Biomarkers & Prognostic Testing
After being diagnosed with melanoma, other tests are available that can provide additional information to inform your treatment options and next steps. These tests can be divided into two broad categories:
- Biomarker Testing to determine what mutations are in your melanoma
- Prognostic Testing to determine the severity of your melanoma or risk of recurrence after surgery
Melanoma Biomarker Testing
Thanks to advancements in research over the last decade, your doctor can now test your melanoma to determine what mutations are present, which mutations are driving the cancer, and if these mutations can be treated with a class of drugs called Targeted Therapies. We call this biomarker testing. This type of testing is recommended for all patients with Stage 3 or 4 melanoma. You may also hear this called ‘genomic testing.’
All cancers, including melanoma, are caused by mutations in the DNA that allow cells to grow uncontrollably and eventually invade surrounding tissue. These mutations are caused by many things, including tobacco, alcohol, pollution, or in the case of melanoma, Ultraviolet (UV) radiation. In fact, an estimated 90% of melanomas are caused by UV radiation from the sun or indoor tanning devices.
Biomarker testing is important because it will help you understand all of the treatment options that may be available to you. In melanoma, your doctor may look specifically for BRAF, NRAS, or cKIT mutations because treatments are available that specifically target these mutations.
While the FDA has only approved therapies focused on the BRAF mutation in melanoma, other mutations may be ‘actionable’ using drugs approved for other cancer types or those still in clinical trials.
For example, KIT-mutant melanoma can be successfully treated in some patients using drugs originally intended for leukemia. Mutations are considered ‘actionable' if there are drugs designed to specifically act on them. Also – due to the incredible pace of research – mutations (or targets) that are not actionable today may be so in the future. This is why many experts recommend testing melanoma for all known mutations, what is called comprehensive biomarker testing.
Keep in mind that you have many treatment options, and just because you have an actionable mutation in your melanoma – that doesn’t necessarily mean that targeted therapies are right for you. Talk to your doctor about the all of your treatment options, including clinical trials.
Melanoma Prognostic Testing
Prognostic tests can be used to estimate the severity of your melanoma and help inform your treatment-decision making. This is an extremely active area of research and includes a variety of institution-specific tests as well as commercially available tests used across multiple institutions.
Estimating Risk of Recurrence With Gene Expression Profiling
A commercially available test, DecisionDx®-Melanoma, can help predict the risk of your melanoma returning after surgery for patients with early stages of melanoma (Stage 1-3).
DecisionDx®-Melanoma is the most commonly used test at this time and predicts an individual’s risk of recurrence or metastasis for patients facing early stage melanoma. It does this by measuring the expression of 31 genes within tumor tissue. DecisionDx®-Melanoma results are used by some doctors and patients to inform their decisions about the need to perform a Sentinel Lymph Node Biopsy (SLNB), deciding what level and frequency of follow-up visits, the need for imaging, and/or to determine if referrals to other specialists are appropriate. Knowing your risk of recurrence can also help your physician evaluate if adjuvant therapy – used after surgery to reduce the risk of melanoma returning – is right for you. Adjuvant therapy is now FDA approved for patients with Stages IIB, IIC, III, and IV melanoma.
The test is available for patients with a melanoma at least 0.3 mm deep. Additional tests are being developed and this is a very active area of research.
Liquid Biopsy: Measuring Circulating Tumor DNA
Though tumors are made of rapidly dividing cells, with time, some of those cells will die and shed their DNA in the blood. This tumor DNA in the blood can be used to detect the presence of cancerous cells in the body. Doctors are now able to determine if – and if found, how much – circulating tumor DNA (ctDNA) is present in your blood. This is sometimes called a ‘liquid biopsy.” CtDNA testing is widely used for cancers of the blood, such as leukemia or lymphoma, and is increasingly being applied to solid tumors such as melanoma.
CtDNA tests, such as Natera’s SignateraTM , can provide additional information in several instances, such as predicting the risk of recurrence, informing the need for adjuvant therapy, measuring for treatment relapse, and helping to inform decision making about treatment discontinuation.
What does the research say about prognostic testing?
The tests described above are relatively new and have not been universally adopted as some doctors believe more testing is needed. Other doctors routinely order these types of tests and consider them an important part of their overall arsenal of tools in providing personalized patient care.
If you are interested in prognostic testing, speak to your doctor about the available options. Be sure to ask what information testing can provide, its limitations, and how it can impact your future care.
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