Ocular cancers are rare malignancies that develop in or around the eye. There are many different types of ocular cancers that vary based on the cellsthe basic structural and functional unit of all living things they develop from.
The eye is a sensory organ that allows us to see by reacting to light. Light passes through the cornea (the clear, front layer of the eye) and enters the eye through an opening called the pupil (the black centre of the eye). The amount of light received by the pupil is controlled by the iris (the coloured portion of the eye). This light is then passed through the lens (the clear, inner portion of the eye) and works together with the cornea to focus light onto the retina (a layer of tissuea group of cells that work together to perform a function at the back of the eye that is sensitive to light). The retina then activates photoreceptors (image forming cells) to convert the light to electrical impulses that travel to the brain via the optic nerve, which is then converted into an image.
Most ocular cancers are more common in males, and tend to develop over the age of 55. However, anyone can develop these diseases.
Types of Ocular Cancers
There are several different types of ocular cancers, which are categorised based on the different cells they develop from.
Ocular Melanoma
Ocular melanomaa type of cancer that develops from melanocytes, which are the cells that produce pigment generally in the skin (but can develop in other areas of the body), or eye melanoma, is a type of melanoma that occurs in the eye. Melanomas develop from melanocytes, which are the cells that produce pigment, generally in the skin. However, they can also develop in the eye and possibly other parts of the body.
For more information on ocular melanoma, please refer to the Rare Cancers Australia Melanoma (Ocular) page.
Retinoblastoma
Retinoblastoma is a rare type of ocular cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs that develops in the retina of the eye. It is a type of blastoma, which are cancers that develop in precursor cells, most often in children. It can occur in one eye (unilateralaffecting one side retinoblastoma, usually non-hereditary), or in both eyes (bilateralaffecting both sides retinoblastoma, often hereditary).
For more information on retinoblastoma, please refer to the Rare Cancers Australia Retinoblastoma page.
Ocular Lymphoma
Ocular lymphomacancers of the lymphatic system is a rare type of cancer that develops from the lymphatic systema network of tissues and organs that help our bodies fight infection and disease, a network of tissues and organs that help our bodies fight infectiona condition where harmful pathogens, such as bacteria, viruses or parasites, have entered the body and disease. Ocular lymphomas can be divided into two categories.
Primary Intraocular Lymphoma (PIOL)
Primary intraocular lymphoma (PIOL) is a rare subtype of ocular cancer that develops from lymphatic cells inside of the eye. While there are no lymphatic cells naturally in the eye, lymphomas cells may invade portions of the eye and develop here. This type of cancer has been linked to people who have a weakened immune system, including people with acquired immunodeficiency syndrome (AIDS), people who have had an organ transplanta surgical procedure that involves removing a failing or damaged organ and replacing it with a healthy one from a donor, and elderly people. PIOL is often aggressive, and may not have as good of a prognosisto predict how a disease/condition may progress and what the outcome might be as other types of ocular cancer.
Ocular Adnexal Lymphoma
Ocular adnexal lymphoma, also known as mucosa-associated lymphoid tissue (MALT) lymphoma of the eye, is a very rare form of ocular cancer that develops in the tissue surrounding the eye, including the eyelids, conjunctival sac, and lacrimal gland. These tumours can be aggressive, but can have a good prognosis when found early.
Medulloepithelioma of the Ciliary Body
Medulloepithelioma of the ciliary body is a very rare form of ocular cancer that develops in the ciliary body, a portion of the eye wall that changes the shape of the lens when the eye focuses. Unlike most ocular cancers, this subtype is slightly more common in females, and is generally diagnosed in children between the ages of two and five. Medulloepitheliomas of the ciliary body are not often aggressive, and generally have a good prognosis.
Medulloepitheliomas of the ciliary body should not be confused with medulloepitheliomas of the brain.
Squamous Cell Cancer of the Conjunctiva
Squamous cell cancer of the conjunctiva is a rare form of ocular cancer that develops in the conjunctiva, a thin, clear, mucinous membrane that covers the eye and lines the eyelid. It is more common in males, and tends to be diagnosed between the ages of 50-75. Squamous cell cancer of the conjunctiva is generally not aggressive, and can have a good prognosis.
Lacrimal Gland Cancer
Lacrimal gland cancer is a rare type of ocular cancer that develops in the lacrimal glands, the small, tear-shaped gland in each eye that secretes liquid (also known as tears) to clean, protect, and lubricate the eyes. These cancers are often aggressive, and may not have as good of a prognosis as other types of ocular cancers.
For more information on rhabdomyosarcomas, please refer to the Rare Cancers Australia Lacrimal Gland Cancer page.
Orbital Rhabdomyosarcoma
Orbital rhabdomyosarcomas are a rare form of ocular cancer that develops in the muscles of the eye. While rhabdomyosarcomas are the most common form of soft tissuetissue/the material that joins, holds up or surrounds inside body parts such as fat, muscle, ligaments and lining around joints sarcomacancer arising from bones and/or soft tissue in children and adolescents, orbital rhabdomyosarcoma is considered to be rare. They are more common in males, and are generally diagnosed between the ages of five and seven. Orbital rhabdomyosarcomas are often aggressive, and may not have as good of a prognosis as other types of ocular cancers.
For more information on rhabdomyosarcomas, please refer to the Rare Cancers Australia Rhabdomyosarcoma page.
Cancers of the Eyelid
Cancers of the eyelid are rare, and are often forms of skin cancer. The two most common forms are basal cell carcinomacancer arising from tissues that line organs (BCC) and squamous cell carcinoma (SCC). When these tumours are found, they are generally treated like any other skin cancer.
For more information on skin cancer, please refer to the Rare Cancers Australia Skin Cancer page.
Adenocarcinoma of the Eye and Adnexa
Adenocarcinomas (cancers arising from mucus-producing glands) of the eye and adnexa are a very rare form of ocular cancer that generally develop in the retina or ciliary body. This type of cancer is slightly more common in females, and often responds poorly to radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells. Because of how rare these cancers are, there has been limited research done into the aggressiveness and prognosis of this disease.
Treatment
If an ocular cancer is detected, it will be staged and graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Stagingthe process of determining how big the cancer is, where it started and if it has spread to other areas and grading helps your doctors determine the best treatment for you.
There are two primary staging and grading systems used in the classification of ocular cancers – The International retinoblastoma staging system and the TMN system.
The International Classification for Intraocular Retinoblastoma (ICIR)
The international classification for intraocular retinoblastoma (ICIR) divides intraocular cancer into five groups based on the characteristics of the tumoura tissue mass that forms from groups of unhealthy cells. These groups include:
- Group A: very low riskthe possibility that something bad will happen, very small tumours not located near critical structures, confined to retina.
- Group B: low risk, small tumours close to critical structures, confined to retina.
- Group C: moderate risk, well-defined tumours with small amounts of spread under the retina (subretinal seeding) or into the vitreous (gel-like substance in the eye) (vitreous seeding).
- Group D: High risk, large tumours with widespread subretinal and/or vitreous seeding, retina may become detached from the back of the eye.
- Group E: Very high risk, very large tumours extending near the front of the eye, may cause bleeding or glaucoma (high intraocular pressure).
TNM Staging System
The TNM system can also be used to classify a ocular cancers. The TNM system is comprised of:
- T (tumour) indicates the size and depth of the tumour.
- N (nodea small lump or mass of tissue in your body) indicates whether the cancer has spread to nearby lymph nodessmall bean-shaped structures that filters harmful substances from lymph fluid.
- M (metastasis) indicates whether the cancer has spread to other parts of the body.
This system can also be used in combination with a numerical value, from stage 0-IV:
- Stage 0: this stage describes cancer cells in the place of origin (or ‘in situ’) that have not spread to nearby tissue.
- Stage I: cancer cells have begun to spread to nearby tissue. It is not deeply embedded into nearby tissue and had not spread to lymph nodes. This stage is also known as early-stage cancer.
- Stage II: cancer cells have grown deeper into nearby tissue. Lymph nodes may or may not be affected. This is also known as localisedaffecting only one area of body cancer.
- Stage III: the cancer has become larger and has grown deeper into nearby tissue. Lymph nodes are generally affected at this stage. This is also known as localised cancer.
- Stage IV: the cancer has spread to other tissues and organs in the body. This is also known as advancedat a late stage, far along or metastatic cancer.
Cancers can also be graded based on the rate of growth and how likely they are to spread:
- Gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I: cancer cells present as slightly abnormal and are usually slow growing. This is also known as a low-grade tumour.
- Grade II: cancer cells present as abnormal and grow faster than grade-I tumours. This is also known as an intermediate-grade tumour.
- Grade III: cancer cells present as very abnormal and grow quickly. This is also known as a high-grade tumour.
Treatment options
Once your tumour has been staged and graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, stage of disease and overall health.
Treatment options for retinoblastomas may include:
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Iridectomypartial removal of the iris.
- Iridocyclectomypartial removal of the iris and the ciliary body.
- Transscleral resectionremoval of an eye tumour (most commonly uveal melanoma) in the ciliary body or choroid through an incision in the sclera.
- Enucleationremoval of the eye and attached optic nerve.
- Orbital exenterationcomplete removal of the eyesocket, including the eyeball and surrounding tissues (muscles, nerves, fatty tissue, and potentially the eyelids).
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells, potentially including:
- Ophthalmic artery infusion chemotherapya type of chemotherapy that involves delivering chemotherapy medication directly to the eye via infusion into the ophthalmic artery.
- Intravitreal chemotherapya type of chemotherapy that involves delivering chemotherapy medication directly into the vitreous humor (gel-like fluid inside the eye).
- Radiation therapy.
- Laser therapya procedure that uses an infrared laser to raise the temperature of the tumour to shrink and damage cancer cells.
- Photodynamic therapya procedure that involves inserting a light-sensitive drug (photosensitiser) to shrink and damage cancer cells when exposed to a light source.
- Cryotherapythe process of freezing off cancerous tumours and/or lesions using liquid nitrogen.
- Targeted therapymedication that targets specific molecular features of cancer cells.
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
While the cause of ocular cancer remains unknown, the following factors may increase the likelihood of developing the disease:
- Family history of ocular cancers
- Genetic mutation in the RB1 (retinoblastoma protein 1) gene.
- Gender and age (being male and being over 50).
- Having pale skin.
- Having a light eye colour, such as blue or green.
- A family history of melanoma.
- Having a growth on or in the eye.
- Certain skin conditions, such as dysplastic naevus syndrome.
- BAP1 cancer syndrome.
- Having a weakened immune system, such as from:
- Having acquired immunodeficiency syndrome (AIDS).
- Having had an organ transplant.
- Being elderly.
Not everyone with these risk factors will develop the disease, and some people who have the disease may have none of these risk factors. See your general practitioner (GP) if you are concerned.
Symptoms
The symptoms of an ocular cancer may include:
- The pupil appears white instead of red when light is shone into it (e.g., in photographs)
- Pain and/or redness in the eye.
- Eyes that suddenly start looking in different directions (crossed eyes or lazy eyes).
- Infection around the eye.
- Abnormally large eyeball.
- Cloudiness in the iris and pupil.
- Poor and/or blurred vision in one or both eyes.
- Loss or peripheral vision.
- Discoloured patches in the sclera.
- Seeing ‘wavy lines’ in your vision.
- Vision flashes.
- A change in pupil shape.
- Drooping eyelid.
- Proptosisbulging or protrusion of one or both of the eyes out of the eye sockets, also known as exophthalmos.
- A lump in or around the eye.
- Feeling that something is in your eye.
- White, painless growth on the surface of the eye.
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis
If your doctor suspects you have an ocular cancer, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Imagingtests that create detailed images of areas inside the body tests, most commonly an ultrasounda type of medical imaging that uses soundwaves to create detailed images of the body of your eye.
- Eye tests, potentially including:
- Ophthalmoscopyan examination of the back of the eye (fundus) to visualise the retina, optic disc and/or blood vessels; also known as a fundoscopy.
- Fluorescein angiographyan eye test that involves using a special dye and camera to examine blood flow in the retina and choroid.
- Electroretinographyan eye test that measures small electrical signals given off by the eye when exposed to different types of light.
- Biopsyremoval of a section of tissue to analyse for cancer cells.