Metastatic Colon Cancer: Overview and More

Colon cancer is cancer of the colon (large intestine). Metastatic colon cancer means that the cancer has metastasized, spreading beyond the colon or rectum, to other organs. In cancers that affect the colon or rectum (colorectal cancer), approximately 20% of cases will have already metastasized at the point of diagnosis. Another 25% will metastasize at a later point.

This article discusses the symptoms, risk factors, and treatment for metastatic colon cancer.

Symptoms

Not every patient will experience symptoms of colon cancer, but some common symptoms include:

• Bloody or narrow stool
• Changes in bowel frequency
• Diarrhea
• Constipation or feeling that the bowel is not empty
• Gas, bloating, and cramps
• Weight loss
• Fatigue
• Vomiting

If cancer has metastasized and spread to other organs, you may experience the following symptoms:

• Headaches, dizzy spells, or seizures if cancer has spread to the brain
• Difficulty breathing if cancer reaches the lungs
• Swollen belly or jaundice if cancer reaches the liver
• Loss of appetite if cancer spreads to the lymph nodes of the stomach

If you have already been diagnosed with colon cancer, monitoring these potential symptoms can indicate whether or not it has spread to other areas of the body. Be sure to inform your healthcare provider if you experience new symptoms.

Risk Factors

There are certain risk factors to be aware of that could increase your likelihood of developing colon cancer. These can include:

• Family history: Having a family history of the disease, particularly a first-degree relative (parent or sibling), can increase your risk.
• Age: Colon cancer is primarily diagnosed in people age 50 and older. Your risk increases the older you get.
• Alcohol: Heavy alcohol use has been linked to many cancers, including colon cancer.
• Smoking: Smoking cigarettes can increase your risk of developing many cancers, including colon cancer.
• Obesity: People who have an unhealthy amount and/or distribution of body fat.
• Other medical conditions: People with diabetes, inflammatory bowel disease (IBD), and polyps (tissue growths) in the colon are at an increased risk of developing colon cancer.

Diagnosis

Various tests and procedures are used to diagnose and determine the current prognosis for colon cancer, including:

• Colonoscopy: A colonoscopy is a procedure using a scope to examine the inside of your colon. This requires a long, flexible, slender tube attached to a video camera and monitor to view the entire colon and rectum. Your gastroenterologist or oncologist can pass surgical tools through the tube to take tissue samples for analysis (a biopsy) and remove polyps.
• Blood tests: For people already diagnosed with colon cancer and undergoing treatment, blood tests are used to measure a chemical called a carcinoembryonic antigen, or CEA. When tracked over time, the level of CEA in your blood may help determine your prognosis and whether the cancer is responding to treatment.
• Imaging tests: Abdominal, pelvic, or chest computed tomography (CT) scans involve X-ray images that allow healthcare providers to look at the colon. They are used to find growths within the colon or other affected organs from different angles.

At diagnosis, cancers are staged, which is the process of determining how much cancer is in the body (tumor size) and if it has spread. Once cancer has spread to other organs, it is considered advanced (stage IV) or metastatic cancer.

In many cases, the stage of colon cancer may not be fully determined until after a colonoscopy or surgery, when the cancerous tissue can be screened by laboratory scientists.

Treatment

Colon cancer can be treated through a variety of methods, but when cancer is more advanced, there are fewer options.

Traditional cancer treatments like chemotherapy are used to improve symptoms and extend life. It is often given after surgery to kill any remaining cancer cells in the body, but it can also be used on its own.

Surgery can be another option for cancer that has spread outside the colon. Affected parts of the colon can be resected (removed), as can certain areas outside the colon, including the liver.

If cancer has metastasized to the liver in a limited way, it's possible to resect parts of the organ to remove cancerous cells. However, this is only an option if there will be enough healthy liver leftover for a person to function.

Surgery may also be considered in instances when cancer has metastasized to the lungs, but only if it's deemed possible to remove the affected areas safely.

Lymph node removal is an option if affected lymph nodes near the cancerous area can be removed. This can also help prevent some of the cancer from spreading throughout the rest of the body.

Prognosis

Survival rates are grouped based on how far cancer has spread, age, overall health, how well cancer responds to treatment, and where the cancer originated.

The five-year survival rate for late-stage, metastatic colon cancer is 14%. However, it's important to note that this number is a statistic and does not necessarily represent your individual case. For example, if liver metastases can be surgically removed, the five-year survival increases to around 50%.

Palliative care, also called supportive care, might be an option when survival is not likely. Supportive care focuses on physical, emotional, and, when appropriate, spiritual support to help the person cope with their cancer journey.

Coping

Finding a support group can help connect people with others who can share experiences and support each other.

The American Cancer Society provides support resources, including a hotline (1-800-227-2345) for people to call to connect with cancer specialists.

The Colorectal Cancer Alliance offers online support groups for patients and their families.

For those diagnosed with early-onset colon cancer (age 45 or younger), an online support group, the Colon Club, connects patients with each other to offer support and understanding.

Summary

In metastatic colon cancer, cancer has spread outside of the colon or rectum into other areas of the body. Treatment options are more limited at this stage but can include chemotherapy and surgery. Prioritizing physical and emotional health is important at this stage of the disease.

A Word From Verywell

Living with advanced colon cancer can be a scary and upsetting experience. However, understanding the treatment options available to you and taking care of your emotional well-being can help. If you feel unwell or experience worsening symptoms, reach out to your oncologist or care team to ensure that your concerns are addressed and that your physical needs are met during this time.