Serum CA 125 level as a predictor of peritoneal dissemination in patients with gastric carcinoma

BACKGROUND. Prediction of peritoneal dissemination is very difficult using current diagnostic tools such as computed tomography, ultrasonography, or V arious tumor markers. The predictive Value of serum CA 125 levels for perit oneal metastasis from gastric carcinoma was studied. METHODS, The sera from 384 patients with gastric carcinoma were measured fo r CA 125 titer using an immunoradiometric assay. Carcinoembryonic antigen, carbohydrate antigen 19-9, and sialyl-Tn antigen were measured in the same samples. RESULTS. The serum CA 125 level was elevated according to the degree of per itoneal dissemination. The reference value for peritoneal dissemination uas determined to be 35 U/mL, resulting in a sensitivity of 39.4%, specificity of 95.7%, and diagnostic accuracy of 90.8%. The diagnostic ability was mor e reliable than the other imaging modalities including computed tomography and ultrasonography and the other useful tumor markers for gastric carcinom a. The serum CA 125 level was elevated after gastrectomy for approximately 2 months, most likely due to the continuous inflammation of the peritoneum and lost predictive significance for peritoneal dissemination during this p eriod. CONCLUSIONS. Measurement of the serum CA 125 titer may be a powerful predic tor of peritoneal metastases in patients with gastric carcinoma. Cancer 199 8;83: 2488-92. (C) 1998 American Cancer Society.