The POSITIVE trial findings, published in The New England Journal of Medicine, offer strong evidence that young patients with breast cancer can safely interrupt adjuvant endocrine therapy to attempt pregnancy without increasing their risk of breast cancer recurrence or new contralateral breast cancer. Before the trial, the risks associated with taking a break from endocrine therapy among young women with hormone receptor-positive breast cancer remained unclear. The single-group trial enrolled more than 500 premenopausal women who had received 18 to 30 months of endocrine therapy and showed that a temporary interruption of therapy to attempt pregnancy did not appear to lead to worse breast cancer outcomes. The authors caution, however, that more data will be essential to confirm the safety of interruption of adjuvant endocrine therapy. Overall, physicians should incorporate these positive data into their shared decision-making process with patients.
