PD-0022 - Decline in CA19-9 during chemotherapy predicts survival in four independent cohorts of patients with inoperable cholangiocarcinoma.
|Date||27 June 2014|
|Event||World GI 2014|
|Session||Poster discussion session IV - Miscellaneous|
|Citation||Annals of Oncology (2014) 25 (suppl_2): ii5-ii13. 10.1093/annonc/mdu164|
M. Grunnet1, I. Christensen2, U. Lassen1, L.H. Jensen3, M. Lydolph4, J. Knox5, M. McNamara5, M. Jital6, J. Bridgewater6, J. Valle7, M. Mau-Sørensen1
Plasma carbohydrate associated antigen (CA19-9) has been approved by the FDA as a tumor biomarker for the monitoring of treatment effect in pancreatic cancer. However, the value of plasma CA19-9 as a biomarker of response to chemotherapy in cholangiocarcinoma is unclear. The aim of this study was to determine if a decline in CA19-9 (CA19-9 response) during chemotherapy is predictive of survival in patients with inoperable cholangiocarcinoma.
Patients with inoperable cholangiocarcinoma treated at a University Hospital were consecutively included in a training set (n = 212). Three validation data sets were established including patients from 1) a Danish County Hospital (n = 60), 2) a Canadian cohort (n = 196) and 3) the randomized ABC-02 trial (n = 410). Patients with a baseline CA19-9 level above 1.5 times the upper limit of normal and at least one CA19-9 value measured ten to twelve weeks after the start of chemotherapy were included in the analysis. Multivariate Cox regression analyses were performed.
Patients meeting the criteria to be included in the analyses were 46 in the training set and 27, 52 and 128 in the three validation sets respectively. Multivariate analysis included radiological response, performance status and age. A hazard ratio (HR) of 0.77 (95%CI: 0.63-0.93, p = 0.008) for death in CA19-9 responders (CA19-9 as a continuous variable) was reached in the training set. The predictive value of CA 19-9 response with regard to overall survival was confirmed in all three validation data sets (HR = 0.77, 95%CI: 0.59-0.99, p = 0.04, HR= 0.79; 95%CI: 0.65-0.96, p = 0.02 and HR = 0.88; 95%CI: 0.80-0.98 p = 0.02 respectively).
CA19-9 response seen 10-12 weeks after start of chemotherapy is a robust predictor of survival in patients with inoperable cholangiocarcinoma in four independent data sets.