Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed carcinoma of the breast

- Unresectable disease

- Locally advanced or metastatic (AJCC stage IV) disease

- Estrogen receptor-negative and progesterone receptor-negative breast cancer defined
as < 10% expression by immunohistochemistry (IHC)

- Measurable disease, defined (per RECIST) as ≥ 1 unidimensionally measurable lesion ≥
20 mm by conventional techniques or ≥ 10 mm by spiral CT scan

- Measurable target lesions must not be in a previously irradiated field

- Patients with locally advanced, unresectable disease must have progression of disease
following no more than one first-line chemotherapy regimen

- Patients with evidence of recurrent disease during or within 6 months after adjuvant
chemotherapy will be considered to have failed one line of chemotherapy for
metastatic disease

- HER2-positive patients, defined as IHC 3+ or fluorescence in situ hybridization
(FISH) amplification > 2.1, must have received trastuzumab (Herceptin®) in either the
adjuvant or metastatic setting and have had recurrence or progression of disease,
respectively

- No known brain metastases

PATIENT CHARACTERISTICS:

Inclusion criteria:

- Male and female patients eligible

- Menopausal status not specified

- ECOG performance status (PS) ≤ 2 (Karnofsky PS 60-100%)

- Life expectancy > 3 months

- Absolute neutrophil count ≥ 1,500/mcL

- Platelet count ≥ 100,000/mcL

- Hemoglobin > 9 g/dL

- Total bilirubin normal

- AST(SGOT)/ALT(SGPT) ≤ 2.5 x institutional upper limit of normal

- Creatinine normal OR creatinine clearance ≥ 60 mL/min

- Urine protein creatinine (UPC) ratio must be ≤ 1.0

- Patients with a UPC ratio > 1.0 must have a 24-hour urine protein < 1,000 mg to
be eligible for study

- Not pregnant or nursing

- Women of child-bearing potential and men must use adequate contraception (e.g.,
hormonal or barrier method of birth control or abstinence) prior to, during, and for
8 weeks after completion of study therapy

- Able to understand and willing to sign a written informed consent document

Exclusion criteria:

- History of allergic reactions attributed to compounds of similar chemical or
biological composition to AZD0530

- QTc interval ≥ 500 msecs

- Any condition that impairs the ability to swallow AZD0530 tablets, including the
following:

- Gastrointestinal tract disease resulting in an inability to take oral medication
or a requirement for IV alimentation

- Prior surgical procedures affecting absorption

- Active peptic ulcer disease

- Intercurrent cardiac dysfunction including, but not limited to, any of the following:

- Symptomatic congestive heart failure

- Unstable angina pectoris

- Uncontrolled cardiac arrhythmia

- History of myocardial infarction within 6 months of treatment

- Uncontrolled intercurrent illness including, but not limited to, ongoing or active
infection or psychiatric illness/social situations that would limit compliance with
study requirements

- Severe restrictive or obstructive lung disease according to baseline pulmonary
function studies including any of the following PFT parameters:

- Total lung capacity < 60%

- Forced vital capacity < 50%

- FEV_1 < 50%

- DLCO < 50%

- Resting room air O_2 saturation < 92% or a decline in O_2 saturation > 4% with
exercise

PRIOR CONCURRENT THERAPY:

- See Disease Characteristics

- Patients with metastatic disease may have received no more than 1 prior chemotherapy
regimen

- No unresolved toxicity ≥ grade 3 from agents received more than 3 weeks earlier

- No chemotherapy, radiotherapy, or investigational therapy within 3 weeks (6 weeks for
nitrosoureas or mitomycin C) prior to entering study

- No luteinizing hormone-releasing hormone agonists within 4 weeks prior to study entry

- More than 7 days since prior and no concurrent use of specifically prohibited CYP3A4
agents

- No concurrent megestrol acetate, even when prescribed for appetite stimulation

- No other concurrent investigational or commercial agents for the treatment of breast
cancer

- No concurrent combination antiretroviral therapy for HIV-positive patients

- No concurrent megestrol acetate