Colon cancer stages
Medical review by Mayo Clinic Staff
Updated: April 14, 2025
After a colon cancer diagnosis, other tests might be needed to find out how far the cancer has spread. This is called staging. Knowing the stage of cancer is important because it helps your healthcare team create the most effective treatment plan.
Staging tests might include imaging scans of the belly, pelvis and chest. These scans create pictures that show the location and the size of the colon cancer. Often, imaging isn’t enough, and surgery is needed to find out the stage of the cancer.
Staging terms
Colon cancer is typically classified in five stages, but there is no stage 5 colon cancer. The stages are 0, 1, 2, 3 and 4. Higher numbers mean more advanced cancer. The lowest numbers mean the cancer is in the colon only. By stage 4, the cancer is considered advanced and has spread to distant areas of the body.
To describe each stage in more detail, healthcare professionals commonly use the TNM system. The TNM system looks at three key factors:
- T. The size of the primary tumor.
- N. How far the cancer has spread in the colon and whether it has spread to nearby lymph nodes.
- M. Whether it has spread to other parts of the body, called metastasis.
Staging terms can get very detailed and complicated, and it’s typical to have questions about what you see on your chart. If you don’t understand something, ask your healthcare team to explain it in a way you’ll understand.
There are five stages of colon cancer, ranging from stage 0, where cancer cells are confined to the inner lining of the colon, to stage 4, where cancer has spread to distant organs.
Stage 0 colon cancer
In stage 0 colon cancer, the earliest stage, cancer cells are only present in the inner lining of the colon.
In stage 0, the earliest stage, cancer cells are only in the innermost layer of the colon. At this stage, the cancer hasn’t spread beyond this inner lining. This is sometimes called carcinoma in situ.
Polyp removal is often the only treatment needed for stage 0 colon cancer. The goal is to remove cancer cells completely. At this stage, cancerous polyps can be removed with a tool during colonoscopy. This is known as a polypectomy. If the cancer is too big, part of the colon may be removed in a procedure called a partial colectomy.
Stage 1 colon cancer
In stage 1 colon cancer, the cancer has grown into the inner layers of the colon wall but has not spread to nearby lymph nodes or distant sites.
In stage 1, the cancer has grown into the deeper layers of the colon. However, the cancer remains in the colon and has not spread to nearby lymph nodes or other parts of the body. When cancer hasn’t spread, it’s considered localized.
As in stage 0 colon cancer, removing cancerous polyps with a polypectomy may be the only treatment needed for stage 1 colon cancer. If the cancer cells are the type to grow and spread quickly, called high grade, more of the surrounding healthy tissue may be taken to ensure all the cancer cells are removed. If the cancer was not in a polyp, a partial colectomy may be done to remove the cancerous section of the colon. Nearby lymph nodes also may be removed.
Stage 2 colon cancer
In stage 2 colon cancer, the cancer has grown through the wall of the colon and may invade nearby tissues, but it has not spread to the lymph nodes or distant organs.
In stage 2, the cancer has spread into the outermost layers of the colon and possibly nearby tissues or organs. However, it has not spread to any lymph nodes. Stage 2 cancer that remains in the colon is considered localized. If it has spread to nearby organs (stage 2C), it’s considered regional.
- Stage 2A. Cancer has reached the outer layers of the colon but has not grown through them. It has not spread to nearby lymph nodes or distant sites.
- Stage 2B. Cancer has grown through the outer wall of the colon. It has not spread to nearby lymph nodes or distant sites.
- Stage 2C. Cancer has grown through the colon wall and has reached nearby organs or tissues. It has not spread to nearby lymph nodes or distant sites.
Surgery to remove the affected section of the colon, called a partial colectomy, may be the only treatment needed. Nearby lymph nodes also may be removed during this procedure. Depending on the extent and type of cancer, chemotherapy may be recommended before or after surgery.
Stage 3 colon cancer
In stage 3 colon cancer, the cancer has spread to nearby lymph nodes but not to distant organs.
In stage 3, the cancer has spread into nearby lymph nodes but not to distant sites in the body. This is known as regional cancer.
- Stage 3A. Cancer has grown through the innermost layers of the colon and possibly the muscle layer. It has also affected a few nearby lymph nodes but not distant sites.
- Stage 3B. The cancer has reached the outermost muscle layer of the colon and possibly the colon wall. It may have reached tissues lining nearby organs or structures. It also has affected a few nearby lymph nodes but not distant sites.
- Stage 3C. The cancer has spread through the outermost layer of the colon and possibly the colon wall. It may have reached the lining of the abdominal cavity. This lining is called the peritoneum. It also has affected a few nearby lymph nodes but not distant sites.
Treatment for stage 3 colon cancer typically involves surgery to remove the affected section of the colon, called a partial colectomy. Affected lymph nodes also may be removed. Chemotherapy may be recommended if the cancer cannot completely be removed with surgery.
For advanced cancer that can’t be removed completely with surgery, you may have chemotherapy or immunotherapy to shrink the cancer first. This way, the cancer can be more easily removed later with surgery. Radiation also may be recommended if the cancer has grown into a nearby organ or if cancer cells are still present.
Stage 4 colon cancer
In stage 4 colon cancer, cancer has spread beyond the colon and nearby lymph nodes to distant organs, most commonly the liver.
In stage 4, the cancer has spread to other parts of the body. This is called metastatic or distant colon cancer.
- Stage 4A. Cancer has spread to one distant organ or distant set of lymph nodes.
- Stage 4B. Cancer has spread to more than one distant organ or distant set of lymph nodes.
- Stage 4C. Cancer has spread to distant parts of the peritoneum.
Treatment for stage 4 colon cancer may include surgery to remove the cancer from affected organs. Chemotherapy or targeted therapy may be used to control the cancer. Immunotherapy may be recommended for people whose cancer cells have specific gene changes. Radiation also can relieve symptoms or temporarily shrink the cancer.
Depending on your situation, you may be eligible to take part in a clinical trial. Ask your healthcare team if there are available options for your type of cancer.
How fast does cancer spread?
Colon polyps can take a long time to grow before becoming cancerous, often 10 to 15 years. Though not all polyps turn into cancer, certain types, such as adenomas, have a higher risk.
Most colon cancer polyps are adenocarcinomas. Once these tumors become cancerous, their growth will vary depending on many factors, including the type of cancer cells, your age and your overall health.
Everyone has a story
It’s important to remember that recent advancements in treatment have significantly improved survival rates and quality of life for many people. Each person’s experience with cancer is unique, and your healthcare team is there to support you every step of the way. Regular follow-ups and monitoring can help manage the disease and catch any recurrences early.
Support group discussions
From Mayo Clinic Connect, our online patient community.
Find more discussions:
Mayo Clinic’s approach to colon cancer staging
Colon cancer treatment can be different based on the stage and location of your cancer. It’s important to have a clear and detailed diagnosis so you can feel confident in your treatment plan. Here at Mayo Clinic, our colon cancer team aims for personalized treatment plans – or plans that are based on your cancer, your health, and your goals for treatment and recovery.
And it all starts with a strong foundation of the right diagnosis. With advanced testing and a deep understanding of colon cancer, the expert team at Mayo Clinic is here to help you understand your cancer and its stage. This can help you make decisions with confidence.
You can also contact our helpful scheduling teams by calling:
Associated procedures
News from Mayo Clinic
- Mayo Clinic Minute: Liver transplant for patients with advanced colorectal cancer
- Liver transplants offer new hope for colorectal cancer patients with liver metastasis
- Mayo Clinic Q and A: Colorectal cancer in young adults
- You’re at risk of colorectal cancer. Know the symptoms. Get screened.
- (VIDEO) Treatment options for advanced colorectal cancer
- Mayo Clinic Minute: Warning signs of colorectal cancer in younger adults
- Mayo Clinic researchers identify proteins linked to immunotherapy resistance in metastatic colorectal cancer
- Mayo Clinic Minute: Are colon and rectal cancers treated differently?
- Mayo Clinic Q and A: Understanding colorectal cancer
- Clinical trials team brings hope and dedication to colorectal cancer study
- New gene markers detect Lynch syndrome-associated colorectal cancer, Mayo Clinic study
- Mayo Clinic researchers publish key findings about cell proteins to determine effectiveness of immunotherapy for colon cancer
