RATIONALE: Drugs used in chemotherapy, such as irinotecan and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells.

PURPOSE: This phase II trial is studying how well giving irinotecan together with carboplatin works in treating patients with metastatic or recurrent small cell lung cancer.

OBJECTIVES:

• Determine the response rates in patients with metastatic or recurrent small cell lung cancer treated with irinotecan hydrochloride and carboplatin.
• Determine the median survival of patients treated with this regimen.
• Determine the toxicity of this regimen in these patients.

OUTLINE: This is a multicenter study. Patients are stratified according to prior chemotherapy (yes vs no) and disease stage (metastatic vs relapsed).

Patients receive irinotecan hydrochloride IV over 90 minutes and carboplatin IV over 15-30 minutes on day 1. Treatment repeats every 21 days for 6 courses in the absence of disease progression or unacceptable toxicity.

DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed small cell lung cancer, meeting 1 of the following criteria:

  • Previously untreated metastatic or extensive disease

    • Malignant pleural effusion or multifocal lung disease is considered metastatic or extensive disease
    • Prior radiotherapy allowed

  • Recurrent disease

    • Limited, metastatic, or extensive disease

    • Relapsed after prior chemotherapy, excluding irinotecan hydrochloride

      • At least 90 days since prior chemotherapy

• Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 1 cm by physical examination or radiographic techniques

• Known brain metastases allowed

PATIENT CHARACTERISTICS:

• ECOG performance status 0-2
• Life expectancy ≥ 3 months
• White Blood Cells > 3,000/mm³
• Absolute neutrophil count ≥ 1,500/mm³
• Platelet count ≥ 100,000/mm³
• Hemoglobin ≥ 9.0 g/dL
• Bilirubin ≤ 1.5 mg/dL
• SGOT ≤ 2.5 times upper limit of normal (ULN) (5 times ULN if liver metastases present)
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for 3 months after completion of study treatment
• No medical disease that, in the opinion of the investigator, would preclude study treatment

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• At least 10 days since prior radiotherapy (including brain)
• No prior irinotecan hydrochloride
• At least 2 weeks since prior and no concurrent anticonvulsants
• No concurrent radiotherapy

Up to 36 months

Of the 80 patients, 72 were assessable.