BACKGROUND Little is known of the prognostic value of CEA/CA 19-9 kinetics during chemotherapy in patients with advanced cholangiocarcinoma (CCA).

METHODS A total of 236 patients with pathologically confirmed advanced CCA received gemcitabine-based chemotherapy were reviewed, and 179 were eligible for analysis. Baseline, pre-, and post-treatment (after two cycles of chemotherapy) CEA and CA 19-9 values were checked, and survival was compared according to various cutting points of baseline measurement or extent of change of tumor marker level.

RESULTS Patients with a ≥ 50% decline in CA 19-9 level had better survival than the others (16.0 vs 9.0 months). However, CEA decline did not predict survival gain. Significant favorable prognostic factors of survival in multivariable analysis included initial treatment response (HR 0.61), distal location of tumor (HR 0.46), baseline CA 19-9 level ≤ 1000 U/mL (HR 0.58), and ≥ 50% decline in CA 19-9 level (HR 0.50). Subgroup analysis was conducted in 114 patients with pre-treatment CA 19-9 > 37 U/mL and bilirubin ≤ 2 mg/dL. Decline ≥ 50% in CA 19-9 level still showed an independent prognostic significance (HR 0.45).

CONCLUSION CA 19-9 but not CEA kinetics serves as a predictor of better survival in patients with advanced CCA on gemcitabine-based chemotherapy. A ≥ 50% decline in CA 19-9 level after two cycles of chemotherapy may have clinical utility as an early indicator of better response to gemcitabine-based chemotherapy.