Neuroblastoma stages & risk groups — what each stage means for your child

Neuroblastoma is staged using the International Neuroblastoma Risk Group (INRG) system, which has four stages. Stage L1 means the tumour is confined to one body compartment and has no image-defined risk factors that would make surgery more complicated. Stage L2 means the tumour is still local or regional but has certain anatomical features that make surgery more complex. Stage M is the equivalent of what used to be called Stage 4 — the cancer has spread to distant parts of the body such as bones, bone marrow, liver, skin, or lymph nodes beyond the local region. Stage MS is a special category for infants under 18 months whose cancer has spread but only to skin, liver, or bone marrow — this stage often behaves very differently from Stage M and may regress spontaneously.

After staging is complete, the oncology team places your child into a risk group — low, intermediate, or high. The risk group is not determined by stage alone. It combines the stage with the child's age at diagnosis, the biology of the tumour cells (including whether the MYCN gene is amplified), the histology (how the cells look under a microscope), and in some classifications the DNA content of the tumour cells. Risk group is the single most important factor in deciding how intensive treatment needs to be. A low-risk child may need only surgery or observation. A high-risk child will need intensive multi-step treatment involving chemotherapy, surgery, and additional therapies.

High risk neuroblastoma stage refers to cases where the combination of stage, age, and tumour biology indicates that the disease is likely to progress or return without very intensive treatment. MYCN amplification — a change where a specific gene is present in many extra copies in the tumour — is one of the strongest markers of high-risk disease. Children over 18 months with Stage M (widespread) disease are usually classified as high risk. High risk does not mean untreatable. It means the treatment plan will be more intensive and will likely include multiple cycles of chemotherapy, followed by surgery to remove the primary tumour, and additional consolidation therapy. Every high-risk case at CION is reviewed by a tumour board before treatment begins.

Age at diagnosis is one of the most important factors in neuroblastoma risk classification. Infants under 18 months tend to have neuroblastoma that behaves less aggressively, even when the disease has spread to certain sites (this is the Stage MS category). Their tumour cells are often biologically different — they are more likely to mature into normal cells or regress on their own, particularly in Stage MS. Children diagnosed after 18 months of age with widespread disease are more likely to be placed in the high-risk category. This age distinction is why two children with what appears to be similar disease spread may receive very different treatment plans.

The initial stage is a fixed assessment made at diagnosis. However, the team monitors how the disease is responding throughout treatment using repeat imaging — including MIBG scans, CT, or MRI — and blood tests. If the disease is responding well, the team may see shrinkage of the tumour and reduction in the number of active areas on imaging. If the disease does not respond or returns after treatment, this is called relapsed or refractory neuroblastoma and will be assessed separately. The response to the first courses of treatment is itself an important prognostic factor and is sometimes used to further refine the risk group.

CION Cancer Clinics operates across 35+ centres in Telangana and Andhra Pradesh. Every child presenting with a suspected or confirmed childhood cancer is assessed by our paediatric oncology team and reviewed by a multi-specialist tumour board before any treatment decision is made. We offer a free first consultation for all cancer patients, with a dedicated 45-minute appointment — so you have time to ask every question and understand your child's stage and risk group fully. Call us on 1800 202 8726 or fill in the form on this page to arrange a callback at a time that suits you.