Evaluating angiogenic cytokines VEGF, basic FGF and TGF- β1 as tumor markers in ascites

Abstract

9627 Background: To differentiate between malignant and nonmalignant ascites is an important clinical problem for further diagnostic and therapeutic procedures. As the majority of angiogenic factors are soluble peptides secreted by tumors, their use have been proposed as tumor markers in effusions. Three angiogenic cytokines were dosed in ascites samples - Vascular Endothelial Growth Factor (VEGF), basic Fibroblast Growth Factor (bFGF) and Transforming Growth Factor - β1 (TGF- β1) - to evaluate their ability to discriminate malignant and nonmalignant etiologies and to establish a correlation between the three growth factors in these two groups. Methods: A total of 63 (32 malignant and 31 nonmalignant) ascites samples obtained from paracentesis were used. Concentrations of VEGF, basic FGF and TGF-β1 in ascites were determined with ELISA (Quantikine, R&D Systems) following the manufacturer’s guidelines and the samples were analyzed in duplicate. Differences between the two groups were tested with nonparametric Mann-Whitney U Test and the correlation between the cytokines was evaluated by Spearmann coefficient. Results: Significantly higher concentrations of VEGF were detected in ascites from patients with cancer, median = 1,265.9 pg/mL, than without cancer, median= 114.1pg/mL, P< 0.0001. Using a ROC curve a 662 pg/mL cut-off value was chosen and a 72% sensibility and 90% specificity was obtained. Only a borderline significant difference between the bFGF levels in malignant and nonmalignant ascites (P value=0.053) had been found, and the ROC curve did not established acceptable values either for sensitivity or specificity. However, when ascites samples from tuberculosis were excluded a significant difference between the two groups was detected and the same was observed in regard to the samples from ovarian cancer compared to those from other neoplasias. TGF-β1 median values were not significantly different between the two groups and once again the ROC curve failed to determine adequate values of sensitivity or specificity. No correlation between the three cytokines studied was found. Conclusions: VEGF but not basic FGF or TGF-β1 is a valuable tumor marker to discriminate between malignant and nonmalignant ascites. No significant financial relationships to disclose.