Gene testing examines a single process within the cell. The aim is to tell if there is a theoretical predisposition to drug response. It costs well in excess of $1,000 to do EGFR by FISH for amplificaton. All of which tells you whether or not to give the Erbitux (one drug).

Chemoresponse analyses more often find NSCLC patients sensitive to other compounds and combinations and can recommend these all from one assay. It costs a lot more to give a single cycle of chemotherapy than it does to test all of the possible options.

Chemoresponse assays with functional profiling tests not only for the presence of genes but also for their functionality, for the interaction with other genes, and processes occuring within the cell, and for their response to anti-cancer drugs.

Genes create the blueprints for the production of proteins within the cell. A protein is a molecule that makes a cell behave in a certain way. It does so by interacting with other proteins in a complex series of steps.

The goal of gene testing is to look for patterns of normal and abnormal gene expression which could suggest that certain proteins might or might not be produced within a cell. However, just because a gene is present it does not mean that an associated protein has been produced.

Although gene testing currently is limited in its reliability as clinical tools, the tests can be important in research settings such as in helping to identify rational targets for development of new anti-cancer drugs.

As you can see, just selecting the right test to perform in the right situation is a very important step on the road to personalizing cancer therapy.