What Is Retinoblastoma - Treatment Of Retinoblastoma - Retinoblastoma - What Is Retinoblastoma

Retinoblastoma studies have been fairly conclusive in stating that no matter what type of retinoblastoma affects a child- be it hereditary or sporadic- the cause remains the same. While it is certainly possible to have retinal cancer occur at random in certain people, for children, the primary victims of retinoblastoma, the disease develops as a result of mutations in the retinoblastoma protein gene known as Rb, or Rb1. In the earliest stages of eye development, cells known as retinoblasts form and start to multiply.

Only after these cells eventually stop their division process are they then able to mature into actual retinal cells, which aid in fulfilling the duties of the retina. Sometimes however, this creation operation will be disrupted and retinoblasts will start rapidly multiplying and growing to the point where they change into cancerous cells. This, essentially, is what causes retinoblastoma. To assure that this does not occur, a specific retinoblastoma protein gene- called the Rb or Rb1 gene- exists for the sole purpose of controlling the retinoblasts and making sure that they mutate normally. Whenever there is any type of change or abnormality in this retinoblastoma protein, however, nothing is able to stop cancer from materializing. Rb1, then, is called a tumor-suppressor gene, since it helps stop the tumor formation process. For retinoblastoma, the mutations of Rb1 are located precisely on chromosome #13. One of two different mutations can cause uncontrolled (and cancerous) cell growth: the first is a mutation inherited from a parent (only one of the parents needs to have one copy of the gene mutation to pass it on to a child), in which case the cancer would be termed inherited, or congenial, retinoblastoma; the second mutation occurs at random, during early retinal development, in which case the cancer is assigned the name sporadic retinoblastoma. The exact reasons for these genetic mutations are not known.

Symptoms of Retinoblastoma: Since young children are unlikely to notice symptoms characteristic of retinoblastoma by themselves, a regular physical examination- or a routine retinoblastoma screening test for those children which are at risk of developing retinoblastoma through family genes- will ensure that any potential signs of the retinal cancer, if present, are located, diagnosed, and treated as soon as possible. Generally, if a child's eye develops any abnormal quality, or, if a child is persistently complaining of poor vision, a trip to an eye specialist should be the next step. There are certain symptoms which can diagnose retinoblastoma in a child almost immediately, so getting a proper exam is crucial. Sometimes, the abnormality can be seen easily, such as the presence of a distinctly white or pink pupil, instead of a normal black one. This is most evident when a child is in a bright area or when he or she is exposed to sudden light, like from the flash of a camera.
Often called a "white reflex" or "cat's eye," this retinoblastoma symptom, known as a leukocoria, is the one most commonly noticed characteristic. The appearance of crossed eyes, or a "lazy eye" (strabismus) as it is commonly called, can also be a sign that retinoblastoma is potentially developing.

Less common, but equally noteworthy symptoms of retinoblastoma include:

Although the above mentioned signs are common characteristics of retinoblastoma, other abnormalities exist which yield similar symptoms. As a result of these discrepancies, a thorough exam and evaluation by a doctor or ophthalmologist is the only way to confidently rule out the possibility of retinoblastoma.

Retinoblastoma Prevention: Although many cancers come attached with a wide range of risk factors and preventative measures which can be taken to help decrease the chances of tumor development (limiting smoking for lung cancer, limiting excessive sun for melanoma, or limiting alcohol intake for liver cancer, for instance), the causes of retinoblastoma cannot be tampered in any way because they pertain to the complex network of DNA within the body. As a result of the genetic influence, there is nothing that can currently be done to help prevent retinoblastoma.

While genetic counseling is always an option for those couples who wish to have children, and it would help them better understand the probability that an Rb1 gene defect could negatively impact their child, scientists are still researching and configuring ways to try and avoid the mutation from occurring in the first place. For couples which show a high risk of a gene mutation being passed down, embryo implantation (through in vitro fertilization) is always an option. The high success rate of treatment for retinoblastoma, however, should give parents assurance that even if their child is, in fact, diagnosed with retinal cancer, a cure for the cancer is very possible. For those children whose family has shown a history of eye cancers, specifically retinoblastomas, a routine screening schedule should be set up immediately after the birth, since this provides the best chance the cancer will be found in it's earliest stages. Other than keeping a watchful eye for certain retinoblastoma symptoms, though, for now, since the causes of retinoblastoma are purely genetic, nothing can be done by mother or child to prevent the cancer from developing.

Screening and Diagnosis of Retinoblastoma: Although retinoblastoma is found early in many children due to evident symptoms, a standard retinoblastoma screening test does not exist. Although a blood test capable of testing for the Rb gene mutation is available, it is usually only used for those children which have a family history of the gene abnormality. For the latter, certain screening procedures, including an MRI, may start right after birth, and continue every few weeks or months after that, depending on if any signs or symptoms of retinoblastoma become evident. Again, such a screening is not standard and only high-risk children will have such extensive exams.

For those children that do show certain signs and symptoms, however, a variety of retinoblastoma diagnostic tests are available.A regular eye exam is usually performed first, preferably by an opthamologist who specializes in eye diseases. The next step typically involves one or more imaging tests, which create a picture of the inner structures of the body through the use of x-rays, sound waves, or radiation. Such tests are extremely important in not only confirming that a retinoblastoma is present, but in getting as many specifics about the tumor as possible, including the size, exact location, and extent of spreading. This eventually allows doctors to assign a "stage," or severity, to the tumor mass. A variety of retinoblastoma diagnostic tests are available for use, including ultrasounds, CT scans, MRI scans, and bone scans. Although popular in the diagnosis of many other cancers, a biopsy is avoided as much as possible, as the risk for cancer cells "floating" to other parts of the eye during the procedure is high. A spinal tap might also be performed if there is spreading to the brain or spinal cord suspected.

Retinoblastoma Prognosis: Although it may become overwhelming with so many different procedures being performed on a young child, the time spent in properly diagnosing and staging a retinoblastoma will only ensure that the most effective treatment is given. Once a doctor has properly examined the cancer, a retinoblastoma prognosis, or outlook, will be delivered to give an idea of the severity of the tumor. Like with all cancers, the less amount of cancer spreading usually means the higher the treatment success rate will be. Because most children are diagnosed within the first three years of life, and treated is administered before metastasis can severely damage other parts of the body, almost all retinoblastoma patients will survive the cancer; specifically, the five-year survival rate is about 90%, although nearly all children far outlive this five year marker. For metastatic retinoblastoma which has spread outside of the eye, however, the five year survival rate drops drastically to about 10%.

Retinoblastoma Treatment: The reason most retinoblastoma prognoses are so positive, of course, is because of the amazing advancements that cancer researchers and scientists have made with cancer treatments in the past decades. Although the treatment administered will be based purely on the cancer stage assigned to the retinoblastoma, many children will often have to take part in more than one treatment procedure to ensure the greatest chance of full cancer eradication and survival. The most common treatments for retinoblastoma include: surgery,which usually means enucleation, or full eye removal; photocoagulation, or laser therapy; thermotherapy or cyrotherapy, which heat and freeze the cancerous cells to their death; external and internalradiation therapy; and lastly, chemotherapy.While all of these treatment possibilities pose their own set of risks and side-effects, the main goal of any retinoblastoma treatment is to first, make sure a child can survive, and second, to make sure a child sustains as much vision as possible.

Even for those children with a severe retinoblastoma case which requires dual enucleation, or removal of both eyeballs, eye prosthetics have progressed to the point where an artificial eye can still move and look like a real eye. As the possibilities of cancer research reach new heights year after year, the possibilities of newer, better, and faster retinoblastoma treatments will similarly come to the forefront. Scientists from all around the world are constantly working to improve upon current treatment methods, like external radiation, and testing new ones, like periocular chemotherapy. Researchers are also studying what causes the Rb gene mutations in the first place, and in time, forms of gene therapy and DNA counteractions will surely be available for those families which pass down the destructive gene abnormality from generation to generation. Progress, in every form, is slowly but surely being made, and retinoblastoma is becoming an increasingly more treatable cancer.