The Different Stages of Cancer and What They Mean

A cancer diagnosis can be scary, difficult to process and understand, and leave you and your loved ones unsure of how to move forward. While it is certainly beneficial to detect cancers as early as possible, today we have treatment options available at each stage. Most types of cancer are divided into 4 (or 5 stages if we include the so called “stage 0”): Stage 0, Stage I, Stage II, Stage III, and Stage IV – with Stage IV being the most advanced. In addition to this scale, another system — the TNM (defined below) staging system — is often used to explain stages of cancer.

• T (tumor) — size of the original tumor
• N (node) — whether or not the cancer is present in the lymph nodes
• M (metastasis) — whether the cancer has spread to a different part of the body from where it started

Outlined below are the different stages of cancer and what each stage means.

The Stages of Cancer: 0–IV

Stage 0

Stage 0 means that there's no cancer, only abnormal cells with the potential to become cancerous. You may also see this referred to as “carcinoma in situ”.

Stage I

Stage I means that cancer has been found, but it is small and has not yet spread to nearby areas or tissues. This stage is considered “early-stage” or “localized cancer”.

Stage II

Stage II means that cancer has started to grow in size but has not spread to other areas. This stage is considered early “locally advanced cancer”.

Stage III

Stage III means that cancer is larger and may also have started to spread to nearby areas, tissues or lymph nodes. This stage is considered late “locally advanced cancer”.

Stage IV

Stage IV means that cancer has spread to areas beyond the region where it started. This stage is considered “advanced” or “metastatic cancer”.

Advancements in medical research — made possible in part through clinical trials — have led to more treatment options. Talk with your doctor about treatment options, and whether joining a clinical trial is an option for you.