Abstract P3-23-03: Use of taxane-containing regimens during pregnancy for the treatment of breast cancer: A systematic review
Authors: Ferrigno Ana S. , Becerril-Gaitan Andrea , Vaca-Cartagena Bryan F. , Azim Hatem A. , Villarreal-Garza Cynthia 
Published: March 2022

Background: Concurrent diagnosis of breast cancer (BC) and pregnancy represents a therapeutic challenge as the indication of any treatment modality requires careful consideration of expected clinical benefit and fetal safety. Anthracycline-based chemotherapy regimens have been extensively studied and proven to be relatively safe to use during gestation. However, there is limited data about the safety of taxane-containing regimens during pregnancy or the predominant prescribing practices in real-world clinical settings despite NCCN and ESMO supporting their use when clinically indicated. This study aimed to systematically review and synthesize available evidence regarding gestational taxane use for BC treatment.. Methods: A literature search was conducted in PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and Web of Science from their inception up to April 14, 2021. Studies considered eligible for this analysis were those that reported gestational taxane use for BC, presented original findings, and disclosed patient-specific outcomes. The retrieved records were independently screened by two authors, with discrepancies resolved by a third. Descriptive statistics were undertaken. Results: A total of 438 unique records were retrieved, of which 32 reports describing 163 BC patients treated with taxane-containing regimens during pregnancy were identified. Of those, 25 publications disclosed sufficient detail to be included in the analysis (63 pregnancies, 64 newborns; median gestational age at taxane initiation = 24 weeks, range 14-32). The most commonly reported regimens were paclitaxel 80 mg/m2 weekly (20%) and docetaxel 75 mg/m2 every three weeks (15%). The median cumulative dose received during pregnancy was 550 mg/m2 (range: 240-1200) for patients treated with paclitaxel and 375 mg/m2 (range: 150-650) for those prescribed docetaxel. A total of 80% were exposed simultaneously or sequentially to other cytotoxic treatments during pregnancy, 13% were additionally treated with anti-HER2 agents, and 10% received G-CSF. Treatment-associated adverse effects or obstetric complications were reported in 41%, predominantly consisting of preterm contractions or rupture of membranes (11%), oligohydramnios (8%), preeclampsia/HELLP syndrome (8%), and cytopenias (8%). The outcome of all pregnancies was reported as live birth. Overall, 52% of deliveries were preterm (&lt;37 weeks) and 27% of the offspring were classified as small for their gestational age. Additionally, neonatal complications of the offspring exposed to taxanes in utero were documented in 18% of cases and consisted mainly of the need for resuscitation or respiratory support (11%) and hyperbilirubinemia (3%).

Conclusions: In this review, a high rate of maternal and fetal adverse outcomes was found in cases exposed to taxanes during pregnancy. Anecdotal evidence suggests that a wide variability of taxane-containing regimens are used in clinical practice, with most cases being exposed simultaneously or sequentially to other systemic treatments. Future studies are needed to fully elucidate the optimal taxane-containing regimen to be used during pregnancy, with a special emphasis on treatment safety.

Use of taxane-containing regimens during pregnancy. Data are shown as n (%). NR: Not reported Gestational age at taxane initiation 1rst trimester 1 (2%) 2nd trimester 26 (41%) 3rd trimester 13 (21%) NR 23 (37%) Taxane agent administered Paclitaxel 32 (51%) Docetaxel 19 (30%) Both/NR 12 (19%) Pregnancy complications Preterm delivery 33 (52%) Preterm contractions/PROM 7 (11%) Oligohydramnios 5 (8%) Pre-eclampsia/HELLP syndrome 5 (8%) IUGR 5 (8%) Method of delivery Vaginal 13 (20%) C-section 16 (25%) NR 35 (55%) Neonatal complications Preterm delivery 33 (52%) Small for gestational age (n=55) 15 (27%) Need for resuscitation or respiratory support 7 (11%) Hyperbilirubinemia 2 (3%)

Citation Format: Ana S. Ferrigno, Andrea Becerril-Gaitan, Bryan F. Vaca-Cartagena, Hatem A. Azim Jr., Cynthia Villarreal-Garza. Use of taxane-containing regimens during pregnancy for the treatment of breast cancer: A systematic review [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P3-23-03.