Core Needle Biopsy and Preoperative Risk Factors as Predictors of Upstaging Atypical Ductal Hyperplasia on Surgical...

BackgroundPatients with atypical ductal hyperplasia (ADH) diagnosed on core needle biopsy (CNB) are recommended for surgical excision. However, the rate of upstaging to malignancy on final pathology varies widely. This study sought to determine the rate of upstaging for ADH diagnosed on CNB and to evaluate risk factors associated with upstaging.MethodsPatients diagnosed with ADH by CNB from 1/2014 to 9/2024 were identified from a prospectively maintained database. Pathology, imaging, demographics, family history of breast cancer, genetic testing, and risk of future malignancy were collected. Univariate and multivariable analysis were performed to evaluate predictors of upstaging.Results456 patients with ADH on CNB met inclusion criteria. Median age was 53 years (range 19-89 years). Overall, 110 (24.1%) patients were upstaged on surgical excision. The highest risk of upstaging was observed in patients with multifocal ADH (71.4%). Upstaged patients were older (P < .001), more likely to have a mammographic mass or architectural distortion (P = .03), abnormal MRI (P = .001), ADH bordering on DCIS or multifocal ADH on biopsy (P < .001). Multivariable analysis identified abnormal MRI as an independent predictor of higher risk (P = .046) and focal ADH as a predictor of lower upstage risk (P = .03). At a median follow-up of 52.5 months, 21 (4.6%) patients developed subsequent DCIS, and 20 (4.4%) patients developed subsequent invasive cancer.ConclusionADH on CNB was upstaged on surgical excision in 24.1% of patients. Multifocal ADH and abnormal MRI findings strongly predict upstaging to malignancy. The 9.6% rate of subsequent malignancy necessitates long-term surveillance for all patients with ADH.