When you or someone you love is diagnosed with colon cancer, the next two questions are almost always: How advanced is it? And what are the treatment options?

With colon cancer, how advanced the disease is – or what stage the disease is in – helps determine the best course of treatment.

Here we’ll describe how the staging process works for colon cancer. We’ll also explain what each stage means, discuss survival rates and cover what treatment options may look like at each stage.

If you’ve been diagnosed with colon cancer, this information can give you a helpful overview of what treatment options exist at each stage. But you should know that your own preferences and goals are very important for determining how you move forward. Your team of doctors and specialists will work with you to create a tailored colon cancer treatment plan just for you.

What are the colon cancer stages?

Staging is the process doctors use to tell if, and how far, cancer has spread. When someone has a higher stage number than someone else, it could mean they have more cancer in their body, the cancer has spread more, or both.

The opposite is also true: The lower the stage number, the less cancer is in the body or the less it has spread.

Colon cancer staging is crucial because it gives cancer care teams – which include surgeons, oncologists, pathologists, radiologists and others – an agreed upon way to talk about the condition. By staging the cancer, care teams can more easily understand diagnoses and collaborate on treatment plans.

How is colon cancer diagnosed?

So, what happens during a colonoscopy? A colonoscopy is a routine procedure that allows your specially-trained primary care doctor or a gastroenterologist to check the lining of your colon and rectum for anything unusual such as inflammation or colon polyps.

Colon polyps can often be removed during the procedure and then sent for testing. Your doctor may also take biopsies of any other suspect areas and send those off for testing too.

If cancer is detected, a CT scan is ordered to look for any distant metastasis and local invasion to the other organs. With the initial pathology reports from your colonoscopy and the CT scan results in hand, staging begins –and it’s time to meet with a colorectal surgeon.

The five stages of colon cancer

There are five possible stages of colon cancer (zero through four). To determine the stage, doctors generally use what’s called a TNM Staging System to answer the following questions:

• Tumor (T) – Has the tumor expanded into the colon wall or rectum? If so, how many layers?
• Node (N) – Has the tumor spread to the lymph nodes? If so, where are the infected lymph nodes and how many are there?
• Metastasis (M) – Has the cancer moved to other parts of the body? If so, where and how much has it spread?

Using your tests and scans, your doctors will evaluate all three measures to determine the cancer stage. In some cases, doctors also use “Grade” (G) to describe how the cancer cells compare to healthy cells. The lower the grade, the more the cancer cells look like healthy cells.

Before the TNM Staging System came along, the SEER database was primarily used to stage colon cancer. SEER stands for Surveillance, Epidemiology, and End Results. Today, the TNM Staging System is the most widely used staging system, but SEER is still used in some contexts – particularly when it comes to estimating survival rates, which we get to later on.

Revealing the colon cancer stages

While all the tests and scans up to this point have been vital in helping your doctors understand your disease, the exact stage of cancer can’t be determined until surgery occurs.

Colorectal surgery usually the first step in Stages 1-3. Surgery allows your surgeon to see what’s happening inside. It also allows them to remove cancerous tissues – which is an important step in preventing the cancer from spreading and determining next steps for your treatment.

What is the colon cancer survival rate?

When it comes to understanding colon cancer survival rates, you need to know the term “relative survival rate”. Relative survival rate compares people with the same type and stage of cancer to the overall population.

For instance, if the cancer has a five-year relative survival rate of 71%, people who have the same cancer type and stage are about 71% as likely to live at least five years after diagnosis as people who don’t have that cancer.

As far as calculating the relative survival rate for colon cancer, this is where the SEER database is often used because it contains historical data. This is what the American Cancer Society (ACS) uses to talk about survival rates.

While similar to TNM, SEER doesn’t group cancers using numbered stages. Instead, it classifies colon cancers into one of the following stages:

• In the localized stage, the cancer has not spread beyond the colon or rectum.
• If the cancer has reached the regional stage, it means the cancer has spread to structures or lymph nodes near the colon.
• In the distant stage, the cancer has spread beyond the region to other parts of the body, such as distant organs and lymph nodes.

SEER numbers don’t account for everything. Other factors like age, health, where the cancer started, and the response to treatment have a say as well. Also the outlook for new cases may actually be better due to advancements in treatment.

Here we see the five-year relative survival rates for colon cancer, according to the ACS. The organization bases these numbers on people diagnosed with colon cancer between 2009 and 2015.

Colon cancer treatment options for every stage

There’s no one-size-fits-all approach to colon cancer treatment. Your treatment plan should be tailored to you and be coordinated across specialists – and that’s where your cancer care team comes in.

At HealthPartners, we believe cancer treatment and care is best managed by a group of doctors and specialists in what’s known as multidisciplinary conferences. This is where colorectal surgeons, oncologists, radiologists, pathologists and other members of your care team gather to discuss the best sequence of treatment for you.

Below we dive into the treatment options your care team may recommend at various colon cancer stages.

Stage 0 colon cancer

What is Stage 0 colon cancer?

Stage 0 colon cancer is when the abnormal cells haven’t grown beyond the inner lining of your colon.

What are the treatment options for Stage 0 colon cancer?

• Surgery – Oftentimes surgery is the only treatment that is needed in this early stage. The size of the growth will determine the type of surgery:
  • Polypectomy – Usually the cancerous polyp or cancerous area can be taken out during a colonoscopy, which is called a local excision.
  • Partial colectomy – If the tumor is too big to be removed through local excision, a surgery to remove part of the colon may be required.

What does the treatment timeline for Stage 0 colon cancer look like?

Including surgery and follow-up exams, Stage 0 colon cancer can usually be treated in one to three months. But your doctor may recommend more frequent colon cancer screenings like colonoscopies or stool tests. A personal history of colon cancer means you’re at higher risk of another bout of the disease.

Stage 1 colon cancer

What is Stage 1 colon cancer?

Stage 1 colon cancer is when cancerous cells have grown more deeply into the wall of your colon, but still haven’t spread beyond your colon or to nearby lymph nodes.

What are the treatment options for Stage 1 colon cancer?

• Surgery – Similar to Stage 0, surgery is often the only treatment that is needed at this stage.
  • Polypectomy – A local excision during a colonoscopy can remove a cancerous polyp. If that polyp is completely removed, and there’s no cancer at the edges of the removed piece, further treatment may not be needed. However, if the polyp is determined to be “high grade” – meaning that cancerous cells can be found at the edges – or if the polyp wasn’t completely removed in one piece, additional procedures may be needed.
  • Partial colectomy – For cancers that are not in a polyp, surgery to remove the cancerous portion of the colon is the most common treatment.

What does the treatment timeline for Stage 1 colon cancer look like?

Timing will vary based on whether the polyp is high grade or whether a partial colectomy is needed. Generally speaking, treatment for Stage 1 colon cancer takes one to six months.

As with Stage 0, your doctor may also recommend more frequent colon cancer screenings in the future.

Stage 2 colon cancer

What is Stage 2 colon cancer?

Stage 2 colon cancer is when the cancer has begun to invade the outer layers or the colon or started to spread outside the colon wall, but has not reached the lymph nodes yet. There are three types of Stage 2 colon cancer:

• Stage 2A – The cancer has grown into but not through the outer layers of the colon. The cancer has not spread to nearby organs or lymph nodes, and it has not spread to distant structures.
• Stage 2B – The cancer has not spread beyond the colon, but it has grown through the wall of the colon.
• Stage 2C – The cancer has grown through the colon wall and has spread to tissues or organs near the colon. It has not reached distant organs, but may have reached 1-3 nearby lymph nodes.

What are the treatment options for Stage 2 colon cancer?

• Surgery – A partial colectomy – along with the removal of the nearby lymph nodes – is the typical course of treatment at Stage 2, regardless of A, B or C status.
• Radiation – Radiation is typically not required for colon cancer of any stage, but in rare cases is offered before or after surgery to treat any cells that surgery may not remove.
• Chemotherapy – Typically at this stage, chemotherapy is suggested if your cancer has a higher risk of coming back due to factors such as the cancer had blocked your colon, caused a colon wall perforation or cancer was found at the edges. After surgery is completed, it’s time to meet with a medical oncologist – a doctor who specializes in nonsurgical cancer treatments.

What does the treatment timeline for Stage 2 colon cancer look like?

The length of treatment for Stage 2 colon cancer will vary based on whether the doctor recommends adjuvant chemotherapy after surgery. But usually, Stage 2 colon cancer takes anywhere from three to nine months to treat. And again, more frequent colon cancer screenings may be recommended in the future.

Stage 3 colon cancer

What is Stage 3 colon cancer?

Stage 3 colon cancer is when the cancer has spread to nearby lymph nodes, but not to other parts of the body. There are three types of Stage 3 colon cancer:

• Stage 3A – The cancer has grown through the inner and middle layers of the colon wall. Depending on the “T” stage, the cancer has likely spread to 1-6 nearby lymph nodes but it hasn’t spread to distant sites.
• Stage 3B – The cancer has grown through the inner and middle layers of the colon wall. It may have also spread to the muscular layers of the colon, or through the colon wall entirely. It has spread to nearby lymph nodes but hasn’t spread to distant sites.
• Stage 3C – The cancer has grown into or through the outermost layers of the colon and possibly the abdominal lining. It has been detected in at least seven nearby lymph nodes, or in the areas of fat surrounding them. It has not spread distantly.

What are the treatment options for Stage 3 colon cancer?

• Surgery – Once again, a partial colectomy along with the removal of nearby lymph nodes is typically the first step in the treatment process at this stage.
• Chemotherapy – At this stage, chemotherapy is often part of the overall treatment plan. This treatment will be led by your medical oncologist – a cancer doctor who is an expert in nonsurgical treatment. While chemotherapy is often used after surgery, it might be needed prior to surgery based on the characteristics of your cancer, its location and your overall health status.
• Radiation – Radiation is used very rarely for colon cancer, but may be recommended in combination with chemotherapy or if surgery isn’t an option.

What does the treatment timeline for Stage 3 colon cancer look like?

Again here, the answer depends on the severity, extent of spreading, the type of treatment you’re undergoing and how you’re responding to those treatments. For most Stage 3 cases, treatment lasts anywhere from six to 12 months and your doctor may recommend more frequent cancer screenings in the future.

Stage 4 colon cancer

What is Stage 4 colon cancer?

Stage 4 colon cancer is when the cancer has spread to other organs and distant tissues; it’s metastasized. Most often, colon cancer spreads to the liver. But it can also spread to your lungs, brain, the lining of the abdominal cavity, or other distant lymph nodes. Similar to other stages, Stage 4 colon cancer has three classification types:

• Stage 4A – The cancer has spread to one distant organ or a distant set of lymph nodes. It may or may not have spread through the colon wall or to nearby lymph nodes.
• Stage 4B – The cancer has spread to more than one distant organ however it has not spread throughout the abdominal cavity lining. It may or may not have spread through the colon wall or to nearby lymph nodes.
• Stage 4C – The cancer has spread to distant areas of the abdominal cavity lining. It may or may not have reached distant organs or lymph nodes, or spread through the colon wall.

What are the treatment options for Stage 4 colon cancer?

• Chemotherapy – At this stage, chemotherapy is almost always the first step. Typically, chemotherapy is given before any surgeries if there are too many masses. If the cancer has spread too far to make surgery a viable option, chemo is the main treatment.
• Surgery – At this stage, surgery is frequently not the first step. That’s because treating the entire body with chemotherapy is more likely prolong life. Those fortunate enough to respond well to chemotherapy, and have limited spread of their cancer, may benefit from removing all known areas of disease. For example, a partial colon resection can be combined with a partial liver resection. In that event the 5 year survival rate may increase to 50%.
• Targeted therapies – Depending on your cancer specific characteristics, target drug therapies may also be recommended to control and treat your cancer. This could be used alongside chemo treatments or if chemo is no longer working.

What does the treatment timeline for Stage 4 colon cancer look like?

Timing varies based on the type of treatment, the patient’s health, whether there’s a recurrence of the cancer, and other factors. Treatment for Stage 4 colon cancer can take anywhere from six to 12-plus months.

Want to learn more about your colon cancer treatment options? We’re here for you.

Whether you just received your diagnosis or you’re looking for new treatment options, we’re here to help.

If you’ve just been diagnosed with colon cancer, find a board-certified colorectal surgeon to start building a treatment plan. We can often get you an appointment within 48-hours of diagnosis. Once you find your surgeon, just give us a call to set your appointment.

If you’re interested in your nonsurgical options or looking for a new oncologist, make an appointment with one of our board-certified oncologists. From clinical cancer trials to using medical cannabis for cancer symptoms, they’ll talk with you about a range of possible therapy options.