Clinical value of tumor biomarkers in ascitic fluid and serum in differentiating benign from malignant ascites and their correlation

Abstract

Objective To evaluate clinical value of tumor biomarkers in ascitic fluid and serum in differentiating benign from malignant ascites and their correlation. Methods From July 2006 to July 2009,67 patients with ascites undergone abdominal paracentesis in Renmin Hospital of Wuhan University were enrolled in the study and divided into malignant and benign groups according to their etiology. Levels of tumor biomarkers in ascitic fluid and serum were determined and their correlation were analyzed. Diagnostic sensitivity and specificity of tumor markers were evaluated. Results There was statistically significant difference in levels of cancer antigen 199 (CA199) in serum and ascitic fluid between the malignant group and the benign one ( P ＜ 0. 01 ), and level of cancer embryonic antigen (CEA) significantly increased in ascitic fluid (P ＜ 0.05 ). Levels of CA199 and CEA in serum were significantly higher than those in ascetic fluid in the benign group (P ＜ 0. 01 and P ＜ 0. 05 ), and level of CA125 was significantly lower in serum than that in ascitic fluid (P ＜ 0. 01 ). Level of alpha-fetal protein (AFP) in serum significantly correlated with that in ascitic fluid in the benign group (r =-0. 992, P ＜0. 01 ). In the malignant group, levels of CA199, CEA and CA125 were significantly higher in ascitic fluid than those in serum (P ＜0.05 or P ＜0. 01 ). Levels of CA199 and CEA in serum significantly correlated with those in ascetic fluid in the malignant group (r =0. 746 and 0. 572, respectively, P ＜0. 01 ), and level of AFP in serum also correlated with that in ascetic fluid (r=0. 384, P ＜0. 05). Ratios of levels of CA199 and CEA in ascetic fluid to those in serum (F/S) were significantly higher in the malignant group than those in the benign group (P ＜0.05 or P ＜0.01). Use of combination of CA199, CEA and CA125 determinations showed a higher sensitivity and specificity in differential diagnosis for benign and malignant ascites (P ＜0.05). Conclusions Determinations of CA199 and CEA are beneficial for differentiating benign ascites from malignant one. Determinations of tumor biomarkers in serum can not fully replace those in ascetic fluid. Combined determinations of CA199, CEA and CA125 can increase their sensitivity and specificity in diagnosis for malignant ascites. Key words: Tumor marker, biological; Ascites; Serum