What is uveal melanoma?

Uveal melanoma is a cancer that develops in the eye. While you may not have heard of this rare cancer (defined as occurring in less than 5 per 10,000 persons per year in EU), it is believed that Ireland may have one of the highest rates of uveal melanoma in Europe, and possibly the world. Between June 2010 and December 2015 there were 253 patients diagnosed with uveal melanoma in Ireland. Every year, there are approximately 50-60 people in Ireland diagnosed with this cancer.

As uveal melanoma can often go undetected, routine visits to the ophthalmologist are most important. Uveal melanoma can be treated by radiation or by removal of the affected eye. Unfortunately, some uveal melanomas will spread or metastasise to other organs, including the liver. Once this cancer has spread to the liver, it becomes more difficult to treat.

Where does uveal melanoma develop?

Uveal melanoma occurs in the uveal tract, the middle layer of the eye which comprises the iris, the ciliary body, and the choroid. Uveal melanoma develops in the uveal tract which contains the coloured or pigmented cells called melanocytes (similar to those found in skin). The iris is the coloured part of the eye that controls the size of the pupil through which light enters the back of the eye. The ciliary body is a structure that helps us focus on objects at different distances by controlling the shape of the lens. The choroid is a tissue rich in blood vessels that nourishes the light-detecting retina in the back of the eye. Most uveal melanomas develop in the choroid (90%), followed by the ciliary body (6%) and the iris (4%).

The uveal tract is made up of the iris, the ciliary body, and the choroid. The most common site for uveal melanoma is the choroid.

What are the symptoms and risk factors of uveal melanoma?

Uveal melanoma is very different to cutaneous melanoma (also known as a malignant skin cancer). This means that the symptoms, risk factors, and treatments for both diseases are also very different. Most patients diagnosed with uveal melanoma are between 50 – 70 years old. Males are more likely to be diagnosed with the disease than females, and uveal melanoma is more common in Caucasians than in non-Caucasians.

Some patients with uveal melanoma will experience no symptoms at all and their cancer may only be unexpectedly detected during a routine eye exam (such as a regular check-up or screening for diabetic retinopathy). Other patients may experience blurred vision, visual loss, or pain in the eye.

Risk factors associated with uveal melanoma include fair skin, an inability to tan, and light-coloured eyes, all of which are a common characteristic in the Irish population. These risk factors may explain why recent studies suggest that Ireland has one of the highest incidences of uveal melanoma in the world. Unlike skin melanoma, there has been no direct link between sun exposure and the development of uveal melanoma.

What are the treatment options available for uveal melanoma?

Generally, there are three types of treatment for the primary eye tumour available to patients in Ireland: brachytherapy, proton beam therapy (which is done in the UK and the EU), and removal of the eye. Brachytherapy is a form of radiotherapy. A radioactive plaque is sutured outside the eye but close to the cancer inside the eye. In Ireland, most patients have brachytherapy. With brachytherapy, there is less radiation to surrounding tissues than proton beam therapy.  Proton beam therapy and removal of the eye are less common. The treatment chosen depends on the size and location of the tumour.

When uveal melanoma spreads or metastases to another organ, it most often spreads to the liver, but it can also spread to the lungs or bone. The current treatment options for metastatic uveal melanoma are limited. Treatments that work for skin cancer (cutaneous melanoma) do not work for uveal melanoma. Treatment options for metastatic uveal melanoma are surgical resection of the tumours(s), ablation of the tumour(s) and/or liver directed therapy, i.e. radiotherapy and targeted chemotherapy. Targeted chemotherapy uses drugs to “target” cancer cells without damaging healthy cells. Although the currently available treatments for metastatic uveal melanoma are limited, there is ongoing international research on new drugs and treatments and several clinical trials are being conducted.

Your medical oncologist can discuss in detail all available treatment options upon diagnosis and advise on the recommended treatment course best suited for you. For further information about clinical trials consult your oncologist, or in the UK, see https://www.cancerresearch.org/cancer-clinical-trials. In the EU, see http://www.clinicaltrialsregister.eu

What supports are available for patients living with uveal melanoma and their families?

Uveal melanoma is a rare cancer. This means you may never have heard of it and may not know anyone else with this type of cancer. While living with a rare cancer can sometimes feel isolating, you are not alone. It can sometimes be difficult to access accurate and up-to-date information but there are supports available to you. Ocular Melanoma Ireland are a non-profit organisation of uveal melanoma patients and patient advocates that are familiar with uveal melanoma through their own personal experiences. Ocular Melanoma Ireland interact with clinicians, researchers, and international ocular melanoma groups (OcuMel UK and CURE OM) to advocate for and support uveal melanoma patients in Ireland. They are contactable through their website (http://www.ocumelirl.org/), and Twitter (https://twitter.com/ocumel_irl?lang=ga).