CCTG MAC18 | POSITIVE study Wednesday, September 28, 2016 A Study Evaluating the Pregnancy Outcomes and Safety of Interrupting Endocrine Therapy for Young Women with Endocrine Responsive Breast Cancer who Desire Pregnancy Young breast cancer patients often face the disease before having addressed their family planning: they may not have time to wait for 5-10 years of treatment completion before considering pregnancy. The best available evidence suggests that pregnancy after breast cancer does not increase a woman’s risk of developing a recurrence from her breast cancer and is safe for the baby. However, the available information was collected retrospectively, and a controlled prospective study is needed to confirm these results. The POSITIVE study evaluates the safety of interrupting endocrine therapy for young women with hormone-sensitive breast cancer who wish to become pregnant. 500 patients from centers around the world are expected to participate over a period of 4 years. Women will be followed for 10 years after the inclusion in the study. Who can take part in the study Pre-menopausal women with: Hormone-sensitive early breast cancer Endocrine therapy for 18 to 30 months 42 years of age or younger at enrolment Wish to interrupt endocrine therapy to attempt pregnancy