A new test that can detect the genetic mutation linked to some types of acute myeloid leukemia is expected to help doctors tailor treatment for patients.

The BloodCenter of Wisconsin has developed the test, called CEBPA Mutation Analysis, to gauge the prognosis of those people already diagnosed with acute myeloid leukemia as well as identify the genetic mutation in those who may develop the inherited version of the blood cancer.

This is the first time the test will be available for clinical use, said Roger Klein, the center's medical director of molecular oncology. It is also the first test developed by a laboratory to specifically identify the inherited form of this leukemia.

Acute myeloid leukemia, or AML, is the second most common form of leukemia. While most cases of this leukemia occur in older adults - the National Cancer Institute has pinned the median age at diagnosis at 67 years - roughly one in five children with leukemia has AML, according to the Web site of the Leukemia and Lymphoma Society.

Prevailing research has found that a mutation of the gene in a healthy individual signals an extremely high risk of developing the disease.

"This is important for children and family members of patients," Klein said.

A physician can run a test if a patient is at risk of inheriting the leukemia, for example, due to a family history of the disease. If the patient is a carrier of the genetic mutation, the doctor will know to monitor the person closely and detect the cancer at its early stages if it develops, allowing for quicker and perhaps more effective treatment.

Test may reveal new information

Inherited cases are rare, accounting for just 1% of all cases of leukemia, according to the BloodCenter. Yet without a clinical test available until now, said Klein, the numbers may be deceiving.

"Once tests are more widespread," he said, "it's conceivable that (inherited AML) is more common than we think."

Because the gene mutation's link to the inherited leukemia was discovered just five years ago, he said, little is known about it.

But the test may not detect mutation in all cases. At times, mutations are located in regions of the gene not covered by the test.

"This means that just because the test is negative, it's not absolutely certain that there is no mutation in the gene, or that it's not caused by the mutation of another gene," Klein said.

In spite of these limitations, he hopes the test will contribute to a broader understanding of the genetics behind rare blood cancers.

Through a slight variation of the test used to identify the inherited type, BloodCenter researchers say they also will be able to expand the test's clinical use.

Test has flexibility

A variation of the test can be used to detect the mutation in a type of non-inherited, or sporadic, form of the leukemia called AML with normal cytogenetics, or CN-AML. This sporadic form accounts for about 50% of all cases of the leukemia, according to Klein. The gene mutation in this form of the leukemia has been found by researchers to serve as a biomarker associated with "relatively favorable outcomes," meaning a patient has a better chance of surviving. About 15% to 18% of CN-AML cases are believed to carry the mutation.

"It is an important step forward," said Guido Marcucci, a researcher with the Clinical Cancer Genetic Program at Ohio State University College of Medicine.

The most significant aspect of the test is that doctors will now be able to test for the mutation in patients diagnosed with the non-inherited leukemia, he said. Other labs, including Marcucci's, have developed CEBPA mutation tests for the sporadic leukemia, but only for research.

This is the first time practitioners will have access to it for clinical use. The test is estimated to cost $250 to $300.

By giving them a sense of the patient's prognosis, doctors may be able to provide better, more personalized treatment.

"The doctor can decide the intensity of the treatment he or she will use on the patient," Marcucci said. It may be one of several factors taken into consideration, for example, in deciding whether to conduct a bone marrow transplant.

Such tailoring of treatment, said Klein, is significant in the practice of personalized medicine, where doctors are able to take the specific genetic makeup of a patient into consideration. Though not the only determinant, he said, the results of a genetic test can be significant for both inherited leukemia and treatment of the sporadic form.

"They are pieces of data in a bigger clinical picture," Klein said.

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