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.

PURPOSE: Phase II trial to study the effectiveness of combining cisplatin with gemcitabine in treating patients who have stage IIIB or stage IV non-small cell lung cancer.

OBJECTIVES: I. Determine the efficacy of the combination of cisplatin and gemcitabine in terms of response rate and progression free survival in patients with stage IIIB or IV non-small cell lung cancer. II. Evaluate this treatment regimen in terms of toxicity and quality of life in these patients.

OUTLINE: This is a multicenter study. Patients receive gemcitabine IV over 30 minutes and cisplatin IV over 1 hour every 2 weeks for 6 courses in the absence of disease progression or unacceptable toxicity. Patients with no disease progression following 6 courses of therapy receive an additional 6 courses of therapy. Quality of life is assessed prior to each course and then every 3 months. Patients are followed every 3 months until death.

PROJECTED ACCRUAL: A total of 37-83 patients will be accrued for this study.

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed non-small cell lung cancer Locally advanced Stage IIIB (T4, Nx, M0, or Tx, N3, M0) OR Metastatic disease Stage IV unresectable disease Following cell types eligible: Epidermoid cell Large cell Adenocarcinoma Bidimensionally measurable disease Unresectable recurrence after primary surgery allowed No brain metastasis

PATIENT CHARACTERISTICS: Age: 18 to 75 Performance status: WHO 0-2 Life expectancy: At least 3 months Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 10 g/dL Hepatic: AST and ALT no greater than 3 times upper limit of normal (ULN) Bilirubin no greater than 1.5 times ULN Renal: Creatinine no greater than 1.10 mg/dL Cardiovascular: No uncontrolled cardiac disease Other: No other significant, uncontrolled underlying medical or psychiatric condition No serious active infection Neurologically stable No other prior malignancy except treated nonmelanomatous skin cancer or carcinoma in situ of the cervix Not pregnant or nursing Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Endocrine therapy: Not specified Radiotherapy: No prior radiotherapy Surgery: See Disease Characteristics Other: At least 30 days since prior experimental therapy No other concurrent experimental drugs