Basic fibroblast growth factor in mesothelioma pleural effusions: Correlation with patient survival and angiogenesis

The expression of angiogenic factors may represent useful markers for diagn osis and prediction of disease outcome. Basic fibroblast growth factor (b-F GF) is a potent angiogenic factor which promotes in vitro growth of endothe lial cells and in vivo vessel formation. We investigated the expression of b-FGF in patients affected with malignant and non-malignant pleural disease s and presenting clinically with non-specific signs and symptoms. We also s tudied the relationships between the expression of b-FGF in patients with m alignant pleural mesothelioma (MM) and tumour aggressiveness, assessed as t umour vessel density (TVD), or patient survival. Basic-FGF was measured by immunoassay in the serum and pleural effusions (PE) of 37 patients. Of thes e, MM was diagnosed in 15/37 patients while the remaining patients had eith er peripheral lung adenocarcinoma (PLA) or benign inflammatory pleural dise ase (BPD). The mean b-FGF level measured 8.6 +/-6.1 pg/ml in the PE of the malignant group (MM + PLA) and 23.9 +/- 19.8 in the PE of the non-malignant group (BPD) (p=0.001). The mean b-FGF level was significantly lower in the PE of MM patients (6.9 +/-5.2 pg/ml) compared to BPD patients (p=0.004). L inear regression analysis showed a significant inverse correlation (r=-0.59 ; p=0.041) between b-FGF levels found in MM PE and patient survival. A note worthy relationship between high serum b-FGF levels and reduced survival wa s also observed (r=-0.57; p=0.052). Interestingly, both serum (r=0.48; p=0. 114) and PE (r=0.26; p=0.413) b-FGF levels in MM patients correlated poorly with TVD. Our data indicate that b-FGF is significantly more expressed in non-malignant compared to malignant PE, this difference being particularly evident between MM and BPD. Our results also suggest that high b-FGF levels correlate with poor MM patient survival through mechanisms which may be in dependent of b-FGF angiogenic potential.