CA 19-9 is a protein often found at higher levels in people with certain cancers, especially pancreatic cancer.

It is not used as a screening test for cancer but as a monitoring tool.

Doctors use CA 19-9 to:

Track the effectiveness of cancer treatment.

Detect recurrence of pancreatic or gastrointestinal cancers.

Assess disease progression.

Elevated CA 19-9 can also occur in non-cancer conditions such as gallstones, pancreatitis, liver disease, or bile duct obstruction.

The test is performed using a blood sample.

nalyte: Carbohydrate Antigen 19-9 (CA 19-9) protein in blood serum.

Normal Range: Usually < 37 U/mL (may vary by lab).

High Levels May Indicate:

Pancreatic cancer (most common use).

Other gastrointestinal cancers (bile duct, stomach, colorectal).

Non-cancer conditions like pancreatitis, liver disease, or bile duct obstruction.

Clinical Use:

Helps monitor cancer treatment response.

Detects recurrence after therapy.

Provides supportive information alongside imaging and other diagnostic tests.