Serum CA125 is a novel predictive marker for pancreatic cancer metastasis and correlates with the metastasis-associated burden.

This study evaluated potential of serum tumor markers to predict the incidence and intensity of pancreatic cancer metastasis as well as patient survival. Retrospective records from 905 patients and prospective data from 142 patients were collected from two high-volume institutions. The levels of eight serum tumor markers (CA19-9, CEA, CA242, CA72-4, CA50, CA125, CA153, and AFP) commonly used in gastroenterological cancer were analyzed in all stages of pancreatic cancer. Serum CA125 levels were the most strongly associated with pancreatic cancer metastasis and were higher in patients with metastatic disease than those without. CA125 levels increased with increasing metastasis to lymph nodes and distant organs, especially the liver. High baseline CA125 levels predicted early distant metastasis after pancreatectomy and were associated with the presence of occult metastasis before surgery. An optimal CA125 cut-off value of 18.4 U/mL was identified; patients with baseline CA125 levels of 18.4 U/mL or higher had poor surgical outcomes. In addition, high serum CA125 levels coincided with the expression of a metastasis-associated gene signature and with alterations in "driver" gene expression involved in pancreatic cancer metastasis. CA125 may therefore be a promising, noninvasive, metastasis-associated biomarker for monitoring pancreatic cancer prognosis.