Sunday, August 25, 2013

Beta-blockers and Cancer

Beta-blockers were first released for clinical use in the 1960s to control angina from coronary artery disease.  They became the go-to drug for hypertension, heart failure, cardiac protection after heart attacks or during surgery, and heart rhythm control.  They work through the blockade of beta-receptors found on many different cell types, preventing cell stimulation through the effects of epinephrine (adrenalin) and norepinephrine on those cell surface sites. These "flight or fight" stress chemicals cause a rise in pulse rate and blood pressure and produce the physical sensations of fear.  As a result, beta-blockade is also useful in controlling anxiety and stage fright.  One of my professors in medical school declared "We should all be on beta-blockers.  After considering the following research, I'm inclined to think he had a good point.

A thick stack of studies supports a mind-body connection in disease. Depression and anxiety have been associated with increased risk of both recurrence and progression of cancer in "the worried not-so-well," a term coined by psychiatrists in Philadelphia. Thanks to Dr. Jacob Schor(1), a Denver naturopath, for putting me on to to a recent article regarding outcomes in women with triple-negative breast cancer(2) (a particularly difficult to treat subset of breast cancer types).

Italian investigators located 800 postmenopausal women diagnosed with TNBC and checked their records to evaluate the effect of beta-blocker usage (prescribed for other conditions) on risk of recurrence and death.  74 of the subjects were on beta-blockers at the time of their diagnosis, and, in the five years that followed, the incidence of recurrence or death in this group was less than half that of those without beta-blockade.  

A number of cancer cell types, including breast and ovarian, are known to have beta-receptors on their cell membranes.  The stress chemicals mentioned above activate a metabolic pathway that promotes unbridled growth of these renegade cells.  Thus, beta-blockers could be down-regulating this process, slowing replication and spread of the tumors.

Beta-blockers are not without side effects--some people feel tired and depressed with regular use.  The pulse slows, and the heart rate response to aerobic exercise is muted.  To further complicate the picture, Boston researchers also published a paper this summer that compared breast cancer deaths over 10 years in nearly 5,000 women diagnosed with Stage I-III tumors as related to use of beta-blockers, ACE inhibitors (another blood pressure drug class) and aspirin(3).  While women on either BP med had reduced rates of death, the most dramatic risk drop occurred in those with regular aspirin use.  As many women on BP meds also take aspirin for cardiac health, the study authors postulate that it may be the aspirin that brings on the benefits.

Should we all be on beta-blockers?  That's still up for debate.
1) Dr. Schor writes an excellent e-mail newsletter.  You can subscribe at

2) Botteri, E, et al. "Therapeutic effect of β-blockers in triple-negative breast cancer postmenopausal women." Breast Cancer Res Treat. 2013 Aug;140(3):567-75. doi: 10.1007/s10549-013-2654-3.

3) Holmes, MD, et al. "Beta blockers and angiotensin-converting enzyme inhibitors' purported benefit on breast cancer survival may be explained by aspirin use." Breast Cancer Res Treat. 2013 Jun;139(2):507-13. doi: 10.1007/s10549-013-2553-7. Epub 2013 May 7.

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