What Happens When Cancer Spreads to the Liver? (2026 Update)

When cancer that started in another organ spreads to the liver (liver metastasis), it is treated as a different disease from primary liver cancer that originates in the liver itself. Treatment is determined by the type of the original cancer along with the number and location of the liver lesions and overall liver function, choosing among surgical resection, local therapy, or systemic drug treatment.

Key Takeaways

• Liver metastasis refers to a state in which a primary cancer has spread to the liver, and its treatment approach differs from that of primary liver cancer, which originates in the liver itself.
• In colorectal cancer, even when liver metastases are present, treatment aimed at a cure may still be pursued if the metastatic lesions can be surgically removed — this is one reason colorectal cancer offers a broader range of treatment options than some other cancers even at stage 4.
• Treatment for liver metastases is chosen among resection, radiofrequency ablation, and radiation therapy, depending on the number and location of the metastases and the state of liver function.
• The 5-year relative survival rate for primary liver cancer in Korea is 40.4% (National Cancer Registration Statistics, 2019-2023), but this is a national statistic for cancers that originate in the liver itself, and it does not directly predict outcomes for patients with liver metastases.
• Liver function grade (Child-Pugh) and portal pressure are key factors that must be considered together whenever treating any lesion in the liver.

What Exactly Is Liver Metastasis?

• Liver metastasis refers to a metastatic lesion in which cancer cells from another organ — such as gastric cancer or colorectal cancer — travel through the bloodstream or lymphatic system and settle in the liver.
• Because the origin of these cells differs from primary liver cancer, in which cancer begins in the liver cells themselves, treatment principles are determined based on the type of the original (primary) cancer.
• For example, according to notes on colorectal cancer, even when liver metastases are present, an aggressive approach combining liver resection, radiofrequency ablation, and chemotherapy may be used if the number and location of the metastases and liver function allow it.
• By contrast, primary liver cancer usually develops on a background of chronic hepatitis or cirrhosis, so in addition to the cancer stage, liver function grade and portal pressure play a much larger role in determining treatment — this is a key difference.

In What Order Is Treatment Decided When Liver Metastasis Occurs?

• Step 1: Imaging tests — Abdominal and chest CT scans are used to determine the number and location of metastases, and liver function tests check whether the liver can tolerate treatment.
• Step 2: Assessing resectability — Doctors evaluate whether the metastatic lesions can be surgically removed and whether the remaining liver function will be sufficient.
• Step 3: Choosing treatment — If resection is possible, surgery is performed; if not, local treatments such as radiofrequency ablation or radiation therapy are considered, and chemotherapy may be given alongside or before these treatments depending on the patient's overall condition.
• Step 4: Follow-up monitoring — After treatment, regular blood tests and imaging studies are used to check for recurrence or additional metastases.
• Throughout this process, liver function grade (Child-Pugh) and portal pressure serve as reference points at every stage, and even lesions of the same size may require different treatments depending on liver function.

How Do Primary Liver Cancer and Liver Metastasis Differ Statistically?

• The 5-year relative survival rate for primary liver cancer in Korea is 40.4% (National Cancer Registration Statistics 2019-2023, National Cancer Center Korea Central Cancer Registry), while the 5-year relative survival rate for liver and intrahepatic bile duct cancer in the U.S. SEER statistics for the same general period is 21.9% (2016-2022).
• These two figures are not the performance results of any specific hospital but national statistics for each country, and since they are not calculated separately for the overall population of liver metastasis patients, they do not directly reflect outcomes for liver metastasis.
• The course of liver metastasis varies greatly depending on the type of the primary cancer (for example, whether it originated in the colon or the stomach) and the extent of the metastasis, so it is important to look at both the statistics for the primary cancer and the treatability of the liver lesions themselves.
• It applies to all cancer statistics that survival rates are population averages and not numbers that predict any individual's outcome.

FAQ — Can Treatment Still Aim for a Cure Even with Liver Metastasis?

It depends on the type of primary cancer. In colorectal cancer, even when metastases are present in the liver or lungs, if those lesions can be surgically removed, treatment combining chemotherapy with resection of the metastases may be pursued with the goal of a cure. If the lesions cannot be removed, systemic chemotherapy becomes the main treatment, and targeted therapies or immune checkpoint inhibitors may be added depending on the results of genetic and biomarker testing.

FAQ — If Liver Function Is Poor, Can Treatment for Liver Metastasis Still Be Given?

Liver function status is a key criterion in deciding which treatment to choose. Whether the liver can tolerate resection is assessed using the Child-Pugh grade, which combines bilirubin, albumin, coagulation values, and the presence of ascites or jaundice; if liver function is reduced, alternatives such as radiofrequency ablation, embolization, or radiation therapy may be considered instead of resection. When liver function is significantly impaired, chemotherapy may actually worsen liver damage, so symptom control and preservation of liver function may take priority instead.

Sources and Notes

• This article was written based on National Cancer Registration Statistics 2019-2023 (National Cancer Center Korea Central Cancer Registry), SEER 2016-2022 statistics, and patient-level guideline materials from the National Cancer Information Center and NCCN related to liver cancer and colorectal cancer.
• This content is provided for general medical information purposes only, and actual diagnosis, treatment methods, and outcomes may vary depending on an individual's condition. Accurate diagnosis and treatment decisions should always be made in consultation with a medical professional.