Would you take a medicine that only helps 1 in 10 people? Your answer might change if the doctor could tell you if you were that 1 in 10. This now might be the situation with Iressa, a drug that effectively treats about 10% of lung cancer patients. Scientists think that they now might be able to figure out who will be helped by Iressa based on the DNA in the patient's particular cancer.
Iressa stops cancers from growing by keeping a protein called epidermal growth factor receptor (EGFR) from working. Apparently, those who responded well to Iressa had DNA changes in the EGFR gene. These changes make the cancers so dependent on EGFR that once Iressa starts working, these cancers can't find another way to grow and so they disappear.
Once a test for this DNA change becomes available, doctors may quickly be able to tell whether Iressa might help you. Until then, if you are Japanese, a woman, and/or a nonsmoker, there is a good chance Iressa may work for you as these mutations were more common in this population.