Biomarker Resource Center
Pancreatic Cancer Biomarkers
Reviewed by XpertPatient Medical Advisory · Updated August 2026 · Primary Source: cancer.gov
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What Is a Biomarker — and Why Does It Matter for Your Treatment?
A biomarker in pancreatic cancer is a signal in your blood or tumor. CA 19-9 is a protein that pancreatic cancer cells release into the blood. BRCA and KRAS are gene mutations found in the tumor itself.
Think of it like a clue. Your doctor collects clues from your biomarker test results. Those clues help build a picture of your cancer. That picture helps you have a more informed conversation with your care team about next steps.
How a Biomarker Test Works
A biomarker is a signal your cancer leaves behind. Your doctor finds it through a biopsy or blood test, reads your results, and uses them to choose the treatment most likely to work for your specific tumor.
Why Do Biomarkers Matter in Pancreatic Cancer?
Every pancreatic cancer patient should have both tumor testing and inherited gene testing done. The results may open doors to care options that were not available just a few years ago — and may also be important for your family members.
The most important pancreatic cancer biomarkers are BRCA mutation status and CA 19-9. Together they help your doctor understand your tumor and monitor how it is responding to treatment.
A good question to ask your doctor: Ask your doctor whether both tumor testing and inherited gene testing — including BRCA — have been done.
Quick Poll
Have you been biomarker tested?
BRCA testing and CA 19-9 tracking are two of the most important steps after a pancreatic cancer diagnosis.
Source: DaCosta Byfield et al., JAMA Network Open, July 2025 · overall advanced cancer biomarker testing rate including pancreatic cancer (n=26,311) · jamanetwork.com
The Tests Your Doctor May Order
Do you have an inherited gene mutation that may affect your care?
BRCA mutations are found in about 5 to 7% of pancreatic cancer patients. If you have one and your cancer responded to platinum-based chemotherapy, a targeted maintenance approach may be an option worth discussing. This result also matters for close family members. Ask your doctor whether BRCA testing has been done.
Is a protein released by pancreatic cancer cells high in your blood?
CA 19-9 is used to track how your cancer is responding to treatment. A falling CA 19-9 usually means treatment is working. About 10% of people cannot produce CA 19-9. Ask your doctor what your level means.
Is there a very common driver mutation in your tumor?
KRAS mutations are present in over 90% of pancreatic cancers. New drugs targeting specific KRAS mutations are now in clinical trials. Ask your doctor whether your specific KRAS subtype has been identified and whether any clinical trials may be relevant.
Is there a rare but important finding that changes your care approach?
MSI-H is found in about 1 to 2% of pancreatic cancers. If your tumor is MSI-H, immunotherapy may be an effective option. Ask your doctor whether MSI testing was done.
Sources: National Cancer Institute · PanCAN · American Cancer Society
Watch & Learn
Common Questions
Pancreatic Cancer Biomarkers — Your Questions Answered
Should every pancreatic cancer patient get BRCA testing?
Yes. Guidelines recommend genetic testing for all patients with pancreatic cancer, regardless of age or family history. Ask your doctor whether this has been done.
What if my CA 19-9 is not elevated?
About 10% of people cannot produce CA 19-9 due to their blood type. If this applies to you, your doctor will use imaging and other markers to track your disease instead.
Are there clinical trials for KRAS?
Yes — this is one of the most active research areas in pancreatic cancer. Ask your oncologist or visit clinicaltrials.gov.
Is there a patient support community?
Yes. The Pancreatic Cancer Action Network at pancan.org offers patient services including a one-on-one Patient Services team.
Knowledge Check
Test what you’ve learned
Three quick questions to help you feel more confident talking with your care team.
Who should get BRCA testing after a pancreatic cancer diagnosis?
Based on what you just read, when is BRCA testing recommended?
What does a falling CA 19-9 level usually mean?
Based on what you just read, what does it mean when CA 19-9 decreases during treatment?
What percentage of pancreatic cancers have a KRAS mutation?
Based on what you just read, how common is KRAS in pancreatic cancer?
Keep these in mind for your next appointment.
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