Neuroblastoma is a type of cancer originating from immature nerve cells, often developing in or around the adrenal glands. It primarily affects infants and young children, making it one of the most common solid tumors in early childhood. This article provides an overview of the different therapeutic approaches used to manage neuroblastoma.
Determining the Treatment Approach
Developing a treatment plan for neuroblastoma is a complex process, tailored for each child. Doctors consider several factors to determine the most appropriate course of action. These include the child’s age at diagnosis, the tumor’s location, and whether the cancer has spread.
A significant factor is the “risk group” assigned to the neuroblastoma: low, intermediate, or high risk. This classification helps predict treatment response and potential for recurrence. Risk group assignment incorporates biological features of the tumor, such as histology, MYCN gene amplification, and chromosomal changes. Younger children with localized tumors often fall into lower risk groups, while older children or those with widespread disease or MYCN amplification are assigned to higher risk categories.
Standard Treatment Modalities
Neuroblastoma treatment often involves a combination of therapies. These approaches are selected based on the tumor’s characteristics and the child’s risk group.
Surgery
Surgery is a common treatment for neuroblastoma, with the primary goal of removing as much of the tumor as safely possible. For low-risk neuroblastoma that has not spread, surgery alone may be sufficient. If the tumor is large or located near important organs, chemotherapy might be administered first to shrink it, making removal easier and safer.
Chemotherapy
Chemotherapy uses drugs to destroy cancer cells throughout the body. These medications are given intravenously, though some may be taken orally. Chemotherapy is used for neuroblastoma that has spread or to reduce tumor size before surgery, particularly in intermediate and high-risk cases. It targets cancer cells that may have traveled beyond the primary tumor site.
Radiation Therapy
Radiation therapy uses high-energy beams to target and destroy cancer cells in a specific area. This localized treatment can be delivered externally, or internally by placing radioactive substances directly into or near the tumor. Radiation therapy is used for high-risk neuroblastoma, or when surgery is not feasible, to control tumor growth or reduce the chance of recurrence in a specific region.
Advanced and High-Risk Therapies
For intermediate or high-risk neuroblastoma, more intensive and specialized treatments are used. These therapies aim to eradicate cancer cells and prevent recurrence.
High-Dose Chemotherapy and Stem Cell Transplant
High-dose chemotherapy involves administering high doses of drugs to eliminate cancer cells, including those resistant to standard treatments. This approach also destroys healthy blood-forming cells in the bone marrow. To counter this, the child’s own blood-forming stem cells are collected before chemotherapy and then reinfused after treatment to help the bone marrow recover. This two-step process, often called an autologous stem cell transplant, is performed in specialized centers.
Immunotherapy
Immunotherapy enhances the body’s immune system to identify and destroy cancer cells. Many neuroblastoma cells display a substance called GD2 on their surfaces. Monoclonal antibodies, such as dinutuximab (Unituxin), are lab-made proteins designed to attach specifically to GD2 on neuroblastoma cells. This attachment helps the immune system recognize and target these cancer cells for destruction. Dinutuximab is commonly used in combination with other agents, like GM-CSF, as part of post-consolidation therapy for high-risk neuroblastoma.
MIBG Therapy
MIBG (meta-iodobenzylguanidine) therapy is a targeted radiation treatment using a substance absorbed by neuroblastoma cells. MIBG is structurally similar to norepinephrine and enters neuroendocrine cells, including neuroblastoma cells, through specific uptake systems. When combined with a radioactive isotope, typically iodine-131 (I-131), MIBG delivers radiation directly to the cancerous cells, minimizing exposure to healthy tissues. This internal radiation therapy is considered for high-risk neuroblastoma, particularly if it has not responded well to initial treatments or has recurred.
Post-Treatment Monitoring and Care
After active neuroblastoma treatment concludes, children enter an important phase of post-treatment monitoring and long-term care. The aim during this period is to confirm the cancer remains in remission, meaning there are no detectable signs of the disease, and to address any potential effects from the therapies received.
Long-term follow-up involves a structured schedule of regular check-ups, which may include physical examinations, imaging scans like MRI or CT, and blood or urine tests. These evaluations are designed to detect any signs of cancer recurrence early, allowing for prompt intervention if needed. The frequency and type of these tests are tailored to the individual child’s risk group and the specific treatments they received.
Children who undergo neuroblastoma treatment may experience “late effects,” which are long-term side effects that can appear months or even years after therapy. These effects vary widely depending on the treatments used, the tumor’s location, and the child’s age during treatment. Potential late effects can include hearing loss, problems with bones and muscles, thyroid dysfunction, growth and development issues, or even a slight increased risk of developing a second cancer later in life. Survivorship clinics play an important role in managing these potential issues, providing specialized care and support to help children thrive after their cancer journey.