Neuroblastoma is a malignant tumor derived from primitive neural crest cells. It belongs to a group of neuroblastic tumors, which include ganglioneuroblastoma (a malignant tumor comprised of mature ganglion cells and nerve fibers, regarded by many to be a fully differentiated neuroblastoma) and ganglioneuroma (a benign tumor composed of Schwann and ganglion cells.
Many parents say that it is difficult for them to understand the differences between neuroblastoma, ganglioneuroblastoma, and ganglioneuroma. To further clarify, ganglioneuroblastoma is a cancerous neural tumor, however, most will act benign. A ganglioneuroblastoma may look similar to a neuroblastoma on imaging, but the prognosis is better for children with these tumors. A ganglioneuroma is a well encapsulated non-cancerous tumor composed of mature ganglion cells and nerve fibers. Ganglioneuromas do not spread to other areas like cancerous tumors. Neuroblastoma is a cancerous tumor that arises from the tissues that form the sympathetic nervous system. It is an aggressive malignancy that tends to metastasize rapidly to other areas of the body.
Progress made in the past few decades has improved survival rates for infants and older children with localized disease. However, long-term survival for older children with metastatic (wide spread) disease at diagnosis remains poor.
Researchers study the clinical and biologic appearance of neuroblastoma to form a better understanding of the disease, the risk of recurrence, and to develop therapies based on factors other than age and stage.
Staging of Neuroblastoma
- Stage 1: Tumor is confined to the area of its origin. It can be completely removed. Disease may or may not remain microscopically (residual disease). Lymph nodes identified on the same (ipsilateral) or opposite (contralateral) side of the body are negative for microscopic disease.
- Stage 2A: The tumor is confined to one side of the body (unilateral) and is not able to be removed completely. Lymph nodes identified on the same (ipsilateral) or opposite (contralateral) side of the body are negative for microscopic disease.
- Stage 2B: The tumor is confined to one side of the body (unilateral) and may or may not be able to be removed completely. Lymph nodes identified on the same (ipsilateral) side of the body show evidence of disease. Lymph nodes identified on the opposite (contralateral) side of the body are negative for microscopic disease.
- Stage 3: Tumor crosses over the midline (or center) of the body and there may or may not be affected lymph nodes in the area; or, the tumor is confined to one side of the body (unilateral) and lymph nodes identified on the opposite (contralateral) side of the body are positive for microscopic disease; or, tumor crosses over the midline (or center) of the body and lymph nodes on both sides of the body are affected.
- Stage 4: Disease is widespread and involves lymph nodes, bone, bone marrow, liver, and/or other organs. This stage does not include infants with stage 4S disease.
- Stage 4S: Tumor is confined to the area of its origin as in stage 1 and 2 with spread limited to liver, skin, and/or bone marrow.
Treatment
There are three main types of treatment for neuroblastoma: surgery, chemotherapy, and radiotherapy. The cornerstone of treatment has been chemotherapy, except in situations where the tumor is completely removed surgically or for infants with stable stage 4S disease.
Chemotherapy
Several different chemotherapeutic drugs have demonstrated potency against neuroblastoma. These include cyclophosphamide, cisplatin, doxorubicin, teniposide, and etoposide. Other drugs, such as ifosfamide, carboplatin, iproplatin, epirubicin, and vincristine are also used.
Treatment usually includes a combination of several chemotherapy drugs. By using this approach, researchers are able to draw benefits, such as how the drugs work together to accomplish its goal.
Surgery
Surgery is useful in diagnosing and treating neuroblastoma. The decision to remove a tumor is based on its location, how it is impacting major blood vessels, the child's prognosis, and other factors. Some institutions will perform liver biopsies at initial surgery.
Complications can arise as a result of surgery, such as Horner syndrome, but this is often as a result of aggressive attempts to remove an abdominal tumor when the child is first diagnosed.
Radiotherapy
Neuroblastoma is considered to be sensitive to radiation therapy. Doses generally range from 15 to 30 Gy, taking into consideration such factors as tumor size and location, as well as the age of the child.
Radiation is used along with other treatment modalities, such as chemotherapy and/or surgery. Radiotherapy also plays an important role in palliation.
Bone Marrow and Peripheral Blood Stem Cell Transplantation
Several institutions are now using transplantation as the treatment of choice for high-risk neuroblastoma. Preparative regimens vary with protocol. Melphalan is often used as a conditioning agent. Many children preparing for transplant will receive total body irradiation (TBI).
Complications
- Neuroblastoma and its treatments can cause a variety of complications. These include:
- kidney failure
- liver failure
- bone marrow failure
- decreased resistance to infection
- neurologic complications
- hearing loss
- inhibited growth
- feeding problems
- secondary malignancies
Pediatric Oncology Resource Center: Neuroblastoma
This page contains information and links on various aspects of neuroblastoma. It is part of the Pediatric Oncology Resource Center, a site produced by parents of children with cancer, hosted by Association of Cancer Online Resources.
Neuroblastoma Hope Foundation
This site provides explanations to medical terms you will need to know. It also contains information on leading research and treatment centers, diagnostic information, explanations of common treatment options, and links to other reliable sites.