OBJECTIVES: Primary * Determine the safety of cisplatin, etoposide, and cyclophosphamide in patients with extensive stage small cell lung cancer. * Determine the effect of this regimen on circulating endothelial cells in the peripheral blood of these patients. Secondary * Determine progression-free survival, tumor response rate, and overall survival in patients treated with this regimen. OUTLINE: This is a multicenter study. * Induction therapy: Patients receive cisplatin IV over 30 minutes-2 hours on day 1, etoposide IV over 1-2 hours on days 1-3 OR etoposide IV on day 1 and orally twice daily on days 2-3, and oral cyclophosphamide twice daily on days 8-19. Treatment repeats every 21 days for 4 courses in the absence of disease progression or unacceptable toxicity. * Maintenance therapy: Patients receive oral cyclophosphamide twice daily in the absence of disease progression. Patients are followed every 3 months for 2 years, every 6 months for 3 years, and then annually thereafter. PROJECTED ACCRUAL: A total of 10 patients will be accrued for this study.
DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed small cell lung cancer * Extensive stage disease (i.e., disease beyond the hemithorax and cannot be encompassed safely by a tolerable radiation field) * Measurable disease * Concurrent CNS metastases allowed provided patient remains asymptomatic * Radiotherapy or surgery for uncontrolled symptoms allowed before study entry PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-2 Life expectancy * Not specified Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 8 g/dL (transfusion allowed) Hepatic * ALT ≤ 2 times upper limit of normal (ULN) * Bilirubin ≤ 2 times ULN Renal * Creatinine ≤ 1.5 mg/dL OR * Creatinine clearance ≥ 60 mL/min Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other malignancy within the past year except adequately treated basal cell or squamous cell skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy * No prior biologic therapy Chemotherapy * No prior chemotherapy Endocrine therapy * Concurrent corticosteroids for brain metastases allowed Radiotherapy * See Disease Characteristics * Prior radiotherapy to any symptomatic site allowed provided the target site(s) was not previously irradiated * No concurrent radiotherapy Surgery * See Disease Characteristics
is designated in this study