EVALUATION OF FIBRONECTIN AS A MARKER OF MALIGNANT ASCITES

The aim of the study was to assess the accuracy of fibronectin, a glycoprotein, for the diagnosis of malignant ascites and to compare it with conventional parameters. Ascitic fluid samples from 50 patients, 25 with intra-abdominal malignancy and 25 without it were analysed for total protein concentration, fluid/serum protein ratio, glucose concentration, leucocyte count, pH, fibronectin concentration (by ELISA) and for malignant cell cytology. Twenty-two of the 25 patients with ascites and intra-abdominal malignancy had documented peritoneal metastases in group A. The 25 patients with non-malignant ascites constituted group B. Mean values of ascitic fluid fibronectin, for groups A and B were 538 +/- 46-mu-g/mL and 60 +/- 4.92-mu-g/mL, respectively (P < 0.001). Within the group with malignant ascites, patients who had positive malignant cytology (n = 12) exhibited a significantly higher ascitic fluid fibronectin concentration than patients with negative cytology (P < 0.05). While mean ascitic fluid protein concentration showed a significant difference (P < 0.01) between the two groups, there was no difference in respect to ascitic fluid pH, glucose concentration and leucocyte count. Malignant cell cytology was positive in 54.5% of group A patients with no false positive report in group B. The diagnostic accuracy for differentiating malignant from non-malignant ascites was 100% for a fibronectin value of greater-than-or-equal-to 110-mu-g/mL as compared with 78.7% for ascitic fluid protein concentration greater-than-or-equal-to 0.5 g/dL, 57.4% for leucocyte count greater-than-or-equal-to 1000/mm3, 56.6% for pH < 7.45 and 78.7% for malignant cell cytology.