According to The New York Times, a study conducted last summer from University Health Network, Toronto, notes women most at risk of breast cancer taking Aromasin greatly reduce their chances of contracting cancer. A new analysis of that study noted that those same women faced a greater chance of suffering significant bone loss and overall loss of bone density. This new information is calling into question whether the pill’s prevention benefits outweigh its risks.
Aromasin has been used since 1999 to treat breast cancer and stop it from returning. While Aromasin isn’t approved for prevention of breast cancer, U.S. doctors are allowed to prescribe approved drugs for other uses.
More than 4,500 post-menopausal women participated in the initial study which had results published last June. Of those participants, 351 were used for a more detailed examination of bone density after taking Aromasin.
In the trial of 351 women at risk of developing breast cancer, those who received Aromasin lost about three times more bone-mineral density after two years than those who took a placebo, researchers led by Angela Cheung at Toronto’s University Health Network wrote in The Lancet Oncology.
The women averaged “6.1 percent decline in the bone mineral density in the wrist, compared with 1.8 percent in decline for women getting a placebo,” the Times reports.
The study was not large enough to draw a distinct conclusion between Aromasin and bone fractures, but women taking the drug to prevent recurrence of breast cancer were almost six times as likely to notice significant bone loss.
These new results contradict earlier studies that suggested Aromasin, also known as exemestane, may help stimulate bone growth. It may also cause doctors and patients to question whether the cancer-preventing benefits associated with the drug outweigh the risks in healthy women, said Jane Cauley, a professor of epidemiology at the University of Pittsburgh.
“One might not be too reassured about the use of exemestane in the prevention setting,” Cauley wrote in an editorial accompanying the research.
The problem presented by the study’s findings is the notion that Aromasin may not be the fail-safe drug that was to be a revolutionary drug for women to take in the prevention of breast cancer. Aromasin was thought to be a drug that could be given to millions of women (including those not at a high risk of breast cancer) to prevent the life-threatening and life-altering condition.
“The use of Aromasin as preventative therapy in post-menopausal women at high risk for developing breast cancer is not included in the Aromasin label in the U.S. and Europe, as well as other countries,” Jenifer Antonacci, a Pfizer spokeswoman, said in an e-mail. “It’s important to note that these data are in the National Comprehensive Cancer Network guidelines relating to the management of post-menopausal women at high risk for developing breast cancer.”
Still, despite the negative findings on the risk of bone loss, Aromasin could be a safe option for women facing the highest risk of breast cancer or those trying to prevent a recurrence after receiving initial treatment.
The most recent analysis of last summer’s study is published on the journal The Lancet’s Web site.