Value of Sentinel Lymph Node Biopsy in Breast Cancer Patients with Previous Excisional Biopsy

PURPOSE Sentinel lymph node biopsy (SLNB) in breast cancer patients with clinically negative axilla will ensure axillary dissection only for cases with lymph node metastasis and provide information about pathologic staging as accurate as the axillary dissection. It was shown that SLNB could be successfully performed regardless of the type of biopsy. The aim of this study was to investigate the feasibility of SLNB after excisional biopsy. METHODS One hundred patients diagnosed with excisional biopsy or guide wire-localization and operated on with SLNB between February 2007 and March 2009 were retrospectively analyzed. SLNB was performed with 10 cc of 1% methylene blue alone or both methylene blue and 1 mCi of Tc-99m nanocolloid combination. Age, tumor localization and size, length of the biopsy incision, size of the biopsy specimen, multifocality, lymphovascular invasion, tumor grade, staining with methylene blue, localization, number and metastatic status of the lymph nodes stained, and success rate with a gamma probe were evaluated. RESULTS Sentinel lymph node (SLN) could not be identified in 9 (16.9%) of patients in the methylene blue group (n=53). In the combination group (n=47), SLN could not be identified in one patient. Of 32 patients with negative SLNB, metastatic involvement was found to be present in 5 patients after axillary lymph node dissection (false negatives). The average numbers of SLNs found in the methylene blue group and combination group were 1.4 and 1.6, respectively. SLN detection and false negative rates in the methylene blue group were 83% and 15.7%, respectively. The rates for the combination group were 98% and 6.4%, respectively. None of the parameters related to patient, tumor or process were found to affect detection rates of SLN. CONCLUSION Only SLNB using a combination method is a safe and reliable technique for breast cancer patients diagnosed with excisional biopsy.