Neuroblastoma

 Neuroblastoma

Overview

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.

Symptoms

Signs and symptoms of neuroblastoma vary depending on what part of the body is affected.

Neuroblastoma in the abdomen — the most common form — may cause signs and symptoms such as:

*Abdominal pain

*A mass under the skin that isn't tender when touched

*Changes in bowel habits, such as diarrhea or constipation

Neuroblastoma in the chest may cause signs and symptoms such as:

*Wheezing

*Chest pain

*Changes to the eyes, including drooping eyelids and unequal pupil size

Other signs and symptoms that may indicate neuroblastoma include:

*Lumps of tissue under the skin

*Eyeballs that seem to protrude from the sockets (proptosis)

*Dark circles, similar to bruises, around the eyes

*Back pain

*Fever

*Unexplained weight loss

*Bone pain

When to see a doctor

Contact your child's doctor if your child has any signs or symptoms that worry you. Mention any changes in your child's behavior or habits.

Causes

In general, cancer begins with a genetic mutation that allows normal, healthy cells to continue growing without responding to the signals to stop, which normal cells do. Cancer cells grow and multiply out of control. The accumulating abnormal cells form a mass (tumor).

Neuroblastoma begins in neuroblasts — immature nerve cells that a fetus makes as part of its development process.

As the fetus matures, neuroblasts eventually turn into nerve cells and fibers and the cells that make up the adrenal glands. Most neuroblasts mature by birth, though a small number of immature neuroblasts can be found in newborns. In most cases, these neuroblasts mature or disappear. Others, however, form a tumor — a neuroblastoma.

It isn't clear what causes the initial genetic mutation that leads to neuroblastoma.

Risk factors

Children with a family history of neuroblastoma may be more likely to develop the disease. Yet, familial neuroblastoma is thought to comprise a very small number of neuroblastoma cases. In most cases of neuroblastoma, a cause is never identified.

Complications

Complications of neuroblastoma may include:

*Spread of the cancer (metastasis). Neuroblastoma may spread (metastasize) to other parts of the body, such as the lymph nodes, bone marrow, liver, skin and bones.

*Spinal cord compression. Tumors may grow and press on the spinal cord, causing spinal cord compression. Spinal cord compression may cause pain and paralysis.

*Signs and symptoms caused by tumor secretions. Neuroblastoma cells may secrete certain chemicals that irritate other normal tissues, causing signs and symptoms called paraneoplastic syndromes. One paraneoplastic syndrome that occurs rarely in people with neuroblastoma causes rapid eye movements and difficulty with coordination. Another rare syndrome causes abdominal swelling and diarrhea.

Diagnosis

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.

Staging

Once neuroblastoma is diagnosed, your child's doctor may order further testing to determine the extent of the cancer and whether it has spread to distant organs — a process called staging. Knowing the cancer's stage helps the doctor decide what treatment is most appropriate.

Imaging tests used to stage cancer include X-rays, bone scans, and CT, MRI and MIBG scans, among others.

The stages of neuroblastoma are indicated by Roman numerals that range from 0 to IV, with the lowest stages indicating cancer that is limited to one area. By stage IV, the cancer is considered advanced and has spread to other areas of the body.

Treatment

Your child's doctor selects a treatment plan based on several factors that affect your child's prognosis. Factors include your child's age, the stage of the cancer, the type of cells involved in the cancer, and whether there are any abnormalities in the chromosomes and genes.

Your child's doctor uses this information to categorize the cancer as low risk, intermediate risk or high risk. What treatment or combination of treatments your child receives for neuroblastoma depends on the risk category.

Surgery

Surgeons use scalpels and other surgical tools to remove cancer cells. In children with low-risk neuroblastoma, surgery to remove the tumor may be the only treatment needed.

Whether the tumor can be completely removed depends on its location and its size. Tumors that are attached to nearby vital organs — such as the lungs or the spinal cord — may be too risky to remove.

In intermediate-risk and high-risk neuroblastoma, surgeons may try to remove as much of the tumor as possible. Other treatments, such as chemotherapy and radiation, may then be used to kill remaining cancer cells.

Chemotherapy

Chemotherapy uses chemicals to destroy cancer cells. Chemotherapy targets rapidly growing cells in the body, including cancer cells. Unfortunately, chemotherapy also damages healthy cells that grow quickly, such as cells in the hair follicles and in the gastrointestinal system, which can cause side effects.

Children with intermediate-risk neuroblastoma often receive a combination of chemotherapy drugs before surgery to improve the chances that the entire tumor can be removed.

Children with high-risk neuroblastoma usually receive high doses of chemotherapy drugs to shrink the tumor and to kill any cancer cells that have spread elsewhere in the body. Chemotherapy is usually used before surgery and before bone marrow transplant.

Radiation therapy

Radiation therapy uses high-energy beams, such as X-rays, to destroy cancer cells.

Children with low-risk or intermediate-risk neuroblastoma may receive radiation therapy if surgery and chemotherapy haven't been helpful. Children with high-risk neuroblastoma may receive radiation therapy after chemotherapy and surgery, to prevent cancer from recurring.

Radiation therapy primarily affects the area where it's aimed, but some healthy cells may be damaged by the radiation. What side effects your child experiences depends on where the radiation is directed and how much radiation is administered.

Bone marrow transplant

Children with high-risk neuroblastoma may receive a transplant using stem cells collected from bone marrow (autologous stem cell transplant).

Before the bone marrow transplant, also known as stem cell transplant, your child undergoes a procedure that filters and collects stem cells from his or her blood. The stem cells are stored for later use. Then high doses of chemotherapy are used to kill any remaining cancer cells in your child's body. Your child's stem cells are then injected into your child's body, where they can form new, healthy blood cells.

Immunotherapy

Immunotherapy uses drugs that work by signaling your body's immune system to help fight cancer cells. Children with high-risk neuroblastoma may receive immunotherapy drugs that stimulate the immune system to kill the neuroblastoma cells.

Newer treatments

Doctors are studying a newer form of radiation therapy that may help control high-risk neuroblastoma. The treatment uses a radioactive form of the chemical metaiodobenzylguanidine (MIBG). When injected in to the bloodstream, the MIBG travels to the neuroblastoma cells and releases the radiation.

MIBG therapy is sometimes combined with chemotherapy or bone marrow transplant. After receiving an injection of the radioactive MIBG, your child will need to stay in a special hospital room until the radiation leaves his or her body in the urine. MIBG therapy usually takes a few days.

TYPE OF DOCTOR AND DEPARTMENT: Pediatric Hematology/Oncology SPECIALIST CAN DIGNOSES THIS DISEASE.