“New Shimmer is a floor wax.”
“No, it’s a dessert topping.”
“It’s a floor wax!”
“It’s a dessert topping!”

These lines open a Saturday Night Live comedy argument between a housewife (Gilda Radner) about to damp mop the kitchen floor, and her husband (Dan Aykroyd) wanting whipped topping on his pudding. As the spat escalates, Chevy Chase enters. He puts an end to the dispute when he cheerfully proclaims:
“Hey, hey, hey. Calm down, you two. New Shimmer is a floor wax AND a dessert topping!”

Atenolol: It lowers blood pressure AND it prevents prostate cancer

An April, 2020 paper based on a study of multiethnic men suggests that a drug called Atenolol is a blood pressure medication AND a prostate cancer preventative.^[i] Atenolol is one of a class of drugs called beta-blockers that are commonly used to lower high blood pressure and reduce cardiac deaths.

The study involved 4516 African-American and Hispanic men who had an initial prostate biopsy during the period 2006-2016. Overall, 2,129 had a biopsy positive for prostate cancer (PCa). Medical records for the previous 5 years showed that 15% of participants were taking a beta-blocker prior to biopsy, and the three most-prescribed drugs were Metoprolol, Carvedilol, and Atenolol.

Only Atenolol made a significant statistical difference in PCa risk levels. Compared with patients who were not on beta-blockers, those on Atenolol had a 38% lower risk of being diagnosed with PCa, with even lower risk reduction of intermediate-risk disease (40%) and high-risk disease (54%); longer use (3-5 years) gave 54% less chance of intermediate-risk PCa and 72% less chance of high-risk PCa.

Theory of how it works

How could a drug proven safe and effective for high blood pressure have positive action for reducing PCa risk? I will devote another blog to the biology, but the basic principal has to do with adrenaline.

Adrenaline is a biochemical molecular messenger (hormone) that changes the behavior of cells that receive its message. Heart cells and blood vessel cells have physical “antennas” called Beta receptors that latch onto adrenaline. The molecule causes the heart to beat faster and blood vessels constrict, plus the kidneys respond by producing a protein that also boosts blood pressure.

Beta-blocker drugs do exactly what the name suggests: they block the receptors from latching onto adrenaline. Thus, heartbeats and blood pressure remain at or close to their base level. In addition, beta-blockers affect the cells that line blood vessels, making it more difficult for them to form new blood vessels. It is this effect that scientists believe acts to prevent PCa, since cancer tumors must build their own blood supply (angiogenesis) in order to nourish themselves.

Why Atenolol and no other beta-blockers?

As noted in the study, patients were mostly taking either Metoprolol, Carvedilol, and Atenolol. Each is formulated differently from the others, with slightly different effects. Metropolol and Carvedilol help prevent death in people with heart failure, and both improve the chances of surviving a heart attack. They also have the ability to lower blood pressure if other first-choice medications don’t work, but Metropolol does not seem as effective as Carvedilol, and may also raise blood sugar levels.^[ii]

Atenolol is also prescribed for cardiac problems like angina, and as a way to improve heart attacks survival. It differs from the other two drugs because its action works nearly twice as long per oral dose. The researchers who conducted the study hypothesize that Atenolol’s ability to linger in the body gives it extra time to discourage opportunistic cancer cells from developing new blood vessels (angiogenesis).

Another study worth noting is a retrospective analysis of nearly 40,000 men with advanced castration-resistant PCa who were treated through the Veterans Administration (VA)^[iii]. Based on research evidence suggesting beta-blockers discourage angiogenesis in mice with in metastatic tumors, the purpose was to explore the survival benefit, if any, for humans taking Metropolol, the only beta-blocker used in the study. After adjusting for all variables, beta-blocker use was not linked with reduced mortality.

Repurposing drugs

It would be a very good thing if Atenolol proves effective in PCa prevention. The chief advantage in repurposing drugs for other conditions is that their safety has already been tested, which saves huge development costs and shortens the time needed to bring them to market. Officially, however, the jury is still out on Atenolol. Experts agree that more studies are needed before It can be prescribed for use against PCa.

While the stakes are much higher for PCa than for floor waxes and dessert toppings, we’re keeping our fingers crossed that some day doctors can tell their patients, “It’s a blood pressure pill AND it helps keep you safe from prostate cancer!”

NOTE: This content is solely for purposes of information and does not substitute for diagnostic or medical advice. Talk to your doctor if you are experiencing pelvic pain, or have any other health concerns or questions of a personal medical nature.

References

[i] Zahalka AH, Fram E, Lin W, Mohn L et al. Use of beta-blocker types and risk of incident prostate cancer in a multiethnic population. Urol Oncol. 2020 Apr 16;S1078-1439(20)30130-27
[ii] https://www.goodrx.com/blog/carvedilol-vs-metoprolol-heart-failure-high-blood-pressure/
[iii] Medpage Today, “Beta Blockers No Help in Advanced Prostate Cancer.” Dec. 5, 2019. https://www.medpagetoday.com/meetingcoverage/suo/83728