Abstract S6-2: 313 Patients with Breast Cancer during Pregnancy — Results from a Prospective and Retrospective Registry (GBG-20/BIG02-03)
Authors: Loibl S , Amant F , Kaufmann M , Ring A , Sileny H , Giermek J , Fehm T , Bontenbal M , Heinrigs M , Lenhard M , Scherr I , Mehta K , von Minckwitz G. 
Published: April 2011

Background: To increase the evidence for treatment of breast cancer during pregnancy, the German Breast Group launched a registry (GBG-29/BIG 02-03) for patients with breast cancer diagnosed during pregnancy. Patients: Every pregnant breast cancer patient was eligible. The primary endpoint is the fetal outcome 4 weeks after delivery. Secondary endpoints were maternal outcome of pregnancy, stage and biological characteristics of breast cancer, breast cancer therapy (treatment, response to chemotherapy, type of surgery, outcome of the mother and newborn after 5 years. Results: From April 2003-June 2010, 313 patients have been prospectively (n=185) and retrospectively (n=128) registered. 24 pts were registered without clinical data and were removed from the data set. The median age was 33 years (range 23-47). T1-2: 71%; T3-4: 25%; inflammatory 4%, N+ 48%; ductal invasive/other 97%, grade 3: 64%, HR+/HER2- 26%; HR+/HER2+ 22%; HR-/HER2- 34%; HR-/HER2+ 18%. At the time of diagnosis the median gestational age was 23 weeks; 23% of all patients were diagnosed during the 1st, 42% during the 2nd and 36% during the 3rd trimester. 29 pts (10%) had an abortion. 260 continued pregnancy. 142/260 (54%) patients received 527 chemotherapy (CHT) cycles (c) during pregnancy with a median of 4 cycles per pt (1 n=8; 2 n=25; 3n=23; 4 n=52; 5 n=14; 6n=19; 8 n=1). CHT regimen used during pregnancy are: EC/AC n=70, FE(A)C n=29; Vincaalcaloids/A n=12; A/E mono n=10; CMF n=14, taxanes n=6. 48% had a caesarean section. Mean weight of the newborns after intrauterine CHT was 2810g (1270-4050g) delivered at median 37 weeks (range 31-42) compared with newborns not exposed to CHT with 2730g (1260-4295g) delivered at median 38 weeks (range 30-42 weeks). Patients w/o CHT during pregnancy had a significantly higher rate of premature deliveries compared with those with CHT (33% vs 17%; p=0.009). Of the 142 babies exposed to CHT adverse events are: 4 infections, 4 congenital malformations, 1 small for gestational age, 1 CPAP, 1 hyperbilirubinemia, 1 neutropenia, and 2 anemia; 1 thalassemia,1 trisomia 18 (died one week after birth), 1 necrotic enterocolitis (died 3 weeks after birth). The group w/o CHT during pregnancy reported temporary apnea; CPAP, hypoglycemia, congenital malformation, icterus, neutropenia (1 each). Overall median DFS of the mothers was 27 (95% CI 22-32) months. OS was 55 (95% CI 32-79) months. Significant differences in DFS were found between DFS in pts w/o CHT during pregnancy, pts with CHT during pregnancy, and pts with an abortion (29 vs 25 vs 15 months; log rank p=0.0372).

Conclusion: Premature deliveries were significantly more common within the group of pts not receiving CHT during pregnancy probably to allow for an early start of CHT. However, fetal outcome in babies, who received intrauterine chemotherapy was not significantly different from those who did not if matched to gestational age. Pregnant breast cancer pts should be treated as closely as possible to standard recommendations. Early delivery with the risk of prematurity of the newborns is unnecessary and an abortion might even have a negative effect on the outcome. Supported by the BANSS Foundation

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr S6-2.