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