Exemestane for breast cancer prevention in postmenopausal women

January 01, 0001

Exemestane for breast cancer prevention in postmenopausal women

Tamoxifen and raloxifene have limited patient acceptance for primary prevention of breast cancer. Aromatase inhibitors prevent more contralateral breast cancers and cause fewer side effects than tamoxifen in patients with early-stage breast cancer. This paper by authors from multiple countries reports a randomized controlled trial of exemestane designed to detect a 65% relative reduction in invasive breast cancer. They included postmenopausal women 35 years of age or older who had at least one of the following risk factors: 60 years of age or older; Gail 5-year risk score greater than 1.66% (chances in 100 of invasive breast cancer developing within 5 years); prior atypical ductal or lobular hyperplasia or lobular carcinoma in situ; or ductal carcinoma in situ with mastectomy.

They found: "A total of 4560 women for whom the median age was 62.5 years and the median Gail risk score was 2.3% were randomly assigned to either exemestane or placebo. At a median follow-up of 35 months, 11 invasive breast cancers were detected in those given exemestane and in 32 of those given placebo, with a 65% relative reduction in the annual incidence of invasive breast cancer (0.19% vs. 0.55%; hazard ratio, 0.35). The annual incidence of invasive plus noninvasive (ductal carcinoma in situ) breast cancers was 0.35% on exemestane and 0.77% on placebo (hazard ratio, 0.47). Adverse events occurred in 88% of the exemestane group and 85% of the placebo group, with no significant differences between the two groups in terms of skeletal fractures, cardiovascular events, other cancers, or treatment-related deaths. Minimal quality-of-life differences were observed."

The authors concluded: "Exemestane significantly reduced invasive breast cancers in postmenopausal women who were at moderately increased risk for breast cancer. During a median follow-up period of 3 years, exemestane was associated with no serious toxic effects and only minimal changes in health-related quality of life."

Maybe this one will fly?

For the full abstract, click here.

N Engl J Med online 4 June 2011 © 2011 to the Massachusetts Medical Society
Exemestane for Breast-Cancer Prevention in Postmenopausal Women. Paul E. Goss, James N. Ingle, José E. Alés-Martínez, et al. Correspondence to Dr. Goss: [email protected]

Category: X. Female Genital System, Breast. Keywords: breast cancer prevention, chemoprevention, exemestane, aromatase inhibitors, randomized controlled trial, journal watch.
Synopsis edited by Dr Linda French, Toledo, Ohio. Posted on Global Family Doctor 14 June 2010

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.