What biomarker testing is recommended for metastatic Bladder Cancer

Biomarker Testing for Metastatic Bladder Cancer

Based on current clinical guidelines, here's what you should know about biomarker testing for metastatic bladder cancer:

NCCN Recommendations for Testing

According to the NCCN Guidelines (Version 2.2025), biomarker testing is an important part of managing metastatic bladder cancer. Here's what's recommended:

Timing of Testing

The NCCN panel recommends that molecular/genomic testing be performed early at the time of initial diagnosis of advanced bladder cancer. This timing is important because it helps:

• Determine which FDA-approved targeted therapies you might be eligible for
• Identify clinical trial opportunities
• Prevent delays in starting appropriate treatment

Specific Biomarkers to Test

1. FGFR3 Genetic Alterations

• Your tumor should be tested for mutations in the FGFR3 gene
• Why this matters: If present, FGFR3 mutations may make you eligible for erdafitinib, an FDA-approved targeted therapy
• Testing method: FGFR RGQ reverse transcriptase polymerase chain reaction (RT-PCR)

2. HER2 Overexpression

• Testing is done using immunohistochemistry (IHC)
• Why this matters: HER2 overexpression may qualify you for fam-trastuzumab deruxtecan, an FDA-approved antibody-drug conjugate therapy
• This is a protein that appears on some cancer cells

3. Microsatellite Instability (MSI-H) and Mismatch Repair (MMR) Status

• The NCCN panel recommends evaluation of these markers
• Why this matters: These findings may indicate eligibility for immunotherapy approaches

4. PD-L1 Testing

• For patients who cannot receive cisplatin chemotherapy, PD-L1 testing may be considered
• Why this matters: Results help determine if checkpoint inhibitor monotherapy (like atezolizumab) might be appropriate as first-line treatment

Scope of Testing

According to NCCN guidelines, a larger genomic panel is often preferred because:

• Bladder cancer is highly mutated (ranked as the 3rd most mutated cancer type)
• Studies show 93% of advanced urothelial carcinoma cases have at least one clinically relevant genetic alteration
• A comprehensive panel can identify rare mutations that may have approved therapies or allow clinical trial eligibility
• The average patient has 2.6 clinically relevant genetic alterations per case

Laboratory Requirements

Testing must be performed in laboratories certified under CLIA-88 (Clinical Laboratory Improvement Amendments) as qualified to perform highly complex molecular pathology testing. This ensures accuracy and reliability of results.

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Questions to Ask Your Oncology Team

1. Have all the recommended biomarkers been tested on my tumor? (FGFR3, HER2, MSI-H/MMR status, and PD-L1)

2. If not all tests were done, which ones are still needed and why?

3. What do my specific biomarker results mean for my treatment options?

4. Based on my biomarker profile, which FDA-approved targeted therapies or immunotherapies am I eligible for?

5. Are there clinical trials available that match my biomarker profile?

6. Was my testing done in a CLIA-certified laboratory?

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Important Context

The NCCN Guidelines emphasize that molecular testing should be conducted in a way that facilitates treatment decision-making and prevents delays in therapy. Your oncologist will use these biomarker results alongside your overall clinical picture—including your performance status, kidney function, and other health factors—to determine the most appropriate treatment approach for YOUR specific situation.

This information is for educational purposes only. Always consult your healthcare team for personalized medical advice and decisions.