Sarah
The reference to cancer being not simple was the genotyping analysis that goes on. Looking for that simple gene and seeing how it is expressed in the individual's cancer cells. The genomic profile is so complicated, with one thing affecting another, that it isn't sufficient and not currently useful in selecting drugs. The cell is a system, an integrated, interacting network of genes, proteins and other cellular constituents that produce functions. You need to analyze the systems' response to drug treatments, not just one target or pathway, or a few targets or pathways.
Some years back, three federal agencies (NCI, FDA and CMS) announced a program to try an identify biological indicators (biomarkers) which may indicate whether a cancer patient is likely to benefit from a given anti-cancer therapy, or even whether they will suffer from certain side effects. Biomarkers were already a part of drug development (Her2 = Herception, etc.), but health officials wanted to routinely incorporate those measurements into clinical trials.
They should be able to detect cancer pathways with biomarkers and choose patients for a trial based on who responds very quickly to a drug. The ordinary trial system did not suffice if they were to encourage new drugs for restricted numbers of patients. Hence the BATTLE clinical trials. Clinical trials designed applying Bayesian adaptive randomization for targeted therapy development in lung cancer. They thought this was a step toward personalized medicine.
http://cancerfocus.org/forum/showthread.php?t=3432
But giving instructions on the genetic differences that determine how a person responds to a drug will still have cancer medicine being prescribed on a trial-and-error basis, with adverse drug reactions remaining a major cause of injury and hospitalizations. There have been technologies, developed over the last twenty years, that hold the key to solving some of the problems confronting cancer medicine: matching individual patients with the treatments most likely to benefit them. Being chemo-sensitive rather than chemo-resistant.
Greg