RESUMO
PURPOSE: Peritoneal metastasis is a crucial factor for the prognosis in gastric cancer, but its diagnosis is difficult before laparotomy. This study analyzed the usefulness of diagnostic imaging and various tumor markers in the detection of peritoneal metastasis in gastric cancer. MATERIALS AND METHODS: The sera from 768 patients with gastric cancer were measured for CEA, CA19-9 and CA125 levels using a commercial immunoradiometric assay. All the patients underwent diagnostic imaging with computed tomography (CT) and ultrasound (US) before laparotomy. RESULTS: Preoperative levels of CEA, CA19-9 and CA125 were above the cut-off levels in 15.4%, 8.7% and 5.7% of all cases, respectively. Eighty-eight patients were diagnosed with peritoneal metastasis by laparotomy. CT and US revealed peritoneal dissemination in 15 of 88 patients (17%). Among the three tumor markers, CA19-9 and CA125 showed similar detection rates of peritoneal metastasis (37.5% and 38.6%, respectively). In particular, the serum CA125 levels showed the best sensitivity (38.6%), specificity (98.4%), and diagnostic accuracy (91.5%), and the highest odd ratio (24.46, 95% CI: 11.17~53.57) for predicting peritoneal metastasis among the markers tested. CEA did not add significant predictive information (p=0.471). CONCLUSION: Preoperative serum CA19-9 and CA125 levels may provide a predictable value in determining peritoneal metastasis in patients with gastric cancer.