Neuroblastoma

Disease information

Overview
Causes
and Symptoms
Treatment

Overview

Neuroblastoma is a type of cancer that develops from early nerve cells meant to become part of the sympathetic nervous system, which controls the body's involuntary functions such as heartbeat and blood pressure. It ranks as the third most common cancer among children, after leukemia, brain tumors, and lymphoma, and is the most common cancer in babies under the age of one. Most cases of neuroblastoma are diagnosed in children before they turn 5 years old, and it's quite rare in children over 10. About three-quarters of neuroblastoma cases start in the abdomen or pelvis, with half of these beginning in the adrenal glands—small glands on top of the kidneys. However, since the sympathetic nervous system extends throughout the body, neuroblastoma can potentially begin anywhere sympathetic nerve cells are found.

Causes and Symptoms

Neuroblastoma is a cancer that develops from early nerve cells, often with no clear cause. However, certain genetic factors, like abnormalities on chromosome 1 or conditions such as Turner syndrome, might increase the risk. There's also some evidence that exposure to anticonvulsants or alcohol during pregnancy could raise the likelihood of a baby developing neuroblastoma.

This type of cancer can start anywhere in the body that has sympathetic nerve tissue, which is why its symptoms can be quite varied. It's most often found as a large mass in the abdomen. The symptoms depend on where the tumor is located: In the chest: It may lead to a hoarse voice, cough, or trouble breathing. In the pelvis: It could cause issues with urination, like needing to go frequently or having trouble starting. Near the spine: It might result in paralysis or make it difficult to move arms or legs. Neuroblastoma can spread to other parts of the body, a process known as metastasis. If it spreads behind the eyes, it can make the eyes bulge or create dark circles. If it affects the bones, it can be painful. General signs of cancer like unexplained weight loss, sweating at night, and fevers with no known cause can also occur, along with symptoms like anemia, diarrhea, and high blood pressure.

Treatment

In treating neuroblastoma, we carefully consider several important factors before deciding on the best course of action. The treatment plan is influenced by how advanced the tumor is, the age of the patient, and the results of genetic tests, which may include looking for changes in oncogenes like N-myc. We use a process known as risk stratification to sort patients into various risk groups. This is a critical step as it helps us tailor the treatment to the specific needs of each patient. Depending on the group they fall into—low, intermediate, or high risk—patients may receive different types of treatment. These treatments can range from surgery to remove the tumor to more aggressive approaches like chemotherapy, radiation therapy, or even stem cell transplants and immunotherapy for those in higher-risk categories. Our goal is always to choose the most effective treatment with the best possible outcome for our patients.

Treatment for low-risk groups

For patients with neuroblastoma who are categorized in the low-risk group, the main treatment is usually surgery to remove the tumor. If the entire tumor can be surgically removed and there are no other concerns, that might be all the treatment needed. However, if the tumor is too large to remove completely, doctors may start with chemotherapy to shrink the tumor before attempting surgical resection. In some cases where the tumor cannot be removed entirely, additional chemotherapy may be given after surgery to target any remaining cancer cells. Furthermore, for patients with the special case of MS (metastatic special) stage neuroblastoma without amplification of the N-myc oncogene—a genetic change that can affect how the cancer grows—doctors may choose to monitor the patient closely without immediate treatment, as this scenario often has a favorable outcome without intervention.

Intermediate-risk group treatment

The main part of the treatment plan involves a strong mix of chemotherapy drugs. If there's any part of the tumor left over after the chemotherapy, we go in and remove it with surgery. After surgery, we usually give some more chemotherapy to help get rid of any cancer cells that might still be there. If needed, we might also use radiation therapy.

High-risk group treatment

For those in high-risk groups, we start treatment with a potent mix of chemotherapy drugs to induce remission. If there's any tumor left after this, we surgically remove it. Then, we administer high-dose chemotherapy and perform a hematopoietic stem cell transplant. If necessary, we can repeat the high-dose chemotherapy and stem cell transplant 2-3 times. If there's still some tumor left after these treatments, we use additional therapies like immunotherapy and differentiation therapy with retinoids to get rid of any remaining microscopic disease. Thanks to the use of high-dose chemotherapy and immunotherapy, we've been able to increase the disease-free survival rate to about 50% in children with high-risk neuroblastoma.

In which cases is hematopoietic stem cell transplantation performed?

For children who fall into the high-risk category, standard surgery and chemotherapy may only offer a cure rate of about 20-50%. So, we use high-dose chemotherapy to try to get rid of the neuroblastoma. However, this treatment can destroy the bone marrow, so we follow it up with a hematopoietic stem cell transplant to help the bone marrow recover. This process of high-dose chemotherapy followed by a stem cell transplant is usually done twice, with a three-month gap in between.

What preparations are required when undergoing hematopoietic stem cell transplantation?

After we've used chemotherapy and surgery to put the disease into remission, we collect hematopoietic stem cells from the bloodstream using a process called leukapheresis.