DISEASE CHARACTERISTICS: Histologically or cytologically proven non-small cell lung cancer (adenocarcinoma, large cell, squamous cell, or mixture) Stage IIIB due to any of the following: Malignant pleural effusion Supraclavicular node involvement Contralateral hilar node involvement Not eligible for CALGB protocols of combined therapy and chest irradiation Stage IV Any stage that has recurred or progressed after surgery or radiotherapy Measurable or evaluable disease Does not include the following: Bone metastases Pleural or peritoneal effusions Irradiated lesions, unless progression documented after radiation therapy No CNS metastases