Is axillary surgery beneficial for patients with adenoid cystic carcinoma of the breast?

Background and Objectives: Adenoid cystic carcinoma (ACC) is a rare, typically triple-negative, breast cancer reported to have a favorable prognosis and low rate of nodal metastasis. No consensus guidelines exist for axillary staging and treatment. Methods: We identified all patients with ACC evaluated at our institution from January 1994 to August 2016. Patient, tumor, and treatment variables were abstracted and analyzed. Results: We identified 20 pure ACCs (0.13% of all invasive breast cancers) with size range 0.2-4.8 cm, in 19 women, median age 59 years. Preoperative axillary ultrasound was normal in 10/13 women and suspicious in 3/13 who had a subsequent negative lymph node fine needle aspiration (FNA). Fifteen patients (75%) had sentinel lymph node surgery and were pathologically node-negative, while the remaining five had no axillary surgery. With 3.6 years median follow-up (range 0.2-38.6 years), three patients experienced an in-breast recurrence at 2, 16, and 17 years, respectively, while none recurred in regional nodes. Conclusions: We observed no cases of nodal metastasis in 20 consecutive cases of ACC of the breast. Preoperative axillary ultrasound with FNA of suspicious nodes accurately predicted pathologic nodal stage. These data suggest axillary surgery might be omitted safely in patients with pure ACC and a clinically negative axilla.