Treatments based on cancer genetics may be ineffective

HealthDay News: Many cancer studies that rely on what scientists call genetic microarrays have critical flaws in their analyses or their conclusions.

This means doctors are taking this flawed research and using it as the basis of treatment for cancer patients -- treatments that may adversely affect patient outcomes.

That's the surprising conclusion of a new study by researchers at the U.S. National Cancer Institute that's published in the Jan. 17 issue of the Journal of the National Cancer Institute.

Microarrays are a tool used to study gene expression, or production. Using microarrays, researchers can study thousands of genes at a time, all on a single glass slide. In cancer research, microarrays are used to study the unique gene pattern of specific tumors, to find new drug targets, and to categorize the characteristics of a patient's tumor to help tailor an individual's treatment.

But, these studies based on microarrays produce vast amounts of data that are easily misinterpreted, the researchers say. Much of the problem owes to a lack of communication between clinicians and the statisticians who analyze the data, according to the new study.

"A lot of the publications trying to tie gene expression to clinical outcomes are flawed," said study co-author Richard M. Simon, chief of the National Cancer Institute's Biometric Research Branch.

It's difficult to analyze a readout where you get 20,000 to 30,000 gene variables, Simon said. "Properly analyzing that data to predict outcomes for patients is difficult," he said.

The genetic technology is very powerful, Simon added. "There are great success stories in being able to use gene-expression technology for being able to figure out which patients respond to what treatment. But there is a need for improvement in the analysis of the data and a close interdisciplinary collaboration with statistical experts in the analysis of these studies," he said.

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