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 irofulven in treating patients with relapsed or refractory non-small cell lung cancer.

OBJECTIVES: I. Determine the response rate to 6-hydroxymethylacylfulvene (HMAF) as salvage chemotherapy in patients with relapsed or refractory non-small cell lung cancer. II. Determine the duration of response to this regimen in this patient population. III. Determine the effect of prior response to chemotherapy on the response to HMAF in these patients. IV. Determine the survival and failure-free survival of patients treated with HMAF. V. Evaluate the toxicity profile of HMAF as salvage therapy in these patients.

OUTLINE: Patients are stratified into relapsed or refractory patient groups based on results achieved with prior therapy. Patients receive 6-hydroxymethylacylfulvene IV over 5 minutes daily for 5 days. Courses repeat every 28 days. Patients with stable or responding disease are treated for a minimum of 6 courses (2 courses beyond optimal response) in the absence of unacceptable toxic effects or disease progression. Patients are followed at least every 3 months for 1 year, then every 6 months until death.

PROJECTED ACCRUAL: A total of 66 patients (33 for each stratum) will be accrued for this study within 12-18 months.

DISEASE CHARACTERISTICS: Histologically or cytologically proven recurrent or refractory non-small cell lung cancer Squamous cell Adenocarcinoma (including bronchoalveolar cell) Large cell anaplastic (giant and clear cell carcinomas) Measurable disease (not bone disease only, pleural or pericardial effusions, or irradiated lesions, unless progression is documented after radiotherapy) No CNS metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-1 Life expectancy: Not specified Hematopoietic: Granulocyte count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hepatic: Bilirubin no greater 1.5 mg/dL SGOT no greater than 2 times upper limit of normal (ULN) Renal: Creatinine no greater than ULN Cardiovascular: No active cardiac disease No unstable angina No myocardial infarction within 6 months No congestive heart failure No inability to tolerate hypotension Other: Not pregnant or nursing Fertile patients must use effective contraception HIV negative No uncontrolled diabetes mellitus No psychiatric disorders No concurrent secondary malignancies except nonmelanomatous skin cancer or patients with less than a 30% risk of relapse

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: At least 4 weeks since prior chemotherapy (6 weeks since mitomycin) At least 1 prior chemotherapy agent or combination, including adjuvant or neoadjuvant therapy for non-small cell lung cancer No more than 1 prior chemotherapy agent or combination for metastatic or recurrent disease No prior HMAF No other concurrent chemotherapy Endocrine therapy: No concurrent hormonal therapy except for nondisease related conditions Radiotherapy: See Disease Characteristics At least 4 weeks since prior radiotherapy No concurrent palliative radiotherapy Surgery: Not specified