Temozolomide as Maintenance Therapy Following Induction Chemotherapy in Extensive Stage Small Cell Lung Cancer

Inclusion Criteria: * Cytologically and/or histologically confirmed small-cell lung cancer with extensive-stage disease * Patients must have measurable disease, this can include brain metastases * Eastern Cooperative Oncology Group (ECOG) Performance Status of 0-1 * Adequate bone marrow function, as defined by: absolute neutrophil count (ANC) \>1,500/µL; platelets \>100,000/µL; hemoglobin \>=9.0 g/dL * Normal organ function, defined as follows: aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \<=2.5 × the upper limit of normal (ULN), or AST and ALT \<=5 × the ULN if liver function abnormalities are due to underlying malignancy; total serum bilirubin \<=1.5 × the ULN; serum creatinine \<=1.5 × the ULN * the time interval from the data of the last chemotherapy to random must be between 3 and 7 weeks * Women of childbearing potential and men with partners of childbearing potential must agree to use a form of birth control that is acceptable to their physician to prevent pregnancy during treatment * Patients must be informed of the investigational nature of this study and sign an informed consent form Exclusion Criteria: * Patients who are pregnant or breastfeeding * Patients receiving other investigational agents * Patients with leptomeningeal involvement * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, or psychiatric illness/social situations that would limit compliance with study requirements * Acquired Immune Deficiency Syndrome (AIDS) based upon current CDC definition or HIV-positive patients on combination antiretroviral therapy. However, HIV testing is not required for entry into this protocol. The need to exclude patients with AIDS from this protocol is necessary because these patients are at increased risk of lethal infections when treated with marrow- suppressive therapy. Excluding patients on HAART is necessary due to the potential for pharmacokinetic interactions with temozolomide.