Pregnancy Outcome and Safety of Interrupting Therapy for Women With Endocrine Responsive Breast Cancer

Official Title

A Study Evaluating the Pregnancy Outcomes and Safety of Interrupting Endocrine Therapy for Young Women With Endocrine Responsive Breast Cancer Who Desire 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. In particular, the most recent data suggest that this is the case also in women with a hormone receptor-positive breast cancer. There is also no indication of increased risk for delivery complications or for the newborn. The aim of the study is to investigate if temporary interruption of endocrine therapy, with the goal to permit pregnancy, is associated with a higher risk of breast cancer recurrence.The study aims also to evaluate different specific indicators related to fertility, pregnancy and breast cancer biology in young women. A psycho-oncological companion study on fertility concerns, psychological well-being and decisional conflicts will be conducted in interested Centres.

Trial Description

Primary Outcome:

  • Breast Cancer free interval (BCFI)
Secondary Outcome:
  • Information on Menstruation recovery and pattern
  • Pregnancy rate (determined by pregnancy test)
  • Pregnancy outcome
  • Offspring outcome
  • Breastfeeding pattern
  • Use of assisted reproductive Technology (ART)
  • Distant recurrence-free interval (DRFI)
Recent decades have witnessed a delay in childbearing for a variety of reasons including cultural, educational, and professional. As a consequence, breast cancer in young women often occurs before the completion of reproductive plans. Infertility has a significant impact on quality of life, resulting in substantial distress in younger women with breast cancer and influencing treatment decisions in a consistent proportion of patients.The best available evidence suggests that pregnancy after breast cancer does not increase a woman's risk of developing a recurrence.For women desiring pregnancy after a breast cancer, 5-10 years of endocrine therapy may substantially reduce the chance of conception; however, a shorter duration of endocrine therapy in this population has not been studied in a prospective manner. Birth outcome after breast cancer has not been shown to be different from that of the normal population, but increased risks of delivery complications, cesarean section, preterm birth and low birth weight have been reported. Endocrine agents are potentially teratogenic: taking into account their median half-life, waiting 3 months after their interruption before attempting conception is considered safe. The limited evidence available on breastfeeding after breast cancer reports successful lactation from the treated breast in approximately 30% of women without detrimental effect on survival. No prospective definitive data are available.

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