Breast Cancer Drug Scores Win in Prevention

Aromasin (exemestane) not only reduces the risk of recurrence of hormone-positive breast cancer in post-menopausal women, it also helps prevent the disease from developing.

Study results, which were released at the annual meeting of the American Society of Clinical Oncology (ASCO) in June, revealed that the aromatase inhibitor lowered the relative risk of breast cancer by about two-thirds. Results were also published in The New England Journal of Medicine.

Paul Goss, MD, PhD, lead investigator of the MAP.3 trial, said the drug, when compared with a placebo, lowered the risk of breast cancer after three years from 55 cases per 10,000 women to 19. “Exemestane offers a new option for consideration of breast cancer prevention for [post-] menopausal women,” and women and their doctors should be aware of this option for breast cancer prevention, he told ASCO attendees during the study presentation.

Two other drugs, tamoxifen and Evista (raloxifene), lower the risk of breast cancer by about 38 to 50 percent. Both drugs are approved by the Food and Drug Administration as chemoprevention, but rare, serious side effects, such as blood clots and stroke, have hindered the widespread adoption of these drugs for women who are at high risk for breast cancer. Although Evista, which is also approved for osteoporosis, has a lower risk of these side effects, it is not commonly prescribed for this indication.

Aromasin has its own risk of side effects, although less severe, with the most common including hot flashes, fatigue, bone mineral loss and joint pain. The drug recently went off patent, and a generic version of the drug became available in May.