DISEASE CHARACTERISTICS:

• Histologically confirmed metastatic non-small cell lung cancer for which no curative therapy exists
• Stage IIIB with pleural effusion allowed
• Measurable or evaluable disease
• CNS metastases allowed if disease stable at least 4 weeks following completion of surgery and/or radiotherapy and no anticonvulsant required

PATIENT CHARACTERISTICS:

Age:

• Over 18

Performance status:

• ECOG 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• Absolute neutrophil count at least 1,500/mm^3
• Platelet count greater than 100,000/mm^3

Hepatic:

• Bilirubin less than 2.0 mg/dL
• SGOT no greater than 3 times upper limit of normal (ULN) (no greater than 5 times ULN if tumor involves liver)

Renal:

• Creatinine clearance at least 70 mL/min

Other:

• No other malignancies within past 3 years except nonmelanomatous skin cancer and carcinoma in situ of the cervix
• HIV negative
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective birth control
• No active infection
• No concurrent medical condition that would preclude study participation

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior systemic chemotherapy for lung cancer
• No prior irinotecan or paclitaxel

Endocrine therapy:

• Not specified

Radiotherapy:

• See Disease Characteristics
• At least 4 weeks since prior wide field radiotherapy
• No prior radiotherapy to greater than 20% of bone marrow allowed

Surgery:

• See Disease Characteristics
• Recovered from prior surgery