Targeted drugs that attack the genetic machinery of cancer with laser-like precision are, in a select group of patients, melting tumors away, often with few side effects. The problem is, almost invariably, these medications eventually stop working. … “It’s so much in our thinking today. As soon as we have an effective drug, we start thinking, ‘How does the drug begin to lose its benefit?” said Dr. Pasi Janne, an oncologist at Dana-Farber Cancer Institute. “This is really rising to the forefront.”
http://www.boston.com/lifestyle/health/articles/2011/11/21/successes_in_fighting_cancer_bring_new_challenge_drug_resistance/
