Six Things You Didn’t Know About Ocular Melanoma
Ocular melanoma has been in the news recently because a group of cases were found in a tight geographic area in Huntersville, North Carolina and Auburn, Alabama. This is unusual for cancer, but when it does happen, it can often help researchers discover a common cause for a disease.
Learn more about how the CDC defines a cancer cluster.
Today, no one has a clear idea of what causes ocular melanoma. While melanoma of the skin is linked to UV exposure from sunlight, there is little evidence to suggest that sun exposure causes melanoma in the eye.
Here are six things you might not know about ocular melanoma.
Can I see ocular melanoma if I look in the mirror?
Sometimes. Ocular melanoma can look like a freckle (called a nevus by experts), on the iris, or part that gives your eye its color. But it can also grow in parts of the eye that aren’t visible from the outside, such as the ciliary body, which is a muscle that sits under the iris and helps contract or dilate the size of your pupil. It can also be found on the choroidal wall, under the retina. If you think of your eyeball as a beach ball, the choroid would be on the inside wall of that beach ball – a place that only an eye specialist can peer into with ophthalmic lenses.
How worried should I be if I see a dark spot on my eye?
Because ocular melanoma is serious cancer that can be difficult to treat, you should have it checked by a specialist. An ophthalmologist or eye doctor with experience treating ocular melanoma will be able to assess whether your eye’s nevus should be treated immediately or simply watched for changes in shape and size. Although about 5-10 percent of the world’s population has a nevus in their eye, only about one in ten thousand of these eye freckles will develop into ocular melanoma.
Is ocular melanoma the same disease as melanoma on your skin?
Not at all. The two diseases are actually quite different. Ocular melanomas are usually more aggressive and resistant to standard treatment than those that start in the skin. They also have a different set of genes driving the disease, which means that targeted therapies that work for skin melanoma won’t necessarily work for ocular melanoma. In addition, the newer immunotherapies called checkpoint inhibitors that work very well for skin melanoma do not work well for ocular melanoma.
Because this disease is quite rare, with only about 2,500 cases diagnosed per year in the United States, doctors who treat this disease are often also active researchers who are working to both understand the disease and find better ways to treat it.
I think I might have ocular melanoma, how do I find help?
Ocular melanoma is diagnosed and treated first by an ophthalmologist and then medical oncologists. Patients should look for specialists who treat the primary uveal melanoma in the eye, and the secondary cancer in the liver. Both types of doctor should have a good deal of experience treating this particular disease. (The Ocular Melanoma Foundation suggests patients find doctors who see at least 30 ocular melanoma cases/year). That experience ensures that patients will have access to the greatest number of options and most up-to-date care.
You may also visit websites sponsored by Melanoma Research Foundation and the CURE OM initiative to learn more about the disease.
What does treatment entail?
There can be two parts of ocular melanoma treatment. The first usually requires eye surgery that allows doctors to place a patch or plaque of radiation therapy directly over cancer in order to kill the tumor cells. At the same time a sample of the tumor is taken and tested to predict the severity of disease, and whether the patient is at risk for metastasis. This first line of therapy is extremely important and can cure about 50 percent of patients. For some patients the tumor may be too large or too near important structures and it may be recommended they undergo removal of the eye, called .
When the primary cancer in the eye spreads, however, it usually spreads to the liver, and requires aggressive treatment. Those that do have aggressive metastatic disease historically had a median survival rate of less than one year. This is in part because traditional treatments are generally ineffective for metastatic ocular melanoma. However, when caught early and optimally treated patients can live longer.
Marlana Orloff, MD, and Takami Sato, MD, are two medical oncologists at the NCI-designated Sidney Kimmel Cancer Center — Jefferson Health who have been working in the communities in North Carolina and Alabama to try to find common link in the cancers. They work closely with Carol Shields, MD, and Jerry Shields, MD, and colleagues, at Wills Eye Hospital, where patients are first diagnosed and treated for their primary tumor. Together, these physicians see hundreds of ocular melanoma patients per year. In cases where the cancer progresses and develops metastases in the liver, Drs. Sato and Orloff work with an advanced interventional radiology team to treat the tumors using liver directed therapies. The treatment team is complemented by a robust network of researchers at the Sidney Kimmel Cancer Center, led by Andrew Aplin PhD, who actively develop new treatment concepts and perfect therapies that are already working through clinical trials.
In recent years, advances in treatments for metastatic ocular melanoma have improved patient survival to more than two years in some cases. The Sidney Kimmel Cancer Center team pioneered a technique called immunoembolization in which immune-stimulating agents called cytokines are injected directly into the liver while blocking the blood supply to the tumor. The team also offers radioembolization, and chemoembolization for more extensive liver metastases, which involve injecting high dose chemotherapy, or radiation therapy, directly at the site of the tumor in the liver, as well as a clinical trials.