Uveal Melanoma (Eye Cancer) Diagnosis & Care

Uveal melanoma is a cancer of the pigment-making cells inside the eye. The uvea has three parts. Where the tumor starts affects how it behaves.

• The iris, the colored ring at the front. Iris melanomas are usually small and slow-growing. People often notice them as a dark spot.
• The ciliary body, a ring of tissue behind the iris. Tumors here tend to be larger and more likely to spread.
• The choroid, the blood-vessel layer at the back. Most uveal melanomas begin here.

It is the most common cancer that starts inside the adult eye. It is still rare. The risk is higher in people with fair skin that burns easily, in people with light-colored eyes, and in older people.

Many people have no symptoms at all. A routine eye exam finds the tumor. When symptoms do appear, they include blurred vision, floaters, flashes of light, a growing dark spot on the iris, a change in the shape of the pupil, or a shift in the position of the eye.

This is one of the few cancers usually diagnosed without a biopsy. An ocular oncologist, an eye cancer specialist, looks at the back of the eye directly. They use ultrasound to measure the tumor's height and base. They also image the retina and its blood flow. The pattern is distinctive enough to make the diagnosis confidently on examination alone.

When a biopsy is done, it is usually for prognosis rather than diagnosis.

If a sample is taken, it can be tested in two ways that predict the chance of spread.

Gene expression profiling sorts tumors into class 1, with a low risk of metastasis, and class 2, with a much higher risk. Chromosome testing looks for loss of one copy of chromosome 3, called monosomy 3. That is also linked with higher risk. Some centers add a marker called PRAME, which further sorts the class 1 group.

This information does not change how your eye is treated. It changes how closely you are watched afterward. It may also make you eligible for trials of treatment aimed at preventing spread.

It is also information some people would rather not have. That is a reasonable position. It is worth deciding before the biopsy, not after.

The goal is to control the tumor and, where possible, keep the eye.

Plaque brachytherapy is the most common approach. A small dish holding radioactive seeds is stitched to the outside of the eye, over the tumor. It stays there for several days. A second short operation removes it. This controls the great majority of small and medium tumors.

Proton beam or stereotactic radiation aims focused radiation from outside the eye. Some centers use it, especially for tumors near the optic nerve.

Enucleation means removing the eye. It is used for large tumors, for tumors causing pain or uncontrolled pressure, and when there is no real chance of useful vision. A prosthetic eye is fitted afterward, and it usually looks natural.

Trials comparing plaque brachytherapy with enucleation found similar survival. So the choice turns on tumor size, location, and what can be saved. Radiation does slowly affect vision in the treated eye over the following years, through changes to the retina and optic nerve. That trade-off is worth discussing openly.

Uveal melanoma spreads through the bloodstream. In most people who develop metastasis, the liver is the first site. This can happen years after the eye was successfully treated.

Because of this, surveillance goes on indefinitely. It means liver imaging with MRI or ultrasound, plus liver blood tests, typically every six to twelve months. Your risk category sets the interval. These appointments can be anxious ones, and it is fair to tell your team that.

Treatment for metastatic uveal melanoma is genuinely difficult. The immunotherapy combinations that transformed skin melanoma work less well here.

Tebentafusp is the first therapy shown in a randomized trial to improve survival in this setting. It only works in people who carry the HLA-A*02:01 tissue type. A simple blood test confirms this, so ask whether it has been checked. Tebentafusp is given weekly. The early doses are given in hospital, because of a reaction called cytokine release syndrome.

Liver-directed treatments and clinical trials are also part of the conversation. In this disease, joining a trial at a specialist center is often among the strongest options available.

• Call 911 or go to an emergency department if you are on tebentafusp and develop a temperature of 100.4°F (38°C) or higher together with light-headedness, trouble breathing, or a spreading rash. That combination can mean cytokine release syndrome, which the drug's label carries a boxed warning about.
• Call your care team the same day if the treated eye becomes suddenly painful, red and hard, or your vision drops sharply over hours rather than months. Radiation changes to vision come on slowly, so a fast change is not part of the expected pattern.
• Call your care team within a day or two if you notice new jaundice, ongoing pain under the right ribs, or unexplained weight loss between your liver surveillance scans. Report these rather than waiting for the next scheduled appointment.

• DailyMed label: KIMMTRAK (tebentafusp-tebn) — boxed warning on cytokine release syndrome
• FDA Drug Trials Snapshot: KIMMTRAK (tebentafusp-tebn)
• NCI drug information: tebentafusp-tebn
• NCI: Intraocular (Uveal) Melanoma Treatment (PDQ®) Health Professional Version
• 15-gene expression profile prognostic test in uveal melanoma