Dr. Sam Li reports:

Older women with a strong family history of breast cancer might soon have a new, safer option to help them avoid developing the disease.

New research from Queen Mary University of London led by Dr. Jack Cuzick, head of the Cancer Research the U.K.'s Center for Cancer Prevention, looked at a drug called anastrozole, a therapy already used to stave off breast cancer recurrence in postmenopausal women who have experienced the disease.

Among the questions Cuzick and his team hoped to answer was whether the same therapy could help prevent breast cancer in women who never had the disease but have a high risk of developing it.

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To answer this question, they studied more than 3,800 women in 18 countries who had a strong family history of the disease - at least two relatives with breast cancer, for example, or women whose mother or sister developed the disease at a young age.

The researchers found that a daily anastrazole pill cut breast cancer incidence in these women by more than half - 53 percent - with few side effects.

"The biggest surprise of our study was that the side effects were less than expected," Cuzick said.

Cuzick presented the new study Wednesday at the San Antonio Breast Cancer Symposium. The study also appears in the journal Lancet.

This would not be the first drug to be used to prevent breast cancer in women who have a high risk of the disease; a small number of women take drugs like tamoxifen and raloxifene for this purpose. But there side effects, which include an elevated risk for blood clots, stroke and other cancers - keep many women away from such treatments. While anastrazole is not without its side effects, the hot flashes and joint pain that accompany its use are generally considered to be less severe than other more serious issues.

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Doctors not involved with the study said the findings were promising. Dr. Angel Rodriguez, a breast cancer doctor at Houston's Methodist Cancer Center, said that based on this study, he will start using the drug for this purpose in his patients.

"We need to raise awareness that medications to prevent cancer exist," Rodriguez said. "It is vastly underutilized in the world. This study further validates their safety - a major concern for most prescribers."

Dr. Lawrence Wickerham, chief of cancer genetics and prevention at Allegheny General Hospital in Pittsburgh, agreed that the finding could change clinical practice. "The results will provide an additional option for postmenopausal women to decrease their risk of developing breast cancer," he said.

Not all doctors agreed, however, that all women who could potentially benefit from this treatment would be willing to endure the side effects of the drug.

"Asking women to take a daily pill to prevent breast cancer is a hard sell, particularly when there is an undertow of other concerns that arise with taking the pill," said Dr. Michael Fisch, chair of medical oncology at the University of Texas MD Anderson Cancer Center in Houston.

Doctor's Take

Breast cancer is a widespread concern among women, especially among those who find themselves related to the estimated one in eight American women who develop breast cancer, and therefore potentially at higher risk themselves.

Many women who are at a higher risk of breast cancer might conclude that the best way to address a life-threatening disease is to prevent it from developing in the first place. This study may very well pave the way for anastrazole to join the growing list of cancer prevention medications as an option that is safer and with more tolerable side effects.

For women who are concerned that they may be at higher risk of breast cancer, the first step may be to seek out expert counseling to understand their options. Once they begin a treatment to prevent breast cancer, they should continue to talk to their doctors about any side effects they are experiencing to determine how to best manage these issues.

As with any treatment, there are some important considerations, but there may also be the opportunity for women to improve the odds in the fight against breast cancer before it is even diagnosed.