HER-2 gene amplification correlates with higher levels of angiogenesis and lower levels of hypoxia in primary breast tumors.
OBJECTIVE
This study investigated the connection among HER-2 gene amplification, HER-2 protein expression, and markers of tumor angiogenesis and oxygenation in patients with operable, invasive breast tumors.


METHODS
From 1988 to 1995, 425 patients with metastatic breast cancer were enrolled in a study of high-dose chemotherapy with autologous transplant. Primary tumor blocks were obtained and evaluated using immunohistochemistry (IHC) staining of vessels with von Willebrand factor antibody. Mean microvessel densities (MVD) were determined by counting von Willebrand factor stained cells in three separate "vascular hot spots" using image analysis. Tumor samples were also stained for HER-2 by IHC, HER-2 gene amplification by fluorescence in situ hybridization, carbonic anhydrase 9 by IHC, and vascular endothelial growth factor (VEGF) by IHC. Plasma from 36 patients with primary tumor samples had VEGF (R&D Systems, MN) and d-dimer (American Diagnostica, Greenwich, CT) levels determined.


RESULTS
There was a significant positive correlation between HER-2 gene amplification and both maximum and average MVD (Spearman coefficient = 0.51 and 0.50; P = 0.03 and 0.05, respectively). There was an inverse correlation with HER-2 gene amplification and expression of the tumor hypoxia marker CA-9 (chi(2) P = 0.02). The level of HER-2 gene amplification correlated with plasma d-dimer levels (Spearman coefficient = 0.43; P = 0.021). Interestingly, tumors with HER-2 by IHC had decreased amounts of VEGF staining (chi(2) = 5.81; P = 0.01). There was no correlation between HER-2 by IHC and MVD or d-dimer. Of all of the variables examined, only average (P = 0.0016) and maximum MVD (P = 0.0128) predicted disease-free survival (Cox univariate model).


CONCLUSIONS
HER-2-amplified breast cancers have increased amounts of angiogenesis, decreased amounts of hypoxia, and increased markers of fibrin degradation. These findings have prognostic, predictive, and therapeutic implications in breast cancer treatment.
Blackwell
Kimberly L
KL
Duke University Comprehensive Cancer Center, Durham, North Carolina, USA. black034@mc.duke.edu
Dewhirst
Mark W
MW
Liotcheva
Vlayka
V
Snyder
Stacey
S
Broadwater
Gloria
G
Bentley
Rex
R
Lal
Anita
A
Riggins
Gregory
G
Anderson
Steve
S
Vredenburgh
Jim
J
Proia
Alan
A
Harris
Lyndsay N
LN
D001943:Breast Neoplasms / Q000473:pathology*; D002256:Carbonic Anhydrases / Q000096:biosynthesis; D018572:Disease-Free Survival; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005337:Fibrin / Q000378:metabolism; D005338:Fibrin Fibrinogen Degradation Products / Q000096:biosynthesis; D006801:Humans; D000860:Hypoxia; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008833:Microcirculation; D009369:Neoplasms / Q000473:pathology; D009389:Neovascularization, Pathologic; D010100:Oxygen / Q000378:metabolism; D011379:Prognosis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000737:chemistry*; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D014841:von Willebrand Factor / Q000378:metabolism
D002256:Carbonic Anhydrases; D005337:Fibrin; D005338:Fibrin Fibrinogen Degradation Products; D010100:Oxygen; D018719:Erb-b2 Receptor Tyrosine Kinases; D042461:Vascular Endothelial Growth Factor A; D014841:von Willebrand Factor; C036309:fibrin fragment D