Abstract 14569: Chemotherapy in Pregnancy: Assessing the Safety of Adriamycin Administration in Pregnancy Complicated by Breast Cancer

Abstract

Introduction: Treatment of Pregnancy Associated Breast Cancer (PABC) with radiation and endocrine therapy is challenging due to potential risks to the fetus. Surgical treatment is safe throughout pregnancy, and chemotherapy agents such as anthracyclines are safe during 2 nd and 3 rd trimesters. Case Presentation: A 39-year-old G4P3 female presented at 8 weeks gestation with a twin pregnancy and a right breast mass with bloody nipple discharge. Past medical history was significant for obesity and chronic hypertension. Biopsy of the mass confirmed weakly ER+/PR-/HER2-, node+, stage IIb PABC. After radical mastectomy and axillary lymph node dissection, 4 Adriamycin and Cyclophosphamide (AC) based adjuvant chemotherapy cycles q3 weeks were started at 12 weeks of gestation with a maternal and fetal echocardiogram, brain natriuretic peptide and troponin measurements after each cycle. A baseline echocardiogram revealed cardiomyopathy with an LVEF of 45% and a severely dilated left ventricle. She was New York Heart Association class II at baseline. Carvedilol 6.25 mg BID was started prior to beginning AC and titrated to 12.5 mg BID due to palpitations after 1 st AC cycle. She tolerated 4 AC cycles with no change in EF from baseline, no symptoms of heart failure, and a normal fetal echocardiogram. Weekly Paclitaxel was resumed to complete 12 cycles prior to radiation treatment. She delivered healthy male and female infants at 32 weeks with no complications (M: APGAR 5 and 7; F: APGAR 8 and 7). Postpartum EF decreased to 40%, necessitating titration of carvedilol to 25mg BID and the addition of Sacubitril/Valsartan 24/26 mg BID. Chest pain complaint after delivery prompted evaluation with computed tomography-based angiogram and cardiac magnetic resonance imaging (CMR), ruling out coronary artery disease. Despite this, no evidence of microvascular disease on CMR symptomatic relief was reported on long-acting nitrates. Discussion: This case demonstrates the importance of multidisciplinary patient management, particularly for those with low LVEF who are at higher risk of decompensation. Despite not knowing the etiology of PABC, she could be suffering from thrombotic microangiopathy of small coronary vessels, which explains relief from nitrates.