used for over a decade in patients and could be repurposed for cancer treatment," Rakesh K. Jain, director of the Steele Laboratory for Tumor Biology at MGH and senior author of the study, said in a statement.

"Unlike anti-angiogenesis drugs, which improve tumor blood flow by repairing the abnormal structure of tumor blood vessels, angiotensin inhibitors open up those vessels by releasing physical forces that are applied to tumor blood vessels when the gel-like matrix surrounding them expands with tumor growth."

In the end, losartan alone affected tumor growth little. However, when combined with standard chemotherapy, growth was delayed and survival extended.

"Increasing tumor blood flow in the absence of anti-cancer drugs might actually accelerate tumor growth, but we believe that combining increased blood flow with chemotherapy, radiation therapy or immunotherapy will have beneficial results," Jain explained.

Given the results, the researchers have already begun a clinical trial in humans with pancreatic cancer.