Hormonal contraceptives do not increase recurrence of breast cancer, mortality

Breast cancer survivors who used hormonal contraception did not have an increased risk for recurrence or mortality compared with those who did not, according to data presented at the American College of Obstetrics and Gynecology Annual Clinical and Scientific Meeting in San Diego.

“Breast cancer survivors are advised to avoid hormone use for contraception or perimenopausal or postmenopausal symptoms,” Sara M. O’Meara, DO, from the department of obstetrics and gynecology at Aurora Health Care in Milwaukee, and colleagues wrote.

O’Meara and colleagues evaluated the risk for recurrence and mortality associated with contraceptive and non-contraceptive hormone use in women aged 18 to 55 years who were diagnosed with stage I to III breast cancer between 2006 and 2015 and entered remission (n = 3,437). To evaluate the time-dependent effects of hormonal contraception and non-contraceptive hormonal therapies, they used multivariable extended proportional hazards models, supporting adjusted HR, overall survival and locoregional and distant recurrence probability estimation, while accounting for time-invariant patient, tumor and treatment effects. Hormonal contraception included the pill, patch, ring, subcutaneous device, injection and intrauterine device.

After breast cancer diagnosis, 91.2% of patients used no hormones (n = 3,134), 4.98% used hormonal contraceptives (n = 171), 3.75% used non-contraceptive hormones (n = 129) and 0.09% used both (n = 3). There was no difference in recurrence risk between patients who used hormonal contraceptives and patients who used no hormones (HR = 0.78; 95% CI, 0.34-1.8). There was also no difference in mortality risk between the groups (HR = 0.52; 95% CI, 0.13-2.15). The 5-year overall survival rate for patients who used hormonal contraceptives was 0.97 (95% CI, 0.9-0.99) compared with 0.95 (95% CI, 0.94-0.96) for those who did not use hormones. Recurrence risk was similar between patients who used non-contraceptive hormones and those who used no hormones (HR = 1.52; 95% CI, 0.77-2.99); however, risk for death was greater in hormone users (HR: 2.95, 95% CI: 1.70-5.09).

“Breast cancer survivors who use hormonal contraceptives are not at increased risk of recurrence or mortality relative to women who do not use hormones,” O’Meara and colleagues concluded. “However, those who use non-contraceptive hormones demonstrate greater mortality risk.”

Related, previous research has revealed that oral contraceptives reduce risk for some cancers. – by Alaina Tedesco

Reference:

O’Meara SM, et al. Hormonal contraception and therapy use in breast cancer survivors: Do recurrence or mortality risks increase? Presented at: American College of Obstetrics and Gynecology Annual Clinical and Scientific Meeting; May 6-9, 2017; San Diego.

Disclosure: The authors did not report any relevant financial disclosures.