Stages of cancer explained: what stage 1 to 4 actually mean

Awaiting medical review

This guide has not yet been reviewed or signed off by Dr Khan. It is published here for his review only and should not be treated as final medical information until that review is complete.

The short answer

The stage of a cancer is a description of two things: how big it is, and how far it has travelled. It is a map of what was found, not a prediction about a person. Stage 1 usually means small and contained. Stage 4 means it has reached another organ. Everything in between is detail about size and lymph nodes.

In short

• TNM records tumour size (T1 to T4), lymph nodes (N0 to N3) and spread elsewhere (M0 or M1).
• The number stage, 1 to 4, is a summary built from those three letters.
• Stage 0 means abnormal cells that have not spread, also called carcinoma in situ.
• Grade is a separate measure: how abnormal the cells look, from 1 to 3.
• NHS standards say treatment should start within 31 days of diagnosis.

In the TNM system, T can be 1 to 4, N can be 0 to 3, and M is either 0 or 1. Source: Cancer Research UK, Stages of cancer.

Almost nobody hears their stage and understands it straight away. It arrives in the middle of an overwhelming week, often as a string of letters and numbers, and it sounds like a verdict.

It is not a verdict. It is a description. This guide explains what each part of it means, in the order you are likely to meet them.

What does the stage of a cancer actually mean?

The important thing to hold onto is what staging is for. It describes the cancer, not the person who has it. Two people with the same stage can have very different outlooks depending on the type of cancer, its grade, their general health and how it responds to treatment.

That is why a number on its own answers fewer questions than people expect, and why your own team can tell you things this page cannot.

What do T, N and M stand for in cancer staging?

So T2 N1 M0 describes a medium-sized tumour, some lymph node involvement, and no spread to distant parts of the body. Once you know the three letters, the string stops looking like code.

What do stages 1 to 4 mean?

Stage 4 is also described as advanced or metastatic. It is the word that frightens people most, and it is worth being precise about what it does and does not say. It says the cancer has reached somewhere else in the body. It does not, on its own, say what treatment can achieve.

How the TNM letters group into number stages differs between cancer types. A T3 in one cancer may sit in a different number stage than a T3 in another, which is why your team works from the specific system for your diagnosis rather than a general chart.

What is stage 0, or carcinoma in situ?

Because it has not spread, stage 0 is often treated with the aim of removing it before it can. Not every abnormal finding is called cancer, and the terminology here can be confusing, so it is worth asking your team to be explicit about what they have found and what they are recommending.

How is grade different from stage?

Grade 2 sits between the two, with cells that do not look normal and may be growing faster than normal.

The two are independent, which surprises people. A small, early-stage cancer can be high grade, and a larger one can be low grade. Cancer Research UK notes that a low grade cancer is likely to grow more slowly and be less likely to spread than a high grade one, which is why your team weighs both together rather than either alone.

Do all cancers use the same staging system?

There is also at least one cancer with a stage 5. In Wilms tumour, a kidney cancer that affects children, stage 5 means there are tumours in both kidneys. Cancer Research UK notes this affects fewer than 10 in every 100 children with the condition, and that each tumour is staged separately.

If your diagnosis uses a system you do not recognise, that is normal and not a sign that something unusual is wrong. Ask which system is being used and what its stages describe.

When does staging happen, and how long does it take?

There are national standards for the timing. The NHS says treatment should start within 31 days of diagnosis, or within 62 days of an urgent referral, and that you will be looked after by a team of specialists who work with you on a treatment plan.

Sometimes the full picture only becomes clear after surgery, when tissue removed during the operation is examined. If that applies to you, your team will say so, and the plan may be adjusted once those results arrive.

Doctors also repeat scans during and after treatment to see how things are responding. That is about tracking progress rather than relabelling the original diagnosis, and if you want to know exactly how your stage is recorded over time, ask your oncologist directly.

What questions are worth asking about your stage?

• What is the stage and the grade, and what does each of them mean for my type of cancer
• Which staging system are you using, if it is not the usual 1 to 4
• Is the staging complete, or are results still to come
• What does this stage change about my treatment options
• Who do I contact between appointments, usually a clinical nurse specialist

If you have just been diagnosed and are working out what happens next, our guide to your first two weeks after a diagnosis covers the practical side. Our cancer type guides explain how staging works for specific cancers, and the FAQ answers many of the questions people ask us most.

One last thing worth saying plainly. A stage is information, and information is what lets you and your team make good decisions together. It is not a sentence, and reading about it is not the same as hearing what it means for you.

Guides like this are free, medically reviewed and paid for by supporters. Most cancer is preventable, and our prevention guide covers what the evidence actually supports.