Erik Jensen, the 53-year-old actor who played Steven Edwards in season five of the AMC drama “The Walking Dead,” announced last week that he has been diagnosed with stage 4 colorectal cancer that has spread to his liver.

“After miraculously surviving a brain aneurysm just a year and a half ago, our beloved Erik Jensen was just diagnosed with Stage IV colorectal cancer,” the actor’s family wrote on a GoFundMe post. “The cancer has metastasized to his liver, but Erik is young and strong (cutting a film during chemo, working full-time as a director and writer throughout) and his doctors think they have a shot at shrinking the tumors enough to do two very major surgeries and get them all out. He can make it through this. But Erik and his family are in for the fight of their lives, and they need your support.”

To learn more about what a Stage IV colorectal cancer diagnosis means and how it’s treated, we sat down with Christopher Lieu, MD, associate director of clinical research at the University of Colorado Cancer Center

What does it mean if someone is diagnosed with Stage IV colorectal cancer?

Stage IV means that cancer has spread beyond the organ that it originated in. Usually when we talk about Stage IV, we talk about cancer spreading to another organ. For colorectal cancer, the most common place for the cancer to spread to is the liver. The second most common location is the lungs.

In Erik Jensen’s case, the cancer did metastasize to the liver. What does it mean that the cancer was discovered after it had already spread?

Survival rates are often much higher when we find the cancer before it spreads to other organs. That shows the importance of screening and early detection, which is why people 45 and older should get a colonoscopy. About a quarter of all patients who are diagnosed with colorectal cancer will be diagnosed with Stage IV.

Jensen’s family said his doctors “have a shot at shrinking the tumors enough to do two very major surgeries and get them all out.” How are the tumors shrunk prior to surgery?

The idea behind giving chemotherapy before surgery is to shrink the cancer and to also kill any other microscopic metastatic disease that might not be visible on a CT scan. The chemotherapy has two purposes. It gives a test of time—if you do chemotherapy, and the next scan shows even more tumors, then you know starting with surgery would have been a bad idea. The second thing it accomplishes is tumor shrinkage, which can sometimes make the surgery more feasible and more successful.

When you say it would have been a bad idea to start with surgery if more tumors are found, what exactly do you mean?

We want to offer a surgery where there’s a chance of cure, but we always worry that the areas that you can see are not the only areas of cancer. By starting with chemotherapy, hopefully you can kill the areas you can’t see. But if you do chemotherapy and the tumor just shows up in other areas, those places were there even before you started, and they’re not responding to chemotherapy. It’s what we call a test of biology. Are the areas that we see the only areas? Is there more cancer lurking behind those areas? Sometimes we cut out all these tumors, and then there will be five more by the time we scan again.

If you do the chemotherapy first to shrink the tumors, how long do you typically wait before you do the surgery?

Usually two to four months. This situation drives home the importance of multidisciplinary care—different subspecialties of medicine communicating and working together to create the best plan for the patient.

In a case like this, what would some of those subspecialties be?

It would be predominantly medical oncology discussing the case with radiology, the people who read the CT scans; pathology, to make sure the diagnosis is correct; and surgical oncology, the people who do the surgery. Interventional radiology, gastroenterology, and radiation oncology are also part of the care team, as well as other important specialties, such as nutrition, genetics, and social work.

This article was originally published October 27, 2023, by the University of Colorado Cancer Center. It is republished with permission.