Risk factors for non-sentinel lymph node metastases in patients with breast cancer. The outcome of a multi-institutional study.
BACKGROUND
In this multi-institutional prospective study, we evaluated whether we could identify risk factors predictive for non-sentinel lymph node (non-SN) metastases in breast cancer patients with a positive sentinel lymph node (SN).


METHODS
In this multi-institutional study, 541 eligible breast cancer patients were included prospectively.


RESULTS
The occurrence of non-SN metastases was related to the size of the SN metastasis (P = .02), primary tumor size (P = .001), and lymphovascular invasion (P = .07). The adjusted odds ratio was 3.1 for SN micro-metastasis compared with SN isolated tumor cells, 4.0 for SN macro-metastasis versus SN isolated tumor cells, 3.1 for tumor size (>3.0 cm compared with </=3.0 cm), and 2.0 for lymphovascular invasion (yes versus no). There were no positive non-SNs when the primary tumor size was </=1.0 cm (n = 24) [95% confidence interval (95% CI) 0%-14.0%]. The proportion of positive non-SNs ranged in a prognostic logistic regression model from 9.7% (95% CI 4.0%-23.0%) for patients with SN isolated tumor cells, tumor size of 1.1-3.0 cm, and without vessel invasion, to 72.6% (95% CI 47.0%-89.0%) for patients with SN macro-metastasis, tumor size >3.0 cm, and with vessel invasion.


CONCLUSIONS
We identified three predictive factors for non-SN metastases in breast cancer patients with a positive SN: size of the SN metastasis; primary tumor size; and vessel invasion. We were not able to identify a specific group of patients with a positive SN in whom the risk for non-SN metastases was less than 5%.
Bolster
Marieke J
MJ
Department of Surgery, Radboud University Nijmegen Medical Center (MC), Nijmegen, The Netherlands.
Peer
Petronella G M
PG
Bult
Peter
P
Thunnissen
Frederik B J M
FB
Schapers
René F M
RF
Meijer
Jos W R
JW
Strobbe
Luc J A
LJ
van Berlo
Charles L H
CL
Klinkenbijl
Jean H G
JH
Beex
Louk V A M
LV
Wobbes
Theo
T
Tjan-Heijnen
Vivianne C G
VC
D000328:Adult; D000368:Aged; D001365:Axilla; D001943:Breast Neoplasms / Q000473:pathology*; D005260:Female; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008875:Middle Aged; D012307:Risk Factors; D021701:Sentinel Lymph Node Biopsy