A nomogram predictive of non-sentinel lymph node involvement in breast cancer patients with a sentinel lymph node micrometastasis.
OBJECTIVE
Predictive factors of non-sentinel lymph node (NSN) involvement at axillary lymph node dissection (ALND) have been studied in the case of sentinel node (SN) involvement, with validation of a nomogram. This nomogram is not accurate for SN micrometastasis. The purpose of our study was to determine a nomogram for predicting the likelihood of NSN involvement in breast cancer patients with a SN micrometastasis.


METHODS
We collated 909 observations of SN micrometastases with additional ALND. Characteristics of the patients, tumours and SN were analysed.


RESULTS
Involvement of SN was diagnosed 490 times (53.9%) with standard staining (HES) and 419 times solely on immunohistochemical analysis (IHC) (46.1%). NSN invasion was observed in 114 patients (12.5%), whereas 62.3% (71) had only one NSN involved and 37.7% (43) two or more NSN involved. In multivariate analysis, significant predictive factors were: tumour size (pT stage < or = 10 mm or >11 and < or = 20 or >20 mm [odds ratio (OR) 2.1 and 3.43], micrometastases detected by HES or IHC [OR 1.64], presence or absence of lymphovascular invasion (LVI) [OR 1.76], tumour histological type mixed or not [OR 2.64]. The rate and probability of NSN involvement with the model are given for 24 groups, with a representation by a nomogram.


CONCLUSIONS
One group, corresponding to 10.1% of the patients, was associated with a risk of NSN involvement of less than 5%, and five groups, corresponding to 29.8% of the patients, were associated with a risk < or = 10%. Omission of ALND could be proposed with minimal risk for a low probability of NSN involvement.
Houvenaeghel
G
G
Institut Paoli Calmettes, Marseille, France. houvenag@marseille.fnclcc.fr
Nos
C
C
Giard
S
S
Mignotte
H
H
Esterni
B
B
Jacquemier
J
J
Buttarelli
M
M
Classe
J-M
JM
Cohen
M
M
Rouanet
P
P
Penault Llorca
F
F
Bonnier
P
P
Marchal
F
F
Garbay
J-R
JR
Fraisse
J
J
Martel
P
P
Fondrinier
E
E
Tunon de Lara
C
C
Rodier
J-F
JF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008875:Middle Aged; D008954:Models, Biological; D049451:Nomograms; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D021701:Sentinel Lymph Node Biopsy