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.