Rate of radial scars by core biopsy and upgrading to malignancy or high-risk lesions before and after introduction of digital breast tomosynthesis

April Phantana-angkool, Meghan R. Forster, Yancey E. Warren, Chad A. Livasy, Amy H. Sobel, Lakesha M. Beasley, Sally J. Trufan, Lejla Hadzikadic-Gusic, Terry Sarantou, Amy E. Voci, Deba Sarma, Richard L. White

Radial scars (RS) commonly present mammographically as architectural distortions, but these lesions may be associated with non-invasive and invasive breast cancer. Digital breast tomosynthesis (DBT) has resulted in higher detection rates of architectural distortion particularly in patients with dense breast tissue. We hypothesized that rates of clinically relevant lesions confirmed surgically would be lower in patients who received DBT imaging compared with those who received standard digital breast imaging. We performed a retrospective review of 223 patients diagnosed with pure RS by core biopsy and surgical excision before and after DBT was introduced. The rate of upgrading to malignancy or high-risk lesion was evaluated. Demographics, biopsy type, and histologic data were analyzed. Univariable logistic regression analysis was used to identify variables that may be associated with upgrading. The rate of identifying RS increased from 0.04-.13% (P < 0.0001) with DBT imaging. The upgrade rate on surgical specimen to invasive or non-invasive cancer was similar before and after DBT; 6% versus 3%, as were findings of a high-risk lesion; 12% versus 22%. No predictive factors were identified for patients upgraded to malignant neoplasms or high-risk lesions. The likelihood of identifying RS has increased with DBT imaging, but rates of upgrading to a malignant neoplasm or high-risk lesion were similar to those before DBT. Although the rate of upgrading to malignancy after DBT was low, an excisional biopsy should be considered as 22% of patients were upgraded to high-risk lesions. These patients are candidates for chemoprevention and/or high-risk surveillance.