This observational study aims to collect and analyze clinical data about patients and their babies affected by breast cancer during pregnancy: the diagnosis, treatment, and health of both the mother and child.

Women under 40 represent a significant sub-group among the population affected by breast cancer. Since women today tend to delay pregnancy into their later reproductive years, the likelihood of developing breast cancer during pregnancy has become more frequent.

Our knowledge about which anticancer treatments to be given to a pregnant woman and her unborn child is still very limited. An essential clinical question is “should doctors follow the standard recommendations applying to non-pregnant patients?”

The ultimate aim of the study is to improve our knowledge of breast cancer during pregnancy, and to guide doctors towards better treatments and clinical practice for their patients in the future.

• Medical and biological data are collected upon registration of each patient in the study (also retrospectively if the patient was diagnosed before registration opened) during the whole pregnancy. Data is collected independently from the type and timing of anticancer treatment given and from pregnancy outcome.

• Comparison will be made with a group of young women <40 years old affected by breast cancer, but not pregnant (called the ‘control cohort’).

• Data about the health of the babies born to women with breast cancer will be collected 4 weeks after delivery.

• Also evaluated will be the following: breast cancer therapies prescribed (treatment, response to chemotherapy, side effects, type of surgery); the diagnostic procedures applied (palpation, ultrasound, mammogram); the biology of the tumour; the treatment side effects on the mother and child; the maternal outcome of pregnancy as well as the long-term effects of therapy on mother and child after 5 years of treatment.

• Biomaterial samples will also be collected: a sample of the tumour and placenta tissue will be collected from patients with breast cancer during pregnancy, and tumour samples will be collected from the non-pregnant patients (control cohort). Tumour biology will be analyzed using standard immunohistochemistry and next generation sequencing technologies.

• Women with histologically confirmed breast cancer who are pregnant (independently from treatment and gestational age)

• Women <40 years with histologically confirmed breast cancer who are not pregnant (patients who have been pregnant recently can also be involved in this cohort)

Overall recruitment: 1500 patients

Coordinating group & Sponsor: German Breast Cancer Group (GBG).

The study was extended to other European countries through the BIG network.

Collaborating groups:

German Breast Group (GBG), Austrian Breast & Colorectal Cancer Study Group (ABCSG), and Borstkanker Onderzoeksgroep Nederland (BOOG)

• Recruitment of patients started in 2003 and the study is still open.

• Total number of patients expected: 1500

• In May 2015 already 1000 patients had been recruited

• First results were published in 2012 (see reference below)

The study is active 12 countries.

200 sites are currently open for recruitment.

• S. Loibl, von Minckwitz G, Gwyn K et al. Breast carcinoma during pregnancy. International recommendations from an expert meeting. Cancer 106 (2006) 237-246 
  
  
• S. Loibl, Han SN, von Minckwitz G et al. Treatment of breast cancer during pregnancy: an observational study, Lancet Oncol. 2012 Sep;13(9):887-96. doi: 10.1016/S1470-2045(12)70261-9. Epub 2012 Aug 16. 

Funding is provided by the German Breast Group. Translational research will be supported through collaborative research initiatives such as those provided by the Deutsches Konsortium fuer Translationale Krebsforschung (DKTK) and other grants.

NCT00196833