Neuroblastoma is a rare type of malignancy that mainly affects infants and young children under the age of 10. Among the various solid tumors of childhood it is, after those affecting the central nervous system (CNS), the most widespread (8%), with an incidence equal to 10 cases per million every year.
Neuroblastoma is a tumor that originates from the cells of the autonomic nervous system, that is the "set of structures (nerve fibers, grouped nerve cells that form the so-called ganglia and nerve-like cells that are found inside the adrenal gland). it controls some involuntary functions such as heart rate, breathing or digestion. In particular in the term neuroblastoma, "neuro"indicates that the tumor is developing in the nerves and"blastoma"that immature or developing cells are involved. In fact, this tumor develops from very primitive nerve cells present in the embryo and fetus, called neuroblasts. Neuroblasts are found throughout the body and as a result the tumor can develop in different areas of the body.
Neuroblastoma most commonly spreads to one of the adrenal glands located above the kidneys, or to nerve tissue located on either side of the spinal cord in the region of the neck, chest, belly, or pelvis. Unfortunately, cancer cells can also spread to other organs, such as the bone marrow, bones, lymph nodes, liver, and skin.Symptoms
The disorders (symptoms) caused by neuroblastoma vary according to the region of the body affected and the areas affected by the metastases. The first annoyances can be uncertain and difficult to identify as they can easily be mistaken for the most common diseases that occur in childhood.
Disorders (symptoms) can include:
- swollen and sore belly which may be associated with constipation or constipation, a defecation disorder consisting in the difficulty of emptying the intestine by expelling feces, and difficulty in urinating, that is to completely empty the bladder
- dyspnea, i.e. labored breathing, and difficulty swallowing (swallowing food)
- presence of a bulge at the base of the neck
- rashes on the skin, such as bluish patches and bruises, particularly around the eyes
- weakness in the legs and unstable walking, with numbness in the lower body
- tiredness, weakness, pale complexion, loss of appetite and weight
- bone pain, rapid eye movements, muscle spasms and coordination difficulties when walking or standing and, rarely, irritability
If you think that the child may be ill, you should urgently contact your family doctor or go to the nearest pediatric hospital.Causes
The cause of neuroblastoma is unknown. In very rare cases, the disease appears in children from the same family, but neuroblastoma is not usually hereditary.
In rare familial forms of cancer (1-2% of all neuroblastomas), the presence of parents who have had a neuroblastoma as a child increases the risk that the cancer may also occur in their children. In most cases, in the sporadic forms, it is not yet clear what causes the development of the tumor. Generally, the causes of neuroblastoma are genetic, but not hereditary, which means that they are linked to mutations in genes not passed on by the parents.Diagnosis
Several types of tests are available to diagnose neuroblastoma. In particular:
- urine analysis, to check for the presence of certain substances, called catecholamines, which are produced by neuroblastoma cells and can be found in the urine
- image diagnostic techniques, as l "ultrasound, computed tomography (CT) scans and magnetic resonance imaging (RM); are techniques that allow you to obtain images of various parts of the body and, above all, to see and analyze these areas in detail
- scintigraphy with metaiodobenzylguanidine (MIBG) linked to a certain amount of radioactive iodine, is an indispensable test to evaluate the site of the primary tumor and identify any metastases: MIBG binds to neuroblastoma cells wherever they are widespread. This diagnostic technique is also very important to evaluate the response to treatment, particularly in the sites where the cancer has spread (metastatic areas).
- biopsyremoving a sample of cells from the tumor tissue to examine it under a microscope to identify the type of tumor present; the sample is usually taken under general anesthesia
- bone marrow biopsies, to evaluate the presence of cancer cells in the bone marrow
At the end of the tests, the doctor will be able to confirm, or not, the presence of neuroblastoma, to know how widespread the disease is and to establish its stage. A correct assessment of the stage of the tumor (staging) allows to quantify the probability of response to treatment and, therefore, to make a forecast on the evolution of the child's disease.
An international staging system called in English "International Neuroblastoma Staging System" is generally adopted for neuroblastoma. (in abbreviation: INNS). It allows to identify four stages of the disease:
- Stage 1, localized tumor removed in a macroscopically radical way, with or without microscopic residues; histologically negative "representative" lymph nodes (lymph nodes adhering to the tumor removed together with the tumor itself, can be histologically positive without leading to a change in stage)
- Stage 2A, localized tumor incompletely excised; "representative" lymph nodes not adherent to the tumor, histologically negative for tumor infiltration
- Stage 2B, localized tumor completely or incompletely removed, with lymph nodes not adherent to the tumor, positive for tumor infiltration
- Stage 3, unilateral inoperable tumor with or without involvement of the regional lymph nodes; or, unilateral localized tumor involving the contralateral regional lymph nodes; or, tumor with bilateral extension due to lymph node infiltration or involvement
- Stage 4, any primary cancer with dissemination to distant lymph nodes, bones, bone marrow, liver, skin and / or other organs (except as described in stage 4S)
- Stage 4S, localized primary tumor (as for stages 1 and 2 A or 2 B), with limited spread to the skin, liver and / or bone marrow
The main treatments for neuroblastoma are:
- surgery, to remove the tumor. Sometimes it can be completely conclusive
- chemotherapy, using a specific drug to kill cancer cells. It may be the only treatment needed or it may be used to shrink the tumor before surgery
- radiotherapy, use of radiation to kill cancer cells. It can be used, after surgery, to destroy any cancer cells still present in the affected area
- high-dose chemotherapy followed by a stem cell transplant obtained from peripheral blood or bone marrow (if these have not been affected by the disease), it consists in taking the stem cells from the patient, freezing them and storing them before starting intensive chemotherapy treatments. At the end of the chemotherapy, which will have destroyed the bone marrow, the stem cells will be "returned" to the patient to protect him from the effects of the treatments. If it has been preserved, stem cells obtained from umbilical cord blood represent a valid alternative
- immunotherapy, based on ways that make the immune system more aggressive towards cancer cells. In particular, in the case of neuroblastoma, the tumor cells to be attacked are recognized by the presence of a protein, called GD2, expressed on their surface. This therapeutic approach, already used successfully for the treatment of other cancers, is still little used for neuroblastoma, but ongoing studies are showing promising results.
In some cases, babies and children under 18 months of age do not need any treatment if they do not have any complaints, as sometimes the cancer can regress, that is, disappear on its own.
Predictions for neuroblastoma recovery are varied and are generally better for younger children with cancer that has not yet spread. Despite intensive care, nearly half of neuroblastomas can recur. In these cases, further treatment will be required.
People with neuroblastoma may be asked to participate in a clinical trial to evaluate the effectiveness of new drugs. The treating physician can provide more information.Bibliography
NHS Choices. Neuroblastoma (English)
Mayo Clinic. Neuroblastoma (English)
National Cancer Institute (NCI). Neuroblastoma treatment - Patient version (English)
Italian Association for Cancer Research (AIRC). Pediatric neuroblastoma
Italian Association for the Fight against Neuroblastoma. Immunological therapy
Sait S, Modak S. Risk of mucocutaneous toxicities in patients with solid tumors treated with sorafenib: an updated systematic review and meta-analysis [Summary].Expert review of anticancer therapy. 2017; 17: 889-90