You know the phrase “four-letter word” to mean cuss words, curses and dirty words. For parents though, perhaps the dirtiest word is actually a six-letter word: cancer.
As an adult, you probably already understand the general nuances of the cancer world; the medical phrases like clinical trials and chemo protocols, the scary symptoms like unexplained fevers and bruising, and the side effects of chemotherapy and radiation. As a general rule of thumb, most adults seem to innately understand these things about cancer. Imagine my surprise when I started reading about retinoblastoma and I found that I needed a biology course simply to understand what it is, beyond just a cancer in the eye. One would think that cancer is enough of a sick joke in and of itself, but to have cancer in the eye? Killer cells multiplying inside the part of your eye that detects light? The thought sickens me. I cannot imagine how the kids diagnosed with this cancer view the world, figuratively and literally. You know what gets me, really gets me, is that cancer is just a bunch of cells that begin to grow out of control, seemingly out of nowhere and for very little, if any, reason. In the same way a group of cells can grow into a beautiful, healthy baby, a group of cells can grow into a nasty cancer.
What is Retinoblastoma?
Retinoblastoma is a cancer of the retina, which is the thin membrane on the inside back of the eye. Retinas have cells called retinoblasts. In healthy children, these cells fill the retina as they divide themselves into new cells. At a certain point, they stop dividing and mature into our light-detecting retinal cells. In rare cases, these cells continue to divide and do not mature; instead, they begin to grow out of control and form the most common type of eye cancer in children – retinoblastoma. This comprises 3% of all childhood cancers, with an average of 275 kids diagnosed in the US each year. Retinoblastoma is diagnosed very early in life, usually before age 3 and can be both hereditary and nonhereditary.
Hereditary retinoblastoma is also known as germline retinoblastoma. Just shy of half of all retinoblastoma patients are diagnosed with this form. These kids are found to have a genetic defect that causes multiple tumors in one or both eyes and can be passed on in families. Germline retinoblastoma increases the odds that other cancers will develop inside or outside the eye, and carries a higher risk of other cancers later in life. Germline retinoblastoma is usually diagnosed by age 1.
On the contrary, nonhereditary retinoblastoma does not come with the increased risk of other cancers, and usually forms in only one eye and is generally diagnosed by the age of 2. This type is slightly more prevalent.
Although cancer is such a dirty word, we are fortunate that modern medical advances have propelled the survival rate of this type of pediatric cancer to between 70% when both eyes are affected and 95% when only one eye is affected. Those are some pretty good odds!
Common Symptoms of Retinoblastoma
Often, retinoblastoma may fail to show symptoms. What kind of world is this when your child has cancer but has no symptoms? Luckily, medical and scientific advances today have added standard tests to pediatric check ups in order to screen for abnormalities or signs of the disease. It’s important to note that some symptoms are less noticeable and doctors may rely on the parent to advocate for anything that seems “off” about their child.
Common symptoms of retinoblastoma include:
- “Cat’s eye” (also called the white pupillary reflex or leukokoria), is a white-yellow orb-like spot seen through the pupil. Many times, this symptom is first noticed in photographs, especially when the flash is used. In children with retinoblastoma, what would normally appear as red-eye from a flash appears whitish instead. Learn more here.
- Poor vision issues
- The presence of strabismus, when one or both of the eyes turn inward or outward (often called “lazy eye”)
- Pain or discomfort in the eye, pressure as the tumor grows
If left untreated, retinoblastoma can spread widely throughout the retina, the tissue beneath the retina, and the fluid in the eye, called vitreous. Large tumors can detach from the retina and break into small tumors. These are aptly named “vitreous seeds”. Floating in the vitreous, these seeds are very difficult to treat. These tumors are also adept at spreading into the optic nerve, brain, bones and bone marrow.
Before retinoblastoma, or any cancer, can be treated, it must be diagnosed in order to plan the most effective treatment. CTs, bone scans, MRIs, ultrasounds, and xrays are all effective methods in the diagnosing of retinoblastoma as well as determining placement, size, and severity of the cancer. Biopsy is normally an integral part of the cancer diagnosis and treatment, but with eye cancers, a biopsy just can’t be done without risking the health of the rest of the eye and the spread of the cancer to the surrounding tissues. Fortunately, experienced doctors can identify retinoblastoma without a biopsy.
Like most pediatric cancers, treatment of retinoblastoma depends on many different factors and there isn’t one simple protocol. Each patient is different and requires the close attention of an ocular oncologist or ophthalmologist to determine what plan is best. The common factors to determine the course of treatment for retinoblastoma are:
- Whether the presence of the tumor in one or both eyes
- Whether the center of vision is affected
- Whether the tumor has spread to other parts of the body (metastasis)
Treatment for retinoblastoma can include surgery, chemo and/or focal therapy, and radiation therapy.
Generally, surgery is used in advanced cases in order to completely remove the cancerous eye, also known as enucleation. This treatment, as scary as it sounds, has a pretty good prognosis in patients with only one eye affected. In most cases, when the cancerous eye is removed, 90% of these children do not require any other treatment as the cancer was removed with the eye. In patients with both eyes affected, the eye with the larger amount of the tumor is removed and then treatment is focused on the remaining diseased eye.
Chemotherapy, as we all know, is a powerful medicine used to stop cancerous cell growth and inhibit the reproduction of more. In the best-case scenario, it’s used to completely kill the cancerous cells. In many cases, the chemo is injected into the bloodstream to allow it to travel to all areas of the body, in essence to kill any cancerous cells in the body. In some cases, the chemo can be injected directly around the eye for local treatment (called periocular, which translates accordingly as “around the eye”).
Fortunately, medical advances have allowed for all the fighting power of multiple chemos as once, called combination therapy. While this type of chemo treatment boosts the eradication of the tumor, chemo alone has not been found to cure retinoblastoma. Patients today are also given focal therapy, a focused laser treatment designed to fight the cancerous cells while minimizing any side effects to surrounding tissues. Cryotherapy, a type of laser treatment using freezing power, may also be used as focal therapy. In some cases, focal therapy continues after a chemo protocol is complete and, if the tumors are small enough, only focal therapy may be used successfully to kill the cancer.
Another way to target the specific cancer cells is photocoagulation. This relatively new science uses lasers to kill either the small tumors or the blood vessels that feed the tumors, thus resulting in starving them off and disabling their growth.
If left untreated or in advanced cases, retinoblastoma can invade the brain or spread to lymph nodes or the bones or bone marrow. When this is the case, children may require a stem cell transplant to reintroduce healthy white blood cells to the body. Stem cell transplants replace the chemo-stricken blood-forming cells in the marrow with donor cells that have never been treated with either chemo or radiation. This gives the patient new, healthy, immature blood cells that with grow into healthy cells, thus rebuilding a healthy system. Some stem cell transplants are called bone marrow transplants because the cells come straight from marrow.
It’s so very difficult to come up with something one person can do to help eradicate cancer of any kind. Sadly, science today is still not advanced enough to inoculate against or prevent retinoblastoma to any degree, but the one constant need for nearly every type of cancer is blood donation and/or bone marrow donation. The Red Cross is a great resource when searching for a blood drive near you and Be The Match, the bone marrow registry website, has all the information necessary to make the decision to selflessly give HOPE to a cancer fighter.