Diagnosis of liver cancer
In evaluating liver cancer, computed tomography (CT) scans are important tools. Additional evaluations — such as blood tests and biopsies — help physicians understand the general health status of a patient, the patient’s liver function, and his or her quality of life. If a patient will be treated by chemotherapy, evaluation often includes an audiogram, or hearing test, and a MUGA heart scan.
CT Scans
After liver cancer is diagnosed, CT scans help determine:
- the size and location of the cancer in the liver
- whether the cancer has spread beyond the liver to form satellite tumors
- the proximity of the tumor to major hepatic blood vessels and if the tumor has invaded the portal vein, the main vein that leads to the liver
- if there are blood clots (thromboses) in any of the major branches of the portal and hepatic veins
- if the lymph nodes are enlarged
A high-speed helical (spiral) triphasic CT scan of the liver allows specialists to evaluate the extent and location of the tumor. A CT scan of the chest and pelvis allow them to determine if the cancer has spread. A bone scan may be performed to exclude or confirm the presence of cancer in bone.
In evaluating CT scans of the tumor, physicians also look for evidence of cirrhosis and its complications, such as ascites, portal hypertension, and splenomegaly (an enlarged spleen).
Blood Tests
Blood tests also help doctors determine the general health status of a patient, including whether he or she has been exposed in the past to hepatitis B or C and if the hepatitis is currently active. In addition, blood test results are a measure of how well the patient’s liver works.
A platelet count is a test that a doctor may order to detect cancer in its early stages. A white cell count that is below the normal range can be a sign of splenomegaly and/or portal hypertension.
Blood tests known as blood chemistries evaluate:
- albumin level
- prothrombin time
- transaminase level (SGOT, SGPT, GGTP)
- blood creatinine level
Blood tests for specific tumor "markers" include tests that detect the presence of:
- alpha-fetoprotein (AFP)
- desgamma carboxy prothrombin (P, or PIVKA-2)
- neurotensin
DCP and neurotensin are markers (in the presence of a normal AFP) for the fibrolamellar variant of liver cancer, which often occurs in children.
Biopsies
In addition to a biopsy of the tumor, radiologists perform a biopsy on a specimen taken from the non-tumorous part of the liver. The liver biopsy helps determine the presence or degree of cirrhosis. A core-needle biopsy, rather than a fine-needle aspiration biopsy, is usually necessary to evaluate the make-up of the tumor.
If the CT scan suggests thrombosis (clotting), then a needle-aspiration biopsy of the portal vein may be necessary. This type of biopsy helps doctors determine if the tumor is actually invading the portal vein. Invasion of the portal vein by a tumor has profound consequences for the long-term outcome of liver transplantation for liver cancer.