The objective of this study was to analyze site-related expression of angiogenic molecules in
breast carcinoma, with the aim of characterizing phenotypic alterations along the
clinical progression from primary
tumor to
pleural effusion. A total of 49
malignant pleural effusions and 68 corresponding solid
tumors were studied for
protein and
mRNA expression of
vascular endothelial growth factor (
VEGF) and its receptor KDR,
interleukin-8 (IL-8),
basic fibroblast growth factor (bFGF) and the
alphaV integrin subunit using immunohistochemistry,
mRNA in situ hybridization (ISH) and reverse transcription polymerase chain reaction (RT-PCR). Expression was analyzed for possible association with
mRNA expression of the Ets-1 and PEA3
transcription factors. The predictive value of angiogenic molecules, PEA3 and Ets-1, and clinical parameters was analyzed for 18 patients. ISH showed the presence of
VEGF,
IL-8 and bFGF
mRNA in the majority of specimens, irrespective of anatomic site (p > 0.05). However,
protein expression of
IL-8 and bFGF was lower in effusions compared to primary
tumors (p = 0.001 for IL-8, p < 0.001 for bFGF). Expression of
alphaV integrin showed an opposite change, with higher level in effusions compared to primary
tumors (p = 0.03). bFGF and
alphaV integrin expression in effusions was also altered compared to
lymph node metastases (p = 0.041 and p = 0.016, respectively).
IL-8 and Ets-1 (p = 0.035) and
VEGF and PEA3 (p = 0.026)
mRNA was co-expressed in effusions. In univariate survival analysis, bFGF
protein expression in effusions (p = 0.015), PEA3
mRNA expression in primary
tumors (p = 0.02) and previous
radiation therapy (p = 0.034) predicted shorter disease-free survival. PEA
mRNA expression in primary
tumors (p = 0.002) and previous
chemotherapy (p = 0.048) predicted poor overall survival, with a similar trend for advanced disease stage at diagnosis (p = 0.05). Our data provide evidence regarding molecular changes that occur along the progression of
breast carcinoma from primary
tumor to effusion, and suggest altered requirement of angiogenic factors in body cavities. The poor disease-free survival for patients with bFGF-positive effusions suggests a role for this
growth factor in mediating
tumor survival rather than angiogenesis at this site.