While uncommon, cancers do occur in children and with a diagnosis there comes, of course, many questions and concerns.

Michael Armstrong, MD, PhD, an expert in treatment of pediatric cancers, explains what neuroblastoma -- one type of pediatric cancer -- is and how it is treated.

-- Dennis Clements MD, PhD, MPH

Michael Armstrong, MD, PhDNeuroblastoma is the third most common cancer in childhood, behind leukemia (blood cell tumor) and brain tumors. It affects 650 to 750 children in the United States each year. Nearly all cases occur before the age of 10 with a peak incidence at age two. Additionally, neuroblastoma is the most common tumor in infancy.

Neuroblastoma is a tumor of the sympathetic nervous system, which is responsible for “fight or flight” responses. It is composed of very primitive cells called neuroblasts similar to those found in the developing nervous system of a baby in utero.

The most common location for neuroblastoma to occur is in the nerve tissue of the adrenal glands, small organs that sit on top of the kidneys.

Neuroblastoma tumors can also occur anywhere along either side of the spinal column in the neck, chest, or abdomen. Neuroblastoma commonly migrates to lymph nodes, bones, bone marrow, liver, and skin.

Symptoms of Neuroblastoma

The most common symptoms found in children with neuroblastoma tumors are caused by the tumor pressing against important structures or from its invasion of the bones or bone marrow. Possible symptoms include:

• An enlarged or bulging abdomen
• Lump in the neck or chest
• Shortness of breath
• Bone pain or limping
• Weakness or paralysis (inability to move a body part)
• Bulging eyes
• Dark circles around the eyes (“Raccoon eyes”)
• Painless, bluish lumps under the skin in infants
• Jerky, involuntary muscle movements
• Uncontrolled eye movements
• Feeling tired
• Easy bruising or bleeding

Diagnosis

If your pediatrician suspects a possible neuroblastoma tumor, the following tests may be performed under the direction of a pediatric oncologist:

• Physical exam
• Blood tests to assess bone marrow, liver, and kidney function
• X-ray, ultrasound, computed tomography (CT) scan, or magnetic resonance imaging (MRI) to look for possible tumor
• MIBG scan --  MIBG is a compound that is taken up specifically by neuroblastoma cells and can be detected by a special scanner. Used to find presence of neuroblastoma tumors throughout the body
• Bone scan -- a specialized test to detect presence of tumor in the bones
• Bone marrow biopsy to assess for presence of neuroblastoma cells in the bone marrow
• A urine test to detect presence of homovanillic acid (HVA) and vanilyl mandelic acid (VMA), two compounds commonly secreted by neuroblastoma tumors
• Tumor biopsy. If a tumor is found on imaging, a pediatric surgeon will obtain a piece of the tumor. This is important to identify the specific type of tumor as well as determine important biologic features of the tumor which may direct therapy 

Treatment of Neuroblastoma

Several treatments of neuroblastoma are available including chemotherapy, surgery, radiation therapy, and autologus bone marrow transplant (using one’s own bone marrow stem cells).

The treatment regimen is determined by the child’s “risk” group. Risk is determined by factors including the child’s age at diagnosis, how much the tumor has spread (stage), and certain characteristics of the tumor cells.

In infants, the tumor often does not require treatment and will regress on its own over time. Other children require much more therapy in order to achieve a remission.

A new innovation in neuroblastoma is directing the child’s own immune system to fight the neuroblastoma. A recent publication reveals that use of an anti-neuroblastoma antibody, called ch14.18, after autologus bone marrow transplant leads to a 20 percent increase in disease-free survival at two years after diagnosis – increasing from 46 percent to 66 percent.

Prognosis

Children with low- or intermediate-risk neuroblastoma have a great prognosis with 80 to 90 percent surviving five years after diagnosis. Children with high-risk neuroblastoma do not have as good an outlook, with close to two-thirds succumbing to their disease.

High-risk neuroblastoma is an area of intense research to improve outcomes for this group. The promising results of antibody therapy are encouraging and hopefully further strides will be made in the upcoming years with the development of new drugs and treatments.

If you are concerned that your child may have a tumor like neuroblastoma, please contact your child’s pediatrician for further evaluation.

-- Michael Armstrong, MD, PhD, specializes in treatment of neuroblastoma, pediatric solid tumors, and leukemia for Duke Children's.

-- Dennis Clements, MD, PhD, is the chief of primary care pediatrics at Duke Children's Hospital.