Study of Arsenic Trioxide in Small Cell Lung Cancer

Drug will be given as a loading dose of 0.32mg/kg/day for 4 days in Week 1, followed by 0.25mg/kg/day twice per week for 5 weeks, followed by 2 weeks of rest, at which time response assessment will be performed. Patients will be restaged prior to the beginning of a new cycle, every 2 months on average. Maximum of 6 cycles of therapy will be administered in the absence of tumor progression or excessive side effects