What Blood Tests Are Used to Diagnose Blood Cancer?

There are several blood tests which may be used to diagnose blood cancers.

Complete blood count

A complete blood count (CBC) is a commonly performed lab test that can detect or monitor many different health conditions. The CBC test measurements include:

  • The number of red blood cells (RBCs)
  • The number of white blood cells (WBCs)
  • The number of platelets
  • The amount of hemoglobin in the blood (hemoglobin is the protein in RBCs that carries oxygen)
  • The percentage of blood that is RBCs, called the hematocrit1

Sometimes, a CBC includes a differential, which measures the different types of WBCs. There are five types of WBCs measured: neutrophils, lymphocytes, monocytes, eosinophils, and basophils.1

In the case of some blood cancers, the cancerous cells multiply and can crowd out the normal production of healthy blood cells, causing the number of RBCs, WBCs, or platelets to be lower than normal. Some counts may be higher than normal in certain situations, such as too many WBCs in leukemia.2

Blood chemistry

Blood chemistry, which may also be called a chemistry panel, is also commonly performed to measure a person’s health status. Different chemicals in the blood (like electrolytes and some proteins) come from the liver, bones, and other organs, and abnormal levels in certain chemicals can indicate that an organ isn’t working properly. Abnormal levels may be caused by cancer, but they can also be indicators of other health problems.1,3

Liver function tests

A liver function test, also called a liver panel or hepatic function panel, is a chemistry test done to evaluate the performance of the liver. Liver function tests can detect acute or chronic inflammation of the liver, or if the liver has an infection, disease or damage.1 The liver filters the blood, removing waste and helping to digest food. Abnormal levels of liver proteins may be caused by cancer, treatments for cancer, other drugs, or other health problems.3

Peripheral blood smear

A peripheral blood smear is a test that may be run as a follow-up if there are abnormal results on the CBC. The blood smear consists of a drop of blood thinly spread on a glass slide and treated with a special stain. The slide is observed under a microscope to analyze the types of cells in the blood. Normally, only mature cells are released from the bone marrow into the blood. However, blood cancers or other conditions may result in the bone marrow releasing immature or abnormal cells into the blood stream. The blood smear will include a description of the appearance of RBCs, WBCs, and platelets, as well as any abnormalities that may be present.1

Blood clotting tests

Blood clotting tests measure if blood coagulates (clots) normally. Clotting is a function of the platelets and proteins called clotting factors. Some blood cancers can reduce the number of platelets and cause frequent bruising or bleeding, and blood clotting tests can help determine if the bruising and bleeding is due to cancer or another cause.1

Tests to rule out other conditions

Some of the symptoms that are common to blood cancer are also commonly caused by other conditions. In some cases, additional blood tests may be used, such as:

    • Testing for viral infections (hepatitis B or C, human immunodeficiency virus (HIV), or cytomegalovirus (CMV))
    • Lactate dehydrogenase to potentially help evaluate cancer, as well as response to cancer treatment3,4
Written by: Emily Downward | Last reviewed: February 2018
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