The primary clinical issue for the management of ocular melanoma is accurately predicting metastatic risk. In earlier times, physicians used the clinical characteristics of a patient's melanoma (tumor size, location, color patterns) to estimate the risk of metastasis. While these characteristics do provide some information and are useful in looking at the trends for a population's risk of metastasis, they are not as reliable for predicting an individual's risk of metastasis.
The DecisionDx-UM test measures the gene expression profile (abbreviated as GEP) or molecular signature of an individual's tumor and identifies the likelihood that the tumor has already spread from the eye (metastasized). The DecisionDx-UM test has been compared to prognostic factors of clinical characteristics, cytological characteristics, and to chromosome 3 (monosomy 3) testing and was found to be more accurate than and superior to (statistically and clinically) all of these other prognostic factors.
The DecisionDx-UM test was developed by Dr. J. William Harbour at Washington University to provide an accurate method for assessing an individual's risk of metastasis during the first 5-years, regardless of the treatment effectiveness of the primary uveal melanoma tumor. Castle Biosciences Inc exclusively licensed this test from the university and completed development and validation so that it could be made available to all physicians and patients. It has been available for routine clinical use since late 2009. DecisionDx-UM test is standard of care for the majority of ocular oncologists.
The American Joint Committee on Cancer (AJCC, version 7, 2010) is the only national organization that reviews uveal melanoma. The AJCC recommends the DecisionDx-UM GEP test for clinical use as the results are "clinically significant" for patient care.
How does it work?
The DecisionDx-UM test evaluates the expression level of a set of genes that are expressed in a patient's eye tumor. These genes determine the molecular signature of the tumor. The molecular signature has been determined to be highly associated with risk of metastasis (spreading) in uveal melanoma. The results of the test provide knowledge as to the likelihood of the tumor having already metastasized. Tumors with a Class 1 signature are associated with a good prognosis and a low likelihood that the tumor has spread (or metastasized), while tumors with a Class 2 signature have a high likelihood that the tumor has spread prior to diagnosis of the eye tumor.
How is the DecisionDx-UM test ordered?
The DecisionDx-UM test can only be ordered by your physician (most commonly an ocular oncologist, retinal specialist, or ophthalmologist) and requires a sample of the tumor.
Many patients receive eye-sparing radiation therapy such as brachytherapy or proton beam irradiation. The DecisionDx-UM test needs to be performed on tumor tissue that is obtained prior to radiation. Thus, it is important for you discuss your interest in the DecisionDx-UM test prior to radiation therapy.
For patients undergoing an enucleation procedure, the tumor specimen can be obtained during the enucleation procedure or it can be ordered at a later date from tumor tissue that the pathology department will store.
How are the results used?
The results of the DecisionDx-UM test are typically used by both the physician and you, the patient. Medical record reviews and the literature show that physicians use the results of the DecisionDx-UM test to:
- Develop patient specific monitoring (also known as surveillance) plans. Patients identified as having a high risk of developing metastasis may receive a high intensity surveillance plan that may include more frequent monitoring with advanced imaging testing such as CT scans, MRI, or PET. In contrast, patients at a low risk of developing metastasis may receive a less intensive surveillance plan – thus balancing the risks of radiation exposure of the advanced imaging testing with the patient's risk of metastasis;
- Initiate referral to a medical oncologist for treatment planning which may include adjuvant treatment; and
- Refer appropriate high risk patients to clinical trials.
- In addition, patients tell us that they also use the results of the DecisionDx-UM test to plan their life. The DecisionDx-UM test results are not a guarantee. But, the results have been shown to be accurate in predicting which patient is at a low risk of developing metastasis from the patient who is at high risk. These patient comments are consistent with two different patient surveys published in 2009, both of which reported that 97% of patients wanted to know prognostic test results.
How is DecisionDx-UM paid for?
Castle Biosciences, Inc. works with Medicare, commercial insurance providers and, in some cases, your physician's institution to secure payment coverage for DecisionDx-UM. Claims will be submitted on the patient's behalf and followed through the system to payment. The Castle Patient Assistance Program is in place to help manage balances due and to provide assistance in cases of financial hardship.