Chronic myeloid leukemia is a type of blood and bone marrow cancer that often develops gradually. Diagnosis commonly begins with routine blood testing when unusual blood cell levels are detected. Further evaluation may include a complete blood count, examination of blood cells, bone marrow testing, and genetic analysis to identify the Philadelphia chromosome or BCR ABL1 gene fusion. These tests help healthcare professionals confirm the condition and understand its characteristics. Regular blood and molecular testing may also be used after diagnosis to monitor changes in leukemia cells and assess how the condition is responding over time.
Chronic myeloid leukemia, often called CML, affects blood-forming cells in the bone marrow. In some cases, it may be discovered during a routine medical examination before noticeable symptoms develop. Blood testing plays an important role in identifying unusual changes in white blood cells and determining whether additional diagnostic procedures are needed. A combination of laboratory, bone marrow, and genetic tests can provide a clearer understanding of the condition.
The diagnostic process often begins with a complete blood count, also known as a CBC. This test measures different components of the blood, including white blood cells, red blood cells, and platelets. People with CML may have an unusually high number of white blood cells, although other blood changes can also occur.
A peripheral blood smear may also be performed. During this test, a healthcare professional examines blood cells under a microscope to identify differences in their appearance, size, or stage of development. These findings can help determine whether further testing is appropriate.
Important blood tests and evaluations may include:
Blood test results alone may not always confirm chronic myeloid leukemia. Additional procedures are commonly used to examine the bone marrow and identify the genetic changes linked with the disease.
Bone marrow testing can provide detailed information about the cells responsible for producing blood. A bone marrow aspiration and biopsy may be performed to collect samples for laboratory examination. These tests can help healthcare professionals assess the number and characteristics of blood-forming cells and determine the phase or extent of the condition.
Genetic testing is another important part of CML diagnosis. Most cases are associated with a genetic abnormality known as the Philadelphia chromosome. This abnormality creates the BCR ABL1 fusion gene, which produces an abnormal protein that contributes to the growth of leukemia cells.
Common diagnostic and monitoring tests include:
After diagnosis, molecular testing may continue at regular intervals to monitor the level of BCR ABL1 and identify changes over time. The frequency and type of testing can vary depending on individual circumstances and the healthcare professional's assessment. Understanding the role of blood, bone marrow, and genetic testing can help explain how chronic myeloid leukemia is identified and monitored throughout ongoing care.