What's this test for?

This test is ideal if you're being evaluated for a tumor and your care team needs more information about what type of cells it's made of. It's commonly used when there's a suspicion of a gastrointestinal stromal tumor (GIST), mast cell disease, certain leukemias, small cell lung cancer, or Ewing's sarcoma. The test looks at a tissue sample to check for a specific protein marker called CD117 (also known as c-kit) that shows up on these types of tumors.

What's included in this test?

This test uses a technique called immunohistochemistry (IHC) to check a tissue sample for the CD117/c-kit protein, along with an expert interpretation of what the staining pattern means. Detecting this marker matters because certain tumors, like gastrointestinal stromal tumors and some mast cell and blood cell cancers, often show this protein on their surface. Knowing whether a tumor is CD117-positive can help clarify the diagnosis and point toward treatments, like tyrosine kinase inhibitors, that specifically target this pathway.

What happens after I get my results?

Your results will be available in your account, with the interpretation explained in plain language so you understand what the finding means for the tissue sample tested. Because this is a specialized tissue-based test tied to a specific diagnostic workup, next steps typically depend on the full clinical picture rather than a simple retest schedule. The standard lab report is downloadable directly from your account for your records or to share as needed. You can also revisit your results anytime and track any related testing over time using the trends feature.

How can I naturally support my body during cancer testing and treatment?

While no natural remedy replaces medical treatment for a tumor, supporting your body with good nutrition, adequate protein, hydration, and rest can help you feel stronger during a diagnostic workup. Gentle movement like walking, along with stress-reduction practices such as deep breathing or meditation, may help you cope with the uncertainty of waiting for results. Avoiding smoking and limiting alcohol can also support your overall health during this time. Always follow the pre-collection or biopsy instructions provided with your order confirmation.

When will I get my results?

Results for this test are typically available within about 7 days after your tissue sample is processed. Immunohistochemistry testing involves several lab steps, including staining and expert interpretation, which is why it takes a bit longer than a standard blood test. You'll be notified as soon as your results are ready to view in your account.

Who should consider this test?

This test is generally considered for people who already have a tumor or suspicious mass identified through imaging or biopsy and need more detail about its specific cell type. It's often used when a GIST, mast cell disorder, certain leukemia, small cell lung cancer, or Ewing's sarcoma is suspected. This test on its own isn't a general cancer screening tool for people without an existing finding.

What does a positive CD117 result mean?

A positive result means the tumor cells tested show the CD117/c-kit protein on their surface, which is common in GISTs, certain mast cell diseases, and some leukemias. This finding helps confirm the type of tumor and can also suggest the tumor may respond to targeted drugs called tyrosine kinase inhibitors. It's one important piece of the diagnostic puzzle, used alongside other tests and imaging to guide next steps.

What does a negative CD117 result mean?

A negative result means the tumor cells tested did not show significant levels of the CD117/c-kit protein. This can help rule out certain diagnoses, like classic GIST, and points toward other tumor types that don't rely on this specific marker. Additional testing is often needed to pin down the exact diagnosis when CD117 comes back negative.

What causes a tumor to test positive or negative for CD117?

Whether a tumor expresses CD117 largely comes down to genetic changes within the tumor cells themselves, not lifestyle or diet. Certain mutations in the KIT gene cause cells to overproduce this protein, which is why it shows up strongly in cancers like GIST and some mast cell diseases. Other tumor types simply don't rely on this genetic pathway, so they test negative.

What should I do if my results show a positive or unclear finding?

If your CD117 result comes back positive or unclear, the next step is usually additional imaging, staging tests, or a treatment planning discussion based on your full diagnostic picture. Keep a copy of your downloadable lab report so you have the details on hand for any follow-up testing. If you're experiencing worsening symptoms like severe pain, unexplained weight loss, or bleeding, seek medical care right away rather than waiting.

Getting your blood test with us is easy, private & backed by the power of science.Long story short: In the test options, use the filters or search box to narrow your choices and find the test you want. If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test. Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout. If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want. When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system. Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way. You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy! If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

How do I know which test to get?

In the test options, find the test you want. If you’re not sure which test to get, we can lend a hand in finding the right option. Just text or call us at 754-799-7833, email us at support@privatemdlabs.com, and we'll gladly help you. We've got your back and reply quickly.

When will my lab results be available?

Most test results will be available within 1–3 business days. Once they're ready, we'll send an email and text message to let you know. After your blood draw, just hang tight and don't worry – we'll keep you updated and in the loop! If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com, and we'll gladly help you.

Is it possible to make changes to my lab order if I made a mistake with the name, date of birth, or any other details?

Absolutely! We totally understand that errors can happen. No worries, we're here to help you. Just reach out to us via text at 754-799-7833 or shoot us an email at support@privatemdlabs.com. Remember to include your order number and let us know the correct information you’d like to update. Our awesome team will jump right in and make sure everything is sorted out and accurate for you. There are no changes necessary if your address is wrong on the requisition though. We don’t mail anything out. Our lab requires an address to be listed to generate an order.

Do you accept health insurance?

Only HSA & FSA is accepted. Our services are strictly self-pay and cannot be submitted to your health insurance provider except for Health Savings Accounts or Flexible Savings Accounts. This policy applies to all insurance companies, including federal health insurance programs like Medicare. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com.

Can I cancel my order?

Yes. We get it – sometimes your needs change. As long as your samples haven’t been collected yet, we’re happy to help you cancel your order. If you have any further questions, please text us at 754-799-7833 or email support@privatemdlabs.com. You can read more about our cancellation policy here.

How can I find a lab location near me?

During the ordering process, you’ll be able to select a specific lab near you, with no strings attached! You can switch it up later easily and visit any of our authorized locations as long as it’s the same lab company you selected your test for (Quest Diagnostics or Labcorp). Before you proceed with your order, feel free to browse through all our lab locations here. This will give you the peace of mind of knowing that there's a lab nearby your home, office or your favorite gym. If you have any questions, please text us at 754-799-7833 or email support@privatemdlabs.com and we'll gladly help you.

CD117 c-kit Tumor Test - GIST & Cancer Marker Panel

Getting your blood test with us is easy, private & backed by the power of science.

Long story short:

In the test options, use the filters or search box to narrow your choices and find the test you want.
If you need a hand navigating through options, text our super friendly support team at 754-799-7833, and we'll provide tailored suggestions to help you find the ideal test.
Once your order is placed, we’ll create your doctor’s lab order remotely, without any need for you to make a trip to a doctor in person or to talk to the doctor. Expect to receive your doctor’s lab order right in your inbox. It will also be in your patient portal if you need to find it later. We’ll also include instructions regarding fasting and other requirements for your test. Your patient portal will be auto-created hassle-free during checkout.
If this is your first time ordering, you'll be prompted to create a password for instant login access to your patient portal. It's a quick way to conveniently access your orders and results whenever you want.
When you’re ready, visit one of our 4,000 locations. Just bring your ID – no printing or faxing of your lab order is needed, as your order and details will already be in the lab system.
Note that most lab locations don’t accept walk-ins, so it’s best to book an appointment in advance. Don’t worry – we’ll provide detailed instructions along the way.
You’ll get your results via email & SMS and dive into understanding your body better. Yup, that easy!

754-799-7833

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