RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die.

PURPOSE: Phase II trial to study the effectiveness of nitrocamptothecin in treating patients who have recurrent non-small cell lung cancer.

OBJECTIVES: I. Determine the response rate, time to progression and overall survival of patients with recurrent non-small cell lung cancer when treated with nitrocamptothecin. II. Assess the toxicities and pharmacokinetics of this regimen in these patients.

OUTLINE: Patients receive oral nitrocamptothecin daily on days 1-5. Treatment continues weekly in the absence of disease progression or unacceptable toxicity. Patients are followed for survival.

PROJECTED ACCRUAL: A total of 20-55 patients will be accrued for this study.

DISEASE CHARACTERISTICS: Histologically or cytologically confirmed recurrent non-small cell lung cancer No more than one prior chemotherapy treatment Bidimensionally measurable disease No prior radiotherapy to target lesion OR Progression since prior radiotherapy

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater than 2.0 mg/dL ALT/AST no greater than 3 times upper limit of normal (ULN) (no greater than 5 times ULN in case of liver metastases) Renal: Creatinine no greater than 2.0 mg/dL OR Creatinine clearance at least 50 mL/min Other: Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception No uncontrolled serious medical or psychiatric illness

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: See Disease Characteristics At least 3 weeks since prior chemotherapy and recovered No prior camptothecin Endocrine therapy: Not specified Radiotherapy: See Disease Characteristics At least 3 weeks since prior radiotherapy and recovered Surgery: At least 2 weeks since prior major surgery