What Is a Cancer Stage?

Following a diagnosis of cancer, the most important step is to accurately determine the stage of the cancer. The stage describes how far the cancer has spread. (Some cancers, such as leukemia, are not staged.) Each stage of cancer may be treated differently.

To begin evaluating and discussing treatment options with your health care team, you need to know the stage of your cancer.

There are many staging systems, but the TNM system is the most common. This system uses three different codes to describe the size and location of the tumor, whether it has spread to the lymph nodes around the tumor, and whether it can be found in other parts of the body. Specifically, “T” refers to the size and location of the tumor, “N” to the number of lymph nodes (tiny bean-shaped organs throughout the body that help fight infection) involved, and “M” to whether the cancer has spread (metastasized) to other parts of the body.

After the T, N, and M categories of your cancer have been identified, your doctor will combine this information to assign a stage (0 to IV) to your cancer. The higher the number, the more serious (advanced) the cancer is.

• Stage 0 - precancer
• Stage I - small cancer found only in the site where it started
• Stage II - larger cancer that may have spread to the lymph nodes
• Stage III - larger cancer that is also in the lymph nodes and possibly in nearby organs
• Stage IV - cancer that has spread to a different part of the body from where it started