Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed relapsed or refractory non-small cell lung
carcinoma (NSCLC)

- Squamous cell carcinoma

- Basaloid carcinoma

- Adenocarcinoma

- Bronchoalveolar carcinoma

- Adenosquamous cell carcinoma

- Large cell carcinoma

- Large cell neuroendocrine carcinoma

- Giant cell carcinoma

- Sarcomatoid carcinoma

- Non-small cell carcinoma not otherwise specified

- Histologic or cytologic documentation of recurrence required if disease previously
completely resected

- Must have had only 1 prior chemotherapy regimen, including adjuvant or neoadjuvant
therapy for NSCLC

- At least 1 unidimensionally measurable lesion

- At least 20 mm with conventional techniques OR

- At least 10 mm with spiral CT scan

- Lesions that are not considered measurable include the following:

- Bone lesions

- Leptomeningeal disease

- Ascites

- Pleural/pericardial effusion

- Abdominal masses not confirmed and followed by imaging techniques

- Cystic lesions

- Tumor lesions in a previously irradiated area

- Controlled CNS metastases allowed if patient is neurologically stable and off
steroids

PATIENT CHARACTERISTICS:

Age:

- 18 and over

Performance status:

- ECOG 0-1

Life expectancy:

- Not specified

Hematopoietic:

- Granulocyte count at least 1,500/mm3

- Platelet count at least 100,000/mm3

Hepatic:

- Bilirubin no greater than 1.5 mg/dL

Renal:

- Creatinine no greater than upper limit of normal

Other:

- Not pregnant or nursing

- Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

- Not specified

Chemotherapy:

- See Disease Characteristics

- At least 4 weeks since prior chemotherapy (6 weeks for mitomycin)

- No prior irinotecan or other camptothecin drug

- No other concurrent chemotherapy

Endocrine therapy:

- See Disease Characteristics

- No concurrent hormonal therapy except for non-cancer-related conditions (e.g.,
insulin for diabetes)

- No concurrent steroids except for adrenal failure

Radiotherapy:

- See Disease Characteristics

- Prior radiotherapy for symptomatic lesions or those that might produce disability
(e.g., painful bone metastases) allowed if other measurable disease present

- At least 4 weeks since prior radiotherapy

- No concurrent palliative radiotherapy

Surgery:

- See Disease Characteristics