What Does Stage 1 Colon Cancer Entail?

Colorectal cancer is the second most common cause of cancer death in the U.S. While this is alarming, the good news is that people with colon cancer live longer when it’s found early. Cancer is typically classified by stage (1 to 4), and earlier stages have a better prognosis. Stage 1 colon cancer is an early colon cancer that only involves the colon and hasn’t spread to other areas of the body. 

Keep reading to find out more about how stage 1 colon cancer is diagnosed and treated.

How is stage 1 colon cancer diagnosed? 

Most people with early-stage colon cancer don’t have any symptoms. So they’re usually not aware they have cancer until it’s found by a screening test, like a colonoscopy.

A biopsy is required to diagnose colon cancer. This involves removing a sample of tissue from the colon and looking at it under a microscope. The tissue can often be removed during a colonoscopy, but in some cases surgery is needed. A pathologist, who is trained to distinguish between cancer cells and normal colon cells, looks at the tissue to make the diagnosis. 

After the cancer is diagnosed, it is removed to determine the stage. Staging and grading are used to understand how cancer is affecting the colon and other parts of the body. These classification methods are also used to make decisions about treatment. As part of these processes, blood tests or imaging tests, like a CT scan, may also be done.

Stage 1 colon cancer is one that stays in the colon but extends into the second or third layers of the colon wall. The cancer hasn’t spread to the surrounding lymph nodes or other parts of the body. This makes it easier to treat.

How do you treat stage 1 colon cancer?

Stage 1 colon cancer treatment involves removing the cancerous tissue from the colon with surgery or during a colonoscopy. 

If a cancerous polyp (growth) can be completely removed during a colonoscopy, surgery may not be needed. This depends on the polyp type, if it can be removed in one piece, and the pathologist’s assessment.

The surgery used to treat colon cancer is called a colectomy. It is done through a large incision in the abdomen or laparoscopically through small incisions. The part of the colon with the cancer is removed along with neighboring lymph nodes, and the healthy parts of the colon are reconnected. 

Sometimes the remaining sections of the colon can’t be reconnected right away. In this case, a colostomy is made, which means that the colon is directed to the outside of the body to form a stoma (opening). A colostomy bag is attached to the stoma, to collect stool from the colon. This is not always permanent and can often be reversed later with another surgery.

While chemotherapy and radiation are used to treat other stages of colon cancer, they’re not recommended for the treatment of stage 1 colon cancer, except in rare circumstances.

Is stage 1 colon cancer curable?

Yes, stage 1 colon cancer is curable. Since stage 1 colon cancer affects only the colon and not other parts of the body, it can be cured by removing it completely. 

Can stage 1 colon cancer come back?

Most people with stage 1 colon cancer do well after treatment. In fact, about 90% of people treated for stage 1 colon cancer live at least 5 years after the cancer is found. 

That being said, colon cancer can come back, which is called recurrence. But the risk of this with stage 1 colon cancer is low compared with other stages. One study looking at the rate of recurrence in about 1400 people found that only 0.5% of those with stage 1 colon cancer had the cancer come back. 

After treatment, it’s important to follow up with your healthcare providers. You may need more frequent colonoscopies after your treatment to check for cancer recurrence. Following a healthy lifestyle and keeping up with other recommended cancer screening tests are also important.

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Written by:

Sarah Pozniak, MD

Sarah Pozniak, MD, has 9 years of experience since graduating medical school (6 since completing residency). She is a board-certified general internal medicine physician and has practiced as a primary care physician in both Utah and Washington, D.C. Currently, she cares for patients with chronic illnesses such as diabetes and high blood pressure using telemedicine as part of a virtual care program.

Edited by:

Mandy Armitage, MD

Mandy Armitage, MD, has combined her interests in clinical medicine with her passion for education and content development for many years. She served as medical director for the health technology companies HealthLoop (now Get Well) and Doximity.

Reviewed by:

Sarah Koller, MD, MS, FACS

Sarah Koller, MD, MS, is board-certified in general surgery and colorectal surgery. She is currently on faculty at the University of Southern California as an assistant professor of surgery.

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