Metastatic liver disease occurs when cancer cells from a tumor elsewhere in the body travel to and grow in the liver. Unlike primary liver cancer, which originates in the liver, these cells are from the original tumor (e.g., breast, colon, lung). This condition is significantly more common than primary liver cancer.
How Cancer Spreads to the Liver
Cancer cells can detach from a primary tumor and enter the bloodstream or the lymphatic system. These cells travel through the body, lodging in distant organs where they can form new tumors. The liver is a common site for cancer to spread due to its rich blood supply.
The liver receives blood from two main sources: the hepatic artery and the portal vein. The portal vein carries blood directly from digestive organs like the colon, rectum, stomach, and pancreas. This direct connection allows cancer cells from these areas to easily reach the liver. Cancers originating in the colon or rectum are the most frequent cause of liver metastases, with up to 70 percent of colorectal cancer patients eventually developing liver involvement. Other common primary cancers that spread to the liver include those of the breast, lung, pancreas, and stomach.
Symptoms and Diagnosis
Metastatic liver disease may not cause noticeable symptoms in its early stages because the liver is a large organ capable of functioning adequately even with some tumor presence. As the disease progresses, signs can emerge, including persistent fatigue, unexplained weight loss, and discomfort or pain in the upper right abdomen. Jaundice, a yellowing of the skin and eyes, can also occur due to impaired liver function or bile flow obstruction. Nausea, loss of appetite, and fever are additional symptoms.
Confirming a diagnosis involves several steps. Blood tests, particularly liver function tests, can indicate if the liver is under stress or damaged. Imaging scans like computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET) are used to visualize tumors and assess their size and number. A definitive diagnosis typically involves a liver biopsy, where a tissue sample is examined under a microscope to identify the specific type of cancer cells present.
Treatment for Metastatic Liver Disease
Treatment strategies for metastatic liver disease are highly individualized, depending on the type and characteristics of the original primary cancer. The aim is often to control the disease, manage symptoms, and improve quality of life, as metastatic cancer in the liver is frequently advanced. A combination of systemic and liver-directed therapies is commonly employed.
Systemic Treatments
Systemic treatments affect cancer cells throughout the entire body. Chemotherapy uses chemical substances to destroy cancer cells and can significantly extend life for patients with liver metastases. It may also be administered before surgery to shrink tumors, making them more amenable to removal. Targeted therapy employs drugs that specifically block the growth and spread of cancer cells by interfering with specific molecules involved in tumor growth, such as anti-angiogenesis drugs that stop the formation of blood vessels that feed tumors. Immunotherapy works by boosting the body’s own immune system to recognize and fight cancer cells.
Liver-Directed Treatments
Liver-directed treatments specifically target tumors within the liver, aiming to destroy or control them while sparing surrounding healthy tissue. Surgical resection removes the cancerous part of the liver and can be an option if tumors are few, small, and confined. Thermal ablation techniques, such as radiofrequency ablation (RFA) or microwave ablation (MWA), use heat to destroy cancer cells, while cryoablation uses extreme cold to freeze them. These procedures often involve inserting a needle through the skin, guided by imaging, to reach the tumor.
Embolization therapies, including transarterial chemoembolization (TACE) or radioembolization (TARE), block the blood supply to liver tumors. During these procedures, tiny particles or radioactive beads are injected directly into the hepatic artery, starving tumors of oxygen and nutrients, and sometimes delivering chemotherapy or radiation. Stereotactic body radiation therapy (SBRT) delivers highly focused, high doses of radiation to liver tumors, minimizing damage to nearby healthy tissues. Hepatic arterial infusion (HAI) pump chemotherapy delivers high concentrations of chemotherapy drugs directly into the hepatic artery via a pump implanted under the skin, providing targeted treatment with fewer systemic side effects.
Prognosis and Symptom Management
The prognosis for individuals with metastatic liver disease varies considerably, influenced by several factors. These include the type and aggressiveness of the primary cancer, the number and size of tumors in the liver, the patient’s overall health status, and how well they respond to treatment. While the median survival for metastatic liver cancer can range from approximately 6 to 20 months, some patients live longer with effective and tailored treatment approaches. Early intervention and ongoing disease management can improve these outcomes.
Palliative Care
Palliative care focuses on providing relief from the symptoms and stress of a serious illness, aiming to improve quality of life for both the patient and their family. This care can be administered alongside active cancer treatments, not just at the end of life. It addresses physical symptoms such as pain, fatigue, nausea, and loss of appetite, which are common with liver metastases.
Palliative care teams also offer emotional and psychological support, helping patients and their families cope with the illness. This approach prioritizes symptom management, leading to better comfort and well-being throughout the treatment journey. The integration of palliative care aims to enhance the patient’s daily living and overall experience.