Differential diagnosis of liver metastases of gastrointestinal stromal tumors from colorectal cancer based on combined tumor biomarker with features of conventional ultrasound and contrast-enhanced ultrasound.

Abstract

To explore the value of tumor marker CA125 and CEA linked with conventional ultrasound (US) and contrast-enhanced ultrasound (CEUS) features in differentiating gastrointestinal stromal tumors liver metastases (GISTLM) from colorectal cancer liver metastases (CRCLM). From December 2005 to February 2019, eighty patients with pathologically proven GISTLM together with 80 CRCLM patients were retrospectively evaluated with contrast-enhanced ultrasound (CEUS). Clinical characteristics such as CA125 and CEA were documented to compare the difference between GISTLM and CRCLM. Univariate analysis was performed to determine significant features in ultrasound and then these features were entered into multivariate logistic regression model to determine diagnostic criteria. By analyzing the tumor marker and imaging features, diagnostic performance was evaluated via receiver-operating characteristic (ROC) analysis. The sensitivity, specificity and accuracy were calculated for the diagnosis of GISTLM. Multiple logistic regression analysis showed that increased CA125 and normal CEA were the independent variables of GISTLM. On conventional US, the features of hypo- or mix-echogenicity and anechoic area were associated with GISTLM. On CEUS, capsule enhancement, starting time of washout > 40s and proportion of non-enhancement area > 20% were the features indicating GISTLM. All of the p values were < 0.05. When linking tumor marker with imaging features, the diagnostic sensitivity improved from 36.3-57.5% to 70.0%, and the area under the ROC (AUROC) curve improved from 0.681-0.750 to 0.838, with a specificity of 97.5%. Combining the imaging features of conventional US and CEUS with serum tumor markers provides a potentially effective diagnostic method in differentiation of GISTLM and CRCLM.