how many stages of cancer are there

Most cancers are described using five main stages: stage 0, I, II, III, and IV, with stage IV being the most advanced.

Quick Scoop: How many stages?

• Many cancers use stages 1 through 4 (so four stages in common conversation).

• For several cancers, doctors also use stage 0 (abnormal or “pre‑cancer” cells), making it effectively five stages: 0–4.

• Staging describes how big the tumor is and how far it has spread, which helps guide treatment and prognosis.

Think of it like a timeline: stage 0 is “hasn’t really started yet,” and stage IV is “has traveled to distant parts of the body.”

Mini breakdown of the stages

• Stage 0 – Abnormal cells are present but not invading nearby tissue; often called “carcinoma in situ” or pre‑cancer.

• Stage I – Cancer is small and localized in one area; often called early-stage cancer.

• Stage II – Cancer is larger and/or has started to grow into nearby tissue, but spread is still relatively limited.

• Stage III – Cancer is larger and/or has spread more extensively to nearby tissues or lymph nodes, often called “locally advanced.”

• Stage IV – Cancer has spread (metastasized) to distant parts of the body and is called advanced or metastatic cancer.

In forum discussions, you might see people say “stage 4 cancer” as shorthand, but in medical reports it’s usually written as stage IV, and may include letters like IIIA or IIIB for more detail.

A quick note on other systems

Doctors also use more detailed systems like TNM (Tumor, Node, Metastasis) to decide which stage number to assign.

Even then, they usually end up grouping everything back into stage 0, I, II, III, or IV so it’s easier to understand and compare.

TL;DR: Most people talk about four stages of cancer (I–IV) , but many cancers actually have five when you include stage 0 , so you’ll often see stages listed as 0–4.

Information gathered from public forums or data available on the internet and portrayed here.