Surgical de-escalation for re-excision in patients with a margin less than 2 mm and a diagnosis of DCIS

The current surgical guidelines recommend an optimal margin width of 2 mm for the management of patients diagnosed with ductal carcinoma in situ (DCIS). however, there are still many controversies regarding re-excision when the optimal margin criteria are not met in the first resection. the purpose of this study is to understand the importance of surgical margin width, re-excision, and treatments to avoid additional surgery on locoregional recurrence (LRR). the study is retrospective and analyzed surgical margins, adjuvant treatments, re-excision, and LRR in patients with DCIS who underwent breast-conserving surgery (BCS). a total of 197 patients were enrolled. re-operation for a close margin rate was 13.5%, and the 3-year recurrence was 7.6%. no difference in the LRR was reported among the patients subjected to BCS regardless of the margin width (p = 0.295). the recurrence rate according to margin status was not significant (p = 0.484). approximately 36.9% (n: 79) patients had resection margins < 2 mm. a sub-analysis of patients with margins < 2 mm showed no difference in the recurrence between the patients treated with a second surgery and those treated with radiation (p = 0.091). the recurrence rate according to margin status in patients with margins < 2 mm was not significant (p = 0.161). the margin was not a predictive factor of LRR p = 0.999. surgical re-excision should be avoided in patients with a focally positive margin and no evidence of the disease at post-surgical imaging.