NEUROBLASTOMA

Symptoms of Neuroblastoma

Symptoms of this will depend on what part of the body has the disease

• • If in the abdomen, it can cause tummy pain, diarrhoea or constipation, palpable mass, abdominal distention
  • If in the chest, it can cause chest pain, wheezing and drooping eyelids
  • Fever, weakness, and unusual weight loss 
  • Lymphadenopathy 
  • Respiratory distress 
  • Thoracic involvement can cause dysphagia and dyspnea 
  • Mass around the cervical region can cause the development of Horner’s syndrome 

Causes of Neuroblastoma

The only probable cause for this disease is genetic mutations. In most cases, a cause is not linked to the occurrence of the cancer

• Genetic Mutation 

Neuroblastoma starts in immature nerve cells. The other name for these immature nerve cells is neuroblasts. A fetus usually produces these neuroblasts as a part of its developmental phase. Most neuroblasts mature by the time the baby is born, though a small number of immature neuroblasts can be found in new-born babies. In most cases, these neuroblasts mature or disappear. Others, however, form a tumour which causes  neuroblastoma. According to research, 1p36 chromosomal regions are absent in 70% of the cases. Furthermore, the expression of CHD5 is also low in cases of neuroblastoma tumours.  

Diagnosis

The tests used to diagnose neuroblastoma include:

• Physical tests: Your doctor will conduct a physical exam on the child  and ask about your child’s well being.
• Blood tests to check full blood count and others
• Urine tests to check the levels of chemicals like catecholamine which neuroblastoma cells produce.
• Serum electrolytes 
• Liver function tests 
• Chest x-ray that helps in the identification of calcifications and mediastinal mass.   
• Other imaging tests help to find mass in the neck, chest, and abdomen. CT scan is one of the methods to obtain scans of the body. Doctors consider this as the gold standard of diagnosis.  
• Biopsy of some tissue in the mass to check for neuroblastoma cells and biopsy of the bone marrow to check if neuroblastoma has spread to the bone marrow — the spongy material inside the largest bones where blood cells are formed

Staging

There are several classifications for the Neuroblastoma. However, the classification of these diseases based on the International Neuroblastoma staging system is as follows; 

• L1: This stage of the disease is localized. It does not involve any vital structures and remains in only one body compartment. 
• L2: This is also a localized type of neuroblastoma. However, it has an image defined risk factors.  
• M: The other name for this stage is distant metastatic disease and it has spread to other organs
• MS: This is also a distant metastatic type of disease. However, it remains confined to the skin, liver and slightly in the bone marrow, but not to the bones. It only affects children that are less than 18 months of age.  

Treatment

The main streamline strategy of treating neuroblastoma is chemotherapy or surgical resection. However, a drawback is that many types of neuroblastomas are resistant to chemotherapy. It increases the chance of relapse during treatment. Doctors may select a treatment strategy based on the stage and risk of the patient. The end goal of the treatment is to reduce the burden of the tumour.  

Surgery

This is often used if the tumour can be easily removed and in children with low-risk neuroblastoma where surgery may be the only treatment needed. In high risk neuroblastoma cases, the surgeon will remove as much of the tumour as possible and then use chemotherapy and radiation to kill remaining cancer cells.

Chemotherapy

It is often used before surgery and bone marrow transplant. It is also used to shrink the tumour if possible before surgery or kill any cancer cells that have spread elsewhere in the body.

Radiotherapy

This uses high-energy X-rays, to destroy cancer cells. Children with neuroblastoma  may receive radiation  if other options are not possible, or after  chemotherapy and surgery, to prevent cancer from coming back.

Immunotherapy

This uses drugs that work by triggering the immune system to recognise and kill cancer cells. Children with neuroblastoma may receive immunotherapy to signal the immune system to kill the bad cells.

Bone marrow transplant

During high dose chemotherapy, the bone marrow may become damaged and kill off the cells that make blood cells. While using chemotherapy, doctors will collect some blood stem cells and store them until after your child has finished the high dose chemotherapy. Then after the high dose chemotherapy, the stem cells are then injected into your child’s body, where they can form new, healthy blood cells.

• Induction chemotherapy is a combination of different drugs. After induction, further treatment can continue with a high dose of chemotherapy. It helps in the revival of the bone marrow. 
• In patients that have high risk, radiotherapy is the first choice of treatment. It helps to gain control of the local and metastatic spread of the tumor. It is not suitable for patients that have the possibility of vertebral damage or arrest of growth and scoliosis.  
• Doctors may only consider surgery if the entire resection of the tumor is possible. However, doctors may perform surgery after radiation or chemotherapy. The reason for this is to decrease tumor size first.  

REFERENCES 

• https://academic.oup.com/tropej/article/61/3/165/1714119 
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3668791/#S4title 

• https://www.orpha.net/data/patho/GB/uk-neuroblastoma.pdf 
• https://www.ncbi.nlm.nih.gov/books/NBK448111/ 
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3668791/