The role of cystatin C and the angiogenic cytokines VEGF and bFGF in patients with esophageal carcinoma.

Angiogenesis is the formation of new blood vessels out of the existing vascular bed. Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are potent circulating angiogenic factors, whereas cystatin C is one of the most important extracellular inhibitors of several cysteine proteinases. Because proteases degrade interstitial connective tissue and basement membranes during tumor growth and metastasis, an association between cystatin C and the angiogenic factors seems plausible. The primary aim of the present study was to investigate if such a correlation exists between these serum markers. The secondary aim was to determine the prognostic value of these circulating cytokines and cystatin C, collected prior to therapy, in patients with esophageal carcinoma.A total of 42 patients with esophageal carcinoma donated serum samples prior to therapy. VEGF and bFGF were correlated to platelet and leukocyte counts and VEGF was correlated to tumor volume (p = 0.04), whereas bFGF was not (p = 0.08). VEGF was significantly correlated with cystatin C (p = 0.027). Survival analysis showed that VEGF regarded as a continuous variable was associated with a significantly poorer survival in the univariate analysis (p = 0.023); however, this was not found for bFGF (p = 0.46). Neither of the angiogenic factors were associated with survival in the multivariate analysis. In the univariate analysis, cystatin c was correlated with survival (p = 0.01), but this was not found in the multivariate analysis (p = 0.28). In conclusion, VEGF was correlated with cystatin C, possible explanations being discussed in the present article. Results of the present study indicate that use of the angiogenic factors as prognostic factors, prior to therapy in patients with esophageal carcinoma, appears limited.