Biomarker Resource Center
Bladder 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 is a signal found in your tumor tissue or blood. In bladder cancer, biomarker tests look for specific gene changes that can guide your care.
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 Bladder Cancer?
Biomarker testing in bladder cancer has become an important part of diagnosis for advanced disease. Your results help your doctor understand which treatment paths are most likely to help you.
The most important bladder cancer biomarkers are FGFR3 mutation status and PD-L1 expression. Together they help your doctor understand whether certain targeted approaches or immunotherapy may be worth discussing.
A good question to ask your doctor: Ask your doctor whether your tumor has been tested for FGFR3 and PD-L1.
Quick Poll
Have you been biomarker tested?
FGFR3 and PD-L1 testing are key steps in understanding your advanced bladder cancer.
Source: DaCosta Byfield et al., JAMA Network Open, July 2025 · overall advanced cancer biomarker testing rate (n=26,311) · jamanetwork.com
The Tests Your Doctor May Order
Does your cancer have a gene change that can be targeted?
FGFR3 mutations are found in some bladder cancers. If your tumor has this mutation, a targeted drug approved specifically for bladder cancer may be an option worth discussing. Ask your doctor whether FGFR3 testing has been done.
Can immunotherapy help your immune system fight the cancer?
PD-L1 testing gives your doctor information about whether immunotherapy may be an option. Ask your doctor what your PD-L1 result means for your care.
Is a protective gene changed in your tumor?
TP53 changes give your doctor information about how your cancer may behave over time. Ask your doctor whether TP53 was tested and what the result means.
Sources: National Cancer Institute · BCAN · American Cancer Society
Watch & Learn
Common Questions
Bladder Cancer Biomarkers — Your Questions Answered
Who should ask about FGFR3 testing?
All patients with advanced or metastatic bladder cancer should ask their doctor about FGFR3 testing. A positive result may open the door to a targeted approach.
What does PD-L1 testing tell my doctor?
PD-L1 is one of the markers your doctor uses when discussing certain care approaches. Ask your doctor what your PD-L1 result means for your situation.
Should I ask about broader genetic testing?
Yes — especially if standard approaches have not worked. Ask your doctor whether broader testing might reveal additional options.
Is there a patient support community?
Yes. The Bladder Cancer Advocacy Network (BCAN) at bcan.org is a trusted resource for patients and caregivers.
Knowledge Check
Test what you’ve learned
Three quick questions to help you feel more confident talking with your care team.
What is FGFR3?
Based on what you just read, what does a positive FGFR3 result mean?
What does PD-L1 testing help decide?
Based on what you just read, what is PD-L1 used for in bladder cancer?
Who should ask about FGFR3 testing?
Based on what you just read, when should FGFR3 testing be discussed?
Keep these in mind for your next appointment.
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