THURSDAY, Nov. 15 (HealthDay News) -- The risks of developing
heart problems while taking the breast cancer drug Herceptin alone
or with other anti-cancer drugs may be even higher for older women
than thought, new research indicates.
Herceptin (trastuzumab) has long been used to treat breast
cancers that overproduce HER-2, also known as human epidermal
growth factor. The drug improves disease-free and overall survival,
but experts have known that it increases the risk of heart failure
because it can affect the ability of the heart to pump blood. It
can also raise the chances of developing cardiomyopathy, where the
heart muscle becomes enlarged or rigid.
Now, a new study that focused on women aged 67 and older has
found that the risk may be higher than believed. The report is
published online Nov. 14 in the
Journal of the American College of Cardiology.
For older women, the message is this, said study leader Dr.
Jersey Chen, an assistant professor of cardiology at the Yale
University School of Medicine: "You should know that your risk of
developing heart failure or cardiomyopathy may be higher than what
is quoted to you [by your doctor]."
Those earlier estimates, Chen said, are based on clinical trials
that mainly looked at younger and, in some cases, healthier
In those studies, the risk of heart failure, for instance,
increased by about 1.6 percent for women on Herceptin. In Chen's
new research, the team found that Herceptin or Herceptin given with
the anti-cancer drugs known as anthracyclines, raise the risk of
either heart failure or cardiomyopathy by about 9 percent in the
first year compared to no chemotherapy.
Chen looked at more than 45,000 women, aged 67 and older, who
had early-stage breast cancer and were treated with a variety of
regimens from 2000 to 2007.
The researchers followed them for three years to see who
developed heart problems.
The rates of either heart failure or cardiomyopathy were higher
for those getting Herceptin and anthracyclines, either separately
or together, than those who did not receive chemotherapy.
Put in other terms, for every 100 patients, 32 of those on
Herceptin and 42 of those on Herceptin and anthracycline had
developed cardiac problems by the three-year mark, compared to 19
of every 100 patients who did not get adjuvant therapy.
Women who are on these therapies, Chen said, may need to seek
additional monitoring. They should discuss the risks and benefits
of the treatment with their doctors.
Women should also put these risks in perspective, said Dr.
Xianglin Du, a professor of epidemiology at the University of Texas
Health Science Center at Houston who has also studied cardiac
problems linked with the drugs.
"Overall, their findings were consistent with what were found in our study published a year ago," she said. "Because many studies demonstrated that the addition of trastuzumab to chemotherapy significantly prolongs survival, women with breast cancer are advised to talk to their oncologists to weigh the benefits against potential risks for a better informed decision."
She agreed that closer monitoring may be needed.
The study was funded by the American Heart Association and a
collaborative agreement by Memorial Sloan-Kettering Cancer Center.
One co-author is a consultant to Celegene, GlaxoSmithKline, Abraxis
Bioscience, GTX, Amgen and Genentech.
To learn more about Herceptin, visit the
U.S. National Library of Medicine.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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