Cancer staging
When doctors diagnose a cancer, they also want to find out what “stage” the cancer has reached. Cancer staging is important because it helps doctors decide on the best treatment. It also gives information about the patient’s likely outlook and their chances of recovery.
To determine the stage of a cancer, a doctor will want to know:
- Where the cancer originated
- The size of the tumor
- How far it has spread in the affected organ
- Whether it has spread into the lymph nodes (glands)
- Whether it has spread to other parts of the body
What does cancer staging involve?
Your doctor will do tests to find out the stage of your cancer. These vary depending on the type of cancer but may include blood tests, x-rays, scans and possibly a biopsy. A biopsy involves removing a small piece of tissue to be looked at under a microscope. The biopsy also enables the doctor to assign a grading to the cancer.
Cancer staging systems
Cancer stages are usually defined using an international classification system, such as the TNM system. TNM takes into account the
Some cancers have other staging systems that are used alongside, or instead of, the TNM system. Often, doctors use a number between 1 and 4 to describe the stage of a cancer. Stage 1 is the earliest stage of cancer, and stage 4 the most advanced. The stages may be divided into smaller categories, for example stages 3A and 3B.
In some cancers, such as melanoma, there is also a stage 0. This means that the tumor is confined to the cells where it originated and has not begun to grow beyond them. Stage 0 cancer is sometimes called “in situ”, meaning “in place”.
You can find information about lung cancer stage 1, stage 2, stage 3 and stage 4 in the lung cancer section of this site.
For information about melanoma stages 0 to 5, go to the melanoma section.
