Metastatic Colorectal Cancer

Metastatic colorectal cancer happens when cancer spreads beyond the colon or rectum and surrounding lymph nodes and into other organs. This is referred to as metastasis, or you may also hear people refer to it simply as mets or mCRC.

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Metastatic colorectal cancer happens when cancer spreads beyond the colon or rectum and surrounding lymph nodes, into other organs. This is referred to as metastasis, or you may also hear people refer to it simply as mets. You may also see it written as metastasized colorectal cancer or mCRC.

Cancer is named based on where it starts, so even if your cancer has spread to the liver, for example, it’s still considered colorectal cancer. But it’s colorectal cancer with mets to the liver.

Any colorectal cancer that has metastasized to a distant organ is considered stage IV colorectal cancer (stage 4 colon cancer/stage 4 rectal cancer). Colorectal cancer stages are based on location and amount of metastatic disease.

The most common organs for metastatic colorectal cancer include:

  • Liver (most common)
  • Lungs
  • Peritoneum (lining of the abdomen)
  • Ovaries
  • Brain
  • Bones
  • Spinal cord

Is my cancer curable? What are my odds?

There are survivors of every colorectal cancer stage, including those who have survived metastatic colorectal cancer. It’s important to talk with your doctor about survival rates and treatment planning, as it will be more aggressive for you.

All stage IV colorectal cancer tumors should receive biomarker testing. It’s imperative that you have a biomarker testing report so you can make informed decisions based on how your tumor is made up. Some therapies may not work for you based on your tumor biomarkers.

Ask about biomarker testing BEFORE you begin any treatments.

Many patients may not be considered curable by their medical teams, but they have lived long lives on therapeutic maintenance programs. Other patients with metastatic disease have been declared no evidence of disease (NED). It’s advisable to work with your doctor on a treatment plan that fits your unique needs and preferences.

Is metastatic colorectal cancer common?

Based on data from the National Cancer Institute’s SEER program, 23% of colorectal cancer patients are diagnosed with distant colorectal cancer, which involves stage IV disease.

Approximately 70% of patients with colorectal cancer will experience metastatic disease at some point— either at diagnosis or after treatment.

How is stage 4 colorectal cancer treated?

Treating metastatic colorectal cancer isn’t a one-size-fits-all approach. Your treatment plan will need to be very unique based on your biomarkers and where the cancer has spread. Some treatment options may include:


It’s important to ask your doctor if you’re operable, as some patients are not. However, depending on where the cancer has spread and how extensively, some patients do face a surgical option. It may be recommended that you undergo other treatment options to shrink or eliminate tumors before surgery.

Here the a few types of surgery stage IV patients may undergo, based on where the cancer has spread:

  • Colon resection or removal
  • Liver resection/partial hepatectomy
  • Hepatic artery infusion (HAI) pump insertion
  • Lung resection
  • Video assisted thoracic surgery (VATS)
  • Chemoembolization
  • Cytoreductive surgery (CRS)
  • Hyperthermic intraperitoneal chemotherapy (HIPEC)
  • Liver transplant
  • Oophorectomy


Chemotherapy may be used alone or in combination with other targeted therapies for metastatic colorectal cancer. Chemotherapy can help improve symptoms and prolong life, and it may be used to shrink tumors prior to surgery. It’s important to know metastatic colorectal cancer cannot be cured by only using chemotherapy. Chemotherapy interferes with rapidly growing cells (including cancer cells) in an effort to stop the cancer from replicating itself.

  • Traditional/systematic/conventional chemotherapy (taken orally or via intravenously)
  • FUDR (concentrated chemo)

Targeted therapy

Targeted therapy is different from chemotherapy. There are FDA-approved targeted therapies that block the growth of cancer by interfering with molecules involved in tumor growth and spreading. Targeted therapy is also administered either orally or intravenously.

  • Small-molecule drugs
  • Monoclonal antibodies


Radiation therapy is more commonly used to treat rectal cancer than colon cancer. When used in colon cancer, it’s typically used to treat tumors that have grown next to or into other organs. It may also be used to relieve side effects. Here are the types of radiation that may be recommended for metastatic patients:

  • External beam radiotherapy (EBRT) – most common approach
  • Radiofrequency ablation (RFA) – which may also use cryotherapy
  • Radioembolization (selective internal radiation therapy (SIRT))
  • Internal radiotherapy
  • Intensity-modulated radiotherapy (IMRT)
  • Intraoperative radiotherapy (IORT)
  • Stereotactic Body Radiation Therapy (SBRT)
  • Radio surgery


Immunotherapy treatments use your immune system to fight diseases. Currently, outside of a clinical trial, immunotherapy for colorectal cancer is only effective in a small portion of patients who are MSI-H; however, clinical trials for immunotherapy in all patients are happening every day.

Clinical trials for colorectal cancer: search our list of trials for treatment of metastatic colorectal cancer.

Is a colorectal cancer recurrence considered metastasis?

Metastasis is when cancer grows into organs beyond where it originated. Recurrence means that after a period of time, you were disease-free, but then the cancer returned. This recurrence or relapse can be local, regional, or distant to where your original cancer formed — meaning it’s not necessarily a metastasis.

A recurrence can appear in the colon/rectum and be contained in that area. When that happens, it’s not considered metastatic.

Medical Review

Cathy Eng, MD

Vanderbilt-Ingram Cancer Center

Last Reviewed: February 5, 2024