 If you are found to be eligible to participate in the study, you will be randomly assigned as in the toss of a coin to receive either erlotinib hydrochloride or placebo. A placebo is a substance that looks like the study drug but has no active ingredients. Neither you nor the investigators will know which treatment group you have been assigned to. However, in the event of a medical emergency, the study chair can find out which group you are in, if necessary. You can be informed which of the groups you were assigned to, after the study has ended. There is no certainty that you will have an effect from the treatment, or if you will be placed in a group with the active study drug. 