Tumor Marker Kinetics as Prognosticators in Patients with Unresectable Gallbladder Adenocarcinoma Undergoing Palliative Chemotherapy

BACKGROUND/AIMS: To determine the prognostic value of carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in gallbladder cancer (GBC) during palliative chemotherapy. METHODS: One hundred and twenty-three patients with pathologically confirmed unresectable GBC were included. Differences in serum CEA and CA 19-9 levels before and after chemotherapy were measured. Receiver operating characteristic curve analysis, Kaplan-Meier analyses of CEA, CA 19-9, and combined changes were performed to assess the optimal cutoff values and survival rates. RESULTS: Patients with decreased tumor markers had significantly better progression-free survival (PFS) and overall survival (OS) than patients with increased tumor markers. The pre- and postchemotherapy CA 19-9 ratio had the highest area-under-the-curve values for predicting 3-month PFS and 1-year OS. In the multivariate analysis, increases in serum CA 19-9 during palliative chemotherapy in patients with unresectable GBC was an independent prognosticator of poor PFS and OS, with hazard ratios of 2.20 (p=0.001) and 1.67 (p=0.020), respectively. Patients with increases >10-fold were considered to have progressive disease, whereas individuals with increases >3-fold were likely to benefit from early imaging follow-up. CONCLUSIONS: CA 19-9 kinetics was a reliable prognosticator of PFS and OS in patients with unresectable GBC who underwent palliative chemotherapy.