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.