When you’re diagnosed with cancer, your doctor will tell you what stage it is. That will describe the size of the cancer and how far it’s spread.
Cancer is typically labeled in stages from I to IV, with IV being the most serious. Those broad groups are based on a much more detailed system that includes specific information about the tumor and how it affects the rest of your body.
It’s important to understand your cancer stage for several reasons:
Your doctor will use information from test results (clinical stage) or possibly the tumor itself (pathologic stage) to decide your overall stage.
Most cancers that involve a tumor are staged in five broad groups. These are usually referred to with Roman numerals. Other kinds, like blood cancers, lymphoma, and brain cancer, have their own staging systems. But they all tell you how advanced the cancer is.
A physical exam and several tests are used to determine your clinical stage — an estimate of how far the cancer has spread. Tests may include blood and other lab tests and imaging scans. Those may be X-rays or any of the following:
You also may have a biopsy, in which a small piece of tissue is taken and looked at under a microscope.
If a tumor is removed with surgery, your doctor will learn more about it and how it’s affected your body. That information is added to your test results to determine the pathologic stage, or surgical stage. This can be different from the clinical stage, and it’s considered more accurate.
Another factor your doctor probably will use to determine your overall cancer stage is the TNM system, short for tumor, node, and metastasis. They’ll measure each of these and give it a number or an “X” if a measurement can’t be determined. The symbols are a bit different for each type of cancer, but this is generally what they mean:
Doctors look at other information about your cancer for clues about how it will behave. These include:
Once your doctor has all this information and has assigned numbers to T, N, and M, they can determine your overall stage.
Stages Don’t Change
Your cancer stage typically stays the same as when you’re first diagnosed, no matter what happens with the disease. For example, if you’re diagnosed with stage II lung cancer, that’s what it will be called, whether it spreads or goes into remission. That’s when cancer cells are gone.
This is because your treatment options and chances of recovery usually are based on how early your cancer is found.
In a few cases, cancer may be restaged with a new round of tests after treatment or if it comes back.