Predicting the risk for additional axillary metastases in patients with breast carcinoma and positive sentinel lymph node biopsy.
OBJECTIVE
To assess whether the risk for nonsentinel node metastases may be predicted, thus sparing a subgroup of patients with breast carcinoma and a positive sentinel lymph node (SLN) biopsy completion axillary lymph node dissection (ALND).


BACKGROUND
The SLN is the only involved axillary lymph node in the majority of the patients undergoing ALND for a positive SLN biopsy. A model to predict the status of nonsentinel axillary lymph nodes could help tailor surgical therapy to those patients most likely to benefit from completion ALND.


METHODS
All the axillary sentinel and nonsentinel lymph nodes of 1228 patients were reviewed histologically and reclassified according to the current TNM classification of malignant tumors as bearing isolated tumor cells only, micrometastases, or (macro)metastases. The prevalence of metastases in nonsentinel lymph nodes was correlated to the type of SLN involvement and the size of the metastasis, the number of affected SLNs, and the prospectively collected clinicopathologic variables of the primary tumors.


RESULTS
In multivariate analysis, further axillary involvement was significantly associated with the type and size of SLN metastases, the number of affected SLNs, and the occurrence of peritumoral vascular invasion in the primary tumor. A predictive model based on the characteristics most strongly associated with nonsentinel node metastases was able to identify subgroups of patients at significantly different risk for further axillary involvement.


CONCLUSIONS
Patients with the most favorable combination of predictive factors still have no less than 13% risk for nonsentinel lymph node metastases and should be offered completion ALND outside of clinical trials of SLN biopsy without back-up axillary clearing.
Viale
Giuseppe
G
Department of Pathology and Laboratory Medicine, European Institute of Oncology, University of Milan School of Medicine, Milan, Italy. giuseppe.viale@ieo.it
Maiorano
Eugenio
E
Pruneri
Giancarlo
G
Mastropasqua
Mauro G
MG
Valentini
Stefano
S
Galimberti
Viviana
V
Zurrida
Stefano
S
Maisonneuve
Patrick
P
Paganelli
Giovanni
G
Mazzarol
Giovanni
G
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001365:Axilla / Q000473:pathology; D001943:Breast Neoplasms / Q000473:pathology* / Q000601:surgery; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009361:Neoplasm Invasiveness; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy