Intro text: 

(Public name: BIG Time for Baby)

Support the BIG Time for Baby project

This academic global study represents a unique opportunity to allow young women who have had breast cancer to plan and try to become pregnant without waiting many years after completing their endocrine treatment. 
It will also improve our scientific understanding of issues related to conception and pregnancy in young women who have had breast cancer by helping us obtain solid data.

This trial will evaluate the pregnancy outcomes and safety of interrupting endocrine therapy for young women with ER+ breast cancer who wish to become pregnant.

 1. Young women with breast cancer are a significant part of the overall breast cancer population  
     - About 15% of patients with breast cancer are diagnosed during their reproductive years
     - In recent decades, women have tended to delay childbearing, so increasingly, breast cancer occurs before they have completed their families.
2. The majority of young women with early breast cancer have estrogen receptor positive (ER+) disease.
3. The long-term survival of women with ER+ breast cancer treated with standard endocrine treatment is good and the treatment benefit is independent of age at diagnosis.

Premenopausal women with ER+ early breast cancer who received endocrine therapy for 18 to 30 months, are 42 years of age or younger at enrolment, and wish to interrupt endocrine therapy to become pregnant.

Overall recruitment goal: 500 patients

Coordinating group and Sponsor: IBCSG


• Treatment interruption
• 3 month break in treatment before attempting pregnancy
• Up to 2-year break to allow conception, delivery and breastfeeding (or potential failure to conceive)
• Endocrine therapy resumption & completion of full duration of endocrine therapy

• Recruitment of patients started in 2014.
• Recruitment of patients started in 2014 and competed in December 2019.
• 518 patients were recruited in total, from 203 participating hospitals across 20 countries   
• First results regarding safety are anticipated within 5-6 years of study activation. 
• Patients will be followed for at least 10 years after enrolment.

203 hospitals from 20 countries around the world, from 11 BIG collaborative groups as well as independent sites.

IBCSG, Fonds Baillet-Latour, national and local funding bodies, and individual donors

ClinicalTrials.gov number: NCT02308085