Neuroblastoma is a type of cancer that originates in immature nerve cells, primarily affecting infants and young children. It is the most common extracranial solid tumor in this age group. This article provides general information about neuroblastoma and its management.
Understanding Neuroblastoma
Neuroblastoma arises from neuroblasts, which are early nerve cells that do not mature properly and instead form a tumor. These cells are part of the sympathetic nervous system, a network of nerves that controls many involuntary body functions. While neuroblastoma can develop anywhere along this system, it most frequently originates in the adrenal glands, located atop the kidneys. It can also appear in nerve tissue near the spine in the neck, chest, or pelvis.
Neuroblastoma is predominantly diagnosed in early childhood. It can behave differently from child to child; some tumors grow slowly or even disappear on their own, while others spread quickly. The disease is categorized into different “risk groups” (low, intermediate, and high) based on factors like the child’s age, the cancer’s stage, and specific characteristics of the tumor cells. These risk groups help guide treatment decisions and predict how the cancer might respond.
Detecting Neuroblastoma
Symptoms of neuroblastoma vary widely depending on the tumor’s location and size. Common indicators include a noticeable lump or swelling in the abdomen, neck, or chest. Children might also experience bone pain, limping, fever, or changes in eye appearance, such as bulging eyes or dark circles around them. Weakness, paralysis, or difficulty with breathing, bowel movements, or urination can also signal the presence of a tumor.
Diagnosis involves medical evaluations. A physical examination helps doctors identify any palpable masses or other physical changes. Imaging tests are then used to visualize the tumor and determine its extent. These can include ultrasound, X-rays, computed tomography (CT) scans, magnetic resonance imaging (MRI), and metaiodobenzylguanidine (MIBG) scans. An MIBG scan involves injecting a small amount of a radioactive substance that attaches to neuroblastoma cells, allowing a special camera to detect them throughout the body.
Laboratory tests are also used for diagnosis. Blood and urine tests check for elevated levels of substances like homovanillic acid (HVA) and vanillylmandelic acid (VMA), which are breakdown products of hormones often produced by neuroblastoma cells. A definitive diagnosis requires a biopsy, where a tissue sample from the tumor is removed and examined under a microscope. This analysis confirms the presence of cancer cells and provides additional information about the tumor’s characteristics.
Treatment Approaches
Treatment plans for neuroblastoma are highly individualized, taking into account the cancer’s risk group, the child’s age, and other specific factors. Surgery is a common treatment, particularly for localized tumors, with the aim of removing as much of the tumor as possible. In some low-risk cases, surgery alone may be sufficient for a cure.
Chemotherapy involves using powerful drugs to kill cancer cells throughout the body. It is often administered in cycles, lasting several weeks to months, and may be used before surgery to shrink a tumor or after surgery to eliminate any remaining cancer cells. Common chemotherapy drugs used for neuroblastoma include carboplatin, cyclophosphamide, doxorubicin, and etoposide. Radiation therapy employs high-energy rays to target and destroy cancer cells. This treatment is frequently used for children with high-risk neuroblastoma or to alleviate symptoms.
Immunotherapy is a more recent approach that harnesses the body’s own immune system to fight cancer. For neuroblastoma, monoclonal antibodies, such as dinutuximab, are used to recognize and attach to specific proteins (like GD2) on the surface of neuroblastoma cells, helping the immune system identify and eliminate them.
Stem Cell Transplant
High-dose chemotherapy followed by a stem cell transplant is a treatment for high-risk neuroblastoma. This process involves administering very high doses of chemotherapy to destroy cancer cells, which also damages healthy bone marrow. It is followed by the infusion of the child’s own previously collected healthy stem cells to restore bone marrow function. Some treatment plans may involve tandem stem cell transplants, where two transplants are given back-to-back.
Navigating Life After Treatment
The long-term outlook for children with neuroblastoma varies depending on factors such as age at diagnosis, the cancer’s stage, and the biological features of the tumor. Younger children and those with lower-risk disease have a better prognosis. For instance, children in the low-risk group can have a 5-year survival rate exceeding 95%, while those in the high-risk group have a 5-year survival rate around 60%. Advances in treatment have led to many children surviving into adulthood.
Ongoing follow-up care is important after neuroblastoma treatment, encompassing scheduled check-ups, imaging scans, and blood tests. These appointments monitor for any signs of cancer recurrence and manage potential late effects of the treatments received. Survivors may face various long-term effects depending on the type and intensity of their treatment, including risks of secondary cancers, hearing loss, cardiac issues, or hormonal imbalances. Survivorship care also addresses the psychological burden on both the child and their family, emphasizing support for reintegration into daily life.