After the initial examination by the doctor, the doctor likely will want to order a number of liver blood tests as well as some imaging studies.
This is necessary to confirm the suspicion of liver cancer and to rule other diseases in or out. Here is a list of blood tests that often are ordered by physicians who just examined a patient with a possible liver cancer. The purpose of the tests is to establish the present liver function and whether or not the constellation of the test results supports the diagnosis of liver cancer.
Other causes of liver disease are also ruled out such as pernicious anemia, which is due to vitamin B-12 deficiency. The traditional liver function tests (transaminases etc.) help to distinguish whether there is an obstruction of a biliary duct within the liver, whether there is cirrhosis of the liver, hepatitis or normal liver function.
Blood tests for liver cancer work-up
|Blood test type:||Explanation why test is done:|
|CEA (=carcinoembryonic antigen)||tumor marker|
|AFP (=alpha-fetoprotein)||tumor marker|
|PT(=prothrombin time) and PTT(=partial thromboplastin time)||measures blood clotting manufacturing capability of liver|
|B-12 level||rule out pernicious anemia|
|liver function tests: transaminases,alkaline phosphatase, lactic dehydrogenase||these liver enzymes show whether they leak into the blood and if bile ducts are blocked|
|platelets and white blood cells||decreases in these cells indicate portal hypertension (see text)|
|hepatitis A,B,C, and D||look for cause of chronic hepatitis, cirrhosis and risk for liver cancer|
|other tests||depending on clinical situation|
With hepatitis present a further test can determine whether it is hepatitis B or C, both of which have a higher risk of causing liver cancer.
Finally, if platelets or white blood cell counts are decreased, this is usually a sign that due to cirrhosis of the liver there is obstruction of the flow of blood from the portal vein system and the pressure is increased in it. Such a condition will lead to an enlargement of the spleen, called “hypersplenism”. The enlarged spleen filters out platelets and white blood cells and they are missing in the blood stream, which is shown in the test. The most common reason for cirrhosis of the liver is chronic alcohol abuse. The next common cause of cirrhosis of the liver is chronic infection with hepatitis B or C.
There are newer serological tests that have been developed with the goal in mind to develop a similarly specific and sensitive test for liver cancer as the PSA test is in the case of prostate cancer. Radio-immuno-assays for alpha-fetoprotein (AFP) are a promising first step. There are ethnic differences: 80%-90% are positive in Asian populations with liver cancer , but only 60%-70% are positive in liver cancer patients in the US and Europe. Other tests are more sensitive, but not specific enough. Only, when some of these tests are combined with ultrasound investigations of the liver, will the sensitivity and specificity reach 98% for liver cancer, not unlike in prostate cancer, where the combination of rectal examination with a PSA blood test is recommended for screening.
Other diagnostic tests are done in the imaging department of the hospital or the X-ray clinic.
The first such test is an ultrasound of the abdomen, gallbladder and liver, which serves as an initial screening test. If this shows an abnormality in the liver, a CT scan (thanks to www.celebritydiagnosis.com for this image) of the liver is then ordered, which can be improved in resolution with by injecting contrast material.
A so-called angioportography, (thanks to www.nature.com/ for this image) where contrast material is injected into an artery called “superior mesenteric artery” that supplies the liver with blood, shows minute detail of the liver tissue and is very useful as a test to look for the exact extent of the cancer within the liver tissue. It also shows any local metastases.
Alternatively an MRI scan can also be ordered instead. However, people who have metal foreign bodies in them from prior injuries are not allowed to undergo MRI scanning, but can have CT scans. In the past before CT and MRI scanning arteriograms were done where the pathological tumor vessels were depicted and used as a diagnostic test. Occasionally this test is still done in special circumstances such as when a partial resection of the diseased liver is planned. A nuclear medicine liver scan is done with Technetium 99m sulfur colloid in a hospital. A variation of this using a rotating gamma camera allows for better imaging with spacial orientation, called single-photon-emission CT (=SPECT scan).
These tests are all very useful to “round up the cancer”. But all the physician knows so far is that there is a biochemical abnormality on the blood tests and that there is a shadow on the various images of the imaging tests.
But there is no histological proof (meaning a cell test for proof of the presence of liver cancer) at this point to indicate that indeed liver cancer is present. As I pointed out in the other cancer chapters, cancer is a histological diagnosis. For this reason a tissue sample has to be taken and sent to the pathologist for a definite tissue diagnosis. This is done by either a percutaneous liver biopsy, an open biopsy or a laparoscopic biopsy. However, it is wise to do all the other tests mentioned above first, as there could be profuse bleeding in a case where there is portal hypertension and where the blood is thinned due to missing clotting factors. What approach the physician will finally take to obtain tissue for a definite diagnosis of the patient’s condition depends to a large extent on these prior findings.
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