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Primary liver cancer is usually hepatocellular carcinoma. The first manifestations of liver cancer are usually nonspecific, delaying the diagnosis. Prognosis is usually poor.
Hepatocellular
Carcinoma
Hepatocellular
carcinoma (hepatoma) usually occurs in patients with cirrhosis and
is common in areas where infection with hepatitis B and C viruses
is prevalent. Symptoms and signs are usually nonspecific. Diagnosis
is based on α-fetoprotein (AFP) levels, imaging
tests, and sometimes liver biopsy. Screening with periodic AFP measurement
and ultrasonography is sometimes recommended for high-risk patients.
Prognosis is poor when cancer is advanced, but for small tumors
that are confined to the liver, ablative therapies are palliative
and surgical resection or liver transplantation is sometimes curative.
Hepatocellular carcinoma is the most common type of primary liver cancer and results in about 14,000 deaths annually in the US. However, it is more common outside the US, particularly in East Asia and sub-Saharan Africa; incidence generally parallels geographic prevalence of chronic hepatitis B virus (HBV) infection.
Etiology
Hepatocellular carcinoma is usually a complication of cirrhosis.
The presence of HBV increases risk of hepatocellular carcinoma by > 100-fold among HBV carriers. Incorporation of HBV DNA into the host's genome may initiate malignant transformation, even in the absence of chronic hepatitis or cirrhosis.
Other disorders that cause hepatocellular carcinoma include cirrhosis due to chronic hepatitis C virus (HCV) infection, hemochromatosis, and alcoholic cirrhosis. Patients with cirrhosis due to other conditions are also at increased risk.
Environmental carcinogens may play a role; eg, ingestion of food contaminated with fungal aflatoxins is believed to contribute to the high incidence of hepatocellular carcinoma in subtropical regions.
Symptoms and Signs
Most commonly, previously stable patients with cirrhosis present with abdominal pain, weight loss, right upper quadrant mass, and unexplained deterioration. Fever may occur. In a few patients, the first manifestation of hepatocellular carcinoma is bloody ascites, shock, or peritonitis, caused by hemorrhage of the tumor. Occasionally, a hepatic friction rub or bruit develops.
Occasionally, systemic metabolic complications, including hypoglycemia, erythrocytosis, hypercalcemia, and hyperlipidemia, occur. These complications may manifest clinically.
Diagnosis
Diagnosis is based on AFP measurement and an imaging test. In adults, AFP signifies dedifferentiation of hepatocytes, which most often indicates hepatocellular carcinoma; 40 to 65% of patients with the cancer have high AFP levels (> 400 μg/L). High levels are otherwise rare, except in teratocarcinoma of the testis, a much less common tumor. Lower values are less specific and can occur with hepatocellular regeneration (eg, in hepatitis). Other blood tests, such as AFP-L3 (an AFP isoform) and des-γ–carboxyprothrombin, are being studied as markers to be used for early detection of hepatocellular carcinoma.
Depending on local preferences and capabilities, the first imaging test be contrast-enhanced CT, ultrasonography, or MRI. Hepatic arteriography is occasionally helpful in equivocal cases and can be used to outline the vascular anatomy when ablation or surgery is planned.
If imaging shows characteristic findings and AFP is elevated, the diagnosis is clear. Liver biopsy, often guided by ultrasonography or CT, is sometimes indicated for definitive diagnosis.
Staging:
If a hepatocellular carcinoma is diagnosed, evaluation usually includes chest CT without contrast, imaging of the portal vein (if not already done) by MRI or CT with contrast to exclude thrombosis, and sometimes bone scan.
Hepatocellular carcinoma is staged based on the following (American Cancer Society classification system—see Table 1: Liver Masses and Granulomas: Staging Hepatocellular Carcinoma ):
Numbers (0 to 4) are added after T, N, and M to indicate increasing severity. The letter “X” means no assessment is possible.
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Table 1
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Staging Hepatocellular
Carcinoma
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Stage
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Designation
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Description
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I
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T1, N0, M0
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Single tumor (any size) with no invasion of blood vessels
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II
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T2, N0, M0
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Single tumor (any size) with invasion of blood vessels
or
Several tumors that are all < 5 cm
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IIIA
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T3, N0, M0
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Several tumors with at least one > 5 cm
or
Tumor with invasion of a branch of the portal or hepatic vein
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IIIB
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T4, N0, M0
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Tumor with invasion of a nearby organ (other than the gallbladder)
or
Tumor that has penetrated the outer covering of the liver
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IIIC
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Any T, N1, M0
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Tumor or tumors of any size with invasion of nearby (regional) lymph nodes
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IV
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Any T, Any N, M1
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Tumor or tumors of any size with spread to other parts of the body and with or without invasion of nearby lymph nodes
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Screening:
An increasing number of hepatocellular carcinomas are being detected through screening programs. Screening patients with cirrhosis is reasonable, although this measure is controversial and has not been shown to reduce mortality. One common screening method is AFP measurement and ultrasonography every 6 or 12 mo. Many experts advise screening patients with long-standing hepatitis B even when cirrhosis is absent.
Treatment
For single tumors < 5 cm or ≤ 3 tumors ≤ 3 cm that are limited to the liver), liver transplantation results in as good a prognosis as liver transplant done for noncancerous disorders. Alternatively, surgical resection may be done; however, the cancer usually recurs.
Ablative treatments (eg, hepatic arterial chemoembolization, intratumoral ethanol injection, cryoablation, radiofrequency ablation) provide palliation and slow tumor growth; they are used when patients are awaiting liver transplantation.
If the tumor is large (> 5 cm), is multifocal, has invaded the portal vein, or is metastatic (ie, stage III or higher), prognosis is much less favorable (eg, 5-yr survival rates of about 5% or less). Radiation therapy is usually ineffective. Some newer chemotherapeutic regimens are promising.
Prevention
Use of vaccine against HBV eventually decreases the incidence, especially in endemic areas. Preventing the development of cirrhosis of any cause (eg, via treatment of chronic hepatitis C [HCV], early detection of hemochromatosis, management of alcoholism) can also have a significant effect.
Other Primary
Liver Cancers
Other primary liver cancers are uncommon or rare. Diagnosis usually requires biopsy. Prognosis is typically poor. Some cancers, if localized, can be resected. With resection or liver transplantation, survival may be prolonged.
Fibrolamellar
carcinoma:
This distinct variant of hepatocellular carcinoma has a characteristic morphology of malignant hepatocytes enmeshed in lamellar fibrous tissue. It usually occurs in young adults and has no association with preexisting cirrhosis, HBV, HCV, or other known risk factors. AFP levels are rarely elevated. Prognosis is better than that for hepatocellular carcinoma, and many patients survive several years after tumor resection.
Cholangiocarcinoma:
This tumor originates in the biliary epithelium. It is common in China, where underlying infestation with liver flukes is believed to contribute. Elsewhere, it is less common than hepatocellular carcinoma; histologically, the two may overlap. Primary sclerosing cholangitis greatly increases risk of cholangiocarcinoma.
Hepatoblastoma:
Although rare, hepatoblastoma is one of the most common primary liver cancers in infants, particularly those with a family history of familial adenomatous polyposis (see Tumors of the GI Tract: Familial Adenomatous Polyposis). It can also develop in children. Some patients with hepatoblastoma present with precocious puberty caused by ectopic gonadotropin production, but the cancer is usually detected because of deteriorating general health and a right upper quadrant mass. An elevated AFP level and abnormal imaging test results may help in the diagnosis.
Angiosarcoma:
This rare cancer is associated with specific chemical carcinogens, including industrial vinyl chloride.
Last full review/revision September 2007 by Steven K. Herrine, MD
Content last modified September 2007
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