Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed thyroid cancer

- Progressive or refractory disease within the past 6 months

- Locally advanced or metastatic disease

- Measurable disease, defined as ≥ 1 measurable lesion defined by RECIST criteria

- Not amenable to surgical resection or external-beam radiotherapy or refractory to
radioiodine therapy

- No untreated brain metastasis

PATIENT CHARACTERISTICS:

- ECOG performance status 0-2

- Life expectancy > 3 months

- ANC ≥ 1,500/mm³

- Platelet count ≥ 100,000/mm³

- Hemoglobin ≥ 9.0 g/dL

- Creatinine < 1.5 mg/dL

- Total bilirubin ≤ 1.0 times upper limit of normal (ULN)

- ALT and AST ≤ 3.0 times ULN

- No known hypersensitivity to the study drug

- No serious uncontrolled systemic intercurrent illness (e.g., infection or poorly
controlled diabetes)

- No history of significant neurological or mental disorder, including seizures or
dementia

- No other malignancy within the past 5 years except for carcinoma in situ of the
cervix or nonmelanomatous carcinoma of the skin

- No active uncontrolled cardiac disease

- No myocardial infarction within the past 12 months

- Able to take oral medication

- No active peptic ulcer disease

- Must have patient compliance and geographic proximity for adequate follow-up

PRIOR CONCURRENT THERAPY:

- At least 30 days since prior mTor-inhibitor therapy (e.g., temsirolimus) or
non-hormonal anticancer therapy

- At least 2 weeks since prior and no concurrent P-glycoprotein, CYP3A4, and CYP3A5
inhibitors or inducers

- No prior surgical procedure affecting absorption

- No other concurrent systemic chemotherapy, investigational drug, or radiotherapy