Top 5 cancers in children
These are cancers of the bone marrow, originating in precursors of white blood cells and account for 30% of childhood cancers. Leukaemia can cause bone and joint pain, fatigue, weakness, pale skin, bleeding or bruising, fever, and weight loss. Most childhood leukaemias are acute, progress rapidly, and need urgent referral to a paediatric oncologist. The main types are:
- Acute lymphoblastic leukaemia (ALL): 75% of leukaemias, originate in lymphocytes.
- Acute myeloid leukaemia (AML): Originate from myeloid cells.
Rare in children and grow more slowly than acute leukemias. For example: chronic myeloid leukaemia.
2. Brain tumours
A brain tumour is an abnormal growth of tissue in the brain. Malignant brain tumoursusually grow rapidly and invade surrounding tissue and spread to other parts of the brain or spinal cord. They may grow back after treatment.
The most common type is a glioma which begin in glial cells (supportive tissue of the brain). There are different types of gliomas:
• Astrocytoma: Forms from astrocytes, a glial cell. It’s the most common and most often originates in the cerebellum.
• Brain stem glioma: Is found in the brain stem. Most can’t be removed surgically.
• Oligodendroglioma: Grows in the cells that make the fatty covering of nerve cells (oligodendrocytes). They usually grow slowly and grow into brain tissue making surgical removal very difficult.
• Ependymoma: Grows in the lining of the ventricles or spinal cord. They often block the flow of the CSF (fluid that surrounds the brain and spinal cord). This may cause increased pressure in the skull.
• Optic nerve glioma: Is found in or around the nerves that send messages from the eyes to the brain. It often affects vision and can also affect hormones since it’s usually at the base of the brain where hormone control is located.
Other types include:
• Embryonal: The most common type is medulloblastoma. This originates in the cerebellum. They tend to grow and spread quickly, but they can often be treated effectively.
• Craniopharyngioma: Starts near the pituitary gland. It’s usually slow-growing and causes symptoms if it presses on the pituitary gland or on nearby nerves. It’s benign.
• Mixed glial and neuronal: Composed of glial and nerve cells.
• Choroid plexus: Starts in the ventricles of the brain and are mostly benign.
• Schwannoma: Starts in myelin-making cells that surround certain nerves. It’s most common in the nerve in the inner ear that helps with balance. It’s called a vestibular schwannoma or an acoustic neuroma and is benign.
Signs and symptoms
Brain tumours may cause increased pressure on the brain in the limited space in the skull = increased intracranial pressure.
- Enlarged head, especially in babies
- Nausea and vomiting
- Personality and mood changes
- Changes in eyesight (double vision) or hearing
- Weakness or paralysis, difficulty with walking
- Difficulty in swallowing
- Abnormal eye and face movement
- Changes in speech
- Hearing loss
- Clumsy movements of the hands, arms, feet, or legs
Neuroblastomas start in early forms of nerve cells in the developing embryo or foetus; they account for 6% of childhood cancers. It presents with abdominal swelling, chest masses, bone pain, bulging eyes, hypertension and fever. Most neuroblastomas begin in the abdomen, either in an adrenal gland or in sympathetic nerve ganglia near the spine, chest, neck, or pelvis. Patients with suspected neuroblastoma should be referred urgently for treatment.
4. Wilms tumour
Wilms tumour (also called nephroblastoma) starts in one, or rarely, both kidneys, and accounts for 5% of childhood cancers. It’s a more commonly disease of the young child (three to five years of age). It can present as a swelling or lump in the abdomen, fever, pain, nausea, hypertension, rarely blood in the urine and a poor appetite. Wilms tumour is often associated with syndromes such as overgrowth syndromes.
Lymphomas start in immune system cells called lymphocytes. These cancers most often start in lymph nodes or lymph tissues (tonsils or thymus). They can also affect the bone marrow and other organs.
Symptoms include weight loss, fever, sweats, tiredness (fatigue), and lumps (swollen lymph nodes) under the skin in the neck, armpit, or groin.
The two main types of lymphoma are Hodgkin lymphoma and non-Hodgkin lymphoma. Hodgkin lymphoma accounts for about 3% of childhood cancers. It’s rare in children younger than five years of age. Non-Hodgkin lymphoma makes up about 5% of childhood cancers.
These cancers grow quickly and require intense treatment.
Prof Gita Naidu (MBChB, FC (Paediatrics), MMed (Paediatrics), PhD) is the Head of Paediatric Oncology, Chris Hani Baragwanath Academic Hospital, Academic Head: Paediatric Oncology, University of the Witwatersrand and the Chair of South African Children’s Cancer Study Group.
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