Lomustine in Treating Patients With Stage III or Stage IV Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: Histologically confirmed non-small cell bronchogenic carcinoma, including the following histologic subtypes: Squamous cell Adenocarcinoma Adenosquamous Large cell anaplastic Bronchoalveolar Non-small cell carcinoma not otherwise specified (NOS) Stage IIIB disease (with a pleural effusion) or stage IV disease Stage IV patients with brain metastases are eligible provided the brain metastases are clinically stable after treatment with surgery and/or radiation therapy Tumors must test positive for aberrant methylation of the MGMT gene by methylation-specific polymerase chain reaction Bidimensionally measurable or evaluable disease PATIENT CHARACTERISTICS: ECOG performance status 0-2 No other active malignancies WBC ≥ 4,000/mm^3 OR absolute neutrophil count ≥ 2,000/mm^3 Platelet count ≥ 100,000/mm^3 Total bilirubin normal AST < 5 times upper limit of normal Serum creatinine ≤ 1.5 mg/dL OR creatinine clearance ≥ 60 mL/min No uncontrolled serious active infection Not pregnant or nursing PRIOR CONCURRENT THERAPY: See Disease Characteristics More than 3 weeks since prior chemotherapy No more than 2 prior chemotherapy regimens No prior therapy with nitrosoureas Recovered from prior radiation therapy