While there is no definitive procedure, in lieu of a liver biopsy, that can diagnose liver cancer, there are several liver cancer tests that can indicate that the condition is present. Certain blood tests, like the alpha-fetoprotein (AFP) test, can help a doctor recognize the overall risk a patient has for cancer and also screen for any cancerous tumors that might already be present. Imaging techniques, like computed tomography (CT) scans, can provide a visual picture of abnormalities, which can be studied further with subsequent testing if a suspicious area is found. The most definitive liver cancer tests, liver biopsies, take a piece of tumor and look for cancerous components under a microscope; sometimes a physician can use a long needle to take a piece of tumor for study, eliminating the need for painful surgery.
AFP liver cancer tests are the most common procedure used to diagnose the condition. AFP is a protein made by immature liver cells; cancerous livers are also known to produce AFP in large quantities. While the presence of raised AFP levels is not totally indicative of liver cancer, it is considered a reliable indicator that cancer may be present or that the liver is in an overly vulnerable state for tumor growth. The sensitivity of the AFP test is around 60%, meaning that an elevated amount of AFP is seen in this percentage of liver cancer patients. In turn, 40% of patients have normal levels of the protein, which lead to limitations with this diagnostic procedure.
A CT scan, often the first imaging technique utilized in the diagnosis of liver cancer, is essentially an advanced X-ray. If a CT scan provides no answer and liver cancer is still suspected, the next test used is usually magnetic resonance imaging (MRI). An MRI uses radio wave frequencies in conjunction with strong magnets to form a detailed image of the liver. Many doctors prefer MRIs to other forms of liver cancer tests because they are sometimes able to distinguish between benign and malignant tumors within the body. The presence of a negative MRI imaging test, combined with a normal AFP test, can help the doctor be reasonably sure that the patient does not have liver cancer, and then he or she can move onto other diagnostic tests without the need for a liver biopsy.