Boston Scientific Corporation

05/01/2026 | Press release | Archived content

What is colorectal cancer, and how is it treated

Every time we have a meal or snack, the food we eat is digested as it passes through our gastrointestinal system. It travels from the mouth and throat into the esophagus, stomach, small intestine and finally through the large intestine, which includes the colon and rectum.

Cell growths on the inner lining of the colon or rectum can, over time, become colorectal cancer: the third most common cancer in the U.S. and globally, and the second leading cause of cancer-related deaths.

The number of people diagnosed with colorectal cancer in their 20s, 30s, and 40s has climbed dramatically in the last few decades and continues to rise. Recent data suggests it is the leading cause of cancer death for those under age 50. While we don't yet know why cases are increasing among younger people, some experts think there may be a tie to rising rates of obesity, diets high in ultraprocessed foods, not enough physical activity and increasing exposure to environmental toxins.

What are the symptoms of colorectal cancer?

In many cases, there are no early warning signs of colorectal cancer. When symptoms surface, they may present like common conditions such as hemorrhoids, diarrhea or irritable bowel syndrome (IBS).

Because of this, it's important to talk to your doctor if you're experiencing any of the following:

  • Bright red rectal bleeding or dark red, tar-like blood in your stool

  • A change in bowel movements, including diarrhea (either intermittent or constant) and/or constipation; a change in stool consistency; or stools that are more narrow than usual

  • Abdominal discomfort and/or pain that prompts you to feel full, bloated or like your bowel isn't completely empty

Of the 150,000 people diagnosed with colorectal cancer each year in the U.S., more than half will have their cancer spread to the liver, which is known as colorectal cancer liver metastases (CRLM).

"I started my career in oncology nursing in 1998 and back then, we never talked about a possible cure for stage 4 malignancies," says Niki Koesel, DNP, ANP, FPCN, senior manager of medical affairs for Boston Scientific. "Now, there is a subset of patients with metastatic disease who can be aggressively treated and potentially live for years."

Hepatic Artery Infusion (HAI) therapy for colorectal cancer liver metastases

When treating CRLM, physicians first look at surgery to remove tumors from the liver. This is called surgical resection, and it's typically combined with systemic chemotherapy. Unfortunately, only about 15% to 20% of patients are considered "resectable" at the time of diagnosis, says Koesel.

To help more patients have a chance for resection, physicians may turn to Hepatic Artery Infusion (HAI) therapy.

HAI therapy delivers medicine continuously and directly to the liver, using a small pump that is surgically implanted under the skin in the abdomen. Activated by body heat, the pump sends medicine through a catheter connected to the hepatic artery, the primary blood vessel flowing into the liver. With HAI therapy, chemotherapy reaches the liver at a concentration 400 times greater than systemic chemotherapy. Because it's delivered directly to the liver and metabolized quickly, HAI therapy does not add side effects to the rest of the body.

HAI therapy can act on tumors in the liver that are visible on scans, as well as cancer cells that are too small to be detected by imaging. For this reason, some patients with CRLM who undergo surgical resection will receive an HAI pump at the time of surgery to prevent the recurrence of the disease, says Koesel.

A better future for patients with liver metastases

Another promising treatment is TheraSphere, a device that delivers a radiation treatment called transarterial radioembolization directly to the liver. TheraSphere is made up of tiny glass orbs containing a concentrated isotope called Y-90 that delivers radiation but only travels a short distance. As a result, it can destroy liver tumors while minimizing damage to the surrounding tissue and tends to come with fewer side effects than traditional external radiation. TheraSphere is currently approved in Europe to treat CRLM, and in the U.S. for non-metastatic hepatocellular carcinoma.

All things told, Koesel is hopeful for the future of patients with CRLM.

"A stage 4 diagnosis used to be an automatic terminal illness. Now, many stage 4 diagnoses become chronic illnesses," she says. "Seeing this change in real time throughout my career has been overwhelmingly positive."

Learn more about how HAI therapy and TheraSphere are helping to expand treatment options for people with cancer in the liver.

Boston Scientific Corporation published this content on May 01, 2026, and is solely responsible for the information contained herein. Distributed via Public Technologies (PUBT), unedited and unaltered, on May 04, 2026 at 14:37 UTC. If you believe the information included in the content is inaccurate or outdated and requires editing or removal, please contact us at [email protected]