Multidisciplinary management of pregnancy-associated breast cancer: a clinical pharmacy perspective on chemotherapy and perinatal outcomes.

Background: Pregnancy-associated breast cancer (PABC) is increasing globally and often presents at advanced stages with aggressive features, requiring chemotherapy that balances maternal efficacy and fetal safety. Although multidisciplinary team (MDT) management is recommended, real-world pharmacotherapy data, especially involving clinical pharmacists in Asian populations, are limited. Objectives: This study aimed to describe the clinical characteristics, chemotherapy regimens, premedication strategies, and maternal-fetal outcomes of PABC managed within an MDT framework, offering a clinical pharmacy perspective on medication management and safety. Methods: This retrospective, single-center, cross-sectional study included patients diagnosed with PABC between January 2019 and December 2025 who received chemotherapy with clinical pharmacist involvement. Demographic characteristics, pathological findings, chemotherapy regimens, premedication protocols, adverse reactions, and maternal-fetal outcomes were extracted from the electronic medical record system by two independent investigators, with discrepancies resolved through consensus. Results: A total of 28 patients were included. The median age at diagnosis was 32.41 ± 3.80 years. The majority of patients (64.29%) were diagnosed during the second trimester, and Stage II was the most common pathological stage (39.29%). Under the multidisciplinary model, the predominant pregnancy chemotherapy was anthracycline, cyclophosphamide, and docetaxel (EC-T), administered to 35.71% of patients. Regimen selection and premedication were routinely optimized. Adverse events managed through pharmacist-involved monitoring included leukopenia (7.14%) and severe myelosuppression (7.14%). Pharmacists also provided fetal safety counseling, growth guidance, and parental reassurance on long-term offspring outcomes, embedding pharmaceutical expertise into multidisciplinary care. Regarding maternal and fetal outcomes, 79.31% of patients delivered by cesarean section, 53.57% had full-term deliveries, and the mean neonatal birth weight was 2730 ± 497 g. Low birth weight occurred in 28.57% of newborns, and 17.86% required admission to the Neonatal Intensive Care Unit (NICU). Conclusion: This study provides real-world evidence for the multidisciplinary management of PABC. In this small sample, second- and third-trimester chemotherapy appeared to be associated with acceptable maternal-fetal outcomes. Integration of clinical pharmacists into the MDT model facilitated evidence-based regimen design, individualized premedication strategies, and proactive adverse event monitoring. These preliminary findings support the feasibility of pharmacist-involved MDT care in PABC, though validation in larger prospective studies with long-term offspring follow-up is needed.