[gdpawel]

Scientists have come to realize that cancer biology is driven by signaling pathways. Cells speak to each other and the messages they send are interpreted via intracellular pathways known as signal transduction. Picture these pathways as if they were phone lines, linking one cell to another.

Many of these pathways are activated or deactivated by chemical reactions. In some cases, programmed cell death is inhibited when these pathways are disrupted. When the cell does not die, as it should normally, cancer forms.

In recent years, research has lead to the creation of “small molecules” to regulate these chemical reactions. Hundreds of these “targeted" agents are currently in development for cancer treatment.

While some physicians are using genomic or proteomic testing to detect mutations in these pathways, cell-based assay labs have taken a different approach. Using functional profiling, they measure the end result of pathway activation or deactivation in the individual.

In addition to testing the tumor against a number of chemotherapeutics, they can also test the effectiveness of molecularly targeted agents and predict whether the "individual" cancer patient will "actually" respond to a targeted agent. To date, results have exceeded the reported results of those who have based treatment regimens on DNA profiles.

The genomic profile is so complicated, with one thing affecting another, that it isn't sufficient and not currently useful in selecting drugs. Because metabolic changes are complex and hard to predict, metabolic profiling will be essential for selecting best treatment.