In addition to the lungs, the liver is one of the most common organs to be affected by metastases, which are tumors formed from cells that break away from a primary tumor to produce new growths at distant sites. Such cells generally travel through the body through the circulatory system or the lymphatic system closely associated with it.

Accordingly, it is not surprising that the liver is such a customary site of metastases since all of the body’s blood is filtered through it. The liver may also be the location of a primary tumor, but this occurrence is much rarer. Americans are about 20 times more likely to develop metastatic liver disease than primary liver cancer.

The prognosis of an individual with metastases in the liver is to some extent related to the site of the primary cancer. Individuals with liver metastases that developed from a primary tumor of the bowels, for instance, often have a better chance of survival than others. This is because liver metastases originating from the bowels frequently develop before cancer cells travel to other locations in the body and only affect a single area of liver tissue. Consequently, patients with cancers that follow this pattern are more readily treatable with surgery, which can sometimes result in a cure. More commonly, however, patients with metastases in the liver undergo chemotherapy.

Chemotherapy generally does not cure individuals with metastatic cancer, but the treatment can prolong their lives. A targeted form of chemotherapy enables significantly higher concentrations of cancer-killing drugs to be utilized to fight the disease than can be safely used in the more common systemic approach. The specialized procedure involves placing a catheter and infusion pump into the main hepatic artery so that floxuridine or other medications can be administered directly to the affected organ. Studies show that this treatment method can add months to the life expectancy of some patients, whereas systemic chemotherapy can help alleviate certain symptoms but does not apparently lengthen the lives of cancer patients whose disease has metastasized to the liver. Similarly, liver tumors are not very responsive to treatment with radiation, so that radiation therapy is also only normally useful for symptom relief.

Typically, metastases in the liver are not discovered due to their symptoms, but rather from routine testing associated with a patient’s primary tumor. Occasionally, however, metastasis-related symptoms are observed before there is any other indication of cancer. Nevertheless, simple analysis of tumor cells can establish that liver growths are secondary rather than primary since such tumors are composed of abnormal cells from a non-hepatic tissue. Thorough examination and imaging usually result in the identification of the primary tumor, but in rare instances no tumor will be found, in which case the patient is said to have cancer of unknown primary origin (CUP).

Metastatic Carcinoma in Liver Tissue at 10x Magnification - Though most any type of cancer may metastasize to the liver, some are more likely to do so than others. Breast, lung, colorectal, stomach, pancreas, and small intestine tumors are among those that are most closely associated with the liver.

Metastatic Carcinoma in Liver Tissue at 40x Magnification - Liver cancer is a particularly deadly form of cancer because symptoms generally do not develop until the disease is well advanced. As the functioning of the organ becomes increasingly hindered, however, signs such as appetite loss, weight loss, fever, jaundice, and fluid accumulation in the abdomen (ascites) may occur.