Colon cancer is the second leading cancer killer in the U.S.1 However, if detected early 90% of people diagnosed survive 5 years or longer.2
Why is this? How does colon cancer progress once it invades the body? For starters, let’s discuss how colon cancer begins.
How Does Colon Cancer Develop?
Most of the time, colon cancer starts as a polyp. A polyp is a growth that can form on the lining of the colon or rectum. Typically they’re harmless; but some can turn into cancer if they are not removed.3
If a polyp does become cancer, physicians use stages to determine the cancer’s progression and the patient’s prognosis.
What Are the Colon Cancer Stages?
At Stage I, the cancer has begun growing through the thin muscles in the colon. It has not yet affected nearby lymph nodes or other parts of the body.
Colon cancer patients diagnosed at Stage I have a 5-year survival rate of 94%.4
At Stage II, the cancer has grown into or all the way through the wall of the colon but has not yet spread to other tissues, organs, or lymph nodes.
Colon cancer patients diagnosed at Stage II have a 5-year survival rate of 82%.5
The cancer has either grown into the outer layers of the colon or expanded through the wall of the colon. It may have affected any number of lymph nodes and attached itself to nearby organs or tissues. It has not traveled to distant sites in other parts of the body.
Colon cancer patients diagnosed at Stage III have a 5-year survival rate of 67%.6
At this last stage of the disease, the cancer may or may not have grown through the wall of the colon, and may have spread to any number of nearby lymph nodes.
To classify as Stage IV, the cancer must have spread to at least one distant organ. The three organs most commonly affected are the lungs, liver, and the lining of the abdominal cavity.
Colon cancer patients diagnosed at Stage IV have a 5-year survival rate of 11%.7
These stages explain why it is so important to detect colon cancer early, when it is most treatable.
Screening can prevent colon cancer and save countless lives, so if you are 50 or older, or considered at higher-than-average risk for colon cancer, download our free Doctor Discussion Guide and talk to your doctor about the various screening options available to you.