DISEASE CHARACTERISTICS:

* Histologically or cytologically confirmed extensive stage small cell lung cancer (SCLC)

* Malignant pleural effusion constitutes extensive stage disease
* Must have disease outside area of prior surgical resection or a new lesion must be present
* Controlled brain metastases allowed (asymptomatic and previously treated with surgery and/or radiotherapy)

* Brain metastases must be re-evaluated by CT scan or MRI after completion of radiotherapy or surgery

PATIENT CHARACTERISTICS:

Age:

* 18 and over

Performance status:

* Zubrod 0-2

Life expectancy:

* Not specified

Hematopoietic:

* Absolute granulocyte count at least 1,500/mm\^3
* WBC at least 3,000/mm\^3
* Platelet count at least 100,000/mm\^3

Hepatic:

* Bilirubin no greater than 1.25 times upper limit of normal (ULN)
* SGOT or SGPT no greater than 2.5 times ULN

Renal:

* Not specified

Other:

* Not pregnant or nursing
* Fertile patients must use effective contraception
* No other malignancy within the past 5 years except adequately treated basal cell or squamous cell skin cancer, carcinoma in situ of the cervix, or other adequately treated stage I or II cancer in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy:

* No prior biologic therapy for SCLC

Chemotherapy:

* No prior systemic chemotherapy for SCLC

Endocrine therapy:

* Not specified

Radiotherapy:

* See Disease Characteristics
* No prior radiotherapy for SCLC except for brain metastases

Surgery:

* See Disease Characteristics
* At least 2 weeks since prior surgery (thoracic or other major surgery) and recovered