Mastectomy margins for ductal carcinoma-in-situ (DCIS): 18 Years of follow-up

Background: In patients undergoing mastectomy for ductal carcinoma in situ (DCIS), the significance of a positive or close (<2 mm) margin and associated recurrence risk is unclear. The study sought to evaluate risk of recurrence in relation to the mastectomy surgical margin. Methods: A single institution retrospective review of patients with DCIS who underwent mastectomy between 2000 and 2010 was performed. Patient demographics, tumor biology, margin status and adjuvant therapy were recorded. The incidence of local recurrence (LR), distant metastasis were analyzed. Results: A total of 282 patients with DCIS were identified. Overall, 12.3% of patients had a pathological positive/close margin (n = 9 tumor on ink and n = 36 <2 mm). Adjuvant radiation was administered to 11 patients with a positive or close margin. At a median follow-up of 12 years, LR was 3.4% (n = 10). None of the patients with LR had a positive or close margin. Additionally, none of the patients who received radiation developed LR. Conclusion: Risk of recurrence after mastectomy for DCIS is low and appears to be unrelated to margin status or the use of radiation therapy. (c) 2023 Elsevier Inc. All rights reserved.