|Authors Mitchell S. Stark and the team recently discovered that early detection of eye melanoma is possible using a simple blood test. / Photo by: dolgachov via 123rf|
A simple blood test to detect eye melanoma is on the horizon. This is based on research that recently appeared in the journal Translational Vision Science and Technology.
In a study titled “A Panel of Circulating MicroRNAs Detects Uveal Melanoma With High Precision,” authors Mitchell S. Stark from the University of Queensland and the team wrote that melanoma of the uveal tract is a cancer of the eye that affects the choroid, ciliary body, and the iris. It is a common intraocular malignancy in adults. Due to its location, uveal melanoma is detected later in life and the patient may already be prone to metastasis or the development of secondary malignant growth from the primary site of cancer.
The team recently discovered that early detection of eye melanoma is possible using a simple blood test.
|Melanoma of the uveal tract is a cancer of the eye that affects the choroid, ciliary body, and the iris. / Photo by: Luca Bertolli via 123rf|
Materials and Methods of Conducting the Study
The researchers prospectively gathered samples of patients from the Queensland Ocular Oncology Service in Brisbane, Royal Perth Hospital, and the Lions Eye Institute. These health records were between June 2012 and September 2015 and all the patients gave their consent. During experiments, blood samples were left to clot for half an hour at room temperature and then they centrifuged it for 10 minutes. Centrifugation means separation of particles from the solution according to their density, shape, and size.
The researchers discovered that there were markers in the subjects’ blood that can tell the difference between melanoma and a benign mole. The early detection technique using only the blood sample also enabled the researchers to identify if the eye cancer has already spread to other areas of the body.
Stark said that through a blood test, they can monitor the early signs of eye melanoma. The team likewise saw the potential of the technique to determine if the melanoma has already metastasized. She added that naevi or moles in the eye are common but they are not easy to monitor because the changes in their color and shape are not always visible on the skin.
The study also discovered that 5 of 31 (16 percent) participants in their Queensland Ocular Oncology Service cohort developed liver metastases and two of the five were confirmed dead after their four- to five-year follow up. "Outcomes are poor for people with melanoma in their eye if their cancer spreads to the liver,” Stark explained.
Since moles in the eye are common, the blood test may enable doctors to better scan the patients if there is a formation of melanoma. The process is done in the early stage of the disease. For instance, a person may visit an optometrist for their regular checkup and the eye doctor finds a mole. Then, they can suggest a blood test for every routine visit to monitor the changes in the mole. If the biomarker in that patient’s blood increases, it can serve as an early warning sign of melanoma, Stark said via medical research platform Medical Xpress. The test can also determine if the patient can be considered as high-risk so they can be closely monitored by their doctor. Ophthalmologist Dr. Bill Glasson AO, who is also the Queensland Ocular Oncology Service director, believed that such a test can be helpful if applied in a clinical setting. It does not just mean earlier diagnosis but also a better outcome for the patient.
Eye Melanoma: Statistics
The Melanoma Institute of Australia stated that unlike skin melanoma, the survival rate in uveal melanoma has not improved since the last 35 years. The US incidence of ocular melanoma is six per million. It is likewise more common among men, with 6.8 per million incidences compared to 5.3 per million in women. The male-to-female ratio of ocular melanoma is at 1.29. This was explained in an earlier study titled “Ocular melanoma: an overview of the current status.”
Authors of the said study said that ocular melanoma is the second most common type of melanoma after cutaneous, which is cancer that starts in the pigment-producing cells of the skin. Cutaneous melanoma causes more than 10,000 deaths each year with a 98 percent five-year survival rate.
Meanwhile, oncologist-approved cancer information platform Cancer.Net noted that three out of four people diagnosed with eye melanoma survive for at least five years. If it does not spread outside the eye, the five-year survival rate is about 80 percent. If it has already spread to distant parts of the body, the patient’s five-year relative survival rate is about 15 percent. The American Cancer Society has also estimated that there will be 3,360 new cancer of the eye and orbit in the US in 2019. It estimated that 1,860 of these will be men and 1,500 women. Common signs and symptoms are watery eyes, blurry vision, loss of peripheral vision in one eye, flashing lights in the visual field, displacement of the eye within the eye socket, and dark spot in the iris.
Hopefully, this new technique in eye cancer detection becomes the norm soon enough so that patients will be able to get treatment at the earliest possible time.