bisphosphonates tied to stroke in cancer patients

[Lani]

Of course this is not a reason to stop treatment with bisphosphonates for
Stage IVs. It may be a reason not to treat bc patients prophylactically with bisphosphonates unless they are on AIs and at risk (a risk-benefit analysis will be necessary ie, risk of stroke vs risk of fracture of major bone) and they will need to evaluate the risk of stroke, heart problems at the dose of bisphosphonate necessary to prevent
fractures in bc patients and or decrease their rate of recurrence (not yet determined I don't think)

Bisphosphonates tied to stroke in cancer patients


By Anne Harding
NEW YORK | Tue Oct 12, 2010 10:27am EDT
(Reuters Health) - Cancer patients treated with osteoporosis-fighting drugs are at increased risk of abnormal heart rhythms and stroke, new research shows.

The benefits of these drugs for preventing and treating cancer after it has spread to the bone-especially in breast cancer patients-still outweigh their risks, said the study's lead author, as long as patients are monitored closely.

"These drugs are still very, very, very valuable drugs," said Dr. James S. Goodwin of the University of Texas Medical Branch in Galveston. "The risk of stroke from atrial fibrillation can be entirely prevented if we're on top of it."

Atrial fibrillation, an irregular beating rhythm in the heart's upper "atrial" chambers, increases stroke risk because blood pools in the poorly functioning chambers, leading to clotting; clots can then break off and travel to the brain, causing a stroke.

Intravenous bisphosphonates, which include Aredia and Zometa, are used in healthy people to treat osteoporosis. Studies had already linked these drugs to atrial fibrillation and stroke, but in 2008 the U.S. Food and Drug Administration concluded after a review of safety data that "healthcare professionals should not alter their prescribing patterns for bisphosphonates and patients should not stop taking their bisphosphonate medication."

Doses of bisphosphonates given to treat cancer patients with bone metastasis are typically 10 times higher than doses used in patients with osteoporosis.

Because these patients may also be on other potentially heart-damaging chemotherapy medications, Goodwin and his colleagues investigated heart risks by reviewing data on nearly 7,000 Medicare patients with cancer who took bisphosphonates and nearly 14,000 cancer patients on Medicare who had not been prescribed the drugs. They report their findings in the Journal of Clinical Oncology.

The cancer patients taking bisphosphonates were at a 30 percent increased risk of atrial fibrillation compared to those who were not given the drugs, the researchers found. While people not on the medications had a 25 percent risk of having atrial fibrillation during the six-year follow up period, the risk for people on bisphosphonates was 33 percent; for stroke, the risks were 15 percent and 19 percent, respectively.

If doctors find that a patient has atrial fibrillation-which they can do by simply listening to the heart-they can immediately prescribe blood-thinning drugs to prevent a stroke, the researcher said.

In an editorial accompanying the study, Dr. Julie R. Gralow of the University of Washington School of Medicine in Seattle concludes that "the jury is still out" on whether bisphosphonates increase the risk of abnormal heart rhythms and stroke. Nevertheless, she adds, "Before prescribing any bisphosphonates, risks and benefits must be carefully weighed by physicians and well-informed patients."

SOURCE: link.reuters.com/car87p Journal of Clinical Oncology, published online October 12, 2010.

[tricia keegan]

Thanks for this Lani, I'm due to begin Fosamax this week and will print this out to speak to my onc about it.

I'm not stage iv but simply had some bone loss on my recent dexa so unsure about this but glad to have your thread comments to discuss with her.

[Laurel]

Don't forget, Tricia, that fish oil makes your platelets slippery, so less likely to coagulate and cause a stroke. Balances the Fosamax I should think.

[Chelee]

This is very concerning to me because it was after I started on Zometa that I started having this very mild heart flutter that comes and goes. It's is mild like I said...but just enough to really grab my attention when it happens. It's like a light irregular beating...and I seriously did notice it not long after Zometa...but I had also started on Navelbine...so it's hard to say for sure? With all these drugs we put in our bodies it's hard to pinpoint which one did what? I'm going to bring this up to my onc at my next appt...and schedule an appt with my Cardio doc. I've been off the Zometa since I saw Dr. Hurvitz...we noticed calcifations in my mouth and she said to stop the Zometa for now. Since I'm stage IV with bone mets I really wanted to stay on Zometa...but it's not looking good for me.

As always...thanks for posting this Lani.

Chelee

[Lani]

a new drug challenging the bisphosphonates is Denosumab, currently FDA approved for osteoporosis treatment, not yet for breast or prostate cancer mets

Not yet sure if it has similar effects on heart--probably worth looking into. It has not yet been used in large numbers of patients, so if there is an effect and it is rare, it may take some time to be discovered, but as it works via a somewhat different mechanism of action...

[tricia keegan]

I've been looking into this drug myself Lani and thank you, thanks also Laurel, I'll bear that in mind