Cancers In Kids

“Retinoblastoma is the most common eye cancer in children, affecting hundreds of children in India and thousands of children worldwide each year, which can be fatal when diagnosed late. About half of the children suffering from this cancer carry a mutation in the RB1 gene that may run in their family (heritable mutation), with potentially fatal consequences to those affected.”

Dr. Ashwin C Mallipatna, MBBS, MS, DNB, 
Pediatric Ophthalmologist

Childhood Cancer – This word combo does not sit right, definitely not right. Childhood should not be blighted with cancer. The very idea of kids suffering through chemotherapy is enough to make your hair stand on end. Yet, there are many cases of children suffering from cancer. Typically, 1% of the total cancer cases diagnosed in the US, every year, are pediatric cancer cases.

In India, estimates suggest that approximately 40-50,000 new cases of childhood cancer are diagnosed every year. The five-year-survival rate for pediatric cancer patients is just 35-40% in India. So, let us take a look at just what form childhood cancers take and what can be done to improve this outlook!

The most common childhood cancers are:

• Brain and Spinal cord tumors (Brain and Spinal cord)
• Wilms Tumor (Kidneys)
• Leukemia (Blood)
• Retinoblastoma (Eyes)
• Rhabdomyosarcoma (Muscles of the limbs)
• Hodgkin’s and non-Hodgkin’s lymphoma (Lymphatic system)
• Osteosarcoma (Bone and muscles)
• Ewing Sarcoma (Bones and muscles)
• Neuroblastoma (Nerves of the fetus)

Most doctors agree that childhood cancers are treatable, if detected and diagnosed early. What can we do to facilitate early diagnosis of such cancers? One obvious answer is to be aware of the symptoms, especially if there is a family history of such cancers. Another opportunity is presented by the more recent availability of genetic testing. For example, Strand offers genetic diagnostic tests for determining the genetic basis of pediatric cancers such as retinoblastoma.

Retinoblastoma is a cancer of the eye that is caused when two genes – RB1 and MYCN – are defective. Deletions of a region of chromosome 13, that contains the RB1 gene, are also responsible for causing retinoblastoma.

The most common symptom of retinoblastoma is the development of a ‘cat’s eye reflex’ or ‘leukocoria’ that is often seen as a white spot in a photograph.

Early diagnosis of retinoblastoma – using genetic diagnostic tests to identify pathogenic RB1 mutations as well as by other ocular diagnostic techniques – is essential for three good reasons:

1. Development of retinoblastoma in the contralateral (other) eye is highly likely, if one eye has developed this cancer and especially if a genetic defect is to blame.
2. Retinoblastoma is highly treatable. There is a chance to save the child’s vision to a great extent, if the disease is diagnosed and treated early.
3. If left untreated, this cancer can also spread to other organs and ultimately, turn fatal.

A genetic test for retinoblastoma, like the one available at Strand, looks for pathogenic mutations in the RB1 gene. Mutations in RB1 can be hereditary and hence, early determination of the presence or absence of pathogenic mutations in a child is essential.

The RB1 gene acts as a tumor suppressor gene. Essentially, if a cell tries to divide out-of-turn, proteins like RB1 and other tumor suppressor proteins quickly act to stop the cell division activity. When such sentinel genes are mutated, their proteins are less efficient in their action and therefore, cancers develop.

Kids who have mutations in the RB1 gene are also at risk for developing cancer of the pineal gland, skin cancers, cancer in muscle cells and cancer of the bone.

Hence, a genetic diagnostic test that provides clear-cut evidence of the status of the RB1 gene, adds valuable information to the treatment plan for the child. Doctors and parents can then keep an eye out for symptoms of other cancers as well and take timely actions.

Write to us at stayaheadofcancer@strandls.com to know more about retinoblastoma as well as other childhood cancers.