Sentinel lymph node biopsy is not necessary in patients diagnosed with ductal carcinoma in situ of the breast by stereotactic vacuum-assisted biopsy.

Abstract

This study evaluated the role and need of a sentinel lymph node biopsy (SLNB) in patients with an initial diagnosis of ductal carcinoma in situ (DCIS) made by stereotactic vacuum-assisted biopsy (VAB). A retrospective analysis was performed of 1,458 patients who underwent stereotactic VAB between January 1999 and December 2012 at Aichi Cancer Center Hospital. The rates of axillary node metastasis and the underestimation of invasive ductal carcinoma (IDC) were examined. Of the 1,458 patients who underwent stereotactic VAB, 199 had a preoperative diagnosis of DCIS and underwent surgery. In these patients, 20 % (39/199) were upstaged to IDC or at least microinvasion in final pathology. Axillary lymph node status was investigated in 81 % (161/199) of initially diagnosed DCIS patients, and resulted in finding lymph node metastasis in 0.62 % (1/161) patients. To assess the potential preoperative predictors of invasiveness, the value of DCIS histological grade on biopsy samples, the distribution of calcifications on mammograms, and the combination of these factors were studied. The underestimation rate was higher (30 %) in the combination of high DCIS histological grade and extensive calcification although there was no significant association (p = 0.23). The rate of lymph node metastasis was extremely low (0.62 %), even when invasive carcinoma was identified on excision in patients initially diagnosed with DCIS by stereotactic VAB. Because of the low prevalence of metastatic involvement, the cessation of SLNB is a reasonable consideration in patients initially diagnosed with DCIS by stereotactic VAB.