Aromatase inhibitors increased risk of heart disease in postmenopausal women with breast cancer

Dec 09, 2010

Postmenopausal women who take aromatase inhibitors as a treatment for breast cancer may be at an increased risk for developing cardiovascular disease, according to the results of a meta-analysis.

These data, presented at the 33rd Annual CTRC-AACR San Antonio Symposium, indicate that women presenting with breast cancer treatment who have risk factors for cardiovascular disease should be considered for a shorter duration of use of .

"It appears that aromatase inhibitors have a significant increase in cardiotoxic side effects, such as heart attack, angina and heart failure," said Eitan Amir, M.D., a senior fellow in the division of and hematology at the Princess Margaret Hospital, Toronto, Canada.

Because some cancers, especially breast cancers, require estrogen to grow and spread, drugs that block estrogen production are often used to treat the disease. Tamoxifen blocks the effect of estrogen in , whereas aromatase inhibitors prevent the production of estrogen.

Each class of drugs also have related adverse effects. For example, although tamoxifen blocks estrogen production in breast tissue, it has the opposite effect in uterine tissue. Previous research has shown that extended use of tamoxifen results in a small increase in the risk for endometrial cancer and venous thrombosis.

On the other hand, in December 2008, the added a warning label to anastrozole, an aromatase inhibitor, which indicated potential increased risk for heart disease. For this reason, Amir and colleagues conducted a meta-analysis to determine if this increased risk for heart disease occurred with the use of any aromatase inhibitor.

The researchers examined data from seven large randomized clinical trials that compared tamoxifen with aromatase inhibitors in postmenopausal women with early-stage breast cancer.

Data from the analysis confirmed that any duration of use of an aromatase inhibitor was associated with a 20 percent higher probability of developing cardiovascular disease. However, use of aromatase inhibitors also resulted in a reduced risk for venous thrombosis and endometrial carcinoma.

As a secondary analysis, they determined if switching from treatment with tamoxifen to aromatase inhibitors had any effect on mortality or adverse effects. Results showed that the risk for serious adverse effects were similar when aromatase inhibitors were used as an initial treatment compared with switching to aromatase inhibitors after treatment with tamoxifen.

"However, it appears from the data — and this is strictly hypothesis-generating — that if a woman switches from one drug to another, there is a reduction in the risk from death from causes other than breast cancer," Amir said. "This potentially suggests that there may be side effects that build up the longer a woman is on a certain drug, but switching drugs may reduce the side effects."

Explore further: Taking the guesswork out of cancer therapy

add to favorites email to friend print save as pdf

Related Stories

Breast cancer study halted

Jun 20, 2007

The U.S. National Cancer Institute halted a $100 million study of drugs designed to prevent breast cancer in women at risk for the disease.

Recommended for you

Pepper and halt: Spicy chemical may inhibit gut tumors

2 hours ago

Researchers at the University of California, San Diego School of Medicine report that dietary capsaicin – the active ingredient in chili peppers – produces chronic activation of a receptor on cells lining ...

Expressive writing may help breast cancer survivors

3 hours ago

Writing down fears, emotions and the benefits of a cancer diagnosis may improve health outcomes for Asian-American breast cancer survivors, according to a study conducted by a researcher at the University of Houston (UH).

Taking the guesswork out of cancer therapy

9 hours ago

Researchers and doctors at the Institute of Bioengineering and Nanotechnology (IBN), Singapore General Hospital (SGH) and National Cancer Centre Singapore (NCCS) have co-developed the first molecular test ...

Brain tumour cells found circulating in blood

10 hours ago

(Medical Xpress)—German scientists have discovered rogue brain tumour cells in patient blood samples, challenging the idea that this type of cancer doesn't generally spread beyond the brain.

International charge on new radiation treatment for cancer

11 hours ago

(Medical Xpress)—Imagine a targeted radiation therapy for cancer that could pinpoint and blast away tumors more effectively than traditional methods, with fewer side effects and less damage to surrounding tissues and organs.

User comments : 0