Choroidal Melanoma - What Are the Chances of a Cure?
definition
The choroidal melanoma is the most common malignant tumor inside the eye in adults. The choroid forms the back part of the vascular skin in the eye. A choroidal melanoma is caused by a degeneration of the pigment-forming cells (Melanocytes) that are important for eye color. As a result, these tumors are often dark in color. The choroidal melanoma often metastasizes, which means that degenerated cells get to other places in the body and accumulate there.
Frequency of choroidal melanoma
Overall, eye tumors are rare compared to other tumors. Choroidal melanoma affects one in 100,000 people each year in Europe. Choroidal melanoma is around 50 times more common in white-skinned people than in dark-skinned people. With increasing age, the risk of choroidal melanoma increases. Most choroidal melanoma diseases occur between the ages of 60 and 70. Up to about 50% of those affected die of liver and lung metastases.
Is choroidal melanoma hereditary?
Choroidal melanoma is a disease that cannot be inherited directly or for which at least no direct heredity is known. However, genetic factors can play a role. For example, people with lighter skin are more likely to have choroidal melanoma. In addition, certain genetic diseases such as neurofibromatosis can be a risk factor for the development of choroidal melanoma. In principle, however, the choroidal melanoma is a disease that mainly occurs in old age and is due to many environmental factors.
Detecting a choroidal melanoma
What are the symptoms of a choroidal melanoma?
In most cases, the choroidal melanoma does not cause any symptoms at first. Therefore, it goes undetected for a long time until it reaches a certain size. Sometimes it is discovered by accident during a routine check-up at the ophthalmologist. When the tumor grows and reaches a certain size and has expanded to the area of sharpest vision, significant visual impairment occurs.
An orange pigment on the surface of the tumor is characteristic of a choroidal melanoma. The ophthalmologist can recognize this in his examinations. The tumor usually bulges, sometimes bumpy. If the doctor can see solid tissue under the bulge during an ultrasound scan, this indicates a choroidal melanoma. During the examinations, the doctor can often detect a detachment of the retina on the lower part of the eye. An intense black color and a size of less than 2mm speak against a choroidal melanoma. Both eyes are rarely affected.
Read more on the subject at: Retinal detachment
How is choroidal melanoma diagnosed?
Every routine ophthalmological examination (e.g. when prescribing glasses) should include an ocular fundoscopy, as this enables a choroidal melanoma to be detected at an early stage. If there is a suspicion of a choroidal melanoma, an ophthalmoscopy at the ophthalmologist, possibly even at the family doctor, is indicated in any case. An ultrasound examination can provide information about the exact location and size of the choroidal melanoma. Abnormalities and other diseases of the choroid can be distinguished here.
Read more on the subject at: Fundoscopy
A so-called fluorescence angiography is carried out for the photographic imaging of the blood vessels of the eye. The finest blood vessels are made visible by fluorence dyes. This allows the doctor to get an idea of the condition of the eye blood vessels.
To rule out metastases, a chest x-ray and an ultrasound examination of the abdominal organs should also be performed. If metastases are suspected, computed tomography and magnetic resonance imaging are recommended. A sample, known as a biopsy, usually of the liver, is also taken if metastases are suspected. Follow-up and follow-up checks are important.
You might also be interested in: Conjunctival tumor
Treating choroidal melanoma
How is choroidal melanoma treated?
Treatment for choroidal melanoma is based on size. If the choroidal melanoma is 2-3 mm, repeated follow-ups are recommended. With a size of 4-8 mm, local irradiation is usually used. Here, a radiation carrier is sewn onto the dermis of the eye and remains for a certain time, depending on the required radiation dose. However, this method is only possible with a small height and a certain size of the tumor.
If the size is more than 8 mm, these local emitters cannot be used and have no effect. Treatment with an infrared laser is possible for flat, small tumors. This is sometimes done in combination with local radiation. For small tumors, freezing with the help of cold sticks down to -78 °, the so-called kyrotherapy, can be recommended. Laser agulation, i.e. sclerotherapy using a laser, is only recommended for small tumors of low height. Here the tumor is strongly heated by means of (laser) light.
Proton irradiation is recommended for larger tumors up to 15 mm. Radiosurgical or surgical removal of the tumor is recommended for medium-sized tumors. If the location of the tumor is favorable, it can be removed from the outside. After the tumor has been removed, antigen-specific stimulation of the immune system is recommended. The aim is to remove the tumor as completely as possible and to preserve the eye. In the case of very extensive tumors, however, removal of the eye is recommended.
chemotherapy
In some cases chemotherapy, often in combination with radiation therapy, is recommended. It is possible to deliver the chemotherapeutic drug directly to the blood vessels of the eye. It is also possible that the Drug in the vitreous humor of the eye is introduced. In both chemotherapeutic procedures, the drug is given in high doses to the affected area. In some cases this could cause the Treatment success improved and the side effects are reduced.
Preventing choroidal melanoma
What are the causes of choroidal melanoma?
It was previously thought that excessive UV radiation may cause choroidal melanoma, similar to skin cancer (Melanoma). Since the vitreous in the eye absorbs the incident UV rays, UV radiation is unlikely to be the main cause of choroidal melanoma.
However, a connection with the loss of a chromosome, namely chromosome 3, was established. In contrast to the skin melanoma, a close relationship to the genes, a so-called genetic disposition, was discovered in the choroidal melanoma. It has been observed that people with a choroidal tumor who had two healthy chromosomes 3 rarely developed the malignant form of choroidal melanoma. Accordingly, they very rarely showed metastases. Those affected with a loss of chromosome 3, on the other hand, very often developed malignant, metastatic choroidal melanomas.
Course of a choroidal melanoma
What is the course of a choroidal melanoma?
The choroidal melanoma grows for a long time without being noticed by the patient, since it does not cause symptoms. Eyesight is restricted only from a certain size. Since the choroid membrane of the eye has no lymphatic vessels, the degenerated melanocytes grow without being recognized by the immune system and can form metastases in other parts of the body early in the course of the disease.
When do metastases occur?
Because the eye is not supplied with lymph vessels, the choroidal melanoma can grow for a very long time without being recognized by the immune system as foreign and malignant. This is also the reason that choroidal melanomas are often metastasized when the diagnosis is made. This means that the degenerated cells of the choroidal melanoma were carried to other parts of the body via the blood and have settled there. The most common locations of metastases in choroidal melanoma are the liver and lungs.
Read more on the subject at: Metastases
Liver metastases
Since the cancer cells are mainly distributed via the blood, organs such as the liver, lungs and bones are mostly affected. Metastases can also occur in the eye itself. Liver metastases can often be treated surgically; alternatively, radiation methods are available. Nevertheless, the prognosis is only limited if such distant metastases are present.
What are the chances of recovery from a choroidal melanoma?
The chances of recovery depend on whether the tumor has been completely removed. The further prognosis depends on various factors, including the size and cell type of the tumor tissue. With large and so-called epithelial cell or mixed-cell tumors, the prognosis is worse than with small and so-called spindle cell tumors. About half of those affected with epithelial cell or mixed cell tumors die within 5 years. However, exceptions confirm the rule, as many individual factors determine the chances of recovery and the course. If metastases form, the overall prognosis is worse.
What's the survival rate?
The survival rate for choroidal melanoma depends primarily on the stage at which the disease is discovered. If only one tumor focus is found in the eye, the statistical survival rate for the next 5 years is around 75%. On the other hand, 25% of affected people develop metastases within the next 5 years, in which the cancer spreads to other organs. In this case, the prognosis is significantly worse. If such distant metastases can already be found, the median survival is around six months. As with many such statistically collected numbers, these are average values. A reliable prediction of the survival of an individual affected person is therefore not possible.
