Stanenas, Sara; Greer, Danielle M.; Kram, Jessica J F; Tjoe, Judy A.; and Dorton, Benjamin, "Hormonal contraception and therapy use in breast cancer survivors: Do recurrence and mortality risks increase?" (2017). Aurora Ob/Gyn Residents. 11.
Annual Clinical and Scientific Meeting, San Diego, CA May 6-9, 2017
INTRODUCTION: Breast cancer survivors are advised to avoid hormone use for contraception or peri-menopausal or postmenopausal symptoms. This study assessed the recurrence and mortality risks of contraceptive and non-contraceptive hormone use in breast cancer survivors.
METHODS: We retrospectively studied women aged 18-55 years who were diagnosed with stage I-III breast cancer during 2006-2015 and entered remission. Multivariable extended proportional hazards models, supporting adjusted hazard ratio (HR), overall survival (OS), and locoregional and distant recurrence probability estimation, were used to examine the time-dependent effects of hormonal contraception (pill, patch, ring, subcutaneous device, injection, intrauterine device) and non-contraceptive hormonal therapies (e.g., menopausal symptoms), while adjusting for time invariant patient, tumor, and treatment effects.
RESULTS: Following diagnosis, 3,134 (91.2%) patients used no hormones, 171 (4.98%) used hormonal contraceptives, 129 (3.75%) used noncontraceptive hormones, and 3 (0.09%) used both. Models incorporating patients who used hormonal contraceptives versus no hormones revealed recurrence risk did not differ between groups (HR: 0.78, 95% confidence interval [CI]: 0.34-1.80). Mortality risk also did not differ (HR: 0.52, 95% CI: 0.13-2.15), with 5-year OS rates of 0.97 (95% CI: 0.90-0.99) and 0.95 (95% CI: 0.94-0.96), respectively. In models incorporating patients who used non-contraceptive hormones versus no hormones, recurrence risk was similar (HR: 1.52, 95% CI: 0.77-2.99) but hormone users incurred greater risk of death (HR: 2.95, 95% CI: 1.70-5.09).
CONCLUSION: Breast cancer survivors who use hormonal contraceptives are not at increased risk of recurrence or mortality relative to women who do not use hormones. However, those who use noncontraceptive hormones demonstrate greater mortality risk.