Sentinel lymph node biopsy for breast cancer: a suitable alternative to routine axillary dissection in multi-institutional practice when optimal technique is used.

PURPOSE: Previous studies have demonstrated the feasibility of sentinel lymph node (SLN) biopsy for nodal staging of patients with breast cancer. However, unacceptably high false-negative rates have been reported in several studies, raising doubt about the applicability of this technique in widespread surgical practice. Controversy persists regarding the optimal technique for correctly identifying the SLN. Some investigators advocate SLN biopsy using injection of a vital blue dye, others recommend radioactive colloid, and still others recommend the use of both agents together. PATIENTS AND METHODS: A total of 806 patients were enrolled by 99 surgeons. SLN biopsy was performed by single-agent (blue dye alone or radioactive colloid alone) or dual-agent injection at the discretion of the operating surgeon. All patients underwent attempted SLN biopsy followed by completion level I/II axillary lymph node dissection to determine the false-negative rate. RESULTS: There was no significant difference (86% v 90%) in the SLN identification rate among patients who underwent single- versus dual-agent injection. The false-negative rates were 11.8% and 5.8% for single- versus dual-agent injection, respectively (P <.05). Dual-agent injection resulted in a greater mean number of SLNs identified per patient (2. 1 v 1.5; P <.0001). The SLN identification rate was significantly less for patients older than 50 years as compared with that of younger patients (87.6% v 92.6%; P =.03). Upper-outer quadrant tumor location was associated with an increased likelihood of a false-negative result compared with all other locations (11.2% v 3. 9%; P <.05). CONCLUSION: In multi-institutional practice, SLN biopsy using dual-agent injection provides optimal sensitivity for detection of nodal metastases. The acceptable SLN identification and false-negative rates associated with the dual-agent injection technique indicate that this procedure is a suitable alternative to routine axillary dissection across a wide spectrum of surgical practice and hospital environments.

Practical guidelines for optimal gamma probe detection of sentinel lymph nodes in breast cancer: results of a multi-institutional study. For the University of Louisville Breast Cancer Study Group.

INTRODUCTION: Multiple radioactive lymph nodes are often removed during the course of sentinel lymph node (SLN) biopsy for breast cancer when both blue dye and radioactive colloid injection are used. Some of the less radioactive lymph nodes are second echelon nodes, not true SLNs. The purpose of this analysis was to determine whether harvesting these less radioactive nodes, in addition to the "hottest" SLNs, reduces the false-negative rate. METHODS: Patients were enrolled in this multicenter (121 surgeons) prospective, institutional review board-approved study after informed consent was obtained. Patients with clinical stage T1-2, N0, M0 invasive breast cancer were eligible. This analysis includes all patients who underwent axillary SLN biopsy with the use of an injection of both isosulfan blue dye and radioactive colloid. The protocol specified that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest node should be removed and designated SLNs. All patients underwent completion level I/II axillary dissection. RESULTS: SLNs were identified in 672 of 758 patients (89%). Of the patients with SLNs identified, 403 patients (60%) had more than 1 SLN removed (mean, 1.96 SLN/patient) and 207 patients (31%) had nodal metastases. The use of filtered or unfiltered technetium sulfur colloid had no impact on the number of SLNs identified. Overall, 33% of histologically positive SLNs had no evidence of blue dye staining. Of those patients with multiple SLNs removed, histologically positive SLNs were found in 130 patients. In 15 of these 130 patients (11.5%), the hottest SLN was negative when a less radioactive node was positive for tumor. If only the hottest node had been removed, the false-negative rate would have been 13.0% versus 5.8% when all nodes with 10% or more of the ex vivo count of the hottest node were removed (P =.01). CONCLUSIONS: These data support the policy that all blue nodes and all nodes with 10% or more of the ex vivo count of the hottest SLN should be harvested for optimal nodal staging.

Preoperative lymphoscintigraphy for breast cancer does not improve the ability to identify axillary sentinel lymph nodes.

OBJECTIVE: To evaluate the role of preoperative lymphoscintigraphy in sentinel lymph node (SLN) biopsy for breast cancer. SUMMARY BACKGROUND DATA: Numerous studies have demonstrated that SLN biopsy can be used to stage axillary lymph nodes for breast cancer. SLN biopsy is performed using injection of radioactive colloid, blue dye, or both. When radioactive colloid is used, a preoperative lymphoscintigram (nuclear medicine scan) is often obtained to ease SLN identification. Whether a preoperative lymphoscintigram adds diagnostic accuracy to offset the additional time and cost required is not clear. METHODS: After informed consent was obtained, 805 patients were enrolled in the University of Louisville Breast Cancer Sentinel Lymph Node Study, a multiinstitutional study involving 99 surgeons. Patients with clinical stage T1-2, N0 breast cancer were eligible for the study. All patients underwent SLN biopsy, followed by level I/II axillary dissection. Preoperative lymphoscintigraphy was performed at the discretion of the individual surgeon. Biopsy of nonaxillary SLNs was not required in the protocol. Chi-square analysis and analysis of variance were used for statistical comparison. RESULTS: Radioactive colloid injection was performed in 588 patients. In 560, peritumoral injection of isosulfan blue dye was also performed. A preoperative lymphoscintigram was obtained in 348 of the 588 patients (59%). The SLN was identified in 221 of 240 patients (92.1%) who did not undergo a preoperative lymphoscintigram, with a false-negative rate of 1.6%. In the 348 patients who underwent a preoperative lymphoscintigram, the SLN was identified in 310 (89.1%), with a false-negative rate of 8.7%. A mean of 2.2 and 2. 0 SLNs per patient were removed in the groups without and with a preoperative lymphoscintigram, respectively. There was no statistically significant difference in the SLN identification rate, false-negative rate, or number of SLNs removed when a preoperative lymphoscintigram was obtained. CONCLUSIONS: Preoperative lymphoscintigraphy does not improve the ability to identify axillary SLN during surgery, nor does it decrease the false-negative rate. Routine preoperative lymphoscintigraphy is not necessary for the identification of axillary SLNs in breast cancer.