Safety of de-escalation of surgical intervention for atypical ductal hyperplasia on percutaneous biopsy: One size does not fit all.

ABSTRACT

BACKGROUND: Oncologic safety of active monitoring (AM) for atypical ductal hyperplasia (ADH) on core-needle biopsy (CNB) is not well defined. We sought to define oncologic outcomes for AM to manage ADH meeting institutional predefined low-risk criteria (LOW). METHODS: ADH was diagnosed on CNB from 10/2015-03/2020. LOW (pure ADH, size <1 cm, >50% removed by CNB, <3 foci, and no necrosis) patients were offered AM; all others were recommended for surgical excision. Oncologic outcomes were compared for AM and surgery. RESULTS: 111 were included, 21 (19%) meeting LOW. AM occurred in 18 (86%) while 3 elected for excision (with 0% upgrade). Of the 18 LOW in AM, 2 required additional CNB (none at ADH site) 0% were diagnosed with cancer over median 23 month follow-up. CONCLUSIONS: There were no missed cancers at ADH site during AM for LOW, confirming the oncologic safety of AM in this select group.