Gemcitabine and Oxaliplatin as Second-Line Therapy in Treating Patients With Stage III or Stage IV Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS: * Histologically proven stage IIIB or IV non-small cell lung cancer (NSCLC) * Failed first-line chemotherapy * Must have received ≥ 1, but no more than 2, prior chemotherapy regimens for stage IIIB or IV NSCLC * Prior radiotherapy or surgery for earlier stage disease allowed, provided target lesions chosen for response assessment have not have been irradiated * At least 1 unidimensionally measurable lesion with diameter ≥ 20 mm by conventional methods OR ≥ 10 mm by spiral CT scan * If a single lesion is identified as the target lesion, histological or cytological confirmation of this lesion is required * No symptomatic brain metastases * Clinically stable brain metastases on a stable dose of (or no longer requiring) dexamethasone allowed PATIENT CHARACTERISTICS: * ECOG performance status 0 or 1 * Absolute neutrophil count ≥ 1,000/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Bilirubin ≤ 1.5 mg/dL * AST and ALT ≤ 2.5 times upper limit of normal (ULN) (5 times ULN if liver involvement) * Creatinine ≤ 1.5 mg/dL * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for 2 months after completion of study treatment * No history of an acute cardiac or CNS event within the past 6 months, including any of the following: * Unstable angina * Myocardial infarction * Clinically relevant arrhythmia * Stroke * No current clinical evidence of congestive heart failure or unstable coronary artery disease * No peripheral neuropathy \> grade 1 * No history of hypersensitivity to study drugs * No serious uncontrolled medical or psychiatric illness, including any of the following: * Serious infection * Interstitial pneumonia * Extensive and symptomatic fibrosis of the lung * No other malignancy within the past year, except for squamous cell or basal cell carcinoma of the skin, carcinoma in situ of the cervix, or superficial transitional cell carcinoma of the bladder PRIOR CONCURRENT THERAPY: * See Disease Characteristics * Recovered from prior surgery * At least 4 weeks since prior cranial radiation for brain metastases * More than 4 weeks since prior participation in another investigational drug study * No concurrent immunotherapy