The Clinical Study Of The Staging Of Endoscopic Ultrasonography In Gastrointestinal Tumors And The Diagnostic Value Of CEA And CA199 In Ascitic Fluid

BackgroundEUS (Endoscopic ultrasonography, EUS) has a special advantage in assessing whether the tumor is outside the esophageal wall and regional lymph node metastasis. The evaluation TN staging of esophageal cancer by HFUS has been reported in China, but there is no application of mechanical radial scanning EUS to assess TN staging of esophageal cancer. In addition, ascitic fluid cytology diagnosing malignant ascites is one of the golden standards, but the positive rate is often less than 50%. When the tumor cells shed less into ascites and / or it is impossible to distinguish the reactive mesothelial cells by conventional methods, the cytology could not make a definite diagnosis. Therefore, we need other clinical examinations to achieve diagnosis. Ascitic fluid CEA and CA199 has been used for the diagnosis of malignant ascites, but its diagnostic value is not yet clear in uncertain malignant ascites. ObjectiveTo study the clinical value of mechanical scanning EUS in preoperative TN staging of esophageal cancer compared with postoperative pathology. To study the diagnostic value of ascitic fluid CEA and CA199 in uncertain malignant ascites by the use of receiver operating characteristic curve.MethodsSelecting 101 patients with endoscopic pathologic diagnosis and surgical treatment of esophageal cancer. All patients were performed by mechanical radial scanning EUS before surgery. Compared with the pathological stage of esophageal cancer after surgery, the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy were calculated in EUS TN staging of esophageal cancer. The accuracy of preoperative EUS TN staging was evaluated.Collections of ascitic fluid date from 86 patients with an identifiable cause of ascites. Before the diagnosis all patients had undergone ascitic fluid cytology and CEA, CA199 concentrations. The sensitivity and specificity of ascitic fluid CEA, CA199 were calculated in uncertain malignant ascites by building receiver operating characteristic curve of ascitic fluid CEA, CA199 and choosing the best cutoff values.ResultsEUS accurately assessed T stage in 81% of patients with esophageal cancer .The sensitivity and specificity to predicte T1 stage were respectively 79% and 100%, 71% and 95% predicting T2 stage, 98% and 75% predicting T3 stage, 57% and 99% predicting T4 stage. EUS accurately assessed N stage in 68% of patients with esophageal cancer. The sensitivity and specificity to predicte N0 and N1 stage were respectively 49% and 100%, 100% and 49%. In 11 patients with nontraversed tumors , 8 patients were correctly assessed in preoperative EUS T staging. If 11 patients with nontraversed tumors were not included, The sensitivity of EUS predicting limited and locally advanced disease was 88%.In 86 patients with ascites, the diagnostic sensitivity and specificity of ascitic fluid cytology were 20.9% and 100%. The level of ascitic fluid CEA and CA199 in malignant ascites were significantly higher than that of benign ascites,the difference of which was statistically significant (P value <0.05). The area under the ROC curve of ascitic fluid CEA and CA199 were 0.86 and 0.76. Using CEA>2.5ng/ml and CA199>20u/ml as positive cutoff values, the sensitivity and specificity to diagnose malignant ascites were 69.7% and 90.6%, 55.8% and 90.6% respectively. In uncertain malignant ascites, the diagnostic sensitivity were 67.6% in CEA and 58.8% in CA199. Similarly, the diagnostic sensitivity was improved to 76.5% by the combination of CEA and CA199 in uncertain malignant ascites.ConclusionsMechanical radial scanning EUS accurately predicted T and N stage in preoperative patients with esophageal cancer,and also exhibited high differential accuracy in limited and locally advanced disease,which were valuable in clinical managements of esophageal cancer.Ascitic fluid cytology had high specificity in the diagnosis of malignant ascites , but the sensitivity was low. In the uncertain malignant ascites, ascitic fluid CEA and CA199 had a higher auxiliary diagnostic value.