Eye cancer is very rare in the UK. We know there are some possible risk factors for different types of eye cancer.
Anything that can increase your risk of getting a disease is called a risk factor.
Different cancers have different risk factors. Having one or more of these risk factors doesn't mean you will get that cancer.
The possible risk factors for eye melanoma include:
Age and gender
Most people diagnosed with eye melanoma are over the age of 50. It is slightly more common in men than women.
Melanoma of the eye is more common in white than black people.
People with blue, grey or green eyes are more likely to develop eye melanoma than people with brown eyes.
People who have abnormal brown spots (pigmentation) on their uvea (called oculodermal melanocytosis) or iris (called iris naevus) are at an increased risk of developing eye melanoma too.
Some families tend to have large numbers of moles on their skin, or moles that are unusual (doctors call them atypical). The atypical moles tend to be an irregular shape or colour. They also have a tendency to become cancerous. People with moles like this have a higher than average risk of skin melanoma and eye melanoma.
Inherited cancer syndromes
Doctors have identified a rare inherited condition called BAP1 cancer syndrome. Families with this have a change (mutation) in the BAP1 gene. People with this gene change have an increased risk of uveal (eye) melanoma, skin melanoma and some other cancers.
We know that over exposure to sunlight is a definite risk factor for melanoma of the skin. It has also possibly been linked to melanoma of the eye but there is only weak evidence for this.
Exposure to UV radiation for some workers
Some studies have reported a slightly increased risk of melanoma of the eye in people working as welders. We don’t know whether this risk is due to UV radiation from the tools used for welding or other factors.
Use of sunbeds
Exposure to artificial UV radiation, for example sunbeds, increases the risk of eye melanoma.
The risk factors for squamous cell eye cancer include:
Infection with HIV
People who have HIV are at a higher risk of squamous cell carcinoma of the conjunctiva of the eye. This is almost certainly because of the effect of the virus on their immune systems.
Drugs that suppress the immune system
People who have an organ transplant need to take drugs to stop their immune systems rejecting the new organ. These drugs damp down the immune system generally. Because of this, these people are at an increased risk of some types of cancer, including squamous cell carcinoma of the eye.
Human papilloma virus infection
Human papilloma virus (HPV) may cause squamous cell carcinoma of the eye in combination with other factors. The virus causes squamous cell cancers elsewhere in the body. Infection with HPV is very common and not everyone infected will get cancer. There are probably other factors working with the HPV that explain why some people get it and others don’t.
Sun exposure has been linked to a higher risk of squamous cell carcinoma of the eye. This type of cancer is more common in areas of the world where the sun’s light is stronger than in the UK.
Anyone whose immune system is not working as well as it should may be more likely to develop lymphoma of the eye. This includes people who:
- are taking drugs to stop organ rejection after a transplant
- have HIV or AIDS
- have auto immune diseases such as rheumatoid arthritis
- are born with rare medical syndromes which affect their immunity
People without these risk factors can still develop an eye lymphoma. There appears to be an increasing number of cases in people who don't have problems with their immune systems. We don’t know why this is. The risk is highest between the ages of 50 and 60.
A bacteria called chlamydophila psittaci may increase the risk of a type of eye lymphoma called ocular adnexal malt lymphoma. Chlamydophila psittaci can be caught by exposure to infected birds or domestic animals such as cats. This infection is rare in Europe and some studies in America have found no link with ocular adnexal malt lymphoma. This may be because of differences in exposure to chlamydophila psittaci in different countries.
People who have HIV or AIDS have a much higher risk of developing Kaposi's sarcoma of the eye than the general population. The risk is still small because this is a very rare tumour.
Retinoblastoma is a rare type of eye cancer. In Britain around 45 children each year are diagnosed. It most commonly affects children under the age of 5.
Inherited gene changes
About 4 out of 10 retinoblastomas (40%) can run in families. Some children are born with a change (mutation) in the retinoblastoma gene (RB1 gene) that they inherit from one of their parents. Or this gene change happened in the very early stages of the child's development in the womb. They can then pass on this mutation to their children in the future.
Scientists are looking into possible causes of the non heritable form of retinoblastoma. One Swedish study has shown that children born to older mothers have a slightly higher risk of retinoblastoma. A more recent study did not find an increased risk for children of older mothers. One study has shown that children whose mothers smoked during pregnancy had double the risk of retinoblastoma but more studies are needed to confirm this.