CA 19-9 in Pancreatic Cancer: Monitoring, Not Screening

A monitoring tool, not a screen

CA 19-9 is a carbohydrate antigen elevated in many pancreatic adenocarcinomas, but it is not specific enough to screen asymptomatic people, and some patients are non-secretors who never elevate it.

Where it helps

• Trending response to chemotherapy or after resection.
• Flagging possible recurrence on surveillance.

Limitations

Biliary obstruction and other cancers can raise CA 19-9, so it is interpreted alongside imaging and staging rather than alone. Resectability still hinges on vascular involvement.