This study is looking at two different treatment options with drugs currently on the market, to determine if one type of treatment may be better than the other.  All of the drugs used in this study have shown some benefit for this cancer.  Patients are "randomized" on this study.  This means a computer tells the study team which treatment you will receive.  Neither the patient or the physician can choose the treatment assignment.  The purpose of Randomized trials is to equally study both treatment options using the same criteria in order to identify if one treatment may be superior to another treatment.