Everolimus in Treating Patients With Locally Advanced or Metastatic Thyroid Cancer

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