Sentinel lymph node biopsy is not warranted following a core needle biopsy diagnosis of ductal carcinoma in situ (DCIS) of the breast

Abstract

IntroductionThe role of sentinel lymph node biopsy (SLNB) in ductal carcinoma in situ (DCIS) is controversial. This study evaluates the risk of clinically relevant SLN metastasis following a core needle biopsy (CNB) diagnosis of pure DCIS. Materials and methodsCases that underwent SLNB following a CNB diagnosis of pure DCIS at our institution over a 4.5 year period were evaluated. Parameters including the DCIS characteristics on CNB, the rate of upstaging to invasive carcinoma at excision and the SLNB result were recorded. ResultsOf 296 patients with a CNB diagnosis DCIS, 181 had SLNB (62%). The rate of invasion at excision in those undergoing SLNB was 30% (54/181). SLN metastasis was detected in 7/181 cases (4%), including 6 cases with isolated tumour cells only (3.5%) and only 1 case with a macro-metastatic deposit (0.5%). ConclusionThe risk of clinically significant SLN metastasis following a CNB diagnosis of DCIS is extremely low, despite a relatively high rate of upstaging to invasive carcinoma at excision. Our findings support the opinion that SLNB is not warranted following a CNB diagnosis of DCIS, particularly for those patients undergoing breast conservation surgery.