Inclusion Criteria:

- Platelet count >= 100,000/mm^3

- Histologically or cytologically confirmed non-small cell lung cancer meeting 1 of the
following criteria:

- Stage IV disease

- Stage IIIB disease with pleural effusion

- Recurrent disease after surgery or radiotherapy

- Measurable disease, defined as >= 1 lesion that can be accurately measured in at
least 1 dimension (longest diameter to be recorded) >= 20 mm by conventional
techniques OR >= 10 mm by spiral CT scan

- Previously treated brain metastasis allowed, provided there is no bleeding, no
midline shift, no need for steroids or anti-convulsants, and no symptoms

- Must agree to obtain residual tumor tissue available from the existing diagnostic
biopsy tumor tissue

- ECOG performance status (PS) 0-1 OR Karnofsky PS 60-100%

- Life expectancy > 12 weeks

- WBC >= 3,000/mm^3

- Absolute neutrophil count >= 1,500/mm^3

- Bilirubin =< 1.5 times upper limit of normal (ULN)

- AST and ALT =< 2.5 times ULN

- Creatinine =< 3 times ULN OR Creatinine clearance >= 60 mL/min

- No uncontrolled congestive heart failure or potentially life-threatening arrhythmia

- No angina at rest

- No neuropathy >= grade 2

- No chronic diarrhea or history of inflammatory bowel disease

- No history of pulmonary fibrosis (other than in an irradiated field)

- No other concurrent serious medical illness

- O2 saturation > 92% on room air

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No history of allergic reactions to compounds of similar chemical or biological
composition to dasatinib

- No QTc prolongation (i.e., QTC >= 480 msec) or other significant ECG abnormalities
that could lead to adverse effects if the QTc interval were prolonged

- No medical condition that impairs the ability to swallow, retain, or absorb dasatinib
including, but not limited to, any of the following:

- Gastrointestinal tract disease resulting in an inability to take oral
medication, requirement for IV alimentation, prior surgical procedures affecting
absorption, active peptic ulcer disease

- No myocardial infarction or ventricular tachyarrhythmia within the past 6 months

- LVEF normal

- No major conduction abnormality (unless cardiac pacemaker is present)

- No ongoing or active infection

- No history of significant bleeding disorder (congenital [von Willebrand's disease] or
acquired [antifactor VIII antibodies])

- No psychiatric illness or social situation that would preclude study compliance

- No prior chemotherapy or biologic therapy for recurrent or metastatic non-small cell
lung cancer

- Adjuvant cytotoxic chemotherapy after surgical resection or chemotherapy with
radiation for locally advanced disease (curative intent) allowed provided disease
recurrence >= 3 months after completion of last chemotherapy dose

- Measurable disease must be outside the radiotherapy port OR clearly growing inside
the port

- No prior radiotherapy to >= 25% of the marrow-containing skeleton

- At least 7 days since prior and no concurrent medications that are inhibitors or
inducers of CYP3A4

- At least 7 days since prior and no concurrent agents with proarrhythmic potential

- No other concurrent investigational agents

- No other concurrent anticancer agents or therapies

- No concurrent antiretroviral therapy for HIV-positive patients

- No concurrent systemic antacids (H2 receptor antagonists and proton pump inhibitors)

- Locally acting antacids allowed except for 2 hours before and after dasatinib
administration