What do the different risk groups for neuroblastoma mean? 

As well as defining the stage of the cancer, your child will also be given a risk group. The risk group guides the treatment plan your child will receive and helps doctors understand how likely it is that the neuroblastoma could come back after treatment (the risk of relapse). Risk groups are related to stages, but they are not the same thing. 

How are risk groups determined? 

Doctors use several factors to decide your child’s risk group, including: 

• The stage of the neuroblastoma (how far it has spread) 
• Your child’s age at diagnosis 
• Certain features in the tumour’s genes (such as MYCN amplification) 
• How the tumour looks under the microscope (histology) 

A system called the International Neuroblastoma Risk Group (INRG) is often used. You might see stages described as “L1”, “L2”, “M”, or “MS”: 

Read more about the stages of neuroblastoma. 

There are three risk groups: 

• Low-risk neuroblastoma: 
  Usually applies to children with early-stage neuroblastoma (such as stage 1 or INRG stage L1), and some children with stage 2 (L1) who are under 12 months old and whose tumour does not have certain genetic changes. Children in this group often need less intensive treatment and have a positive outlook. 

• Intermediate-risk neuroblastoma: 
  Often includes children with stage 3 (L2) or stage 4 (M) neuroblastoma who are under 12 months old and whose tumour does not have unfavourable genetic features. Treatment is more intensive than for low-risk neuroblastoma, but the outlook is still generally good. 

• High-risk neuroblastoma:
  Includes children with stage 2 (L1), 3 (L2), or 4 (M) neuroblastoma who are over 12 months old, or whose tumour has certain genetic changes (such as MYCN amplification), regardless of age or stage. High-risk neuroblastoma needs the most intensive treatment, and the risk of the cancer coming back is higher. 

Your child’s medical team will explain which risk group applies to your child and what this means for their treatment and outlook.