Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed small cell lung cancer

- Extensive stage with disease progression or recurrence after first-line therapy
with either a cisplatin or carboplatin

- Patients who received prior primary curative chemoradiotherapy for limited stage
disease but who have experience subsequent recurrent disease* within the primary
tumor site or previously irradiated field OR with distant metastases are
eligible NOTE: *Patients with clinical evidence of recurrent disease do not
require a confirmatory biopsy to be eligible

- Measurable disease by plain radiographs, CT scan, or MRI within the past 28 days

- Measurable disease inside the prior radiotherapy field allowed provided the
lesion is progressing by CT scan OR there is measurable disease outside of the
prior radiotherapy field

- Must have disease outside the area of prior surgical resection OR a new lesion
must be present

- Must have received only 1 prior platinum-based regimen which contained either a
cisplatin or carboplatin AND have the information necessary to be placed in 1 of the
following groups:

- Platinum-sensitive disease, defined as an initial response to platinum-based
therapy and subsequent progression > 90 days after last platinum-based treatment

- Platinum-refractory disease, defined as no response to platinum-based therapy,
disease progression during platinum-based therapy, or disease progression ≤ 90
days after completion of platinum-based therapy

- Brain or leptomeningeal metastases by CT scan or MRI allowed provided the patient is
asymptomatic, has no deficits on neurologic exam, and is not receiving corticosteroid
therapy to control symptoms

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- Zubrod 0-1

Life expectancy

- Not specified

Hematopoietic

- Absolute neutrophil count ≥ 1,500/mm^3

- Platelet count ≥ 100,000/mm^3

- No bleeding diathesis

Hepatic

- Bilirubin ≤ 2 times upper limit of normal (ULN)

- Alkaline phosphatase ≤ 2 times ULN

- ALT or AST ≤ 2 times ULN

- PT OR INR AND PTT < 1.5 times ULN (except for patients on warfarin or heparin)

Renal

- Creatinine normal OR Creatinine clearance ≥ 60 mL/min

Cardiovascular

- No significant history of cardiac disease, including any of the following:

- Uncontrolled hypertension

- Unstable angina

- Congestive heart failure

- Myocardial infarction within the past 6 months

- Cardiac ventricular arrhythmias requiring medication

Gastrointestinal

- No uncontrolled inflammatory gastrointestinal (GI) disease (e.g., Crohn's disease or
ulcerative colitis)

- No intractable nausea or vomiting

- No GI tract disease resulting in an inability to take oral medication

- No malabsorption syndrome

- No requirement for IV alimentation

- Able to swallow pills and/or receive enteral medications via gastrostomy feeding tube

Other

- Not pregnant or nursing

- Fertile patients must use effective contraception

- Willing to provide smoking history

- 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 adequately treated
stage I or II cancer in complete remission

PRIOR CONCURRENT THERAPY:

Biologic therapy

- Not specified

Chemotherapy

- See Disease Characteristics

- At least 90 days since prior chemotherapy

Endocrine therapy

- See Disease Characteristics

- No concurrent systemic corticosteroids

- Concurrent topical and/or inhaled steroids allowed

Radiotherapy

- See Disease Characteristics

- At least 3 weeks since prior radiotherapy and recovered

- No concurrent radiotherapy to measurable lesions

Surgery

- See Disease Characteristics

- At least 2 weeks since prior surgery (thoracic or other major surgery) and recovered

- No prior surgical procedures affecting absorption

Other

- Concurrent prophylactic or therapeutic anticoagulation treatment with warfarin or
heparin allowed

- Concurrent nonenzyme-inducing anticonvulsants (e.g., Keppra^®) allowed for patients
requiring anticonvulsants