Quick Facts
- Sample: Blood (serum)
- Fasting: Not required
- Turnaround Time: 1-4 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Monitor treatment progress — track how well your pancreatic or biliary cancer therapy is working over time.
- Detect recurrence early — identify rising tumor marker levels before symptoms appear after treatment.
- No referral needed — order online and visit a nearby lab for a blood draw.
- Convenient serial testing — easily reorder for ongoing monitoring every 3–6 months as recommended.
- Comprehensive cancer insight — pair with imaging and other markers for complete health assessment.
Who Is This Test For?
- Individuals currently undergoing treatment for pancreatic, bile duct, or gallbladder cancer
- Patients in remission monitoring for cancer recurrence after surgery or chemotherapy
- People with chronic pancreatitis or primary sclerosing cholangitis under physician surveillance
- Those with unexplained symptoms like jaundice, abdominal pain, or unintended weight loss
- High-risk individuals with strong family history of pancreatic cancer seeking additional monitoring tools
- Patients whose doctors recommend CA 19-9 testing alongside imaging for diagnostic workup
How It Works – Just 3 Steps
- Order online — Select your test, pay securely, and schedule your blood draw.
- Visit a lab — Get your blood drawn at any of the 2,000+ convenient lab locations nationwide.
- Receive results — Access results online in your secure account within days.
FAQ
What does CA 19-9 measure? CA 19-9 measures a protein produced by pancreatic, liver, and biliary tract cells that often rises with certain cancers.
Can this test diagnose pancreatic cancer? No. CA 19-9 alone cannot diagnose cancer; it's used with imaging and clinical evaluation for monitoring and assessment.
What is a normal CA 19-9 level? Normal levels are typically 0–37 U/mL, though some healthy individuals may have slightly elevated levels or produce no CA 19-9.
Why might my CA 19-9 be elevated without cancer? Elevated levels can occur with benign conditions like pancreatitis, cirrhosis, gallstones, and other inflammatory digestive disorders.
How often should I retest CA 19-9 during cancer treatment? Most oncologists recommend testing every 3–6 months during treatment and surveillance to track trends over time (NCCN 2025).
Do I need to fast before the test? No fasting is required, but inform your lab if you have liver disease or active inflammation.
More Details
What is the purpose of this test?
The Carbohydrate Antigen (CA) 19-9 Blood Test measures the level of CA 19-9, a tumor marker protein elevated in over 80% of pancreatic cancer patients and frequently associated with bile duct and gallbladder cancers (Pancreatic Cancer Action Network 2024). While CA 19-9 is not a diagnostic test on its own, it serves as a valuable monitoring tool for assessing treatment response, detecting disease progression, and identifying potential recurrence after cancer therapy. The test quantifies this protein in your bloodstream, providing your healthcare team with objective data to guide treatment decisions and follow-up care.
Because CA 19-9 can also be elevated in non-cancerous conditions such as pancreatitis, cirrhosis, cholangitis, and gallstones, this test is most useful when interpreted alongside imaging studies, other tumor markers, and your complete clinical picture (MedlinePlus 2022). Healthcare providers focus on trends in CA 19-9 levels over time rather than single measurements, as rising levels may indicate disease progression while decreasing levels suggest positive treatment response.
Who would benefit from this test?
This test is particularly valuable for individuals undergoing treatment for pancreatic cancer, cholangiocarcinoma (bile duct cancer), or gallbladder cancer who need regular monitoring of their tumor marker levels. Patients in remission after cancer surgery or chemotherapy benefit from serial CA 19-9 testing to detect early signs of recurrence, often before symptoms develop or imaging changes appear. The American Association for the Study of Liver Diseases recommends CA 19-9 monitoring for cholangiocarcinoma patients, especially those with primary sclerosing cholangitis (AASLD 2023).
People with chronic inflammatory conditions affecting the pancreas or biliary system may also benefit from CA 19-9 monitoring under physician guidance. High-risk individuals with a strong family history of pancreatic cancer can use this test as part of a comprehensive surveillance strategy, though it should never be used as a standalone screening tool. The test is most valuable when your doctor has recommended it based on your symptoms, medical history, or existing diagnosis.
When should I order the Carbohydrate Antigen (CA) 19-9 Blood Test?
Consider ordering this test when advised by your healthcare provider for monitoring cancer treatment effectiveness, assessing recurrence risk, or evaluating unexplained symptoms suggestive of pancreatic or biliary disease. If you're currently in cancer treatment, your oncologist will typically recommend testing every 3–6 months to track your response and adjust therapy as needed (NCCN 2025).
You may also order this test if you experience persistent symptoms that could indicate pancreatic or biliary tract problems, including:
- Persistent upper abdominal pain radiating to the back
- Jaundice (yellowing of skin or eyes)
- Unexplained weight loss exceeding 10% of body weight
- New-onset diabetes without clear risk factors
- Chronic nausea, vomiting, or digestive difficulties
- Dark urine or pale, greasy stools
If you have a history of chronic pancreatitis, primary sclerosing cholangitis, or inflammatory bowel disease with biliary involvement, periodic CA 19-9 testing may help your doctor monitor for potential complications. Always discuss your test results with a healthcare provider who can interpret them in the context of your complete medical situation.
How do I interpret the results?
CA 19-9 levels are measured in units per milliliter (U/mL), with the normal reference range typically 0–37 U/mL. However, interpretation is more complex than simply comparing your result to this threshold. Approximately 5–10% of the population lacks the genetic ability to produce CA 19-9, meaning they will always have undetectable levels even with cancer present (Canadian Cancer Society 2024).
For patients with known cancer, trends matter more than absolute values. Serial measurements showing declining levels typically indicate successful treatment response, while rising levels may signal disease progression or recurrence requiring further investigation. Here's a general interpretation guide:
Remember: CA 19-9 has approximately 70% sensitivity and 90% specificity for pancreatic cancer, meaning it can miss some cancers and be elevated in non-cancerous conditions.
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
The CA 19-9 test requires minimal preparation, making it convenient for regular monitoring. No fasting is required before your blood draw, and you can take your regular medications unless your doctor advises otherwise. You should inform the testing laboratory if you have active liver disease, cholestasis, pancreatitis, or inflammatory conditions, as these can affect your baseline CA 19-9 levels and help with accurate interpretation.
Avoid scheduling this test during acute illnesses or infections when possible, as inflammation can temporarily elevate CA 19-9 levels. If you're having the test for cancer monitoring, try to have your blood drawn at approximately the same time of day for each test to maintain consistency. Bring a list of your current medications and any previous CA 19-9 results to help establish your personal trend pattern.
How often should I get tested?
Testing frequency depends on your specific clinical situation and your healthcare provider's recommendations. Establishing a consistent testing schedule helps track meaningful trends over time.
- Active cancer treatment (chemotherapy or radiation) – Every 2–3 months
- Post-surgery surveillance (first 2 years) – Every 3–4 months
- Long-term remission monitoring (after 2 years) – Every 6 months
- High-risk surveillance (family history or chronic disease) – Every 6–12 months
- Initial diagnostic workup – One-time baseline, then as directed
Your oncologist may adjust this schedule based on your individual response to treatment, changes in symptoms, or imaging findings. More frequent testing may be warranted if your levels are rising or if you're experiencing new symptoms. Conversely, stable results over several years may allow for less frequent monitoring.
Why early detection matters
Pancreatic cancer remains one of the most challenging cancers to treat, with a 5-year survival rate below 7% when detected at advanced stages. However, serial CA 19-9 monitoring offers prognostic value and can detect recurrence an average of 5–6 months before clinical or radiographic evidence appears, providing a critical window for intervention. Regular monitoring allows your healthcare team to adjust treatment strategies promptly when levels begin rising, potentially improving outcomes.
For patients with chronic pancreatitis or primary sclerosing cholangitis, who face elevated pancreatic and cholangiocarcinoma risk respectively, periodic CA 19-9 testing combined with imaging surveillance helps identify malignant transformation at earlier, more treatable stages. While CA 19-9 alone is not sufficient for screening, it serves as an important component of comprehensive high-risk surveillance protocols when properly utilized.
Related tests you may consider
CA 125 (Cancer Antigen 125) — This complementary tumor marker helps assess ovarian cancer and can provide additional information for pancreatic cancer monitoring, especially in cases where CA 19-9 is non-informative.
CEA (Carcinoembryonic Antigen) — This broader tumor marker aids in differential diagnosis and monitoring of gastrointestinal cancers, providing supplementary information when used alongside CA 19-9.
Comprehensive Metabolic Panel (CMP) — This essential panel evaluates liver and kidney function, which is critical for interpreting elevated CA 19-9 levels and ruling out benign causes of elevation.
