Liver Cancer

Liver Cancer, or Hepatocellular carcinoma (Hepatoma) is one of the major causes of cancer deaths worldwide especially in Africa and East Asia; it is the 4th commonest cancer among males in Singapore. Chronic hepatitis B (HBV) and hepatitis C (HCV) infection, ethanol, aflatoxins, hemochromatosis, Wilson’s disease and alpha1-antitrypsin deficiency are risk factors for hepatoma. They cause cirrhosis that predisposes to development of hepatoma.

Among asymptomatic patient with risk factors such as chronic HBV carrier, screening has the best chance of detecting small hepatoma and thus curative resection.

Outside of screening program, the presentation of hepatoma is non-specific. The dominant symptoms may be related to the underlying cirrhosis eg. liver function decompensation or complications from portal hypertension such as ascites or variceal bleeding. Some patients may present with vague abdominal discomfort, unexplained weight loss or abdominal mass. Occasionally, patients can present with acute abdominal pain from rupture of hepatoma. In rare instances, metastatic hepatoma to the brain, bone or lung may be the initial presentation.

Due to its non-specific symptomatology, diagnosis of hepatoma requires a high index of suspicion. The actual detection of hepatoma relies on combination of identifying common risk factors, serum tumor marker (alpha-fetoprotein) and the characteristic features of the tumor on radiologic imagings.

In endemic countries, the incidence of chronic HBV infection among patients with hepatoma can be as high as 90%. 70-80% of hepatoma has elevated serum alpha-fetoprotein. Alpha-fetoprotein level of more than 200ng/ml in the present of a solid space-occupying lesion in the liver is highly suggestive of a hepatoma.

Ultrasound scan is a very good screening tool for mass lesion in the liver in high risk patient. It is inexpensive, non invasive and readily available. However, it is operator dependent and lacks ability to provide a topographic picture that is needed in planning surgical intervention.

Contrast enhanced triphasic computerized tomography scan (CT scan) can provide high quality images of the liver and the tumor within it. Hepatoma is typically a hypervascular solid tumor with/without a clear capsule in the background of liver cirrhosis. The tendency of the tumor to invade portal veins and hepatic veins can also be clearing see on the CT scan. The added advantage of CT images is ability in studying the adjacent organs at the same time.

Magnetic resonance imaging (MRI) is a newer imaging technology that does not involve ionizing radiation. Its accuracy in detecting hepatoma is similar to CT scan but the cost is higher.

Characterizing small tumors (those <2cm) can be difficult on CT scan or MRI especially when the tumor marker is not elevated to diagnostic level. In such cases, short of doing a biopsy of the tumor, lipoidol CT scan may add confidence to the diagnosis of hepatoma. This works on the principal that hepatoma retains lipoidol (an oil based contrast) after injection through hepatic arteriography. A non-contrast enhanced plain CT scan is done 10 days to 2 weeks later, the retained lipoidol in the heptoma will light up brightly on the background of non-enhanced uninvolved liver parenchyma.

Hepatic artery angiography may also demonstrate the characteristic tumour blush of hepatoma.

In majority of patients, the diagnosis of hepatoma can be reached confidently with the combination of positive HBV or HCV viral serology, raised alph-fetoprotein and a CT scan showing a characteristic space-occupying lesion in the liver. Biopsy of the tumor is usually not necessary prior to surgical resection. Biopsy of the tumor is needed when the radiologic features of lesions are atypical; especially when the serology and tumor markers are not also supportive of the diagnosis; in patient whose tumor is technically unresectable or those who are deemed not suitable for operation due to other reasons.

Biopsy of the tumor can be done percutaneously under ultrasound or CT guidance; or laparoscopically (with keyhole operation). Core biopsy has better yield than fine needle aspiration but is associated with small risk of tumor bleeding and seeding along needle tract.

Hepatoma is one of the more aggressive malignant tumor. The chance of cure is related to the stage of the tumor and the severity of the underlying liver cirrhosis at the time of diagnosis. A patient with well preserved liver function and a small size tumor (less than 3cm) confined to one lobe of the liver has a good chance of cure after adequate resection of the tumor.

Non-operative treatments of HCC have a place in non-resectable disease and in patients who are poor surgical candidates.

Surgical resection, when possible, remains the best chance of cure in patients with hepatoma. The objective of surgical resection is to excise the tumor with clear margin and at the same time preserve as much normal functioning liver as possible to sustain life. This is a very difficult balance to achieve because of the often associated underlying liver cirrhosis in majority of patient with hepatoma. In general, the prerequisites for surgical resection are:

” Good cardio-pulmonary fitness for major operation
” No other serious medical conditions
” Relatively well preserved liver function – not jaundice, no bleeding tendency, adequate protein in the blood, no excessive fluid in the abdomen and normal cognitive state.
” Tumor confined to one lobe of liver and without invasion of major vessels in the liver

In order to better select patients for surgical resection, a specially dye clearance test of the liver maybe necessary prior to the operation. This involves injection of the diluted dye (Indocyanine green) into a vein in your arm and collecting blood sample from you at 5mins interval for the next 20mins. Poor clearance of the dye after 15minutes predicts poor outcome following operation.

Surgical resection of liver and liver tumor has evolved to become a safe operation with less than 5% surgical mortality. This is largely due to better understanding of the anatomy and physiotherapy of the liver, improvement in surgical techniques as well as the advances in the anesthesiology and surgical care of patient after liver surgery.