The liver is the most common site for colon or colorectal cancer to spread to. Surgery is the primary treatment, but there are other options such as ablation, radiation therapy, or chemotherapy.

Colon cancer is a type of cancer that starts in your colon, which makes up the majority of your large intestine. Colon cancer is often grouped together with rectal cancer, so you’ll often see these cancers called colorectal cancer (CRC).

Like all cancers, CRC may spread (metastasize) to more distant parts of the body. The liver is a common site for CRC to spread to.

Continue reading to learn more about what happens when CRC spreads to the liver, including symptoms, treatments, and outlook.

The liver is the most common site for colorectal cancer to spread to. In fact, it’s estimated that 25% to 50% of CRC cases spread to the liver over the course of the illness.

CRC can spread quickly. A 2019 study looked at 118 biopsy samples from 23 people with CRC that had spread to the liver or brain. Researchers found that CRC may begin to spread early on in the illness, often before it’s even been diagnosed.

It’s estimated that 10% to 15% of people with CRC have already had it spread to their liver at the time of their CRC diagnosis. Because of this, your doctor may test for liver metastasis while initially diagnosing CRC.

When CRC has spread to the liver, it means that the cancer has reached an advanced stage. You may see this referred to as stage 4 CRC or metastatic CRC.

Defining metastasis

If CRC spreads to the liver or other more distant tissue, you may hear your doctor say that you have a metastasis. Some people may use a shorthand version of this word: “mets.”

Simply put, metastasis is the spread of cancer to a more distant region of the body. Cancer often does this by moving through the bloodstream or lymphatic system to reach areas far from the original tumor site.

Not including the lymph nodes or liver, other common metastatic sites for CRC are the lungs and the lining of your abdomen. While rare, it’s also possible for CRC to spread to other areas like the bones and brain.

Some signs that CRC has spread to the liver include:

If you’ve received a diagnosis of CRC and begin having some of the symptoms above, contact your care team. They can do tests to determine if your cancer has spread to your liver.

If you have not been previously diagnosed with CRC, it’s still important to see your doctor if you have the symptoms above. While they may not be due to metastatic CRC, they could be caused by another liver condition that needs to be treated.

If you have symptoms that suggest CRC has spread to your liver, there are tests that your doctor can do to see if metastasis has occurred.

Imaging plays a big role in diagnosing cancer spread. It can help your doctor get a view of your liver to check for the presence of one or more tumors.

Some of the preferred imaging methods to use include CT scans and MRIs. It’s also possible your doctor may use an ultrasound or positron emission tomography (PET) scan.

Blood tests may be ordered as well, including:

If you have not been diagnosed with CRC, but your doctor suspects CRC with liver metastasis, tests to diagnose CRC may also be done. In addition to what’s mentioned above, this can involve a diagnostic colonoscopy with biopsy.

It’s also possible that the liver may be evaluated during surgical treatment for CRC. If suspicious areas are present on or around the liver, your surgeon will collect a sample for analysis.

The main treatment for CRC that’s spread to the liver is surgery. However, it’s important that surgery doesn’t negatively affect the function of your liver.

When deciding if surgery is a treatment option, your healthcare team will take several factors into account:

  • the number of tumors present
  • the location of the tumors
  • the size of the tumors
  • your overall health, which includes whether or not you already have existing liver disease

After surgery, you’ll likely receive chemotherapy. This is called adjuvant chemotherapy and helps to kill any remaining cancer cells.

It’s estimated that surgery is an option in only 10% to 20% of people with CRC liver metastasis. In some situations, having chemotherapy or radiation therapy prior to surgery can reduce the size of the tumor and make surgery more possible.

When surgery isn’t possible

If surgery isn’t recommended, there are other potential treatments that may be used either alone or in combination. These include:

  • Ablation: Ablation involves using an ultrasound to place a needlelike probe into the tumor. Then, radio waves can be used to heat the probe, killing the surrounding cancer cells.
  • Radiation therapy: Stereotactic radiosurgery can be used to deliver a large amount of radiation to a small, specific area of the liver. Whole liver radiation is less common and is mostly used as a part of palliative care.
  • Chemotherapy: Chemotherapy uses drugs that target the growth and division of cancer cells. It may be given orally or by an IV and can help to kill the cancer cells or slow down their growth.
  • Targeted therapy: Targeted therapy hones in on specific markers on cancer cells. Targeted therapy, either alone or with chemotherapy, may be used to treat CRC liver metastases. Some examples of targeted therapy drugs that may be used are:
    • cetuximab (Erbitux)
    • panitumumab (Vectibix)

Currently, the outlook for CRC that has spread to the liver is poor. According to the National Cancer Institute’s SEER Database, the 5-year relative survival rate for people with CRC that has spread to distant tissue is 15.1%.

However, according to a 2016 research review, surgery for CRC liver metastases can boost long-term survival and may even provide a cure. In fact, the 5-year survival rate after curative surgery may be up to 58%, compared to 11% or less without treatment.

Recurrence is possible after surgery. A 2017 review of research notes that 60% to 70% of people will experience a recurrence in the liver or in other distant tissue. The likelihood of a recurrence decreases as time passes.

Overall, the outlook can depend on many factors, including the specific characteristics of the cancer, how much of the liver is affected, and whether it has spread to other places. Your age and overall health also play a role.

What is a relative survival rate?

A relative survival rate shows how long someone with a specific condition may live after their diagnosis compared with someone without the condition. For example, a 5-year relative survival rate of 70% means that 70 out of 100 people diagnosed with a condition are still living at least 5 years from the time of diagnosis.

It’s most important to remember that figures are estimates, and everyone is different. Talk with your doctor about your specific condition.

The liver is the most common metastatic site for CRC, meaning the liver is the place colorectal cancer is most likely to spread when it spreads to other locations. In some cases, liver metastasis is diagnosed at the same time as CRC.

The main treatment for CRC that has spread to the liver is surgery. Treatments like chemotherapy may be used before or after surgery to help kill cancer cells.

But not all people with this cancer can have surgery. In this case, treatments like ablation, radiation therapy, or chemotherapy may be used.

While the outlook for colorectal cancer that has spread anywhere is currently poor, your outlook can be improved and possibly cured with surgical treatment. If you have CRC with liver metastasis, talk with your care team to get a better idea of your individual outlook.