Do we still need axillary staging in the context of mastectomy after at least one breast conservative surgery for ductal carcinoma in situ?

Abstract

Goals: Sentinel lymph node biopsy (SLNB) is indicated when a mastectomy is performed by Ductal Carcinoma In Situ (DCIS). When mastectomy is performed after one or more attempts of breast conservative surgery (BCS), the need to perform SLNB
is questionable. The goal of this study was to determine the histological upgrade rate and SLNB results in this specific group of patients.
Methods: Retrospective study of a case series of patients submitted to total mastectomy and SLNB by CDIS after BCS between 2008 and 2016.
Outcomes: We analysed 1,071 cases and selected 81 that fulfilled the inclusion criteria. The median age was 55 years. The diagnosis was made by screening tests in 88.6% of the cases. Microcalcifications were the main presentation (78.8%). The mastectomy totalisation was performed after one attempt of BCS due to positive or inadequate margins. The resection margins were positive in 46.9% of the cases. Residual disease in the mastectomy specimen was identified in 65.4%. The post-mastectomy upgrade rate was 4.9% (one case with microinvasion and three cases with invasion). The median number of sentinel nodes (SN) isolated were 2 (0-5) and the rate of lymph node metastasis was null.
Conclusions: In this sample, the histological upgrade rate was very low. We didn´t find lymph node metastasis in any case, even in those cases with upgrade to invasive carcinoma. These findings suggest that lymph node staging can be safely omitted in DCIS patients submitted to mastectomy after attempted BCS.