Eye cancer can be serious because it can spread to other parts of your body.

There are various types of eye cancer, but they are all pretty rare.

The American Cancer Society estimates there will be 3,490 new cases of eye cancer in 2023 in the United States. However, these figures may include cancers that start from other organs, such as the skin.

The most common cancer that starts in the eye, intraocular melanoma, affects only about 5 in 1 million people.

Eye cancer spreads when cancer cells detach from the original tumor and pass via the bloodstream or lymph nodes to form new tumors in other organs. Doctors refer to this process as metastasis.

In this article, we explore how likely it is for eye cancer to spread, how quickly it can spread, which organs it affects, and signs and symptoms of metastasis. We also discuss treatment, diagnosis, and outlook.

Eye cancer can spread to other parts of the body, but not always. The risk of eye cancer, specifically intraocular melanoma, spreading varies greatly.

According to a 2020 research review, up to 50% of intraocular melanomas may spread. Your risk may vary depending on where the tumor originates.

For example, according to the review, if the cancer begins in the iris, the chance it spreads is around 7%. But if it starts from the ciliary body (the middle wall of the eye), the risk is 33%.

Eye cancer tends to metastasize to the liver, but it also depends on the type of eye cancer.

For example, the American Cancer Society states that conjunctival melanoma can rarely spread to the lungs and brain. When it does spread to these areas, the cancer is increasingly difficult to treat.

How quickly eye cancer spreads varies widely depending on many factors, like the type of cancer, your overall health, and how early you get a diagnosis.

Age is another important factor. Studies have demonstrated that intraocular melanoma survival rates decrease with age at the time of diagnosis. Like other cancers, the earlier you begin treatment, the better your chances of recovery.

For example, uveal melanomas can start in the:

  • colored iris
  • circular ciliary body behind the iris
  • choroid layer beneath the retina

Melanomas that start from the iris are visible and very slow to grow. This makes them very easy to detect and treat. Other uveal melanomas can be more aggressive and spread.

Conjunctival melanomas start in the moist tissue layer that covers the eyeball. They are relatively rare yet aggressive since they have direct access to the lymphatic system.

Another problem with estimating how fast eye cancer spreads is that research indicates the growth rate depends on the tumor size.

According to a 2018 article, uveal melanomas grow much faster when the tumors are young and tend to peak even during treatment.

This means that while it may take years for its cells to get to another organ, those cells tend to grow and multiply fast, increasing the risk of death.

Signs and symptoms of eye cancer include:

  • changes in your vision, such as blurry vision or sudden loss of sight
  • floaters, which are spots or squiggles that appear to float in your field of view, or flashes of light
  • change in the size or shape of your pupil, which is the dark center of your eye
  • a dark spot growing on the iris, which is the colored part of your eye
  • change in the position of your eyeball within its socket
  • bulging of the eye
  • changes in the way your eye moves

If eye cancer spreads, these symptoms may become more noticeable. You may also experience pain in other parts of your body where the cancer has spread.

For example:

While these symptoms could indicate that eye cancer has spread, they can also result from less serious, noncancerous conditions.

It’s crucial to speak with a doctor if you experience any of these symptoms so you can get treatment if necessary.

Note

Remember, some people with eye cancer do not have any symptoms unless the cancer grows.

Keeping up with regular health screenings and attending all your medical appointments can help detect, diagnose, and treat any issues early.

Your medical team may use a staging system, such as the TNM system, to assess whether cancer has moved beyond the eyes. TNM stands for tumor, node, and metastasis:

  • Tumor (T) describes the size of the original tumor and whether it has moved into nearby eye structures.
  • Node (N) refers to whether the cancer has spread to lymph nodes.
  • Metastasis (M) considers whether the cancer has spread to other parts of the body.

Your doctor may use various tests and imaging tools to stage your eye cancer and determine whether it has spread. These tests include:

If your eye cancer has spread, the treatment approach will be a bit different. Your treatment may include:

The outlook, or prognosis, for people with eye cancer that has spread varies. It largely depends on where the cancer spreads.

When eye cancer metastasizes, it most commonly spreads to the liver. When this happens, people may survive for 1 year. However, some people may live longer. Some research shows an overall survival ranging from 6–30 months.

It’s possible for eye cancer to metastasize, or spread, to other parts of the body. Its speed and growth can depend on the type and original location of the tumor.

Getting regular eye exams and telling your doctor about any symptoms is crucial to detect eye cancer early. The earlier eye cancer is treated, the better chances of a good outcome.