Elevated Serum Vascular Endothelial Growth Factor and Basic Fibroblast Growth Factor Levels in Patients with Thymic Epithelial Neoplasms

Neovascularization, an essential event for the growth of solid tumors, is regulated by a number of angiogenic factors, among which vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF), are considered to exert potent angiogenic activity. In this study, we investigated whether serum VEGF and bFGF levels could be predictors of the development and extension of thymic epithelial neoplasms. The subjects of this study were 37 patients with thymoma, 6 with thymic carcinoma, and 23 healthy volunteers. Serum samples were collected before clinical treatment. Serum VEGF levels were significantly (P < 0.05) elevated in the patients with thymic carcinoma (1 080 ± 1 185 pg/ml) compared with those in the healthy volunteers (407 ± 589 pg/ml). Serum bFGF levels were also significantly (P < 0.05) elevated in the patients with thymic carcinoma (2 740 ± 631 pg/ml) compared with those in the healthy volunteers (1 728 ± 1 192 pg/ml). However, the serum VEGF and bFGF levels did not significantly differ between the patients with thymoma and the healthy volunteers. Serum VEGF and bFGF levels did not significantly differ according to the stage and pathological subtype of thymoma. Moreover, there was no correlation between the serum levels of VEGF and those of bFGF. Thus, while serum VEGF and bFGF levels may serve as markers for thymic epithelial tumors, it is unlikely that circulating VEGF and bFGF could be used as markers for assessing the progression of thymoma tumors. Received: November 10, 2000 / Accepted: May 15, 2001