CA125, CEA, CA19-9, and Heteroploid Cells in Ascites Fluid May Help Diagnose Peritoneal Carcinomatosis in Patients with Gastrointestinal and Ovarian Malignancies

BACKGROUND: This study explored the value of ascites and serum CA125, CEA, and CA19-9 levels and ascites DNA ploidy analysis for the diagnosis of peritoneal carcinomatosis (PC) in patients with gastrointestinal and ovarian malignancies, which can cause ascites and may disseminate peritoneally. METHODS: We measured ascites and serum levels of CA125, CEA, CA19-9 and performed an ascites DNA ploidy analysis in 58 patients with PC and 44 patients without PC. RESULTS: We found that a high expression level of CA125 in ascites fluid was associated with the occurrence of PC in patients with gastrointestinal and ovarian malignancies (P<0.001), and that high CEA and CA19- 9 levels in ascites fluid were associated with PC in patients with gastrointestinal malignancies (P=0.001, P=0.002). But, these tumor marker expression levels in ascites fluid were not significantly associated with the PC stage (P>0.05). We found similar serum levels of CA125, CEA, and CA19-9 between patients with gastrointestinal and ovarian malignancies and PC and those without PC (P>0.05). We found that the presence of three or more cells with heteroploid in the ascites samples was significantly associated with PC in gastrointestinal and ovarian malignancies (P<0.001). In addition, the best ROC curves and highest AUCs were achieved by combining the CA125 level and heteroploid cell analysis results (AUC for gastrointestinal and ovarian malignancies, 0.815, AUC for gastrointestinal malignancies, 0.873). Moreover, the combined ascites CA125 level and result of heteroploid cell analysis provided the best diagnostic sensitivity and specificity for PC (75.9% and 79.5%, respectively, in gastrointestinal and ovarian malignancies; 85.0% and 86.7%, respectively, in gastrointestinal malignancies). CONCLUSION: Ascites levels of CA125, CEA, CA19-9, and heteroploid cells can be considered valuable markers for the diagnosis of PC in patients with gastrointestinal and ovarian cancer.