RESUMO
BACKGROUND: For patients with ductal carcinoma in situ (DCIS) undergoing breast conservation surgery (BCS), guidelines advise a margin width of at least 2 mm, with studies demonstrating decreased recurrence risk compared to narrower margins. However, limited data exist establishing if this margin is appropriate in mastectomies, and specifically for nipple-sparing mastectomy (NSM). Consequently, we evaluated the margins of DCIS patients undergoing NSM and resulting oncologic outcomes. METHODS: A single-institution retrospective review was performed in patients with DCIS or DCIS with microinvasion (DCIS + MI) undergoing NSM from April 2010 to December 2021. Patient and tumor characteristics, margin status, treatment, and outcomes information were collected. The association between margins and local-regional (LRR) and distant recurrence (DR) were examined. RESULTS: 161 patients were included, comprising 284 NSM (164 therapeutic, 120 prophylactic). 153 patients had DCIS and 8 had DCIS + MI. Most patients had hormone sensitive, 123 (76.4%), and nuclear grade 2, 72 (44.7%), disease. In total, 35 (21.7%) patients had positive or <2 mm margins. Of these, 21 (60%) involved the anterior margin. At a median follow-up of 45 months (range 0-151), 2.5% (n = 4) had a LRR and .6% (n = 1) had a DR. Of patients with a recurrence, only 2 had positive or <2 mm margins, 1 had received endocrine therapy, and none received adjuvant radiation. DISCUSSION: No specific margin status was found to correlate with recurrence for patients with DCIS or DCIS + MI undergoing NSM, with an altogether low recurrence risk. Overall, this suggests that recommended DCIS margins in BCS doesn't necessarily apply in NSM, where margins of <2 mm may be acceptable.
RESUMO
The American Society of Breast Surgeons recommends sending separate nipple margins (NMs) when performing nipple-sparing mastectomies (NSMs). However, the definition of a positive NM is vague. We evaluated NM management and outcomes in breast cancer patients undergoing NSM from 2010 to 2021 at our community-based hospital system through a retrospective review and descriptive analysis. A total of 619 patients (1086 NSM) were included. Median invasive tumor size was 1.5cm and median follow-up 30 months. Fourteen therapeutic NSMs had tumor within the NMs. Nine were positive using the definition "any tumor within the separate NM," and nipple-areolar complex (NAC) excised. Two were negative when positive was defined as "any tumor on ink," and were observed without recurrence. Our results suggest positive NMs warranting NAC excision could be interpreted as "any tumor on ink" and NSMs can be safely performed with low rates of positive NMs and recurrences in high-volume hospitals.