Pregnancy-Associated Breast Cancer: Imaging and Management

Pregnancy-associated breast cancer (PABC), commonly defined as breast cancer diagnosed during pregnancy or within 1 year postpartum, is an uncommon but clinically important condition. Diagnosis is frequently delayed because physiologic breast enlargement, increased nodularity, and increased breast density during pregnancy may obscure both clinical and radiologic findings. Imaging is central to early detection, characterization of suspicious lesions, axillary assessment, image-guided biopsy, and selective staging. Ultrasound is the preferred first-line imaging modality in pregnant patients because it is highly effective in dense breasts, widely available, and free of ionizing radiation. Mammography remains an important adjunct when malignancy is suspected or confirmed and is considered safe during pregnancy, with negligible fetal radiation exposure. Contrast-enhanced breast magnetic resonance imaging (MRI) is generally avoided because gadolinium crosses the placenta and fetal safety remains uncertain. Suspicious lesions should undergo prompt core needle biopsy. Management of PABC requires multidisciplinary coordination. Surgical treatment can be performed in all trimesters, whereas chemotherapy is contraindicated during the first trimester. Radiotherapy, endocrine therapy, anti-HER2 therapy, and most newer targeted agents are generally postponed until after delivery. This review summarizes current evidence on the imaging evaluation and multidisciplinary management of PABC.