What are the ASCO guidelines for the pharmacologic reduction of breast cancer risk?

Updated: Feb 04, 2021
  • Author: Pavani Chalasani, MD, MPH; Chief Editor: John V Kiluk, MD, FACS  more...
  • Print

ASCO guidelines on endocrine therapy to reduce breast cancer risk recommend the following [163] :

  • In premenopausal women who are at least 35 years old and have completed childbearing, tamoxifen (20 mg/day for 5 years) remains the standard of care for risk reduction. Low-dose tamoxifen (5 mg/day) may be an alternative in women with intraepithelial neoplasia.

  • Anastrozole, exemestane, or raloxifene should not be prescribed for breast cancer risk reduction in premenopausal women.

  • In postmenopausal women, the choice of endocrine therapy includes anastrozole (1 mg/day) in addition to exemestane (25 mg/day), raloxifene (60 mg/day), or tamoxifen (20 mg/day).

The ASCO guidelines delineate the risk thresholds for use of individual agents, along with the benefits and risks that clinician and patient should discuss when considering endocrine therapy for primary breast cancer prevention. In particular, SERMs carry warnings about risk of thromboembolic events, and aromatase inhibitors carry warnings about bone mineral density (BMD) reduction. Hence, tamoxifen and raloxifene are not recommended for use in women with a history of deep vein thrombosis, pulmonary embolus, stroke, transient ischemic attack, or during prolonged immobilization. [163]

Anastrozole is relatively contraindicated in women with a history of osteoporosis and/or severe bone loss, and should be used only with caution in postmenopausal women with moderate BMD loss. If anastrozole is used, the addition of bone-protective agents such as bisphosphonates and RANKL inhibitors should be considered. Regular exercise and adequate calcium and vitamin D supplementation should be encouraged in all patients receiving aromatase inhibitors. [163]

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!