Diagnostic algorithm based on ratio of ascites-serum tumor markers is superior to tumor markers in the differentiation of benign ascites from malignant ascites

BackgroundDifferential diagnosis between benign ascites and malignant ascites remains challenging in clinical practice, the aim of our study is to determine the differential value of the ratio of ascitic-serum tumor markers between benign ascites and malignant ascites.Methods418 patients with new-onset ascites were retrospectively enrolled in this study. The pertinent data of patients enrolled were collected; diagnostic value of tumor markers, ascites-serum tumor marker ratio, and diagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio in patients with ascites were investigated.Results81.25% of the patients with benign ascites had low (<1) ratio of ascites-serum tumor markers (Max [A/S CEA, A/S CA15–3, A/S CA19–9]); and 91.88 % of patients with benign ascites had the ratio of ascites-serum tumor marker less than 1.5. On the other hand, 94.96% of the patients with malignant ascites had high (≥1) ratio of ascites-serum tumor markers; and 97.29% of patients with malignant ascites had the ratio of ascites-serum tumor markers more than 0.67. Finally, diagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio showed 96.37% of the sensitivity, and 94.37% of the accuracy in the diagnosis of malignant ascites, while ascitic tumor markers with a sensitivity of 78.29%, and an accuracy of 84.93%.ConclusionsDiagnostic algorithm based on ascitic tumor markers and ascites-serum tumor marker ratio exhibited an excellent performance in distinguishing benign and malignant ascites, which should be recommended in patients with new‐onset ascites in clinical practice.