The purpose of this study is to learn about dacomitinib for the possible treatment of lung cancer. This study is seeking participants who: * have lung cancer that could not be controlled. * have a type of gene called epidermoid growth factor receptor. A gene is a part of your DNA that has instructions for making things your body needs to work. * have received dacomitinib for their lung cancer. All participants in this study had received dacomitinib. Dacomitinib is a tablet that is taken by mouth at home. They continued to take dacomitnib until their cancer was no longer responding. The study will look at the experiences of people receiving the study medicine. This will help to see if the study medicine is safe and effective.