Breast cancer recurrence risk after hormonal contraceptive use in survivors of reproductive age

Objective: To assess the risk of recurrence with hormonal contraceptive use in breast cancer survivors of reproductive age.

Study design: In this retrospective study, women ages 18-51 years who were diagnosed with primary stage 0-3 breast cancer between 2006-2016 and subsequently entered remission were included. Patients with missing information within the cancer registry or electronic medical record and those with a history of hysterectomy and/or sterilization procedure prior to diagnosis were excluded. Hormonal contraception use was defined as being prescribed an oral contraceptive pill (OCP), patch, vaginal ring, medroxyprogesterone injection, etonogestrel implant, or levonorgestrel-releasing intrauterine device (IUD). Women were separated into two groups, hormonal contraceptive users and non-users. Basic descriptive and inferential statistics were used to compare groups as appropriate. The primary outcome reviewed was local or distant breast cancer recurrence. Secondary outcomes included all-cause mortality and pregnancy.

Results: Following exclusions, 1370 women remained in the cohort. Ninety-seven women (7.08 %) received a prescription for a form of hormonal contraception. When comparing groups, hormonal contraceptive users were more likely to be between 18-40 years of age (46.39 % vs. 17.99 % non-users;P < 0.01) and never smokers (68.04 % vs. 38.57 % non-users; P < 0.01). Patients did not differ between groups based on any other demographic or cancer-related characteristic, including tumor hormone receptor expression. Overall, 92 patients (6.72 %) experienced local or distant recurrence during the study period. Recurrence did not differ between groups (6.19 % users vs. 6.76 % non-users; P = 0.83). All-cause mortality and pregnancy rates also did not differ between hormonal contraceptive users and non-users.

Conclusion: The study shows no increased risk of recurrence associated with hormonal contraceptive use after breast cancer diagnosis and remission.