Pemetrexed Disodium and Carboplatin in Treating Patients With Extensive-Stage Small Cell Lung Cancer

DISEASE CHARACTERISTICS:

Histologically or cytologically confirmed small cell lung cancer

Previously untreated disease
No mixed histology

Extensive-stage disease

Clinically significant effusions (e.g., symptomatic pleural effusion) must be drained prior to treatment
Measurable disease, defined as ≥ 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan

No symptomatic, untreated, or uncontrolled CNS metastases

CNS metastases previously treated with whole-brain radiotherapy allowed

PATIENT CHARACTERISTICS:

Age

18 and over

Performance status

ECOG 0-2

Life expectancy

At least 12 weeks

Hematopoietic

Absolute neutrophil count ≥ 1,500/mm^3
Platelet count ≥ 100,000/mm^3
Hemoglobin ≥ 9.0 g/dL

Hepatic

Total bilirubin ≤ 1.5 times upper limit of normal (ULN) OR
Direct bilirubin normal
ALT and AST ≤ 3 times ULN (5 times ULN if there is liver involvement)

Renal

Creatinine clearance ≥ 45 mL/min

Cardiovascular

No angina pectoris
No congestive heart failure within the past 3 months, unless ejection fraction > 40%
No cardiac arrhythmia
No myocardial infarction within the past 3 months
No hypertension, including labile hypertension

Pulmonary

No interstitial pneumonia
No extensive and symptomatic interstitial fibrosis of the lung

Other

Not pregnant or nursing
Negative pregnancy test
Fertile patients must use effective contraception
No history of poor compliance with antihypertensive medication
Able to take folic acid, cyanocobalamin (vitamin B_12) supplementation, or dexamethasone
No uncontrolled diabetes
No serious condition that would preclude study participation
No clinically significant infection
No significant traumatic injury

No other malignancy within the past 5 years except carcinoma in situ of the cervix or nonmelanoma skin cancer

Low-grade (Gleason score ≤ 6), localized prostate cancer allowed even if diagnosed < 5 years prior to study entry
No seizure disorder
No other severe and/or uncontrolled medical condition

PRIOR CONCURRENT THERAPY:

Biologic therapy

No concurrent immunotherapy
No concurrent immunomodulating agents

Chemotherapy

No other concurrent chemotherapy

Endocrine therapy

No concurrent hormonal therapy

Radiotherapy

See Disease Characteristics

Prior palliative radiotherapy allowed

No prior palliative radiotherapy to the chest except for ≤ 3 fractions for superior vena cava syndrome
No concurrent radiotherapy

Surgery

More than 4 weeks since prior major surgery* (i.e., laparotomy) or open biopsy
More than 2 weeks since prior minor surgery* NOTE: *Insertion of a vascular access device is not considered major or minor surgery

Other

More than 4 weeks since prior investigational therapy
No concurrent Hypericum perforatum (St. John's wort)
No concurrent inducers or inhibitors of CYP3A4
No concurrent medications that are metabolized by CYP3A4
No aspirin dose ≥ 1.3 grams per day for ≥ 10 days prior to and after study treatment
No other concurrent cytostatic or cytotoxic agents