Colorectal cancer is cancer that begins in the colon or rectum. This type of cancer is staged from stage 0, which is very early cancer, to stage 4, which is metastatic colorectal cancer.

Metastatic colorectal cancer is cancer that has metastasized. This means it has spread to regional or distant sites, such as other organs or lymph nodes.

Though cancer can spread to any other part of the body, colorectal cancer most often spreads to the liver, lung, or peritoneum, according to the National Cancer Institute.

Approximately 21 percent of people newly diagnosed with colorectal cancer have distant metastatic disease at the time of diagnosis.

Metastatic colorectal cancer to distant sites is rarely curable. Once cancer spreads, it can be difficult to control.

However, there are treatments available that can help stop or slow the growth of the cancer and manage symptoms.

Continuous developments in colorectal cancer treatments have improved survival rates in people with metastatic colorectal cancer.

Colorectal cancer is more likely to cause symptoms in later stages once the cancer has grown or spread.

Symptoms of colorectal cancer include:

Signs and symptoms of metastatic colorectal cancer

Symptoms of metastatic colorectal cancer depend on where the cancer has spread and the size of the metastatic tumor load.

  • jaundice or abdominal swelling, when cancer has spread to the liver
  • shortness of breath, when cancer has spread to the lung
  • bone pain and fractures, when cancer has spread to the bone
  • dizziness, headache, or seizures, when cancer has spread to the brain

Colorectal cancer usually begins as a polyp that develops in the inner lining of your rectum or colon and grows and converts slowly over several years.

Once the cancer develops, it can grow further into the wall of your colon or rectum and go on to invade blood or lymph vessels.

Cancer cells can spread into nearby lymph nodes and also be carried in your blood vessels to other organs or tissues.

The most common places for colorectal cancer to spread are the liver, lung, and peritoneum. But cancer can also spread to other parts of your body, such as the bones and brain.

Some people have metastatic colorectal cancer at the time of their initial diagnosis. Others find out their cancer has spread months or even years after their initial colorectal cancer diagnosis.

The main test used to diagnose colorectal cancer is a colonoscopy, along with biopsy and other cell and tissue studies.

Metastatic colorectal cancer is diagnosed using imaging tests to see if and where the cancer has spread.

A biopsy may be performed on a distant tumor to check if it is a metastatic tumor or a different type of primary cancer.

Imaging tests used to diagnose metastatic colorectal cancer include:

  • CT scan. A CT scan is used to see if colorectal cancer has spread to lymph nodes or other organs in your chest, abdomen, or pelvis. A CT scan can also be used to guide a biopsy to confirm metastases in organs, such as the liver.
  • Ultrasound. An abdominal ultrasound may be used to see if colorectal cancer has spread to the liver. A biopsy can also be performed with ultrasound guidance, if needed.
  • MRI. A pelvic or abdominal MRI scan may be used to see where cancer has spread within the pelvis and if any lymph nodes are involved.
  • X-ray. A chest X-ray is often used to see if colorectal cancer has metastasized to the lungs. X-rays may also be used to check for bone metastases.
  • PET scan. A PET scan is often used to check for metastases throughout the body, including the brain. It can also be used for staging and to plan treatment, such as surgery, for metastatic tumors. A combination PET/CT scan may also be used.

Treatment for colorectal cancer depends on a number of factors, including the extent of the spread and size and location of the tumors. Your age, overall health, and potential side effects from cancer treatment are also considered.

Your doctor will work with you to determine the best treatment for your specific situation.

Metastatic colorectal cancer is rarely curable. The goal of treatment is usually to prolong your life and relieve or prevent symptoms.

In rare instances, metastatic colorectal cancer may be cured by surgically removing all the tumors.

Most of the time, metastatic colorectal cancer treatment is ongoing in hopes of controlling the cancer for as long as possible. Everyone responds to treatment differently, so some may work better for you than others.

Surgery may be performed to relieve or prevent complications, such as blockage of the colon. When there are only a few metastases limited to the lungs or liver, surgery may be used to remove them, as well as the primary tumor, to try to improve survival.

Chemotherapy, radiation therapy, and targeted therapies may be used alone or in combination to shrink tumors, relieve symptoms, and prolong survival. There have been a number of targeted therapies approved in recent years for metastatic colorectal cancer.

Your doctor may also prescribe medication to manage pain, nausea, and other side effects of cancer or treatment.

It’s important to understand that metastatic cancer, even if not curable, can sometimes be controlled for months or years.

The development of colorectal cancer treatments in recent years has helped people live longer with metastatic colorectal cancer.

The most recent relative five-year survival rate for distant metastatic colorectal cancer is 13.8 percent. This means that 13.8 percent of people with metastatic colorectal cancer are still alive at five years after diagnosis.

Survival rates are only estimates and cannot predict individual outcome. They do not take many important factors into account, such as a person’s age or health problems, certain tumor markers or proteins, or what treatments were used and how a person responded to treatment.

Your doctor can help put this number into perspective based on your individual situation.

Finding support is important when you have received a diagnosis of metastatic cancer. Talk to your doctor and loved ones about how you’re feeling and ask for support to help you cope.

Along with turning to friends and family, some people find comfort in speaking to a spiritual advisor or clergy.

The American Cancer Society can connect you to support services and other resources in your area, and online support. You can also get referrals for support groups and services through your doctor or cancer center.

Being told you have metastatic colon cancer may make you feel scared and angry, or even hopeless, but metastatic disease doesn’t mean that you’re beyond help or hope.

Treatments are available that can help you enjoy more time with loved ones, and researchers are continuing to study new ways to prevent the growth of metastatic cancer cells.