Colon Cancer Stages 0–4: Subtypes, Remission, Outlook

Colon cancer staging involves defining the severity of your disease based on how much cancer is in your body. It describes the extent to which the disease has spread and, if so, how far it has spread from the primary site. While every person’s disease is unique, each stage of colon cancer tends to have a similar prognosis and treatment options across populations.

Colon cancer occurs when cancer cells grow in your colon (large intestine). While the term “colon cancer” is often used interchangeably with the term “colorectal cancer,” they are not the same. Colorectal cancer refers to any cancer of the large intestine, which includes both colon cancer and rectal cancer.

The four stages of colon cancer are numbered 1 through 4. Stage 0 is a preclinical stage. The lower the stage number, the less your cancer has spread. Higher numbers mean that the cancer has spread more.

Colon Cancer Staging System

Colon cancer is staged at the time of your diagnosis before treatment begins. It does not change even if your disease improves or worsens.

Colon cancer is most often staged using the American Joint Committee on Cancer (AJCC) guidelines. These guidelines use pathological staging, which determines the staging based on tissue removed during surgery.

Clinical staging, which stages cancer using results from physical exams, lab reports, and imaging tests performed before surgery, is considered less accurate than pathological staging.

The AJCC uses the TNM system, which evaluates three key pieces of information to determine cancer staging. Each letter refers to a specific disease characteristic:

• T: Describes the size and location of the primary tumor
• N: Describes the number of nearby lymph nodes affected by cancer
• M: Describes whether the cancer has metastasized (spread) to other parts of your body

Within each stage, the letters “T,” “N,” and “M” are followed by numbers or letters to provide more details about these factors. When the T, N, and M categories are determined, it is combined in a process called stage grouping to assign an overall stage to the disease.

Based on the AJCC system, the stages of colon cancer include:

Stage 0 (Carcinoma In Situ)

Stage 0 cancer is considered a preclinical stage of colon cancer. It involves the following features:

• Stage grouping: Tis, N0, M0
• Stage 0 cancer is the earliest stage. It is also known as carcinoma in situ or intramucosal carcinoma (Tis). Stage 0 colon cancers have not grown beyond mucosa (the innermost layer of moist tissue lining your colon). It is usually limited to one or more polyps (tissue bulging from the surface of an organ) and does not involve nearby lymph nodes (N0) or distant sites (M0).

Stage 1

Stage 1 cancer is the earliest stage of colon cancer. It involves the following characteristics:

• Stage grouping: T1 or T2, N0, M0
• Stage 1 colon cancer has progressed to a tumor, which is abnormal tissue that develops because of excessive cell growth. It has grown past the mucosa, deeper into the layers of your colon wall to involve the second layer of colon tissue called the submucosa (T1). It may also have grown into the muscularis propria, or the third layer of colon tissue (T2). Stage 1 cancer has not spread to nearby lymph nodes (N0) or distant sites (M0).

Stage 2

Stage 2 colon cancer has metastasized outside your colon to invade the surrounding tissue but not your lymph nodes. Stage 2 cancer is subdivided into subcategories 2A, 2B, and 2C:

Stage 2A:

• Stage grouping: T3, N0, M0
• Stage 2A cancer has grown into the muscularis propria layer of the colon wall but has not spread beyond it (T3). It does not affect nearby tissues, organs, lymph nodes (N0), or distant sites (M0).

Stage 2B:

• Stage grouping: T4a, N0, M0
• Stage 2B colon cancer has grown through the serosa (the outermost layer of the colon wall) but has not gone outside the colon (T4a). It has not spread to nearby tissues, organs, lymph nodes (N0), or distant sites (M0).

Stage 2C:

• Stage grouping: T4b, N0, MO
• Stage 2C has grown through the wall of the colon and has become attached to or grown into other nearby tissues or organs (T4b). Cancer at this stage has not yet spread to nearby lymph nodes (N0) or distant sites (M0).

Stage 3

Stage 3 colon cancer has spread into nearby lymph nodes but has not metastasized, affecting other areas of your body. Stage 3 is divided into three categories, each of which has additional subcategories:

Stage 3A:

• Stage grouping: T1 or T2, N1/N1c, M0
• Stage 3A cancer can include disease that has grown through the mucosa into the submucosa (T1) and may also have grown into the muscularis propria (T2). It has spread to one, two, or three nearby lymph nodes (N1) or into areas of fat near the lymph nodes but does not affect the nodes themselves (N1c). It has not spread to distant sites (M0).

Or, stage 3A can involve:

• Stage grouping: T1, N2a, M0
• In these circumstances, Stage 3A colon cancer describes a disease that has grown through the mucosa into the submucosa (T1). It has also spread to four to six nearby lymph nodes (N2a) but has not spread to distant sites (M0).

Stage 3B:

• Stage grouping: T3 or T4a, N1/N1c, M0
• With these characteristics, stage 3B has grown into the outermost layers of the colon (T3) or through the wall of the colon (T4a) but has not affected nearby organs. It has spread to one, two, or three nearby lymph nodes (N1a or N1b) or into areas of fat near the lymph nodes but not the lymph nodes themselves (N1c). This cancer has not spread to distant sites (M0).

Or, stage 3B can involve:

• Stage grouping T2 or T3, N2a, MO
• This version of stage 3B involves cancer that has grown into the muscularis propria (T2) or into the outermost layers of the colon (T3). It has spread to four, five, or six nearby lymph nodes (N2a). It has not spread to distant sites (M0).

Or, stage 3B can involve:

• Stage grouping T1 or T2, N2b, M0
• This category of stage 3B cancer describes cancer that has grown through the mucose and into the submucosa (T1) and possibly into the muscularis propria (T2). The disease has spread to seven or more nearby lymph nodes (N2b) but has not spread to distant sites (M0).

Stage 3C:

• Stage grouping :T4a, N2a, M0
• The cancer has grown through the outermost wall of the colon to the tissue that wraps around the organs in the abdomen (visceral peritoneum) but has not reached nearby organs (T4a). It has spread to four to six nearby lymph nodes (N2a). It has not spread to distant sites (M0).

Or, stage 3C can involve:

• Stage grouping: T3 or T4a, N2b, M0
• This category involves colon cancer that has spread through the outermost layers of the colon (T3) or the wall of the colon to the tissue that wraps around the organs in the abdomen (T4a) but has not reached nearby organs. It has spread to seven or more nearby lymph nodes (N2b). It has not spread to distant sites (M0).

Or, stage 3C can involve:

• Stage grouping: T4b, N1 or N2, MO
• This category describes colon cancer that has grown through the wall of the colon and is attached to or has grown into other nearby tissues or organs (T4b). It has spread to at least one nearby lymph node or into areas of fat near the lymph nodes (N1 or N2). It has not spread to distant sites (M0).

Stage 4

Stage 4 cancer, also called metastatic colon cancer, involves cancer that has traveled through your lymph system and bloodstream to other parts of your body. With colon cancer, the lungs and liver are the organs most often affected.

Stage 4A:

• Stage grouping: Any T, Any N, M1a
• This stage involves cancer that may or may not have grown through the wall of the colon (Any T). It may or may not have spread to nearby lymph nodes (Any N). It has spread to one area or organ that is distant from your colon, such as a liver, lung, ovary, or a distant set of lymph nodes, but it has not spread to distant parts of the peritoneum (the lining of the abdominal cavity) (M1a).

Stage 4B:

• Stage grouping: Any T, Any N, M1b
• This stage involves cancer that may or may not have grown through the wall of the colon (Any T). It may or may not have spread to nearby lymph nodes (Any N). It has spread to more than one area or organ that is distant from your colon, such as a liver, lung, ovary, or a distant set of lymph nodes but not to distant parts of the peritoneum (M1b).

Stage 4C:

• Stage grouping: Any T, Any N, M1c
• In this stage, your colon cancer may or may not have grown through the wall of the colon or rectum (Any T). It may or may not have spread to nearby lymph nodes (Any N). It has spread to distant parts of the peritoneum and may or may not have spread to distant organs or lymph nodes (M1c).

Colon Cancer Staging and Prognosis

Your colon cancer staging can impact your disease prognosis (a prediction or estimate of the chance of recovery or survival from the disease). A prognosis is typically based on statistics calculated on how a disease acts in studies of the general population.

It’s important to understand that since your prognosis is based on average statistics, it means that there is always the chance that you will do better or worse than what is considered average.

Many factors can influence your colon cancer prognosis. These concerns include:

• Location of your colon cancer
• Colon cancer stage and grade
• Degree of penetration of the tumor through the bowel wall
• Presence or absence of lymph node involvement
• Presence or absence of distant metastases
• Your age at diagnosis
• Your general health and other medical conditions
• Available treatments for your stage of colon cancer
• How your treatment is working
• Surgical removal of your primary tumor
• Outcomes (survival rates) of other people with your stage of colon cancer

A cancer prognosis usually considers the five-year survival rate. This represents the percentage of people in a study or treatment group who are alive five years after they were diagnosed or started treatment for colon cancer.

In the United States, five-year survival rates for colon cancer as reported by the Surveillance, Epidemiology, and End Results (SEER) Program include:

• Stage 1: About 92% five-year survival rate
• Stage 2A: 87% five-year survival rate
• Stage 2B: 65% five-year survival rate
• Stage 3A: About 90% five-year survival rate
• Stage 3B: 72% five-year survival rates
• Stage 3C: About 53% five-year survival rate
• Stage 4 (metastatic colon cancer): About 12% five-year survival rate

Does Treatment Cure Colon Cancer?

Colon cancer is considered a highly treatable disease. It can often be cured when diagnosed while it is still localized to the bowel and has not spread to involve other tissue or organs. Surgery is the primary form of treatment. It can achieve a cure in about 50% of people with colon cancer.

While surgery can be successful, recurrence following surgery for colon cancer is a significant problem. Recurrent colon cancer can often be more complicated to treat than the initial disease. It is often the ultimate cause of death, which is why cancer survivors are advised to visit their providers regularly after treatment concludes.

Next Steps With Diagnosed Colon Cancer

A diagnosis of colon cancer can be devastating news. As you begin to process this information, you will have to make decisions regarding treatment and lifestyle changes. The urgency of making these decisions will be determined by the severity and location of your colon cancer.

Here are some next steps to ensure that you get the best possible care if you are diagnosed with colon cancer:

Communicate With Your Healthcare Provider

Talk openly with the healthcare provider who delivers your diagnosis. Don’t hesitate to ask as many questions as you need to in order to clearly understand your medical condition and recommended next steps, and treatment options.

Take time to write or record their answers since it will likely involve a lot of new information all at once. If possible, take a family member or friend with you so they can take notes while you discuss your situation.

Get a Second Opinion

Getting a second opinion on your diagnosis and treatment plan is always a good idea. This may be valuable if your cancer was discovered by a healthcare provider who does not specialize in your type of cancer. As part of the process, ensure that the second healthcare provider has access to all the medical records and imaging tests used to determine your diagnosis.

Inform Yourself

Learn all you can about colon cancer and how to cope with it. The more you know about colon cancer, the easier it will be to discuss your condition with healthcare providers and participate in decisions regarding your treatment.

You can investigate treatment options through the National Cancer Institute’s Cancer Information Service, which can provide recommended treatment plans from the National Cancer Institute based on your diagnosis, the location of your primary cancer, and the stage of your colon cancer.

Carefully Decide on a Treatment Plan

After you get a second opinion and gather the information you need to make an informed decision, you should prepare to make decisions regarding your treatment plan. These choices will involve the type of treatment you receive, where you receive it, and who administers it.

Continue to Stay Informed

Your involvement in ensuring you get the best possible care does not stop with choosing a treatment plan. Stay as informed as possible about what is happening and how it affects your progress. Talk to your healthcare provider about ways you can work to stay healthy and fit to support the success of your treatments.

Take Advantage of Support Services

Depending on your medical condition and living situation, you may benefit from using support services during and after your treatment. This can be helpful if you don’t have family or friends who can lend a hand.

If that is the case, check with your healthcare provider or cancer treatment advocate to learn about the resources available to you through your health insurance, local social service organizations, and volunteers.

Take Stock of Your Finances

While money is likely the last thing you want to worry about when you receive a diagnosis of colon cancer, you should determine the cost of your treatment and how you will pay your portion of the costs.

Contact your health insurance plan to find out about your plan limits and how you can make the most of the coverage you have. This may affect where you receive treatment and the type of treatment you can afford.

Determine how you will deal with time lost from work and if you qualify for disability insurance. If finances are a problem, discuss your situation with your healthcare provider, who can direct you to resources for financial assistance and financial aid.

Take Charge of Your Future

As a person with cancer, you don’t have to feel that the future is out of your hands. Remain actively involved in monitoring your progress. Contribute to your health and well-being by making the recommended lifestyle changes to support your treatment and recovery.

Observe your healthcare provider’s advice for follow-up care after your treatment ends to remain as healthy as possible and monitor your health for signs of recurrence.

Stage of Recurrent Colon Cancer

Recurrent colon cancer is colon cancer that returns after a period called remission. Remission is a partial or total disappearance of colon cancer signs and symptoms after treatment.

Among people treated for colon cancer, about 30% to 40% develop recurrent disease, with the risk of recurrence lower for people diagnosed with stage 1 disease vs. stages 2 or 3.

When colon cancer recurs, it usually appears as a distant metastasis in your liver or lungs. When it recurs locally, it affects the pelvis or peritoneum. Most recurrences of colon cancer occur within the first two to three years after treatment for the initial disease.

In most cases, the formal stage of cancer remains the same as when it was first diagnosed, even if it returns or spreads after a period of remission. Under certain circumstances, recurrent colon cancer may be restaged, though it is uncommon.

If your healthcare provider decides to restage recurrent colon cancer, the same exams, imagining tests, biopsies, and surgeries used to stage the initial disease are repeated to identify the new stage. When a conclusion is reached, the new stage is identified with a lowercase “r” before the recurrence or retreatment stage.

Summary

Colon cancer staging helps describe the extent of your disease so healthcare providers know how much the disease has spread and if so, how far. Staging is used to make decisions about your treatment and determine a prognosis. Surgery is the standard treatment for colon cancer in stages 1 through 4.

While useful, colon cancer staging is only one part of your disease story. Factors such as your age at diagnosis, tumor grade, and other health conditions can impact your disease outcomes.

Getting an early diagnosis and treatment is the best way to improve your results. Maintaining a schedule of follow-up appointments and screenings as advised after treatment can support your long-term success as a colon cancer survivor.