Neuroblastoma is a cancer that arises in immature nerve cells of the sympathetic nervous system called neuroblasts. It is developed mostly in young children. It is a cancer of embryonic stem cells of the nerve tissue, and usually begins in the adrenal glands, neck, abdomen, chest or spinal cord. Neuroblastoma occurs when neuroblasts undergo changes that make their growthbecomes abnormal, leading to development of cancerous or malignant tissue. The tumor can be associated with certain genetic disorders such as Hirschsprung’s disease (please see below).
The nervous system consists of the central nervous system (CNS) and peripheral nervous system (PNS). CNS comprises the brain and the spinal cord; and the PNS includes parts of the nervoussystem that are located outside of the CNS. The nervous system consists of the somatic nervoussystem, which controls the voluntary body movements such as walking; and the autonomic nervous system that controls the involuntary body functions such as breathing and digestion.
The autonomic nervous system includes the sympathetic nervous system and the parasympathetic nervous system. It runs various activities of the body to a state of rest while the sympathetic nervous system prepares the body for action. The nerves of this system controlthe fight-or- flight response. They react to situations that require strength and perception, mainly situations that cause fear, anger, excitement or embarrassment
Epidemiology and Evolution
The main age of Neuroblastoma diagnosis in children is between one and two years. Its incidence is approximately one case per 100,000 children. This remains the most common cancer in children under one year. It is mainly a childhood cancer, although a few cases have been reported in adults.
Neuroblastoma is known to be one of the few cancers to present regressions of an undifferentiated state to a completely non-cancerous (benin) cellular state, which can lead tospontaneous healing. This favorable trend is, however, far from constant. In fact, evolution is highly variable.
Cause and risk Neuroblastoma
Neuroblastoma causes are really known to scientists. There is no known single cause of neuroblastoma. Most cancers are due to many risk factors. However, some children with neuroblastoma have no identifiable risk factors.
Age and gender seem to play certain role in its development. Approximately 80% of neuroblastoma cases occur before the age of 5 years. This is the most common cancer in infants less than 1 year. The disease is rare in children over 10 years. It affects slightly more boys than girls: for 5 boys who develop neuroblastoma, 4 girls have it.
Scientists believe that the following factors increase the risk of developing neuroblastoma
Family History – Approximately 1-2% of children who are diagnosed with neuroblastoma have a family history of the disease, especially if the cancer has manifested in one of their siblings or with their identical twin.
Genetic Disorders – It is known that neuroblastoma tends to develop in children with genetic disorders relating to conditions that affect neural crest cells. These conditions include:
- Hirschsprung’s disease
- Beckwith– Wiedemann syndrome
- DiGeorge syndrome, also called 22q11.2 deletion syndrome
- hyperinsulinemic hypoglycemia and pancreatic nesidioblastosis
- Von Recklinghausen’s disease(VR), a rare type of medical condition also called neurofibromatosis type 1
Other Possible risk factors
The fact that most cases of neuroblastoma occur at a very young age, It is also believed that prenatal exposure to alcohol due to alcohol consumption of the mother during pregnancy mayinterfere with normal development of neural crest cells, thus causing the disease. Certain drugs such as diuretics, anticonvulsants, oral contraceptives and fertility hormones are also suspected.
Signs and Symptoms of Neuroblastoma
Neuroblastoma symptoms vary depending on the organ affected. The disease can developanywhere along the peripheral nervous system, then its signs and symptoms are not easily recognizable at the beginning. However, the most common symptoms occur because the tumorpresses on nearby tissues as it develops, or when the cancer has spread to the bones. In most cases, the neuroblastoma does not cause malfunction of the peripheral nervous system.
Signs and symptoms of neuroblastoma may also be caused by other medical conditions. It isimportant to consult a physician if of these any unusual symptoms occur.
|Neuroblastoma in the Abdomen||Neuroblastoma in the Chest||Neuroblastoma in the Neck area||Neuroblastoma in the spinal cord|
|· swelling of the abdomen
· difficulty urinating
· nausea andvomiting
· loss of appetite
· weight loss
· abdominal fullness
· swelling in thegroin or legs
· difficulty swallowing
· difficulty breathing orshortness of breath
· sweating andirritability due to increased production ofcatecholamines
|· visible neck mass
· difficulty breathing
· difficulty swallowing
· discoloration in the iris of the eye
· drooping eyelids (ptosisipsilateral)
· small pupils(miosis)
· inability to sweat(anhidrosis)
|· weakness in legs
· walking abnormalities (wobbly gait)
· incontinenceor difficulty in urination
· irregular bowel movements
· anemia, paleness, easy bruisingand bleeding
Depending on the severity of the disease there may be other signs and symptoms, which may include:
- mild fever
- weight loss
- Bone pain
- increase in blood pressure
- Flushing of the face and neck
- Raccoon eyes – dark circles and protruding eyes
- Hard, bluish masses under the skin
- Opsomyoclonus(dancing eyes dancing feet syndrome)
severe diarrhea caused by an increased production of a hormone called vasoactive intestinal peptide (VIP)
Neuroblastoma treatment depends on the stage and location of the tumor. When the cancer islocated, it is usually curable. However, the life expectancy of children with advancedneuroblastoma remains low despite aggressive therapies.
In more advanced cases, platinum-compound chemotherapycisplatin is administered, along with Etoposide alternated with vincristine, doxorubicin and cyclophosphamide. Topotecan appears to be given in serious cases, but relapses are frequent. Bone narrow transplant after aplastic chemotherapy is often include in the treatment options.
Some oncologists use surgery, radiation therapy or other chemotherapy drugs. Biological therapyand other forms of therapy are sometimes recommended. Usually, the health care giverdiscusses the options with the parents of the sick child to determine the best treatment plan to be adopted.
Treatment plans is designed to meet the unique needs of each child with Neuroblastoma; there is no unique regimen. The final decision is based on risk involved and category of the tumor being treated. Children with neuroblastoma are classified as high, medium or low, depending on the age of the child, stage of cancer or characteristics of neuroblastoma cells.
Clinical Trials – Clinical trials are designed to find better methods of prevention, detection and treatment of neuroblastoma. In USA, few clinical trials are available to children with neuroblastoma.