CA125 as a Pancreatic Tumor Marker

Primary Pancreatic Tumor Markers

The National Comprehensive Cancer Network recommends CA19-9 as the most established tumor marker for pancreatic cancer, with sensitivity of 40-70% and specificity of 50-80%, though it lacks high accuracy when used alone 1
CA19-9 is commonly expressed and shed in pancreatic and hepatobiliary diseases and many malignancies, making it not tumor-specific 2
The National Comprehensive Cancer Network suggests that CA19-9 measurements should be performed after biliary decompression is complete, as benign biliary obstruction can yield false-positive results 2, 3
Approximately 10% of individuals lack Lewis antigen and cannot produce CA19-9, limiting its utility in these patients 1

CA125 is one of several tumor-associated antigens studied in connection with pancreatic adenocarcinoma, alongside CA19-9, CEA, and others 2
CA125 is more commonly associated with epithelial ovarian cancer than with pancreatic cancer 4

The National Comprehensive Cancer Network recommends that diagnosis of pancreatic cancer should not rely solely on serum tumor marker measurements 1
CA125 can be elevated in benign conditions including pancreatitis, benign hepatocellular diseases, endometriosis, and pelvic inflammatory disease 4
A CA125/CEA ratio >25 favors ovarian origin over gastrointestinal origin when evaluating a malignancy of uncertain primary 4

A low postoperative serum CA19-9 level and decreasing serial CA19-9 levels following surgery correlate with better survival for patients undergoing resection for pancreatic cancer 2