Irinotecan and Gemcitabine in Treating Patients With Recurrent or Progressive Stage III or Stage IV Non-Small Cell Lung Cancer

DISEASE CHARACTERISTICS:

* Histologically or cytologically confirmed non-small cell lung cancer (NSCLC), meeting 1 of the following stage criteria:

  * Stage IIIA or IIIB disease

    * Progressive disease
  * Stage IV disease

    * Failed 1 prior platinum-based chemotherapy regimen, including adjuvant therapy
* Measurable or evaluable disease, as defined by 1 of the following criteria:

  * At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR \> 10 mm by spiral CT scan
  * Lesions apparent on CT scan that do not meet the criterion for measurability
* Brain metastases allowed provided patient has received definitive therapy for metastases, is asymptomatic, and has extra-CNS metastases

PATIENT CHARACTERISTICS:

Age

* 18 and over

Performance status

* ECOG 0-1

Life expectancy

* More than 12 weeks

Hematopoietic

* WBC ≥ 3,000/mm\^3
* Absolute neutrophil count ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3

Hepatic

* AST and ALT ≤ 1.5 times normal
* Alkaline phosphatase \< 1.5 times normal
* Bilirubin ≤ 1.3 mg/dL

Renal

* Creatinine ≤ 1.6 mg/dL OR
* Creatinine clearance ≥ 50 mL/min

Cardiovascular

* No unstable angina
* No congestive heart failure
* No myocardial infarction within the past 3 months
* No life-threatening ventricular arrhythmia requiring maintenance therapy

Other

* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective barrier contraception during and for 3 months after completion of study treatment
* No uncontrolled seizure disorder
* No uncontrolled diabetes mellitus
* No active infection requiring systemic therapy
* No other malignancy within the past 5 years except nonmelanoma skin cancer or carcinoma in situ of the cervix
* No other unstable or serious condition

PRIOR CONCURRENT THERAPY:

Biologic therapy

* Not specified

Chemotherapy

* See Disease Characteristics
* At least 3 weeks since prior chemotherapy
* Prior irinotecan allowed
* No prior gemcitabine
* No more than 1 prior chemotherapy regimen for NSCLC, excluding gefitinib
* No other concurrent chemotherapy

Endocrine therapy

* Not specified

Radiotherapy

* At least 4 weeks since prior radiotherapy
* No concurrent radiotherapy

Surgery

* Not specified

Other

* More than 1 month since prior participation in another clinical trial using an investigational agent
* No other concurrent investigational agents