Outcome and risk factors for local recurrence after breast conserving surgery in patients affected by ductal carcinoma in situ

Ductal carcinoma in situ (DCIS) is a tumor with long term survival and low local recurrence rate. Although the progression of these lesions is rare, the current guidelines recommend breast conservating surgery (BCS) with adjuvant radio and/or endocrine therapy, often resulting in an overtreatment for patients. The aim of this single-center study was to evaluate the long-term outcome of the breast conservating surgery of DCIS followed by adjuvant radio and/or endocrine therapy and to identify prognostic factors associated with the risk of recurrence.Patients treated for DCIS with BCS and radiation therapy between March 2006 and January 2019 were retrospectively reviewed using a prospectively maintained database. Analysis of the potential risk factors was performed to evaluate the risk of subsequent ipsilateral and contralateral recurrence.Out of 2894 patients, two hundred eighty-eight (10%) patients were treated for DCIS. After a median follow-up of 85 months (IQR 27-124), the incidence of recurrence was 6% (18 patients). Nine of them (3%) had an ipsilateral local recurrence (LR) with a median disease-free survival of 19 months (IQR 12-35). The remaining nine patients had contralateral metachronous breast cancer (CBC) with a median DFS of 29 months (IQR 14-36). Margin status, multifocality, hormone receptor status and Her-2/Basal-like subtype were identified as risk factors for the local recurrence with a OR of 5.58 (1.44-21.54), 7.46(1.89-24.48) 0.25 (0.06-0.96) and 4.86 (1.26-18.71) respectively.DCIS had been confirmed to have long term survival. Margin status, multifocality, hormone receptor status and Her-2/Basal-like subtype could be identified as reliable risk factors for the progression of the disease.