Recently, there have been major advances in our understanding of how cancer progresses. As scientists have sequenced thousands of cancer genomes, patterns are starting to emerge. One clear insight we have gained is the likelihood that no single drug will be able to defeat cancer. The reason most cancers become drug resistant and come back is because their DNA mutates quickly. Cancer cells that are not killed by the drugs survive, continue to grow and replace the cells that have been wiped out.-link
An interesting article dealing with cancer research and the pharmaceutical industry.