Ipsilateral and concurrent breast cancer and atypical ductal hyperplasia: Does atypia also need surgical excision?

Abstract

Background: Standard of care for management of ADH identified on percutaneous biopsy is surgical excision. Research efforts have focused on utilizing strict multidisciplinary review to identify patients at lowest risk for upgrade that may benefit from omission of surgery. However, having an ipsilateral breast cancer, in addition to the site of ADH, has been an exclusion criterion for consideration of observation over excision of the site of ADH. Methods: This retrospective analysis examined patients who had both a breast cancer and an additional site of ADH in the same breast diagnosed on percutaneous biopsy, who underwent surgical excision of both areas at our institution from 2008-2018. Imaging characteristics (size of cancer, size of ADH, distance between cancer and ADH, percutaneous biopsy technique) and pathologic features (histologic subtype of cancer, cancer grade and prognostic markers, extent of ADH, presence of necrosis or micropapillary features in the ADH) were reviewed from the biopsy, as well as the final surgical pathology at the site of ADH excision to determine features associated with ADH upgrade. Results: Sixty-two women had biopsy proven ADH and a breast cancer at separate sites in the same breast over the 10-year study period. The overall upgrade rate at the site of ADH was 17.7% (n=11), with 9 cases to ductal carcinoma in situ (DCIS) and 2 to invasive breast cancer (IBC). The most common associations with upgrade were the presence of ipsilateral DCIS over IBC (p=0.034), using ultrasound guidance for biopsy of ADH (p=0.019), and the presence of cell necrosis in the ADH (p=0.039). Neither the radiographic size of the ADH nor the distance of the ADH from the ipsilateral cancer were associated with upgrade. The group at lowest risk for upgrade had stereotactic biopsy of the site of ADH and no necrosis associated with ADH, which resulted in 0% upgrade rate. Conclusion: When an ipsilateral breast cancer is present, the upgrade rate at the site of ADH is on par with reported contemporary ADH upgrade rates without ipsilateral breast cancer present. Similar to those studies of ADH alone, upgrade was significantly associated with biopsy modality and presence of ADH necrosis. When considering the ipsilateral breast cancer, upgrade rate for ADH was not affected by the size of the cancer, size of atypia, or distance between the ipsilateral malignancy and atypia. This suggests that omission of surgical excision for ADH in patients with concurrent breast cancer may be appropriate, like those with isolated ADH, when a select low risk subset undergoing rigorous multidisciplinary review can be identified.