Neuroblastoma is a cancer originating from immature nerve cells, known as neuroblasts. It primarily affects infants and young children, often developing before age five. Suprarenal neuroblastoma specifically refers to tumors that begin in the adrenal glands, small glands located on top of each kidney that produce hormones.
Neuroblastoma is the most common cancer in infants, with approximately 800 new cases diagnosed annually in the United States. It is also the most common extracranial solid tumor in childhood.
What is Suprarenal Neuroblastoma?
Suprarenal neuroblastoma develops from primitive neuroblasts, nerve cells that fail to mature correctly. These cells are part of the sympathetic nervous system, controlling involuntary bodily functions like heart rate, blood pressure, and digestion. Approximately 35% of neuroblastomas arise in the adrenal glands, often in the adrenal medulla. This classifies it as an embryonal neuroendocrine tumor, stemming from cells meant to form parts of the nervous and endocrine systems during fetal development.
Neuroblastoma exhibits variable behaviors. Some tumors may spontaneously regress, especially a unique form known as Stage 4S, which can occur in infants younger than 18 months and typically spreads to the liver, skin, or bone marrow but often has a favorable outlook. Other tumors can grow rapidly and metastasize to distant parts of the body, including bone, bone marrow, lymph nodes, and the liver.
Recognizing and Diagnosing Suprarenal Neuroblastoma
Identifying suprarenal neuroblastoma often begins with observing general signs and symptoms. An abdominal mass or swelling is common due to the tumor’s location. Other symptoms include abdominal pain, weight loss, or decreased appetite. If the tumor presses on nerves, symptoms like bone pain, limping, or weakness can occur.
Diagnosis involves several tests to confirm neuroblastoma and determine its extent. Imaging tests like ultrasound, MRI (Magnetic Resonance Imaging), and CT (Computed Tomography) scans visualize the tumor’s size and location. An MIBG (metaiodobenzylguanidine) scan, a specialized nuclear medicine test, uses a radioactive substance taken up by neuroblastoma cells to identify tumors and their spread.
Urine tests are important, as neuroblastoma cells produce high levels of catecholamines. Their breakdown products, homovanillic acid (HVA) and vanillylmandelic acid (VMA), can be detected in urine. A biopsy, taking a tissue sample from the tumor, confirms the diagnosis. Bone marrow biopsies may also check for cancer spread.
Treatment Options for Suprarenal Neuroblastoma
Treatment for suprarenal neuroblastoma is tailored to each child, considering the tumor’s stage, age, and biological markers. A multidisciplinary team develops a comprehensive plan, often combining multiple approaches.
Surgery aims to remove as much of the tumor as possible. For localized tumors, surgery alone may suffice. If the tumor is large or near vital structures, chemotherapy might be given first to shrink it (neoadjuvant chemotherapy), making surgical removal safer.
Chemotherapy uses anticancer drugs to destroy cancer cells throughout the body, administered in cycles. Common drugs include cyclophosphamide, cisplatin, doxorubicin, vincristine, and etoposide, often in combinations. It is a standard treatment for intermediate and high-risk neuroblastoma.
Radiation therapy uses high-energy rays to destroy cancer cells, shrinking tumors or eliminating remaining cells after surgery or chemotherapy. It is more common for high-risk neuroblastoma, sometimes after a stem cell transplant. Types include external beam radiation and radioisotope therapy, such as MIBG therapy, which delivers a radioactive substance systemically.
High-dose chemotherapy followed by stem cell transplantation is an intensive option for high-risk neuroblastoma. This approach kills cancer cells but also destroys healthy blood-forming cells in the bone marrow. Stem cells, collected from the child’s own blood before treatment, are then infused back to restore blood cell production. Some children may receive two transplants (tandem transplants). Immunotherapy, using the body’s immune system to fight cancer, is another treatment, with monoclonal antibodies like dinutuximab beta targeting specific proteins on neuroblastoma cells.
Outlook and Ongoing Care
The outlook for suprarenal neuroblastoma varies significantly, influenced by the child’s age at diagnosis, cancer stage, and tumor characteristics. Younger children, especially those under 18 months, often have a more favorable prognosis, even with metastatic Stage 4S disease. Tumor histology, or how cancer cells appear under a microscope, also plays a role; more normal-looking cells generally indicate a better outlook.
The MYCN oncogene’s amplification is associated with more aggressive disease and a less favorable prognosis, particularly in children over one year. The extent of cancer spread at diagnosis is another key factor, with localized tumors having a better outlook than widely metastasized ones. Survival rates for low- and intermediate-risk neuroblastoma can exceed 90%. Outcomes for high-risk neuroblastoma have improved with intensive multi-modal therapies, with some studies showing over 60% long-term survival.
After treatment, ongoing care and long-term follow-up are important. This includes regular monitoring for recurrence and late effects of treatments. Radiation therapy can affect healthy tissue growth, and chemotherapy can lead to long-term toxicities like effects on heart function, hearing, and kidney health. The multidisciplinary care team supports the child through survivorship, addressing emerging health issues.