Supplementary Material for: Predictors for Upgrade to Breast Cancer in Patients with B3 Lesions Diagnosed by Core Biopsy: A Retrospective Cohort Study

Background
The optimal approach to B3 lesions is controversial, and the risk of malignant upgrade varies between studies. This study aimed to evaluate the factors affecting the risk of upgrading to breast cancer in patients diagnosed with B3 lesions by core biopsy.
Methods
A total of 410 patients diagnosed with B3 lesions by core biopsy and subsequently undergoing surgical excision were evaluated. Patients who did not undergo surgical excision or were not followed up at our center were excluded. Patients were analyzed based on demographic, clinical, radiological and pathological findings.
Results
All 410 patients included in the study were women, with a median age of 47 years (range 21-78). An upgrade to in-situ or invasive disease was observed in 117 of the 410 patients (28.5%). In univariate analysis, age, mammographic findings, histopathological type, and atypia in core biopsy were identified as significant factors affecting the upgrade rate (p=0.046, p=0.028, p<0.001, and p<0.001, respectively). In multivariate analysis, the presence of atypia (p<0.001) and a diagnosis of ADH (p=0.026) were determined to be independent variables that increase the upgrade rate.
Conclusion
Surgical excision or Vacuum-assisted excision may be more appropriate for atypical ductal hyperplasia and B3 lesions with atypia on core biopsy.