What Causes Neuroblastoma in Children?

Neuroblastoma in children is caused by neuroblasts that do not mature. They do not become the normal nerves or adrenal cells that they should mature into at birth. These immature neuroblasts form a tumor.

During development in the womb, a fetus makes immature nerve cells. At birth, these neuroblasts are supposed to develop into nerves and adrenal cells that make nerve fibers and adrenal glands. In most newborns, a tiny amount of immature neuroblasts do not mature and usually disappear. For some infants, these neuroblasts remain and form a cancerous tumor.

Neuroblastoma in children is usually present at birth. It often goes undetected, however, until a tumor appears and causes symptoms. The majority of children affected are diagnosed by the time they are 5 years old. In rare instances, a malignant tumor is detected before birth in an ultrasound, but it is not common to find tumors before the age of 1.

Doctors believe that neuroblastoma in children is caused by a genetic abnormality in the first chromosome. The short end of this chromosome has a missing or rearranged section. This causes the extra amplification of the oncogene known as MYCN. An oncogene is a gene that causes cancer by making a cell become malignant. An amplification of MYCN leads to an unregulated and rapid growth of cancer cells.

Some children have inherited genes, from one or both parents, that makes them more likely to acquire cancers. For neuroblastoma in children, conditions such as fetal hydantoin syndrome and neurofibromatosis often lead to neuroblastoma. The initial genetic abnormality exists at conception, and then the second abnormality becomes active at birth.

The tumors that grow with neuroblastoma in children usually begin in the nerve tissue of the pelvis, chest and/or neck. Tumors also can start growing in adrenal gland tissue. The adrenal glands sit on the top of the kidneys and make hormones that the body needs.

Neuroblastoma spreads rapidly. It can quickly spread to other parts of the body. Most cases of neuroblastoma in children also result in another metastatic carcinoma. Metastatic tumors of the lungs, bones, lymph nodes, bone marrow and liver are common.

Treatment for neuroblastoma in children will vary, depending on the size, location and growth rate of the tumors. Most often, surgery is recommended to remove as much of the tumor or tumors as possible. From that point, radiation and chemotherapy will help kill any remaining cancer cells. In some cases, the cancer cells cannot be completely killed, but they can be forced into dormancy with aggressive treatment.