The role of mammography in the detection and diagnosis of pregnancy-associated breast cancer

Abstract

Purpose: To evaluate the role of mammography in the diagnostic workup of pregnancy-associated breast cancer (PABC). Materials and methods: This retrospective single-institution study included patients diagnosed with PABC from February 2009 to January 2024 and imaged by mammography. The additional diagnostic value of mammography as statistically compared with ultrasound (US) was evaluated, focusing on rate of initial detection, identification of additional cancer, changes in lesion size ≥1 cm, and changes in T-staging. Results: A total of 167 patients with newly diagnosed PABC were included (mean age, 37.0 years ±4.4), including 30/167 (18 %) who were pregnant (mean pregnancy duration, 6.3 months ±2.7) and 137/167 (82 %) who were lactating. Almost all patient had dense breasts (163/167, 97.6 %), including 77 % with extremely dense breasts. Most PABCs (137/167, 82.0 %) were visible on mammography, including cases in which mammography was the sole detection modality (n = 21), had additional positive stereotactic biopsy (n = 17, 10.2 %), showed changes in lesion size by ≥1 cm (n = 35, 21.0 %) (P < 0.001), or changed the T-staging (n = 35, 21.0 %). Excluding cases with duplicate contributions, mammography added value in 64/167 (38.3 %) patients. Conclusion: Despite the high proportions of increased mammographic density, mammography successfully demonstrated most pregnancy-associated breast cancers and frequently provided valuable additional information for their evaluation. Regardless of how PABC presents clinically, mammography and US must serve as complementary tools in the diagnostic evaluation of PABC.