Leukemia Leukemia Treatment

Monitoring Treatment in CML

Medically Reviewed On: December 22, 2010

During treatment for CML, your doctor will rely on various tests to help him or her determine how well you are responding.  These include tests that are used to initially diagnose the disease.

Hematological Response
Since the first step in treating CML is to normalize blood cell counts, doctors begin monitoring with blood tests to count the number of white blood cells, red blood cells and platelets in the body. The white blood cell will be very elevated in untreated CML.

If the overall white blood cell count continues to decrease and the number of red blood cells and platelets return to normal, then treatment is working. In the chronic phase of CML, white blood cell counts often return to normal quickly. This is called a complete hematological response.

These blood tests will continue throughout treatment, to ensure that blood cell counts are maintained at normal levels. A return to abnormal levels might signify the relapse of disease.

Cytogenetic Testing
During your initial diagnosis, your doctor will likely order cytogenetic testing to check for the presence of the Philadelphia chromosome, a specific genetic abnormality that is found in bone marrow and in blood cells of patients with CML. As leukemia appears, these irregular cells increase in number as compared to normal white blood cells.

Cells are removed from the marrow and analyzed for the presence of the Philadelphia chromosome. Marrow is chosen because it is here that blood cells are dividing, and it is at this stage in the life cycle of cells that their chromosomes can be seen via a microscope. Twenty or thirty blood cells are analyzed. In some cases, especially before treatment when white blood counts may be extremely high, cytogenetic testing can be performed on sample of blood instead of marrow.

Spotting only one cell with the Philadelphia chromosome is enough to confirm a diagnosis of CML, but often, at the time of diagnosis, all twenty or thirty cells contain the Philadelphia chromosome.  As successful therapy continues, your doctor will track reductions in the percentage of these cells.

The degree to which your body is responding to treatment is described in percentages.  Any reduction in the percentage of cells containing the Philadelphia chromosome is considered a cytogenetic response.  If the number of leukemic cells with the Philadelphia chromosome falls to fewer than 35 percent, that is considered a major cytogenetic response. If cytogenetic testing reveals that there are no more cells with the Philadelphia chromosome, or zero percent, that is considered a complete cytogenetic response.

Page 1 of 2 Next Page >>