PTH-114 Usefulness of pre-treatment serum CA19-9 concentration in prediction of prognosis for patients with intrahepatic bile duct tumours

Abstract

Introduction Serum concentration of Carbohydrate Antigen 19-9 (CA19-9) has been related to survival of patients with Cholangiocarcinoma (CCA). We evaluated the cut-off value of serum CA19–9 to define predictive management strategies in patients with CCA. Method Three hundred and forty-one (341) Patients were retrospectively reviewed at a regional hepatobiliary centre in Liverpool, UK. The hospital integrated database was used to extract clinical and laboratory data. The receiver operating characteristic curve (ROC) of serum concentration of CA19–9 by location of tumour and type of treatment offered were assessed. The cut-off value of CA19–9 providing optimal prognosis was used to evaluate differences in survival of the patients using Kaplan-Meier survival log-rank test. Results One hundred and sixty-four (48%) patients had valid pre-treatment CA19–9 measurements. Among treatment groups; biliary stent was placed in 67(41%); surgical resection in 43 (26.2%); chemotherapy in 36 (22.0%); while 18 (11%) had supportive care. For site of lesion, ROC for CA19–9 was 0.74 (95% CI: 0.62–0.84; sensitivity: 80.9%; specificity: 60.0%, p = 0.0002). For prognosis of intrahepatic disease and ROC for hilar lesions was 0.62 (95% CI: 0.51–0.71; sensitivity: 90.2%; specificity: 36.1%, p = 0.05). By treatment modality, surgical resection showed significant relationship with pre-treatment CA19–9 value (ROC: 0.75; 95% CI: 0.60–0.87). Serum concentration of >34 IU/ml was defined as the cut-off predictive of prognosis for those who had surgical resection (sensitivity: 76.9% and specificity: 73.3%, p = 0.001). The median survival of patients who had surgical resection with serum CA19–9 >34 IU/ml was 18 months whereas for those with a value ≤34 IU/ml, 5 year survival was 80%. Conclusion Serum CA19–9 concentration is a useful predictor of prognosis in patients with intrahepatic lesions as well as those undergoing resection for IHBD tumours. Validation of this cut-off value requires further studies. Disclosure of interest None Declared.