Cancer of the liver

Liver cancer (hepatocellular carcinoma) is a cancer arising from the liver. It is also known as primary liver cancer or hepatoma. The liver is made up of different cell types. However, liver cells (hepatocytes) generally make up 80% of the liver tissue. Thus, the majority of primary liver cancers (over 90 to 95%) arises from liver cells and is called hepatocellular cancer or carcinoma.

When patients or physicians speak of liver cancer, however, they are often referring to cancer that has spread to the liver, having originated in other organs (such as the colon, stomach, pancreas, breast, and lung). More specifically, this type of liver cancer is called metastatic liver disease (cancer) or secondary liver cancer. Thus, the term liver cancer actually can refer to either metastatic liver cancer or hepatocellular cancer

Generally there are two types of cancers of the liver:
* Primary liver cancer (most commonly hepatocellular carcinoma) originates in the liver.
* Metastatic liver cancer results from the spread (metastasis) of cancer from other areas of the body.

Metastatic liver cancer is more common than primary liver cancer and is sometimes the initial clinical manifestation of cancer originating in the GI tract, breast, lung, or pancreas.

Symptoms and Signs

Abdominal pain is the most common symptom of liver cancer and usually signifies a very large tumor or widespread involvement of the liver. Early liver metastases may be asymptomatic. Nonspecific symptoms of cancer (eg, weight loss, anorexia, fever) often develop. The liver may be enlarged, hard, or tender; massive hepatomegaly with easily palpable nodules signifies advanced disease. Hepatic bruits and pleuritic-type pain with an overlying friction rub are uncommon but characteristic. Splenomegaly is sometimes present, especially when the primary cancer is pancreatic. Concomitant peritoneal tumor seeding may produce ascites, but jaundice is usually absent or mild initially unless a tumor causes biliary obstruction.

In advanced liver cancer, the tumor can spread locally to neighboring tissues or, through the blood vessels, to elsewhere in the body (distant metastasis). Locally, liver cancer can invade the veins that drain the liver (hepatic veins). The tumor can then block these veins, which results in congestion of the liver. The congestion occurs because the blocked veins cannot drain the blood out of the liver. (Normally, the blood in the hepatic veins leaving the liver flows through the inferior vena cava, which is the largest vein that drains into the heart.) In some patients, the tumor frequently blocks the inferior vena cava. Blockage of either the hepatic veins or the inferior vena cava results in a very swollen liver and massive formation of ascites. In some patients, as previously mentioned, the tumor can invade the portal vein and lead to the rupture of esophageal varices. In the last stages, progressive jaundice and hepatic encephalopathy presage death.

Diagnosis

Liver metastases are usually suspected in patients with weight loss and hepatomegaly or with primary tumors likely to spread to the liver. If metastases are suspected, liver function tests are often done, but results are general not specific for the diagnosis. Alkaline phosphatase, γ–glutamyl transpeptidase, and sometimes LDH typically increase to a greater degree than do other test results; aminotransferase levels vary. Imaging tests have good sensitivity and specificity. Ultrasonography is usually helpful, but CT with contrast or MRI with contrast is often more accurate. Liver biopsy guided by imaging provides the definitive diagnosis and is done if other tests are equivocal or if histologic information (eg, cell type of the liver metastasis) may help determine the treatment plan.

Treatment

Treatment depends on the extent of metastasis. With solitary or very few metastases due to colorectal cancer, surgical resection may prolong survival. Depending on characteristics of the primary tumor, systemic chemotherapy may shrink tumors and prolong life but is not curative; hepatic intra-arterial chemotherapy sometimes has the same effect but with fewer / milder systemic adverse effects. Radiation therapy to the liver occasionally alleviates huge pain due to advanced metastases but does not prolong life. Extensive disease is fatal and is probably best managed by palliation for the patient and support for the family

Hematologic Cancers and the Liver

The liver is commonly involved in advanced leukemia and related blood disorders. Liver biopsy is not needed. In hepatic lymphoma, especially Hodgkin's disease, the extent of liver involvement determines staging and treatment but this may be difficult to assess. Hepatomegaly and abnormal liver function tests may sometime reflect a systemic reaction to Hodgkin's disease rather than spread to the liver, and biopsy often shows nonspecific focal mononuclear infiltrates or granulomas of uncertain significance. Treatment is directed at the hematologic cancer.