Paget’s disease of the breast: Insights from imaging to guide surgical management

Paget’s disease (PD) of the breast is a rare condition accounting for only 1–3% of breast cancers, as evident by the paucity of published data and small cohort analyses.1 Due to its multifocal variation and the unreliability of mammography and ultrasound to detect underlying breast cancer in PD, mastectomy had long been the standard of care for adequate disease control.1,2 However, further studies comparing mastectomy to breast-conserving surgery (BCS) followed by adjuvant radiation have shown no statistical difference in overall survival.3 This raises the question: with modern-day imaging, how can we optimize pre-surgical planning for patients with PD, where the presence of clinically and radiographically occult breast cancer carries a significant risk? Future studies may also explore the potential utility of contrast enhanced mammography (CEM), which has been shown to be another useful imaging modality for assessing extent of disease and has similar performance characteristics to breast MRI, in select populations.8 Although not specific to patients with PD, the PROCEM study will prospectively randomize 440 patients to CEM or no further imaging.9 This study seeks to evaluate the potential added value of CEM in the preoperative staging of breast cancer, and as such, the primary endpoint for this study will be changes in primary treatment.9 Findings from this study could potentially be extrapolated to patients with PD and improve our ability to define true extent of disease pre-operatively, which may then improve surgical decision making and allow for more patients eligible for breast conservation to be accurately identified. In summary, the study by Mousa-Doust et al. adds to our understanding that mammography and ultrasound may not fully capture the extent of underlying breast cancer in PD. This suggests that MRI may be warranted in patients with an otherwise negative clinical and radiographic presentation.