Temozolomide in Patients With Progressive or Recurrent Non-small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologically confirmed progressive or recurrent stage IV non-small cell lung cancer (NSCLC) Patient with brain metastases on CT or MRI scan are included Symptomatic cases must have had brain radiotherapy at least one month prior to registration Patients without brain metastases: At least one target lesion Bidimensionally measurable Not previously irradiated PATIENT CHARACTERISTICS: Age: Under 70 Performance status: WHO 0-2 Life expectancy: Not specified Hematopoietic: Absolute neutrophil count greater than 2,000/mm3 WBC greater than 3,500/mm3 Platelet count greater than 100,000/mm3 Hepatic: Bilirubin no greater than 1.46 mg/dL Transaminases less than 2 times upper limit of normal Renal: Creatinine no greater than 1.70 mg/dL Creatinine clearance greater than 60 mL/min Other: No prior or concurrent malignancies at other sites with the exception of adequately treated in situ carcinoma of the cervix or basal and squamous carcinoma of the skin Not pregnant or nursing Negative pregnancy test 24 hours prior to commencing temozolomide PRIOR CONCURRENT THERAPY: No other investigational drugs allowed during this study Biologic therapy: Prior biologic therapy allowed No concurrent biologic therapy allowed No concurrent growth factor to induce neutrophil increase No concurrent erythropoietin Chemotherapy: No prior chemotherapy for metastatic disease At least 3 months since any neoadjuvant and adjuvant treatment, and induction chemotherapy preceding radical radiotherapy Endocrine therapy: See Protocol Outline Concurrent steroids should be maintained on the lowest dose possible Radiotherapy: Prior radiotherapy allowed Concurrent local radiotherapy to nonbrain lesions allowed Concurrent palliative radiation therapy of bone lesions permitted No concurrent radiation to target lesions No concurrent brain radiotherapy Surgery: Prior surgery allowed