Tarceva® (erlotinib) is a drug that blocks a receptor called the Epidermal Growth Factor Receptor (EGFR) on certain cells including tumor cells. Blocking this receptor has been shown to shrink tumors in some patients. Tarceva®(erlotinib) is approved for commercial use by the U.S. Food and Drug Administration for treatment of Non-Small Cell Lung Cancer (NSCLC) after failure of at least one chemotherapy treatment. However, it is not approved for the first treatment of Non-Small Cell Lung Cancer (NSCLC), which is the treatment used in this study.