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Cancer dynamics are not linear. Cancer biology does not conform to the dictates of molecular biologists. Once again, we are forced to confront the realization that genotype does not equal phenotype.
The first chink in the armor of this argument came when scientific reviewers issued an “expression of concern” regarding the validity of the method. Further analyses revealed evidence that the technologies for the prediction of response in individual patients could not be reproduced. As the reviewers stated, “The scientific community should be able to replicate the results with the reported data available.”
They continued, “Having tried, we can confidently state that this is not yet true.” The NCI convened a group of 31 scientists, who concluded, “It is absolutely premature to use these prediction models to influence the therapeutic options open to cancer patients.”
While much attention has been given to the genomics field, the NCI has determined that - at this time - treatment selection results cannot be duplicated and the genomic methodology is not ready for clinical application.
In a nutshell, cancer cells utilize cross talk and redundancy to circumvent therapies. They back up, zig-zag and move in reverse, regardless of what the sign posts say. Using genomic signatures to predict response is like saying that Dr. Seuss and Shakespeare are truly the same because they use the same words. The building blocks of human biology are carefully construed into the complexities that we recognize as human beings. However appealing gene profiling may appear to those engaged in this field (such as Response Genetics, Caris, the group from Duke and many others) it will be years, perhaps decades, before these profiles can approximate the vagaries of human cancer.
Functional profiling analyses, which measure biological signals rather than
DNA indicators, will continue to provide clinically validated information and
play an important role in cancer drug selection. The data that support
functional profiling analyses is demonstrably greater and more compelling
than any data currently generated from DNA analyses. Functional profiling
remains the most validated technique for selecting effective therapies for
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