What is neuroblastoma?
Neuroblastoma is a cancerous tumour that begins in nerve tissue of infants and very young children. The abnormal cells are often found in the nerve tissue that is present in the unborn baby and later develops into a detectable tumour. Neuroblastoma is rare in children older than 10 years of age, however, it does occur occasionally in adults.
The tumour usually begins in the tissues of the adrenal gland found in the abdomen, but may also begin in nerve tissue in the neck, chest, and/or pelvis. The adrenal glands are positioned on top of the kidneys. These glands secrete hormones and other important substances that are required for normal functions in the body such as the nervous system.
In Australia, approximately 60 children are diagnosed with neuroblastoma each year. It is often present at birth, but not detected until the tumour begins to grow and compress the surrounding organs. Most children affected by neuroblastoma have been diagnosed before the age of 5. In rare cases, neuroblastoma can be detected before birth by a foetal ultrasound. It is the most common solid tumour cancer in childhood.
Neuroblastoma cancer cells can spread (metastasize) quickly to other areas of the body (i.e., lymph nodes, liver, lungs, bones, central nervous system, and bone marrow). Approximately 70 percent of all children diagnosed with neuroblastoma will have some metastatic disease.
What causes neuroblastoma?
The only risk factor that has been established for neuroblastoma is heredity. Recent research indicates that a common genetic variation of the gene 6p22 on chromosome 6 doubles the risk of this disease. Also, having this particular variation increases the chance that a child will develop a more aggressive form of the disease.
The average age at diagnosis in genetically linked cases is around nine months. When the cancer presents in several different areas of the body at once, this suggests it may be a genetically inherited cancer.
What are the symptoms of neuroblastoma?
The following are the most common symptoms of neuroblastoma. However, each child may experience symptoms differently. The symptoms of neuroblastoma vary greatly depending on size, location, and spread of the tumour. Symptoms may include:
- abdominal mass, either felt during an examination or seen as swollen abdomen
- tumours in the face or head can cause swelling and bruising of the area around the eyes and uncontrolled eye movement
- compression of kidney or bladder by the tumour may cause changes in urination
- bone marrow involvement may present as pain, limping, paralysis, or weakness
- diarrhoea may be present; diarrhoea is caused by a substance produced by the tumour (vasoactive intestinal peptide, or VIP)
- high blood pressure and increased heart rate may occur depending on location of tumour and the organs the tumour compresses
The symptoms of neuroblastoma may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.
How is neuroblastoma diagnosed?
In addition to a complete medical and physical examination, diagnostic procedures for neuroblastoma may include the following:
- blood tests – including a complete blood count, blood chemistries, kidney and liver function tests, and a urinalysis.
- multiple imaging studies – to evaluate primary tumour and determine extent/location of any metastases, including:
- computed tomography scan (Also called a CT or CAT scan.) – a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
- magnetic resonance imaging (MRI) – a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
- x-ray – a diagnostic test that uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film.
- ultrasound (Also called sonography.) – a diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.
- bone scans – pictures or x-rays taken of the bone after a dye has been injected that is absorbed by bone tissue. These are used to detect tumours and bone abnormalities.
- bone marrow aspiration and/or biopsy – a procedure that involves taking a small amount of bone marrow fluid (aspiration) and/or solid bone marrow tissue (called a core biopsy), usually from the hip bones, to be examined for the number, size, and maturity of blood cells and/or abnormal cells.
- spinal tap/lumbar puncture – a special needle is placed into the lower back, into the spinal canal. This is the area around the spinal cord. The pressure in the spinal canal and brain can then be measured. A small amount of cerebral spinal fluid (CSF) can be removed and sent for testing to determine if there is an infection or other problems. CSF is the fluid that bathes your child's brain and spinal cord.
- biopsy of primary tumour and/or metastatic lesions
Diagnosing neuroblastoma also involves staging and classifying the disease which determines treatment options and prognosis. Staging is the process of determining whether cancer has spread and, if so, how far. There are various staging systems that can be used for neuroblastoma. Always consult your child's physician for information on staging. One method of staging neuroblastoma is the following:
- stage 1 – involves a tumour that does not cross the midline of the body, is completely resectable, and has not spread to other areas of the body. The lymph nodes on the same side of the body as the tumour do not have cancer cells present.
- stage 2A – involves a tumour that does not cross the midline of the body, but is not completely resectable. This stage of tumour has not spread to other areas of the body, and lymph nodes on the same side as the tumour do not have tumour cells present.
- stage 2B – involves a tumour that may or may not be completely resectable, has not spread to other areas of the body, but lymph nodes on the same side of the tumour have tumour cells present. Lymph nodes on the opposite side of the tumour must be negative for tumour cells in this stage of disease.
- stage 3 – involves a tumour that crosses the midline of the body, is not completely resectable, and lymph nodes are positive for tumour cells. This stage also includes a tumour that does not cross the midline, but the lymph nodes on the opposite side also contain tumour cells.
- stage 4 – involves a tumour that has metastasized to distant lymph nodes, bone marrow, liver, skin, and/or other organs (except as defined in stage 4S).
- stage 4S – a child is younger than 12 months and has a tumour that may have metastasized (spread) to liver, skin, and/or bone marrow (includes minimal bone marrow involvement; more extensive bone marrow involvement should be classified as stage 4). The tumour is on one side of the body and is localized. It may have spread to the lymph nodes on the same side of the body.
Treatment for neuroblastoma:
Specific treatment for neuroblastoma will be determined by your child's physician based on:
- your child's age, overall health, and medical history
- extent of the disease
- your child's tolerance for specific medications, procedures, or therapies
- expectations for the course of the disease
- your opinion or preference
Treatment may include (alone or in combination):
- surgery (for tumour and/or metastatic resection, and removal of lymph nodes involved)
- radiation therapy
- bone marrow transplant and peripheral blood stem cell transplantation
- retinoid therapy
- supportive care (for the side effects of treatment)
- antibiotics (to prevent/treat infections)
- continuous follow-up care (to determine response to treatment, recurrent disease, and late effects of treatment)
Treatment options should be discussed with your child's physician.
Long-term outlook for a child with neuroblastoma:
Prognosis greatly depends on:
- the extent of the disease.
- the size and location of the tumour.
- a presence or absence of metastasis.
- the tumours’ response to therapy.
- the age and overall health of your child.
- your child's tolerance of specific medications, procedures, or therapies.
- new developments in treatment.
As with any cancer, prognosis and long-term survival can vary greatly from individual to individual. Prompt medical attention and aggressive therapy are important for the best prognosis. Continuous follow-up care is essential for a child diagnosed with neuroblastoma. Side effects of radiation and chemotherapy, as well as recurrence of the disease, can occur in survivors of neuroblastoma. New methods are continually being discovered to improve treatment and to decrease side effects.