2017 ASCO Annual Meeting!
Session: Patient and Survivor Care
Type: Poster Session
Time: Saturday June 3, 1:15 PM to 4:45 PM
Location: Hall A
Safety of pregnancy in patients (pts) with history of estrogen receptor positive (ER+) breast cancer (BC): Long-term follow-up analysis from a multicenter study.
Patient and Survivor Care
2017 ASCO Annual Meeting
Poster Board Number:
Poster Session (Board #55)
J Clin Oncol 35, 2017 (suppl; abstr LBA10066)
Author(s): Matteo Lambertini, Niels Kroman, Lieveke Ameye, Octavi Cordoba, Alvaro Pinto, Giovanni Benedetti, Maj-Britt Jensen, Shari I. Gelber, Maria Del Grande, Michail Ignatiadis, Evandro De Azambuja, Marianne Paesmans, Fedro Peccatori, Hatem A. Azim Jr.; Institut Jules Bordet, Brussels, Belgium; Danish Breast Cancer Cooperative Group, Rigshospitalet, Copenhagen, Denmark; Data Centre, Institut Jules Bordet - Université Libre de Bruxelles (ULB), Brussels, Belgium; Vall d’Hebron University Hospital, Barcelona, Spain; Hospital Universitario La Paz, Madrid, Spain; Macerata Hospital, Macerata, Italy; The Danish Breast Cancer Cooperative Group, DBCG Secretariat, Rigshospitalet, Copenhagen, Denmark; Dana-Farber Cancer Institute, Boston, MA; European Institute of Oncology, Milan, Italy; Istituto Europeo D' Oncologia, Milan, Italy
Background: Physicians and pts remain concerned on the safety of pregnancy following BC, particularly in women with history of ER+ disease. Previously, we showed no detrimental effect of pregnancy on BC outcome within the first 5 years following conception (Azim et al. JCO 2013). Here, we report long-term follow-up data. Methods: In this multicenter retrospective study, pts with pregnancy after BC (pregnant cohort) were matched (1:3) according to tumor and treatment characteristics with pts without subsequent pregnancy (non-pregnant cohort). To adjust for guaranteed time bias, each non-pregnant pt should have been disease free for a minimum time not inferior to the time elapsing between BC diagnosis and conception in the matched pregnant one. Primary endpoint was disease-free survival (DFS) in pts with ER+ BC. Secondary endpoints were DFS and overall survival (OS) in ER-negative and all pts irrespective of ER status. We also evaluated the impact of induced abortion on BC outcome. Results: The study included 1,207 pts, 333 pregnant and 874 non-pregnant. A total of 57% of pts had ER+ BC. After 12.5 years from conception, no DFS difference was observed between pregnant and non-pregnant pts with ER+ BC (hazard ratio [HR] 0.94; 95% confidence intervals [CI] 0.70-1.26; p = 0.68), ER- BC (HR 0.75; 95% CI 0.53-1.06; p = 0.10), and all pts (HR 0.85; 95% CI 0.68-1.06; p = 0.15). There was no OS difference between the 2 cohorts in pts with ER+ BC (HR 0.84; 95% CI 0.60-1.18; p = 0.32), but a significant improved OS was observed in the pregnant cohort for ER- pts (HR 0.57; 95% CI 0.36-0.90; p = 0.01) yielding a significant overall estimate (HR 0.72; 95% CI 0.55-0.94; p = 0.02). Abortion did not have any impact on outcome (HR 0.80; 95% CI 0.56-1.13; p = 0.20), irrespective of ER status. Conclusions: This is the largest study addressing the safety of pregnancy in pts with history of ER+ BC. Long-term follow-up confirms that pregnancy is safe and should not be discouraged irrespective of ER status. Our results further strengthen the rationale of the ongoing IBCSG-BIG-NABCG POSITIVE trial (NCT02308085) addressing the role of temporary interruption of adjuvant endocrine therapy to allow pregnancy.