The "Sentinel Chain": a new concept for prediction of axillary node status in breast cancer patients.
OBJECTIVE
More than half the breast cancer patients with positive sentinel lymph nodes (SLN) do not harbor additional metastases in non-sentinel nodes (NSN). The aim of this study was to identify a subgroup of patients with positive SLNs and negative NSNs, on the basis of tumor involvement patterns in multiple radioactive nodes.


METHODS
Between 2000 and 2004, 290 patients with primary invasive breast cancer and clinically negative axillary nodes had a SLN biopsy in our breast unit. Radiotracer was identified intraoperatively in the axilla. All radioactive nodes were removed and radioactivity was measured in each node extracorporeally. Nodes were ranked according to radioactivity, constituting a "Sentinel Chain", and the histopathological status of each node was reported. The different metastatic involvement patterns of the Sentinel Chain were correlated with the metastatic status of the NSNs after axillary dissection. Information was charted in a prospective database.


RESULTS
Of 290 patients, 216 (74.5%) had multiple radioactive nodes. Ninety patients (31%) had SLN metastases. Fifty patients had multiple ranked radioactive nodes and positive SLNs. Twenty-five of these patients had a sequential involvement pattern, with tumor-bearing high radioactivity nodes, and uninvolved low-radioactivity nodes. In the 23 of these 25 patients who had axillary dissection, NSN involvement was detected in only one patient (4.3%), whereas in 24 patients with other involvement patterns of the Sentinel Chain, NSN involvement reached 54.2% (p<0.001).


CONCLUSIONS
Tumor-free status of NSN may be predicted using the Sentinel Chain concept in some breast cancer patients with positive SLNs.
Carmon
Moshe
M
Department of Surgery, Shaare Zedek Medical Center, Affiliated with the Faculty of Health Sciences, Ben Gurion University of the Negev, Jerusalem, Israel. mcarmon@szmc.org.il
Olsha
Oded
O
Schecter
William P
WP
Raveh
David
D
Reinus
Constantin
C
Hershko
Dan D
DD
Beller
Uziel
U
Golomb
Eliahu
E
D001365:Axilla; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D004396:Coloring Agents; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000000981:diagnostic imaging / Q000473:pathology*; D008207:Lymphatic Metastasis; D011237:Predictive Value of Tests; D011877:Radionuclide Imaging; D012394:Rosaniline Dyes; D021701:Sentinel Lymph Node Biopsy; D013667:Technetium
D004396:Coloring Agents; D012394:Rosaniline Dyes; D013667:Technetium; C008769:sulfan blue