(RxWiki News) Beta blockers, which are used to treat high blood pressure, block the action of a stress hormone. And this hormone can encourage cancer cells to grow and spread.
So it's been thought that beta blockers help lower the risk of colorectal cancer.
New research finds that high blood pressure medications don't lower a person's colorectal cancer risks, despite current thinking to the contrary.
Have your doctor review all the medications you're taking.
Previous lab and animal studies have found that the stress hormone, norepinephrine, can promote cancer cell growth and invasion. Beta blockers inhibit or block the activity of norepinephrine.
It stood to reason, then, that beta blockers had anti-tumor properties. This was what led to the theory in recent years that the medication lowered the risks of colorectal cancer.
To examine this theory more closely, Michael Hoffmeister, PhD, of the German Cancer Research Center, and his colleagues interviewed 1,762 patients with colorectal cancer and 1,708 people without cancer between 2003 to 2007.
The researchers found no association between beta blocker use and colorectal cancer risk after taking into consideration patient weight, smoking history and other factors. Previous studies hadn't considered these factors.
Going further, the researchers analyzed how long patients had taken beta blockers, specific types of the medication, active ingredients and sites within the body where colorectal cancer develops. They still found no links.
So the researchers report that these findings don't support the theory that using beta blockers lower colorectal cancer risks.
The study also points out the importance of taking into consideration individual patient characteristics and other factors that can have an impact on how medications affect cancer risks.
These are the findings of a study published May 14, 2012 in Cancer, a peer-reviewed journal of the American Cancer Society. This study was supported by the German Research Council and the German Federal Ministry of Education and Research. The authors made no conflict of interest disclosures.