What is low-risk neuroblastoma?

Neuroblastoma is a rare cancer that develops in very early nerve cells called neuroblasts. These cells form while a baby is growing in the womb and are part of the sympathetic nervous system. Most neuroblasts mature and disappear before birth. If some of these immature cells grow or divide in an uncontrolled way, they can form a tumour. 

The name comes from: 

• Neuro – nerve 
• Blast – immature cell 
• Oma – tumour 

Low‑risk neuroblastoma is a subset of the disease with specific features. According to the International Neuroblastoma Risk Group system used by doctors, low-risk usually means your child’s tumour is localised (in one area) and the test results suggest it has favourable features. Tumours classed as L1 (localised without certain imaging risk features) are often low risk. Some L2 tumours (localised but with imaging risk features) can also be low risk in younger infants when the tumour biology is favourable (for example, no MYCN amplification).  

How doctors define low‑risk neuroblastoma 

Doctors consider several things together: 

• Where the tumour is and whether it has spread: “Localised” tumours are confined to one area. The INRG system calls these L1 or L2.  

• Imaging features (IDRFs): These features show whether the tumour touches or wraps around important structures. L1 has no IDRFs; L2 has one or more.  

• Biological features: Tumours without MYCN amplification and with favourable histology are more likely to be low risk. Age matters too - infants tend to have better outcomes.  

Read more about the stages of neuroblastoma. 

What “low‑risk” usually means for treatment 

For many children in the low‑risk group, treatment is minimal. Options may include: 

• Active observation with regular scans and check‑ups 

• Surgery to remove the tumour if needed 

• Chemotherapy might be required for those with L2 disease 

• Radiotherapy might be required for those with L2 disease 

Your child’s plan is individual, and your child's medical team will discuss the safest approach. 

Read more about the treatment for low-risk neuroblastoma.