Tissue microarray-based study of patients with lymph node-negative breast cancer shows that HER2/neu overexpression is an important predictive marker of poor prognosis.
BACKGROUND
Despite good prognosis in most cases of lymph node (LN)-negative breast cancer, individual patients may have markedly different clinical outcomes. Here, we investigated the prognostic significance of HER2/neu overexpression in these tumors.


METHODS
We employed a tissue microarray to examine HER2/neu overexpression by immunohistochemical staining in 359 consecutive patients diagnosed with LN-negative breast cancer, who underwent surgery from January 1993 to December 1998.


RESULTS
HER2/neu overexpression was detected in 81 of 359 (23.1%) patients. The 10-year disease-free survival (DFS) values (81.2% versus 61.8%, P value 0.000) and overall survival (OS) rates (85.7% versus 63.9%, P value 0.000) were significantly different between cases with HER2/neu-negative or HER2/neu-positive tumors. After multivariate analysis, HER2/neu status and tumor size were identified as independent prognostic factors for 10-year OS. Moreover, HER2/neu overexpression was significantly associated with poorer clinical outcomes in an intermediate-risk group identified by the St Gallen classification (10-year DFS, 79.6% versus 61.8%, P value 0.000; 10-year OS, 84.7% versus 63.9%, P value 0.000).


CONCLUSIONS
Our results show that HER2/neu overexpression is an important independent prognostic factor for LN-negative breast cancer cases and support the theory that more intensive adjuvant chemotherapy is required in the population with HER2/neu overexpression.
Choi
Y H
YH
Department of Interanl Medicine, Asan Medical Center, University of Ulsan College of Medicine, Songpa-gu, Seoul, South Korea.
Ahn
J H
JH
Kim
S-B
SB
Jung
K-H
KH
Gong
G-Y
GY
Kim
M-J
MJ
Son
B-H
BH
Ahn
S-H
SH
Kim
W K
WK
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000096:biosynthesis*; D001943:Breast Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000473:pathology / Q000601:surgery; D018567:Breast Neoplasms, Male / Q000188:drug therapy / Q000201:enzymology / Q000473:pathology / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D046228:Microarray Analysis; D008875:Middle Aged; D015999:Multivariate Analysis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis*; D012307:Risk Factors; D015996:Survival Rate
D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases