Rare illness neuroblastoma typically only affects around 100 children in the UK every year.

In recent months though, it’s received more attention as the family of six-year-old Bradley Lowery have campaigned to raise awareness as well as funds for him to receive treatment overseas.

As he spends his sixth birthday in hospital, we find out everything you need to know about neuroblastoma.

[Read more: Who is Bradley Lowery? Everything you need to know]

What is it?

Neuroblastoma is a rare childhood cancer, typically affecting children under five.

The cancer develops from specialised nerve cells called neuroblasts that are left behind from development in the womb.

Currently, it’s not known what exactly causes it but generally it is not hereditary.

Tumours most commonly occur in the adrenal glands located above the kidneys, or in nerve tissue that runs alongside the spinal cord, in the neck, chest, abdomen or pelvis.

Sometimes they can spread to bone marrow, bone, lymph nodes, liver or skin.

Just like other cancers, the progress of neuroblastoma is expressed in stages.

Stage L1 means it’s not spread and can be removed with surgery, while L2 means the cancer has not spread but it would not be safe to remove it surgically.

Stage M means the cancer has spread and stage Ms means the cancer has spread to the skin, liver or bone marrow in a child aged under 18 months.

What are the signs and symptoms to look out for?

Symptoms of neuroblastoma can vary depending on where in the body the tumour is located and if the cancer has spread.

Some symptoms can be mistaken for more common conditions that occur during childhood.

Signs to look out for include:

  • A swollen or painful tummy
  • Trouble swallowing or breathlessness
  • A lump found in their neck
  • Blueish lumps in the skin or bruising around the eyes
  • Leg weakness causing an unsteady walk along with constipation and difficulty passing urine
  • Fatigue, paleness, loss of appetite and weight loss
  • Bone pain, a limp or general irritability
  • High blood pressure
  • Rarely: jerky eye and muscle movements

[Read more: Cancer prevention: 9 surprising ways to fight off cancer]

How can you test for it?

Just as there are many different symptoms, there are a number of ways to test for neuroblastoma.

These include:

  • A urine test
  • Ultrasound, CT or MRI scans
  • An MIBG scan
  • Biopsies
  • Bone marrow biopsies

What are the treatments?

In some cases, babies under 18 months in stage L1 or Ms who have no presenting symptoms will not need any treatment as sometimes the cancer will go away on its own.

Other treatments include surgically removing the cancer, chemotherapy, radiotherapy, stem cell transplants and immunotherapy.

Sadly, almost half of neuroblastomas can return despite intensive treatment.

The outlook tends to be better for younger children whose cancer has not spread.