A new study linking the breast cancer prevention drug Aromasin (exemestane) to decreased bone density and bone loss has stunted optimism surrounding the drug.
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.
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. Still, the benefit of preventing breast cancer may outweigh that risk.
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.
In previous studies, Aromasin did not present the risk of blood clots as its predecessors, tamoxifen and raloxifene, have. Each of those drugs has not proven to be an effective method of preventing breast cancer in women because of their known risk of causing blood clots. Though Aromasin does not present that risk, the further analysis of last summer’s study noted it carries that risk of bone loss.
The most recent analysis of last summer’s study is published on the journal The Lancet’s Web site. In an accompanying commentary to the findings, a University of Pittsburgh epidemiologist believes the results will put a damper on the hopes that Aromasin would be revolutionary in that it could be the first drug proven to prevent breast cancer without presenting any known side effects.
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.
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. After two years, 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.