Role of VEGF and CD44v6 in differentiating benign from malignant ascites

Abstract

Aim: To detect the vascular endothelial growth factor (VEGF) and soluble splice variant 6 of CD44 (sCD44v6) levels in ascites and to explore their role in differentiating benign from malignant ascites.

Methods: Cirrhotic ascites (n=36), tuberculosis ascites (n=8) and malignant ascites (n=23) were collected and studied. Concentrations of soluble VEGF and sCD44v6 in various kinds of ascites (n=67) were measured using a sandwich enzyme-linked immunoadsorbent assay.

Results: VEGF and sCD44v6 levels in malignant ascites were 640.74+/-264.81 pg/ml and 89.22+/-38.20 ng/ml, respectively, both of which were significantly higher than those in cirrhotic ascites and tuberculous ascites (q=18.98, 11.89 and q=8.92, 5.09; P<0.01). However, the levels of VEGF and sCD44v6 in cirrhotic and tuberculous ascites had no significant difference (q=0.48, 0.75; P>0.05). Furthermore, VEGF levels in malignant ascites in patients with ovarian cancer were higher than those with gastric and colon cancer (q=5.03, 6.79; P<0.01, respectively). But differences of VEGF levels between gastric and colon cancer were not significant (q=1.90, P>0.05). Whereas, sCD44v6 levels in malignant ascites from patients with ovarian, gastric and colon cancer had no significant difference (q=0.06, 0.91, 0.35; P>0.05, respectively). In comparison with cirrhotic and tuberculous ascites, when the upper limit of its VEGF mean levels 119.44 pg/ml (70.90+/-48.54) and sCD44v6 mean levels 63.59 ng/ml (44.42+/-19.17) was taken as the minimum cutoff limit, the sensitivity and specificity of VEGF and sCD44v6 of this assay to the diagnosis of malignant ascites were 91.3%, 90.9% and 73.9%, 88.7% respectively.

Conclusion: Elevated levels of VEGF and sCD44v6 may be useful in differential diagnosis of benign and malignant ascites.

Figure 1

Comparison of VEGF concentrations in different kinds of ascites. Group 1: cirrhotic ascites, Group 2: tuberculous ascites, Group 3: malignant ascites.

Figure 2

Comparison of sCD44v6 concentrations in different kinds of ascites. Group 1: cirrhotic ascites, Group 2: tuberculous ascites, Group 3: malignant ascites. Concentrations of sCD44v6 in group 3 were significantly higher than those in groups 1 and 2 (P < 0.01).

Figure 3

Concentrations of VEGF and sCD44v6 in different kinds of malignant ascites. Group A: ovarian cancer; Group B: gastric cancer; Group C: colon cancer. Concentrations of VEGF in group A were higher than those in groups B and C (P < 0.01), while the difference of CD44v6 levels among groups A, B and C was not statistically significant (P > 0.05).