[gdpawel]

There have been attempts to develop molecular-based tests to examine a broader range of chemotherapeutic drugs. New technologies for measuring the expression (biological activity) of literally hundreds to thousands of genes as part of a single test. There are two main technologies involved: RT-PCR (reverse transcription polymerase chain reaction) and DNA microarray.

The main reason why the functional profile platform has not focused upon genomic analyses is that cancer is more complex than its gene signature.Contained within the genes of each human is the information to create every protein, every enzyme, every lipid, every carbohydrate and all the organs and systems dependent upon their function. What is not known is how all of those 25,000+ genes are regulated to produce the unique features that constitute us as human entities.

As one of the researchers in the functional profile platform describes it, from the moment of conception, when the male and female genetic materials are fused into what is known as a zygote, our informatics are established. What enables that single cell to become the multi-trillion-cell organism that we recognize as human is not the gene, but the gene regulation. The informatics are static — the regulation is highly fluid.

Simply exploring the information contained within the human cell provides you with a blueprint of what may be, but no clear evidence that the outline structure will ever come to be in all of its functional complexity. In this regard, genomic analyses cannot approximate the vagaries and manifold variations that define us as individuals.

To look at this a different way, we can describe genetic information as 'permissive', that is it tells you what you may or may not become. Functional information is 'predictive', it tells you exactly what you are. The functional profile platform has moved away from genomic analyses for the very reason that they provide only a veneer of information. The substance of cancer, its responsiveness to therapeutics and its ultimate cure, require a more definitive analysis. By studying human cellular behavior within the context of vascular, stromal and inflammatory elements, the functional profiling platform provides the closest approximation of human biology possible.

Human beings are demonstrably more than the sum of their genes. Cancer biology and the study of cancer therapy are many things, but simple is not one of them. Complex problems require solutions that incorporate all of their complexities, however uncomfortable this may be for genomic investigators.

Hence the headlong rush to develop tests to identify molecular predisposing mechansims whose presence still does not guarantee that a drug will be effective for an individual patient. Nor can they, for any patient or even large group of patients, discriminate the potential for clinical activity among different agents of the same class.

Genetic profiles are able to help doctors determine which patients will probably develop cancer, and those who will most likely relapse. However, it cannot be suitable for specific treatments for "individual" patients. The NCI has concluded (J Natl Cancer Inst. March 16, 2010), it cannot determine treatment plans for patients. It cannot test sensitivity to any of the targeted therapies. It just tests for "theoretical" candidates for targeted therapy.