A “miracle” breast cancer drug appears to have preventive benefits, but also serious drawbacks

A pound of prevention

Beware the coming hype!

That was my warning last summer, coming on the heels of a very promising study about exemestane, a breast cancer drug that’s better known by the brand name Aromasin.

Study results suggested that the preventive use of Aromasin might cut the risk of breast cancer in post-menopausal women who have an increased risk of the disease.

That sounds pretty impressive. But before doctors start handing out this drug like packs of Gummi Bears, there are several critical details every woman needs to be aware of.

Quality of YOUR life

After last year’s study, your doctor might tell you that Aromasin cut breast cancer risk by more than half in post-menopausal women. And technically, that’s true.

But here’s a somewhat less impressive way of looking at the same results: According to New Scientist, if 94 menopausal women take Aromasin for three years, one case of breast cancer would be prevented.

But that’s okay, according to some, because the study produced “no serious toxic effects” and only “minimal changes in health-related quality of life.”

That’s fine, unless it’s YOUR quality of life.

Generally, it looks like Aromasin increases adverse effects normally associated with menopause.

For instance, out of 2,240 who took Aromasin and 2,248 who took placebo, there were 900 cases of hot flashes reported in the Aromasin group, and 718 reported in the placebo group.

Insomnia: 230 cases in the Aromasin group – 189 in the placebo group.

Diarrhea: 188 in Aromasin – 75 in placebo.

Arthritis: 247 in Aromasin – 196 in placebo.

Back pain: 306 in Aromasin – 222 in placebo.

So for a longshot 1 in 94 chance of avoiding breast cancer over three years, you might significantly increase your risk of adverse events.

And now the other shoe just dropped…

In the current issue of The Lancet Oncology, researchers report a potential serious bone problem: “2 years of treatment with exemestane worsens age-related bone loss in postmenopausal women despite calcium and vitamin D supplementation.”

For some women, Aromasin may be a life-saver. But anyone who tells you this drug is a magic bullet of breast cancer prevention with hardly any side effects to speak of is basically wishing it to be true.

Sources:
“Bone density and structure in healthy postmenopausal women treated with exemestane for the primary prevention of breast cancer: a nested substudy of the MAP.3 randomised controlled trial” The Lancet Oncology, Vol. 13, No. 3, March 2012, thelancet.com

“Exemestane for Breast-Cancer Prevention in Postmenopausal Women” New England Journal of Medicine, Vol. 364, 6/23/11, nejm.org

“’Statins’ for cancer could prevent many breast cancers” Andy Coghlan, New Scientist, 6/22/11, newscientist.com