DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed recurrent small cell lung cancer (SCLC) after platinum-containing chemotherapy regimen with or without thoracic radiotherapy

  • Limited stage or extensive stage SCLC

• Measurable disease

  • At least 20 mm by conventional techniques OR
  • At least 10 mm with spiral CT scan
• No pleural effusions, bone metastases, brain metastases, or abnormal radionucleotide scans as sole evidence of disease

• No symptomatic or uncontrolled brain or leptomeningeal disease

  • Previously treated brain metastases allowed if neurologically stable

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• Zubrod 0-2

Life expectancy:

• Not specified

Hematopoietic:

• WBC at least 2,500/mm^3
• Platelet count at least 70,000/mm^3

Hepatic:

• Bilirubin no greater than 1.5 mg/dL
• SGOT no greater than 2 times upper limit of normal

Renal:

• Creatinine no greater than 1.5 mg/dL OR
• Creatinine clearance at least 60 mL/min

Cardiovascular:

• No symptomatic heart disease
• No myocardial infarction within the past 6 months

Other:

• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception for 1 month before, during, and for 2 months after study
• No pre-existing retinal degenerative disease (e.g., retinitis pigmentosa or associated disorders)
• No other serious concurrent illness
• No other malignancy within the past 5 years except localized nonmelanoma skin cancer or carcinoma in situ

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• See Disease Characteristics
• At least 3 weeks since prior chemotherapy
• No more than 2 prior chemotherapy regimens

Endocrine therapy:

• Concurrent steroids allowed at stable dose

Radiotherapy:

• See Disease Characteristics
• No prior radiotherapy to study lesions

Surgery:

• Not specified

Other:

• At least 3 weeks since prior systemic retinoid or carotenoid therapy
• No concurrent anticonvulsants