RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. It is not yet known whether combination chemotherapy with or without epirubicin and cyclophosphamide is more effective in treating patients with extensive stage small cell lung cancer.

PURPOSE: Randomized phase III trial to compare the effectiveness of combination chemotherapy with or without epirubicin and cyclophosphamide in treating patients who have extensive stage small cell lung cancer.

OBJECTIVES: I. Compare the overall survival and survival without recurrence of patients with extensive stage small cell lung cancer after receiving cisplatin and etoposide with or without epirubicin and cyclophosphamide. II. Compare the relative dose and intensity of cisplatin and etoposide between the two groups of patients. III. Compare the complete and objective response rate and quality of life of these patients. IV. Compare the toxic effects of these 2 regimens in these patients.

OUTLINE: This is a randomized, multicenter study. Patients are randomized to one of two treatment arms. Arm I: Patients receive etoposide IV on days 1 and 3 and cisplatin IV on day 2. Arm II: Patients receive etoposide and cisplatin as in arm I, plus epirubicin IV on day 1 and cyclophosphamide IV on days 1 and 3. Treatment is repeated in both arms every 28 days for up to 6 courses. Patients who achieve a partial or complete response receive cerebral and/or thoracic radiotherapy. Patients with residual tumor may receive oral etoposide for 3 of every 4 weeks. Patients are followed every 3 months.

PROJECTED ACCRUAL: A total of 216 patients will be accrued for this study within 2.5 years.

DISEASE CHARACTERISTICS: Histologically proven extensive stage small cell lung cancer Extends beyond hemithorax and supraclavicular lymph nodes Pleural effusions allowed Bidimensionally measurable disease Bone marrow metastases allowed No symptomatic CNS metastases or carcinomatous meningitis

PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: 0-2 Life expectancy: Not specified Hematopoietic: Neutrophil count at least 2,000/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 1.5 times normal Renal: Creatinine less than 1.24 mg/dL OR Creatinine clearance greater than 60 mL/min Cardiovascular: No cardiac insufficiency No uncontrolled cardiac disease LVEF greater than 50% OR ECHO greater than 30% Other: Not pregnant Fertile patients must use effective contraception No psychoses No active infection No loss of weight greater than 10% during the last 3 months No other malignancy except nonmelanomatous skin cancer or stage I cervical cancer

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior or concurrent immunotherapy Chemotherapy: No prior or other concurrent chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior or concurrent radiotherapy Surgery: No prior or concurrent surgery