Health Watch -- Detecting Cancer Changes

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A blood test may help doctors know if a patient's cancer is progressing.

Cancer itself is a genetic mutation in cells, and those mutations continue as cancer progresses, making it more difficult to treat. Now, researchers at UT Southwestern Medical Center at Dallas have developed a blood test that may help doctors learn when genetic changes happen in certain kinds of breast cancer. Noticing these changes may allow doctors to provide better treatment.

The test detects and evaluates cells that are shed from the primary tumor into the bloodstream. Doctors can compare these shed cells to the primary tumor to see if any genetic changes are happening.

The test looks for amplification of a certain gene in these tumor cells. Even if the gene isn't amplified in the primary tumor, if the amplification occurs in enough cells, these cells may become dominant in time, changing the nature of the tumor.

There is drug therapy available that has been proven effective in treating the kind of cancer involving the amplified gene. Researchers believe this blood test can give doctors an early warning that the tumor could be changing so they can alter treatment quickly. More studies are planned to see if drug treatment based on this blood test causes patients to go into remission.

Dr. Jonathan Uhr, the UT Southwestern microbiologist who led the study, says that cancer is like a moving target, and this test may help doctors know what bullets to put in their gun.


June 2004