What is Neuroblastoma?
Neuroblastoma is a cancer that develops from immature nerve cells found in several areas of the body.
Neuroblastoma most commonly arises in and around the adrenal glands, which have similar origins to nerve cells and sit atop the kidneys. However, neuroblastoma can also develop in other areas of the abdomen and in the chest, neck and near the spine, where groups of nerve cells exist.
Neuroblastoma most commonly affects children age 5 or younger, though it may rarely occur in older children.
Some forms of neuroblastoma go away on their own, while others may require multiple treatments. Your child’s neuroblastoma treatment options will depend on several factors.
Neuroblastoma Key Points
- Neuroblastoma is a disease in which malignant (cancer) cells form in nerve tissue of the adrenal gland, neck, chest, or spinal cord.
- Neuroblastoma is sometimes caused by a gene mutation (change) passed from the parent to the child.
- Signs and symptoms of neuroblastoma include bone pain and a lump in the abdomen, neck, or chest.
- Tests that examine many different body tissues and fluids are used to detect (find) and diagnose neuroblastoma.
- A biopsy is done to diagnose neuroblastoma.
- Certain factors affect prognosis (chance of recovery) and treatment options.
Causes of Neuroblastoma
Neuroblastoma occurs when neuroblasts grow and divide uncontrollably instead of developing into nerve cells. The exact cause of this abnormal growth is unknown, but scientists believe it’s related to a defect in the genes of a neuroblast that allows it to divide uncontrollably.
Signs and Symptoms of Neuroblastoma
The symptoms vary depending on where your child’s tumour is. The first symptoms are vague, such as tiredness, loss of appetite and pain in the bones. More specific symptoms will depend on where the neuroblastoma starts:
- If the tumour is in the abdomen, your child’s tummy may be swollen and they may complain of constipation or have difficulty passing urine.
- If the tumour affects the chest area, your child may be breathless and have difficulty swallowing.
- If the tumour occurs in the neck, it’s often visible as a lump and occasionally affects breathing and swallowing.
- Occasionally, there are deposits of neuroblastoma in the skin that appear as small, blue-coloured lumps.
- If the tumour is pressing on the spinal cord, children may have weakness in the legs and walk unsteadily. If your child is not yet walking, you may notice reduced leg movements. They may also have constipation or difficulty passing urine.
- Very rarely, children may have jerky eye and muscle movements, and general unsteadiness associated with the neuroblastoma.
- Your child may also have high blood pressure.
Stages of Neuroblastoma
As with most cancers, neuroblastoma is defined by stages that reflect the condition’s spread. There are many staging systems, but the most widely used until recently is shown first, with the more recently agreed stages in brackets:
- Stages 1 and 2 (L1) – the cancer is in one site and has not spread
- Stage 3 (L2) – the cancer has spread to local structures, but not to distant parts of the body
- Stage 4 (M) – the cancer has spread to distant parts of the body
- Stage 4s (Ms) – this special stage is for tumours diagnosed in babies under the age of 12 months; although it may have spread to other parts of the body, the outlook is fairly good, because it can get better on its own
Risk factors for Neuroblastoma?
A risk factor is anything that affects your chance of getting a disease such as cancer. Different cancers have different risk factors.
Lifestyle-related risk factors such as body weight, physical activity, diet, and tobacco use play a major role in many adult cancers. But these factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers, including neuroblastomas.
No environmental factors (such as exposures during the mother’s pregnancy or in early childhood) are known to increase the chance of getting neuroblastoma.
Tests and procedures used to diagnose neuroblastoma include:
- Physical exam. Your child’s doctor conducts a physical exam to check out any signs and symptoms. The doctor will ask you questions about your child’s habits and behaviors.
- Urine and blood tests. These may indicate the cause of any signs and symptoms your child is experiencing. Urine tests may be used to check for high levels of certain chemicals that result from the neuroblastoma cells producing excess catecholamines.
- Imaging tests. Imaging tests may reveal a mass that can indicate a tumor. Imaging tests may include an X-ray, ultrasound, computerized tomography (CT) scan, metaiodobenzylguanidine (MIBG) scan and magnetic resonance imaging (MRI), among others.
- Removing a sample of tissue for testing. If a mass is found, your child’s doctor may want to remove a sample of the tissue for laboratory testing (biopsy). Specialized tests on the tissue sample can reveal what types of cells are involved in the tumor and specific genetic characteristics of the cancer cells. This information helps your child’s doctor devise an individualized treatment plan.
- Removing a sample of bone marrow for testing. Your child may also undergo bone marrow biopsy and bone marrow aspiration procedures to see if neuroblastoma has spread to the bone marrow the spongy material inside the largest bones where blood cells are formed. In order to remove bone marrow for testing, a needle is inserted into your child’s hipbone or lower back to draw out the marrow.
Treatment for Neuroblastom
Most cases of neuroblastoma need treatment. The type will depend on factors (such as the child’s age, the characteristics of the tumor, and whether the cancer has spread) that determine risk.
The three risk groups are: low risk, intermediate risk, and high risk. Children with low-risk or intermediate-risk neuroblastoma have a good chance of being cured. However, about half of all children with neuroblastoma have the high-risk type, which can be difficult to cure.
Because some cases of neuroblastoma disappear on their own without treatment, doctors also sometimes use “watchful waiting” before trying other treatments.
Typical treatments for neuroblastoma include surgery to remove the tumor, radiation therapy, and chemotherapy. If the tumor hasn’t spread to other parts of the body, surgery is usually enough.
Unfortunately, in most cases the neuroblastoma has spread by the time it’s diagnosed. In these cases, chemotherapy and surgery are usually the primary treatments and may be done along with with radiation therapy and stem cell or transplantation.
Another treatment the doctor might suggest is retinoid therapy. Scientists believe that retinoids (a class of substances chemically related to vitamin A) can help cure neuroblastoma by encouraging cancer cells to turn into mature nerve cells. Retinoids are often used after other treatments to help prevent the cancer from growing back.
Newer treatment options include tumor vaccines and immunotherapy using monoclonal antibodies, special substances that can be injected into the body to seek out and attach to cancer cells. They’re sometimes used to stimulate the immune system to attack the neuroblastoma cancer cells.