Value Added of Preoperative Contrast-Enhanced Digital Mammography in Patients With Invasive Lobular Carcinoma of the Breast

Background

Invasive lobular carcinoma (ILC) is the second most frequently diagnosed breast cancer, accounting for 5% to 15% of all invasive breast cancers, yet it remains radiologically elusive in many cases. The goal of this study was to compare the ability to accurately assess disease extent with contrast-enhanced digital mammography (CEDM) and full-field digital mammography (FFDM) in patients with biopsy-proven ILC.

Patients and Methods

A single-institution retrospective review of patients diagnosed with ILC with preoperative CEDM was performed. One of 3 blinded radiologist readers rereviewed cases within 1 month of another. Final size diameter was based on the largest dimension on recombined CEDM or FFDM and compared to the reference standard histopathology. Bland-Altman plots were used to visualize the differences between tumor size on imaging and pathology.

Results

Thirty women were included. Mean tumor diameter was 27.0 mm (range, 7.0-118 mm) on postoperative histology, 26.0 mm on CEDM, and 16.4 mm on standard mammogram. For CEDM versus FFDM, 5 (16.7%) of 30 versus 9 (30.0%) of 30 cases underestimated pathology by > 10 mm and 5 (16.7%) of 30 versus 3 (10.0%) of 30 overestimated histopathology by > 10 mm, respectively. Two (6.7%) of 30 cases required surgical reexcision. Both Lin (0.87 vs. 0.55) and Pearson (0.87 vs. 0.70) correlation coefficient measures were higher for CEDM versus FFDM.

Conclusion

CEDM outperforms standard digital mammography in ability to accurately assess disease extent in patients with biopsy-proven ILC, resulting in improved surgical outcomes. Future studies should compare surgical outcomes in patients with preoperative magnetic resonance imaging and CEDM in patients with ILC.