Diagnosis of malignant versus tuberculous ascites using tumor markers and globulin ratios in serum and ascites: A Fisher discriminant model

BACKGROUND AND STUDY AIMS

This study was conducted to investigate the significance of tumor and biochemical markers in serum and ascitic fluid in the differential diagnosis of tuberculous and malignant ascites.

PATIENTS AND METHODS

Based on findings from natural orifice transluminal endoscopic surgery and postoperative pathology or cytology of 63 patients, they were divided into the malignant group (31 patients) and the tuberculous group (32 patients). Levels of tumor markers, albumin, globulin, and lactate dehydrogenase were measured simultaneously. Data were statistically analyzed, and a Fisher discriminant model was established. The receiver operating characteristic curve was constructed to confirm the discriminant value.

RESULTS

The levels of carcinoembryonic antigen (CEA), cancer antigen 125 (CA125), cancer antigen 19-9 (CA 19-9), and globulin in serum and ascitic fluid were different between the tuberculous and malignant ascites groups (P < .05). The ratios of ascites-to-serum levels of CEA, CA125, and CA 19-9, as well as the ratio of serum-to-ascites of globulin levels, were different between the two groups (P < .05). The Fisher discriminant model was established based on the ascites-to-serum ratios of CEA, CA125, and CA 19-9 levels and the serum-to-ascites ratio of globulin levels. The area under the curve was 0.908, the sensitivity was 0.838 (26/31), and the specificity was 0.875 (28/32).

CONCLUSION

A Fisher discriminant model can be established using serum and ascites tumor markers and globulin ratios, which is valuable in the differential diagnosis of tuberculous versus malignant ascites.

Value of measurement of gradient and ratio of ascites-serum tumor markers in differential diagnosis of tuberculous ascites and malignant ascites

AIM

To assess the value of measurement of the gradient and ratio of ascites-serum tumor markers in the differential diagnosis of tuberculous ascites and malignancy-related ascites.

METHODS

Sixty patients with ascites were divided into two groups, namely, 31 cases of malignant ascites and 31 cases of tuberculous ascites. Tumor markers in serum and ascites were simultaneously detected to calculate and compare the gradient and ratio of serum-ascites tumor markers between the two groups.

RESULTS

The positive rates of CEA and CA199 in the malignant group were significantly higher than those of the tuberculosis group (P < 0.01). The positive rates of CA125 and α-fetoprotein (AFP) showed no significant difference between the two groups (P > 0.05). Ratio analysis of tumor markers in ascites and serum revealed that CA125, CA199, and CEA ratios were statistically significant between the two groups, with CA125 ratio having the most significant difference (P < 0.01). Ascites-serum gradient analysis showed that CA125, CEA, and CA199 gradients were significantly different between the two groups (P < 0.01). The ratio and gradient of AFP were not significantly different between the two groups (P > 0.05).

CONCLUSION

At the cutoff values of CA125 ratio > 2.16, CA125 gradient > 264.05 ng/mL, CEA ratio > 4.8, CEA gradient > 23.05 ng/mL, CA199 ratio > 0.96, and CEA gradient > -0.20 ng/mL, the diagnostic value of combining the gradients and ratios of the three tumor markers are more helpful to distinguish tuberculous ascites and non-liver cancer ascites than any of the three markers alone.