Uveal Melanoma

General Background

TumorEyeFINAL-for-web1.jpg

Uveal melanoma is a malignant cancer of the eye in adults. It is rare – there are only an estimated 1200-1800 cases per year in the United States. Melanomas are tumors of pigmented cells. Skin melanomas often arise from nevi (the medical term for “moles”). Similarly, uveal melanomas are tumors thought to arise from nevi within the pigmented layers of the eye – the choroid, iris or ciliary body.

The tumor is made up of a mass of cells which can be brown, yellow, or white in color. This section will discuss the tumors which are in the ciliary body or choroid. These are layers of tissue in the middle and back of the eye, meaning they cannot be seen to the naked eye without special ophthalmic equipment.

Typically choroidal and ciliary body melanoma are anywhere from 2 millimeters to 12 millimeters tall and 5 to 18 millimeters wide at the time that they are diagnosed. So although the overall size of the tumor is small (often smaller than a jelly bean), the impact on the eye is significant because the structures of the eye are so delicate.

Which patients get uveal melanoma?

Most of the time, we cannot identify exactly why patients have developed this cancer because the risk factors are largely unknown. The disease is more common in patients who:

  • Are Caucasian
  • Have light colored eyes (Blue, Green)
  • Are in their 60’s or older

There is nothing in the diet or other environmental risk factor that has been clearly and consistently linked to the development of this cancer, except perhaps exposure to extremely high doses of radiation in the case of arc welders. In a small percentage of patients, there is a tendency in the family to develop this cancer as well as other cancers.

How is uveal melanoma diagnosed?

Unlike other cancers, most of the time we diagnose this cancer without a biopsy. The reason for this is we have the ability to characterize the tumor with many sophisticated testing techniques such as ultrasound, ophthalmic photos, ophthalmic fluorescein angiography (a testing with a special dye), and optical coherence topography (a magnified view of the retina). In some cases in which the tumor cannot be visualized (such as bleeding) or if the tumor looks atypical, a biopsy may be done to make the diagnosis. At the time of surgery, we often do perform biopsies both for confirmation of the diagnosis and for genetic testing. We use sophisticated retinal instruments to do these biopsies nearly risk-free.

What are the typical symptoms?

Many patients have no symptoms and the tumor is discovered during a routine examination. Some patients have floaters or decreased vision. Pain is not a common symptom in this condition.

In many cases, melanomas arise from pre-existing nevi (freckles or moles) which are benign in appearance and then transform into true cancers. This transformation can occur slowly or rapidly and can happen in a patient who has had a normal eye exam before the cancer diagnosis. Some of these cancers are in a part of the eye (the ciliary body or anterior retina) which is especially difficult to see or detect on a routine exam except with special equipment.

Our team will perform an imaging study of your whole body (often a PET/CT or a MRI or a CT scan) to check to see if the tumor has spread already. The vast majority of patients do not have metastases (cancer cells that have spread to other parts of the body) at the time their diagnosis is made.

Treatment

Commonly used treatments for uveal melanoma at centers of excellence include:

Plaque therapy (radiation seeds) – These are radiation beads that can be made of Iodine-125, Ruthenium, or other more rarely used isotopes. The treatment involves tiny beads of radiation known as seeds, custom-chosen and designed for each patient based on the size and shape and configuration of his/her tumor. The seeds are placed in a bottle-cap shaped implant that is backed in pure gold to protect all the healthy surrounding tissues. The radiation patch is inserted onto the outside surface of the eye in a surgical procedure. It stays there for several days while the radiation treats the tumor. After several days, the patch is removed from the surface of the eye in a second surgery. The radiation kills the tumor cells so that they stop growing. The advantage of this treatment is that patients can keep their eye and many patients enjoy good vision.

Proton Beam Therapy – another form of radiation utilizing proton energy

Laser treatment (TTT, transpupillary thermotherapy)

Enucleation – Enucleation, or permanent surgical removal of the eye, is the oldest form of treatment for uveal melanoma. Modern enucleation surgery takes about one hour and involves removal of the eye, leaving intact the muscles that move the eye as well as the conjunctiva (the skin of the eye) and the eyelids. Dr. Schefler inserts a sphere-shaped implant into the orbital cavity (where the eye used to be) to fill the space and the patient’s eye muscles are attached to the implant to create movement. After approximately six weeks, when the tissues has healed, the patient is referred to an ocularist. The ocularist fits the patient for an ocular prosthesis (a special contact lens) which is painted to match the patient’s fellow eye. The prosthesis does not move perfectly like a normal eye, but it looks extremely natural. In a normal social setting, most people have no idea that a patient has had an enucleation. The advantage of this treatment is that it is fast, definitive, and requires limited ophthalmic follow-up. The disadvantage is that you don’t get to keep any of your vision or your eye.

Enucleation-collage.jpg

Prosthesis-Collage.jpg

Comparing Treatments

Collaborative Ocular Melanoma Study (COMS)

biopsy.jpgThere was a large multicenter study across the U.S. in the 1980’s and 1990’s sponsored by the National Institute of Health in which enucleation was compared to plaque surgery. The study demonstrated that survival for patients was the same regardless of which treatment they had. Given the results of this study, many patients are able to choose between these treatments.

Genomics

We at RCH have pioneered the use of a new minimally invasive technique to perform fine needle aspiration biopsies for the purpose of retrieving tissue for genetic testing. The biopsy is painless and nearly risk-free and does not result in visual loss. It is performed prior to plaque surgery during the same setting. Various types of genetic testing can be done on uveal melanoma cells and then patients are given information about the results. These results can be used to decide how often patients need to be followed after their plaque surgery or enucleation or to enroll patients into experimental clinical trials.

Research in uveal melanoma

Test-Tubes.jpgWe have many research trials in choroidal nevi and uveal melanoma at Retina Consultants of Houston. These include:

  • Multiple studies of the genetics of patients’ tumors and the genetics in their blood to understand better which ones have tumors that will grow or not grow and which ones will develop metastases (cancer cells that have spread to other parts of the body).

  • Treatment studies – studies in which patients are given injections of new medications to improve their vision after plaque therapy and minimize the radiation treatment side effects.

  • Family history studies – understanding the relationship between patients’ family histories of cancer and their own risks for developing cancer.