Blood Pressure Medicine May Increase Risk of Breast Cancer Recurrance

ACE Inhibitors Seem to Raise Risk

U.S. News and World Report, “ACE Inhibitors Seem to Raise Risk of Breast Cancer Recurrence”

April 21, 2011, By Amanda Gardner

http://health.usnews.com/health-news/family-health/heart/articles/2011/04/21/ace-inhibitors-seem-to-raise-risk-of-breast-cancer-recurrence

But another blood pressure medication has a protective effect, preliminary research suggests

THURSDAY, April 21 (HealthDay News) -- Two commonly used blood pressure medications seem to have opposite effects on the chances of breast cancer recurring in women with a personal history of the disease.

Preliminary findings show that ACE inhibitors increased the risk of recurrence, which surprised even the researchers, who published their study online in the journal Breast Cancer Research and Treatment.
On the other hand, beta blockers seemed to reduce the risk, which is in keeping with prior studies on the subject.

Fortunately, when the two drugs were combined, beta blockers seemed to mitigate the increased risk of recurrence linked with ACE inhibitors.

The study reflects the increasing interest among scientists in the effect the "microenvironment" -- which can include chronically used medications in addition to alcohol, tobacco and physical activity -- might have on the course of a particular woman's breast cancer.

"Tumors may be living in the breast before we even known about it. The microenvironment may either facilitate or keep under control whether the cells disseminate," said study first author Dr. Patricia A. Ganz, director of cancer prevention and control research at the Jonsson Comprehensive Cancer Center at University of California Los Angeles.

The study suggested that certain medications used to treat heart disease and high blood pressure might have an adverse effect on breast cancer survivors, she and the other researchers noted.

A 2010 study by Jonsson Comprehensive Cancer Center researchers on mice had already looked at beta blockers and cancer spread (or metastasis). That study began by documenting that stress can affect how fast and how widely a tumor spreads in rodents. The mice were confined in a small tube for a couple of hours a day, and the resulting stress prompted immune cells to gather in the tumor cells, enabling quicker metastasis and a 30-fold increase in cancer spread, deeper analysis revealed.

But in this animal model, beta blockers managed to block the signals that were recruiting the immune cells, explained Ganz.