Treatment Patterns and Clinical Outcomes of Adenoid Cystic Breast Carcinoma: A Single-Institution Experience

Background: Adenoid cystic breast carcinoma (ACC) is a rare subtype of triple-negative breast cancer. We aim to characterize the treatment patterns and clinical outcomes of women diagnosed with ACC at a large medical center. Methods: Female patients diagnosed with ACC at our institution between 2009 and 2019 were retrospectively identified. Patients with limited clinicopathologic data were excluded. Results: In our final study cohort (n = 9), the majority of ACCs (6/9, 66.7%) were hormone receptor (−) (HR−) and HER-2/neu (−) (HER2−), while 3 ACCs were HR+ HER2−. Two patients received adjuvant chemotherapy, and 4 patients received adjuvant radiotherapy. The crude local and distant recurrence rate of our cohort was 22.2% and 11.1% (median follow-up of 36 months). Conclusions: The majority of ACCs were triple negative but some ACCs were HR+. The unadjusted local and distant recurrence rates were not negligible, suggesting that adjuvant chemotherapy and radiotherapy may be warranted in select cases.