Carbohydrate antigen 19-9 is a prognostic and predictive biomarker in patients with advanced pancreatic cancer who receive gemcitabine-containing chemotherapy
Bauer TM et al. – In patients who have advanced pancreatic cancer treated with gemcitabine-containing regimens baseline CA19-9 is prognostic for outcome. A decline in CA19-9 after the second cycle of chemotherapy is not predictive of improved mOS or mTTP; thus, CA19-9 decline is not a useful surrogate endpoint in clinical trials. Clinically, a ? 5% rise in CA19-9 after 2 cycles of chemotherapy serves as a negative predictive marker.Methods
- Individual patient data from 6 prospective trials evaluating gemcitabine-containing regimens from 3 different institutions were pooled.
- CA19-9 values were obtained at baseline and after successive cycles of treatment.
- The objective of this study was to correlate a decline in CA19-9 with outcomes while undergoing treatment.
- A total of 212 patients with locally advanced (n = 50) or metastatic (n = 162) adenocarcinoma of the pancreas were included.
- Median baseline CA19-9 level was 1077 ng/mL (range, 15-492,241 ng/mL).
- Groups were divided into those levels below (low) or above (high) the median.
- Median overall survival (mOS) was 8.7 versus 5.2 months (P = .0018) and median time to progression (mTTP) was 5.8 versus 3.7 months (P = .082) in the low versus high groups, respectively.
- After 2 cycles of chemotherapy, up to a 5% increase versus >/= 5% increase in CA19-9 levels conferred an improved mOS (10.3 vs 5.1 months, P = .0022) and mTTP (7.5 vs 3.5 months, P = 0.0005).