SABCS 2022: Can Patients With Hormone Receptor–Positive Breast Cancer Interrupt Endocrine Therapy for Pregnancy?

By: Julia Fiederlein Cipriano
Posted: Tuesday, January 3, 2023

Based on the primary results of the POSITIVE trial, which were presented during the 2022 San Antonio Breast Cancer Symposium (SABCS; Abstract GS4-09), young patients with early-stage hormone receptor–positive breast cancer who temporarily interrupted endocrine therapy while attempting to conceive did not confer a greater short-term risk of recurrence than those from an external cohort who did not pause their therapy for pregnancy. Ann Partridge, MD, MPH, of Dana-Farber Cancer Institute, Boston, and colleagues revealed that many women on the study went on to conceive and deliver healthy babies.

“The POSITIVE trial provides important data to support young women with hormone receptor–positive early breast cancer who are interested in a pregnancy and taking a break from endocrine therapy to pursue one,” commented Dr. Partridge in a press release from the American Association for Cancer Research.

A total of 518 patients younger than age 43 with stage I to III disease who completed 18 to 30 months of endocrine therapy opted to interrupt this treatment for approximately 2 years to attempt pregnancy. At a median follow-up of 41 months, 44 patients had experienced a breast cancer–free interval (defined as the time from enrollment to the first breast cancer event). According to the investigators, the 3-year rate of breast cancer–free interval failure was similar to that of a comparative external control cohort from the SOFT/TEXT trials (8.9% vs. 9.2%).

Of the 497 patients who were followed for pregnancy status, 74.0% had at least one pregnancy, and 63.8% had at least one live birth; a total of 365 babies were born. Based on the results of a competing risk analysis, 76.3% of patients had resumed endocrine therapy, 8.3% had a breast cancer–free interval event or died before resumption, and 15.4% had not yet resumed endocrine therapy.

Disclosure: For full disclosures of the study authors, visit sabcs.org.

2022 San Antonio Breast Cancer Symposium