CA 19-9 as a biomarker in advanced pancreatic cancer patients randomised to gemcitabine plus axitinib or gemcitabine alone.

BACKGROUND

Response assessment in advanced pancreatic cancer (APC) is difficult and predictive markers are needed. There are insufficient data on the value of carbohydrate antigen 19-9 (CA 19-9) and cytostatic-targeted therapies. Axitinib, a selective vascular endothelial growth factor (VEGF) receptors 1, 2, 3 inhibitor, may increase overall survival (OS) in APC.

METHODS

We assessed serum CA 19-9, clinical outcomes and diastolic blood pressure (dBP) in APC patients receiving gemcitabine plus axitinib (Gem+A) or gemcitabine alone.

RESULTS

In the total population (N=95), median OS was significantly longer in patients with baseline CA 19-9 values at or below the median than in those with values above it (12.2 months [95% confidence interval (CI), 8.6-16.6%] vs 5.0 months [95% CI, 3.9-5.7%]; P<0.0001). This also reached significance in the Gem+A arm (median OS, 12.5 months [95% CI, 8.6-16.6%] vs 4.9 months [95% CI, 3.6-5.6%]; P<0.0001). Patients with any dBP>90 mmHg had significantly longer OS than those who did not. However, there was no predictive significance of CA 19-9.

CONCLUSION

Baseline CA 19-9 levels had prognostic value for OS, but caution is advised in interpreting CA 19-9 as a predictive biomarker for novel cytostatic agents such as VEGF-targeted therapies in phase II studies.