Size of breast cancer metastases in axillary lymph nodes: clinical relevance of minimal lymph node involvement.
BACKGROUND
Overt ipsilateral axillary lymph node metastases of breast cancer are the most significant prognostic indicators for women who have undergone surgery, yet the clinical relevance of minimal involvement (isolated tumor cells and micrometastases) of these nodes is uncertain.


METHODS
We evaluated biologic features, adjuvant treatment recommendations, and prognosis for 1,959 consecutive patients with pT1-3, pN0, minimal lymph node involvement (pN1mi or pN0i+), or pN1a (single positive node) and M0, who were operated on and counseled for medical therapy from April 1997 to December 2000.


RESULTS
Patients with pN1a and pN1mi/pN0i+, when compared with patients with pN0 disease, were more often prescribed anthracycline-containing chemotherapy (39.1% v 33.2% v 6.1%, respectively; P < .0001) and were less likely to receive endocrine therapy alone (9.8% v 19.4% v 41.9%, respectively; P < .0001). At the multivariate analysis, a statistically significant difference in disease-free survival (DFS) and in the risk of distant metastases was observed for patients with pN1a versus pN0 disease (hazard ratio [HR] = 2.04; 95% CI, 1.46 to 2.86; P < .0001 for DFS; HR = 2.32; 95% CI, 1.42 to 3.80; P = .0007 for distant metastases) and for patients with pN1mi/pN0i+ versus pN0 disease (HR = 1.58; 95% CI, 1.01 to 2.47; P = .047 for DFS; HR = 1.94; 95% CI, 1.04 to 3.64; P = .037 for distant metastases).


CONCLUSIONS
Even minimal involvement of a single axillary node in breast cancer significantly correlates with worse prognosis compared with no axillary node involvement. Further studies are required before widespread modification of clinical practice.
Colleoni
Marco
M
Division of Medical Oncology, Department of Medicine, Istituto Europeo di Oncologia, Via Ripamonti 435, 20141, Milan, Italy. marco.colleoni@ieo.it
Rotmensz
Nicole
N
Peruzzotti
Giulia
G
Maisonneuve
Patrick
P
Mazzarol
Giovanni
G
Pruneri
Giancarlo
G
Luini
Alberto
A
Intra
Mattia
M
Veronesi
Paolo
P
Galimberti
Viviana
V
Torrisi
Rosalba
R
Cardillo
Anna
A
Goldhirsch
Aron
A
Viale
Giuseppe
G
D000328:Adult; D001365:Axilla; D001943:Breast Neoplasms / Q000188:drug therapy / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis / Q000473:pathology*; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D011379:Prognosis