Pausing Endocrine Therapy for Pregnancy Did Not Increase Risk of Recurrence for Those With HR+ Breast Cancer

Fertility preservation and/or assisted reproductive technologies (ART) did not impact 3-year cancer recurrence rates for those with hormone receptor (HR)-positive breast cancer who paused endocrine therapy to become pregnant, according to results of the POSITIVE trial (NCT02308085).

Fertilization preservation can be used to maintain reproductive potential for patients, which can include ovarian stimulation used for subsequent cryopreservation of oocytes or embryos, cryopreservation of ovarian tissues, and use of gonadotropin-releasing hormone analogs during chemotherapy to reduce the risk of ovarian failure, according to the study investigators. ART also includes techniques to help individuals become pregnant, which included the transfer of cryopreserved embryos, ovarian stimulation for in vitro fertilization, intrauterine insemination, embryo or egg donation, and more.

Fertilization preservation can be used to maintain reproductive potential for patients, which can include ovarian stimulation used for subsequent cryopreservation of oocytes or embryos, cryopreservation of ovarian tissues, and use of gonadotropin-releasing hormone analogs during chemotherapy to reduce the risk of ovarian failure, according to the study investigators. Image Credit: © TarikVision - stock.adobe.com

“With the increasing age of childbearing, it is becoming more likely that women will be diagnosed with breast cancer before starting or completing their families,” Hatem A. Azim Jr., MD, PhD, an adjunct professor at the School of Medicine and Breast Cancer Center at the Tecnológico de Monterrey in Mexico, said in a press release. “Many [patients with breast cancer] may opt for fertility preservation prior to starting cancer treatment and/or may use ART to increase their chances of pregnancy.”

The results of the trial, presented at the San Antonio Breast Cancer Symposium, demonstrated that individuals with HR+ breast cancer could pause endocrine therapy for up to 2 years to become pregnant, without increasing the risk of recurrence; however, investigators reported that the safety of conceiving after fertility preservation and/or ART for patients is still unclear.

Azim and colleagues conducted a secondary analysis of the POSITIVE trial to determine the impact of fertility preservation and ART on those who paused endocrine therapy to become pregnant. There were 497 individuals included in the study, 74% of whom became pregnant. Among individuals who underwent fertility preservation, 179 used embryo or oocyte cryopreservation prior to enrollment and 215 used some form of ART to attempt pregnancy, with the most common procedures being ovarian stimulation for in vitro fertilization and cryopreserved embryo transfer.

Younger age and cryopreserved embryo transfer were associated with high chances of pregnancy, and 82.4% who underwent the transfer became pregnant, according to the the study investigators. Furthermore, investigators found that ovarian stimulation for cryopreservation was not associated with worse disease outcomes, showing only 9.7% of patients who underwent the procedure had recurrence of breast cancer within 3 years compared to 8.7% of those who did not undergo the procedure.

Further, investigators found those who were younger became pregnant sooner, with 80% of those younger than 25 being pregnant compared to 50% who were older than age 40 years, according to Azim.

“Participants who underwent cryopreserved embryo transfer during the study had higher pregnancy rates with no apparent short-term detrimental impact on breast cancer outcome,” Azim said in the press release.“Our data demonstrate the efficacy and short-term safety of different fertility preservation and ART options, building on the primary results of the POSITIVE trial and providing vital information for fertility counseling of young [patients with] breast cancer.”

Additionally, another analysis showed that menstrual cycles returned within 6 months of pausing the endocrine therapy in most individuals who had amenorrhea at the entry of the trial. The type of adjuvant endocrine therapy had no impact on time to pregnancy, according to the investigators. However, the investigators noted that a limitation of the study was the short follow-up time, according to the press release.

Reference

Patients with HR-positive breast cancer may use fertility preservation and assisted reproductive technologies without increased risk of recurrence. News release [Email]. San Antonio Breast Cancer Symposium. December 7, 2023. Accessed December 6, 2023.