ASPO Abstracts
Risk versus benefit of chemoprevention among raloxifene and tamoxifen users with a family history of breast cancer
Category: Lifestyles Behavior, Energy Balance & Chemoprevention
Conference Year: 2019
Abstract Body:
Purpose: Tamoxifen and raloxifene have been approved for the primary prevention of breast cancer in high-risk women, but are associated with an increased risk of serious side effects. Few studies have characterized risk-benefit profiles for chemoprevention among women who initiate tamoxifen or raloxifene outside of the clinical trial setting. The objectives of this study were to describe risk-benefit profiles of women with a family history of breast cancer who reported use of tamoxifen or raloxifene for primary breast cancer prevention, and to evaluate characteristics associated with tamoxifen and raloxifene use.Methods: Use of raloxifene and tamoxifen for chemoprevention was self-reported in 2014-2016 by participants in The Sister Study, a prospective cohort of women with a sister who had been diagnosed with breast cancer. After exclusions, 432 current raloxifene users and 96 current tamoxifen users were matched to 4307 and 953 non-users, respectively, on age and year of cohort enrollment. Conditional logistic regression was used to evaluate characteristics associated with chemoprevention use. Risk-benefit profiles were examined using published indices that assess the level of evidence (none, moderate, strong) that the benefits of chemoprevention outweigh the risk of serious side effects.Results: Among current chemoprevention users, 44% of tamoxifen users and 5% of raloxifene users had no evidence of a net benefit. In analyses of factors associated with chemoprevention use, having strong evidence of benefit was a significant predictor of raloxifene use, but not of tamoxifen use. Conclusion: In our sample of women with a first-degree family history of breast cancer, raloxifene was more commonly used for breast cancer prevention than tamoxifen. Most raloxifene users, but <60% of tamoxifen users, were likely to benefit. Use of risk-benefit tables can help women and their healthcare providers make an informed decision about breast cancer chemoprevention.
Keywords: breast cancer, tamoxifen, raloxifene