From the Guidelines
Elevated Carbohydrate Antigen 19-9 (CA19-9) levels are primarily associated with pancreatic cancer, but can also be caused by other conditions such as cholangiocarcinoma, colorectal cancer, gastric cancer, and benign conditions like pancreatitis and cholangitis. The most common causes of elevated CA19-9 levels include:
- Pancreatic adenocarcinoma, where CA19-9 serves as a tumor marker with levels often exceeding 1,000 U/mL 1
- Cholangiocarcinoma (bile duct cancer) 1
- Colorectal cancer 1
- Gastric cancer 1
- Benign conditions like pancreatitis (both acute and chronic), cholangitis, cholecystitis, liver cirrhosis, and other hepatobiliary diseases 1
- Inflammatory bowel diseases like ulcerative colitis and Crohn's disease may also increase CA19-9 levels 1 It's essential to note that about 5-10% of the population lacks the Lewis antigen, making them unable to produce CA19-9 even in the presence of cancer 1. CA19-9 elevations should always be interpreted in clinical context, as levels between 37-100 U/mL often represent benign conditions, while values above 1,000 U/mL more strongly suggest malignancy, particularly pancreatic cancer 1. The marker is most useful for monitoring treatment response and detecting recurrence rather than as a standalone diagnostic test 1.
From the Research
Causes of Elevated CA19-9 Levels
Elevated Carbohydrate Antigen 19-9 (CA19-9) levels can be caused by various conditions, including:
- Malignant pancreaticobiliary disease, such as pancreatic adenocarcinoma and cholangiocarcinoma 2, 3
- Benign pancreaticobiliary disease, such as chronic pancreatitis and biliary calculous disease 2
- Other non-hepato-pancreatico-biliary conditions, such as pneumonia, pleural effusion, renal failure, and systemic lupus erythematosus (SLE) 4
- Jaundice due to biliary obstruction 2
- Xanthogranulomatous cholecystitis (XGC), a rare benign condition of the gallbladder 5
Conditions Associated with Elevated CA19-9 Levels
The following conditions have been associated with elevated CA19-9 levels:
- Pancreatic cancer 2, 3, 4, 6
- Cholangiocarcinoma 2, 3
- Gallbladder cancer 3
- Ampullary carcinoma 2, 3
- Neuroendocrine tumors 2, 3
- Colorectal cancer 4
- Lung cancer 4
- Liver cancer 4
- Ovarian cancer 4
- Hepatobiliary disease 4
- Pneumonia 4
- Pleural effusion 4
- Renal failure 4
- SLE 4
Clinical Significance of Elevated CA19-9 Levels
Elevated CA19-9 levels can indicate:
- Unresectable lesions and poor prognosis in pancreatic cancer 3, 4
- Malignant disease, particularly pancreatic adenocarcinoma and cholangiocarcinoma 2, 3
- Benign conditions, such as XGC, that may mimic malignant disease 5
- Advanced stage disease at the time of diagnosis in patients with normal CA19-9 levels 6