Predictive Value of Serum Carbohydrate Antigen 19-9 (CA19-9) for Early Mortality in Advanced Pancreatic Cancer.

INTRODUCTION: Levels of carbohydrate antigen 19-9 (CA19-9) in metastatic pancreatic cancer are used in daily practice as a marker of response to chemotherapy. The association between CA19-9 levels and mortality remains uncertain. This study sought to determine the most accurate level of CA19-9 associated with early mortality, both at diagnosis and during the course of metastatic disease.

METHODS: This research is a retrospective analysis of 64 patients with metastatic adenocarcinoma of the pancreas evaluated from January 2010 to December 2015. A receiver-operating characteristic (ROC) curve analysis was performed to evaluate the CA19-9 value and the association with early death (death within 2 months after diagnosis of advanced disease). The survival analysis was estimated by the Kaplan-Meier method, and variables of interest were assessed by proportional hazards regression Cox models.

RESULTS: The mortality rate was 92.2%, and the estimated median survival was 11.0 months. For the ROC curve analysis of initial CA19-9, an area under the curve of 0.868 (95% confidence interval 0.782 to 0.954) was obtained; the cutoff of 2504 U/ml had a sensitivity of 100% and specificity of 82.8% for early death. The effect of initial CA19-9 and chemotherapy contributed independently to the survival time, and every increase of 1000 CA19-9 units increased the risk of death by 9% (p = 0.0003).

CONCLUSION: CA19-9 levels in advanced pancreatic adenocarcinoma are associated independently with worse prognosis and early death. CA19-9 levels could be considered as a stratification factor for future clinical trials.