Neuroblastoma is a rare type of childhood cancer, but it is the third most common type of childhood cancer, behind leukemia and brain tumors. However, only 600 to 1,000 cases are diagnosed in the U.S. every year.
Neuroblastoma often begins in infancy and about one-third of children are diagnosed by their first birthdays. About 75% are diagnosed by age 5. Some children are born with neuroblastomas, but they aren’t diagnosed until later, when a baby or child begins to show symptoms.
In 70 to 80% of children, the cancer has already spread to other body parts by the time that it is diagnosed. The prognosis is poor for many—but not all—children with neuroblastomas. In some cases, after babies are diagnosed, the tumor spontaneously resolves without treatment. Those who are diagnosed before they’re 18 months old tend to have a greater chance of survival.
“Neuroblastoma is a fascinating tumor and one of the few cancers that can have spontaneous regression, especially if diagnosed before birth or in the first eighteen months of life,” says Smilow Cancer Hospital pediatric hematologist-oncologist Farzana Pashankar, MD. “In recent years, the treatment for neuroblastoma has evolved significantly. And now with multimodality therapy including chemotherapy, surgery, radiation, stem cell transplant, and immunotherapy, the outcome has markedly improved, even for children diagnosed with metastatic neuroblastoma.”
What is neuroblastoma?
Neuroblastomas are solid tumors that originate in developing nerve cells. (Changes to genes or chromosomes may cause developing nerve cells to multiply uncontrollably, leading to the formation of neuroblastomas.) They often form before birth, during the fetal stage. This type of cancer is almost exclusively diagnosed during childhood, typically in younger children.
Neuroblastomas are most commonly found in the adrenal glands, which help to produce hormones. They may also appear in the abdomen, chest, neck, spinal cord or pelvis. When this type of cancer spreads to other body parts, it’s commonly discovered in the lymph nodes, bone marrow, bones, liver, or skin.
Some neuroblastomas are more aggressive than others. Doctors classify these tumors as “low-risk,” “intermediate-risk,” or “high-risk.” Low-risk tumors are most likely to be cured. The same may be true for intermediate-risk tumors, but high-risk tumors may be difficult to treat.
What causes neuroblastoma?
Doctors don’t yet know why most children develop neuroblastomas. About 1 to 2% of children may have a family history of neuroblastoma (known as familial or Inherited neuroblastoma). Genetic mutations in the ALK gene and PHOX2B gene are associated with inherited neuroblastomas.
In families with cancer predisposition syndromes such as Li-Fraumeni syndrome, Beckwith-Wiedemann syndrome, and Noonan syndrome, children are at increased risk of developing neuroblastoma.
What are the symptoms of neuroblastoma?
Children who have neuroblastomas may experience:
- A lump or swollen area in the abdomen, chest, or neck
- Bone pain
- Swollen stomach
- Difficulty breathing
- Easy bruising or bleeding
- Unexplained weight loss
- Eyes that bulge
- Dark circles or bruising around the eyes
- Drooping upper eyelids
- Uncontrollable eye movements
- “Jerky” movements
- High blood pressure
- Bluish, painless lumps beneath the skin
What are the risk factors for neuroblastoma?
Babies and children may be at increased risk of neuroblastoma if they have had:
- A family history of neuroblastoma
- Cancer predisposition syndromes in their family
How is neuroblastoma diagnosed?
Sometimes a pediatrician or parents will find a mass in a baby or child’s abdomen during a well visit. Other times, the child may complain of pain or other symptoms.
When doctors suspect that a baby or child has a neuroblastoma, they will ask about the child’s personal and family medical history, perform a physical examination, and do a series of tests to diagnose the condition.
During a physical exam, a doctor will carefully examine the child to identify any swollen areas or lumps.
The doctor may order imaging tests, such as:
- Chest X-ray
- Ultrasound of the abdomen
- CT scan
- A nuclear scan, such as an MIBG body scan or a bone scan
Doctors may test the urine for different markers that indicate neuroblastoma. They may also order blood tests to check for abnormalities.
When a mass is identified, doctors will biopsy the tissue to determine whether it contains genetic mutations associated with neuroblastoma. Testing of biopsied tissue may also determine whether someone is missing certain chromosomes or if there are extra copies of certain chromosomes; both conditions may occur when someone has neuroblastoma. For example, extra copies of the MYCN gene may indicate neuroblastoma. If doctors suspect that the cancer has spread to the bones, they may do a bone marrow biopsy.
In rare cases, a neuroblastoma may be identified and diagnosed in an unborn baby by fetal ultrasound, while a woman is still pregnant.
How is neuroblastoma treated?
The type of treatment varies, depending on the age of the child upon diagnosis, the location of the tumor, whether it has spread, and its genetic makeup.
Many babies who are diagnosed before their first birthdays who have tumors on their adrenal glands may not require treatment or even a biopsy; doctors may instead recommend watchful waiting with regularly scheduled imaging exams and urine tests. In many cases, the tumors may resolve without medical intervention.
When a child is diagnosed after the first birthday and the tumor is low-risk and in a location that makes it possible to be surgically removed, surgery is recommended. Sometimes, it may be followed by chemotherapy. After surgery and chemotherapy, if the cancer doesn’t respond well, the child may receive radiation therapy.
Sometimes, it may not be feasible to have intermediate-risk neuroblastomas surgically removed, so chemotherapy may be given to shrink the tumor. Radiation may also be offered.
If a child has high-risk neuroblastoma, several treatments may be offered:
- Chemotherapy combining two or more medications, which work together to kill cancer cells
- Surgery, which may remove cancerous tumors
- Radiation therapy, which targets cancerous cells with external beams of radiation or with intravenous radioactive iodine
- Stem cell transplant after high-dose chemotherapy, which kills cancerous cells and helps the bone marrow create healthy blood cells
- Targeted therapy, a treatment that is designed to pinpoint specific cancer cells without harming healthy neighboring cells
- Immunotherapy treatments, such as monoclonal antibodies, which help the body’s immune system better fight the cancer
What is the outlook for people with neuroblastoma?
Different types of neuroblastoma have different outlooks, depending on the genetic mutation responsible for the cancer, the age at diagnosis, and other risk factors. In children with low- or intermediate-risk neuroblastoma the outcome is excellent. Up to 90% of babies survive and be cured if the cancer is caught early. And the condition resolves in some babies without treatment.
In children with high-risk neuroblastoma or who are diagnosed with metastatic neuroblastomas that has spread to other parts of the body, the prognosis has significantly improved in recent years and over 60% of these patients can be cured.
Children who have neuroblastomas may be at risk for other types of cancer later on, including leukemia, particularly if they have been treated with chemotherapy.
What makes Yale Medicine's approach to neoplasms unique?
“The management of neuroblastoma, especially in patients with high-risk disease is complex and involves multimodality therapy with chemotherapy, surgery, radiation, stem cell transplant, immunotherapy, and targeted therapy,” says Dr. Pashankar. “At Yale Medicine, we have a dedicated multidisciplinary team of oncologists, surgeons, pathologists, radiation oncologists, and bone marrow transplant physicians who work together to provide each child with personalized state-of-the-art care. As members of the Children’s Oncology Group, we have the latest clinical trials available for our patients and continue to make significant advances in treating these children.”