Sentinel nodes in breast cancer: relevance of axillary level II nodes and optimal number of nodes that need to be removed.
BACKGROUND
In some patients, the radiocolloid used to perform sentinel lymph node biopsy (SLNB) for breast cancer appears in a number of lymph nodes and in different levels of the axilla. Most positive sentinel lymph node specimens (SLNSs) removed during SLNB are identified in level I of the axilla and within the first 4 SLNSs. Our objective was to verify the staging accuracy of harvesting only the first 4 SLNSs and to determine the relevance of SLNSs that reside in level II of the axilla.


METHODS
A prospective database documenting the method of identification, radioisotope count, order of retrieval, and axillary level of SLNSs from 893 SLNBs was analyzed.


RESULTS
A median of 2 SLNSs (range 1-9) were removed per patient. More than 4 SLNSs were found in 8.0%. All SLNSs harboring the largest nodal metastases were identified within the first 4 harvested. Twenty-one percent (184 of 870) of patients had level II SLNSs; 4.9% (9 of 184) were positive. When SLNSs were positive in both levels I and II, the nodal metastases were always of greater or equal size in the level I nodes. Only one patient (0.5%) had a positive level II SLNS macrometastasis (> 2 mm, pN1), with a negative level I SLNS, but it was the hottest node and was removed first.


CONCLUSIONS
Removal of more than the first 4 hottest SLNSs does not improve staging accuracy. Level II nodes can be ignored if a hotter level I SLNS is first identified.
Boileau
Jean-François
JF
Department of Surgical Oncology, Princess Margaret Hospital, University Health Network and University of Toronto, Toronto, Ontario, Canada. boileaujf@hotmail.com
Easson
Alexandra
A
Escallon
Jaime M
JM
Leong
Wey L
WL
Reedijk
Michael
M
Youngson
Bruce J
BJ
McCready
David R
DR
D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision / Q000379:methods; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D021701:Sentinel Lymph Node Biopsy