Assessing prognosis in metastatic pancreatic cancer by the serum tumor marker CA 19-9: Pretreatment levels or kinetics during chemotherapy?

Background: The carbohydrate antigen 19-9 (CA 19-9) is currently the most widely used serum tumor marker in pancreatic cancer (PC). CA 19-9 pretreatment levels as well as CA 19-9 kinetics during systemic chemotherapy can provide prognostic information regarding survival of patients with metastatic PC. Case Reports: We report the clinical course of 2 patients with metastatic PC who underwent palliative chemotherapy with gemcitabine. Both patients showed a significant elevation of pretreatment CA 19-9 levels (7,505 and 150,000 U/ml, respectively), however, subsequently they experienced a highly significant reduction (> 90%) of CA 19-9 kinetics under gemcitabine chemotherapy. A good disease control and a clinical benefit response were achieved in both patients. Time to tumor progression was 30 weeks and 28 weeks, overall survival 14 months and 11 months, respectively. Conclusion: These data indicate that CA 19-9 kinetics under chemotherapy may possibly serve as a useful surrogate marker for time to tumor progression and survival in advanced PC.