New ASCO Breast Cancer Guideline
Aromatase inhibitor added to recommendations (July 8)
The American Society of Clinical Oncology (ASCO) has updated its 2009 guideline on pharmacologic interventions for breast cancer risk reduction.
The new guideline recommends that clinicians discuss the selective estrogen receptor modulator (SERM) tamoxifen (Nolvadex, AstraZeneca), 20 mg/day for 5 years, as an option to reduce the risk of ER-positive breast cancer in women aged 35 years or older who are at risk of the disease.
Women at increased breast cancer risk are defined as individuals with a 5-year projected absolute disease risk of 1.66% or greater (based on the National Cancer Institute’s Breast Cancer Risk Assessment Tool or an equivalent measure) or those diagnosed with lobular carcinoma in situ.
The guideline also states that the SERM raloxifene (Evista, Lilly), 60 mg /day for 5 years, and the aromatase inhibitor exemestane (Aromasin, Pfizer), 25 mg/day for 5 years, should be discussed as options for breast cancer risk reduction in postmenopausal women.
The addition of exemestane to the society’s guideline is a major change. Earlier guidelines had stressed that the use of aromatase inhibitors to prevent breast cancer was not recommended outside of clinical trials.
Aromasin (exemestane) is currently approved only for the adjuvant treatment of early breast cancer and the treatment of advanced breast cancer, not for breast cancer risk reduction.The new guideline was published in the Journal of Clinical Oncology.
Source: JCO; July 8, 2013.