Tamoxifen and aromatase inhibitors are two different types of hormonal therapy medicines used to stop hormone-receptor-positive breast cancer from coming back in post-menopausal women. The study reviewed here found that women who took an aromatase inhibitor were 31% more likely to have heart problems or a heart attack than women who took tamoxifen. Still, women who took tamoxifen were slightly more likely to develop serious blood clots or have a stroke than women who took an aromatase inhibitor.
It's important to know that "31% more likely" DOESN'T mean that women who take an aromatase inhibitor have a 31% risk of having heart problems. The chances of having a serious complication, such a heart attack, stroke or blood clot, are small whether you take tamoxifen or an aromatase inhibitor.
The aromatase inhibitors are:
Aromatase inhibitors help stop breast cancer from coming back by preventing the formation of estrogen (estrogen can stimulate breast cancer growth). Tamoxifen is a SERM (selective estrogen receptor modulator). Tamoxifen works by blocking the effects of estrogen on breast cancer cells.
Because these two types of hormonal therapy medicines work differently, each one has different side effects. Aromatase inhibitor side effects include muscle and joint aches and pains. Aromatase inhibitors also can weaken bones, cause osteoporosis, and increase the risk of breaking a bone. Tamoxifen can actually strengthen bones, but many women taking tamoxifen have troublesome hot flashes.
If you're a post-menopausal woman and have been treated for hormone-receptor-positive early breast cancer, hormonal therapy medicine can be a good way to lower the risk of the cancer coming back. Hormonal medicines used this way (also called adjuvant hormonal therapy) are usually prescribed for 5 years. Research has shown that aromatase inhibitors are slightly better than tamoxifen at lowering the risk of breast cancer coming back. But for a number of reasons, including side effects and cost, tamoxifen may still be a better choice for some women.
If taking hormonal therapy medicine to reduce the risk of breast cancer coming back is part of your treatment plan, talk to your doctor about the pros and cons of both aromatase inhibitors and tamoxifen. Try to keep two things in mind:
Together, you and your doctor can decide which hormonal therapy medicine is best for YOU.
NEW YORK (Reuters Health) - Aromatase inhibitors, a class of drugs used to ward off the recurrence of breast cancer after surgery, increase the risk of cardiovascular disorders slightly more than does treatment with tamoxifen, a new study shows.
Aromatase inhibitors are superior to tamoxifen in some circumstances, the researchers point out in the medical journal Cancer, but previous reports have suggested a trend toward increased cardiac events in association with their use.
To look into this, Dr. Federica Cuppone from Regina Elena National Cancer Institute, Rome, and colleagues analyzed data from seven studies involving a total of nearly 20,000 postmenopausal women with early breast cancer.
After follow-up periods ranging from about 2 years to 5 years, there was a small 31 percent relative increase in cardiovascular adverse events with aromatase-inhibitor treatment compared with tamoxifen treatment.
On the other hand, the overall rate of all side effects, including blood clots and strokes, was somewhat higher among women given tamoxifen, the researchers point out.
The team concludes that, although the risk of cardiac events was increased with aromatase inhibitors, "it appears lower than was suspected previously."
In summary, they say that this risk has to be balanced against the decreased risk of risk of blood clots and perhaps strokes, as well as improved survival free of breast cancer seen with aromatase inhibitors.
SOURCE: Cancer, January 15, 2008.
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