This phase II trial is studying how well bortezomib works in treating patients with metastatic thyroid cancer that did not respond to radioactive iodine therapy. Bortezomib may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth

PRIMARY OBJECTIVE:

I. Determine the efficacy of bortezomib, in terms of tumor response rate, in patients with metastatic papillary or follicular thyroid cancer unresponsive to prior radioiodine therapy.

SECONDARY OBJECTIVE:

I. Determine the clinical activity of this drug, in terms of progression-free survival, in patients treated with this drug.

OUTLINE: This is an open-label, multicenter study. Patients receive bortezomib IV over 3-5 seconds on days 1, 4, 8, and 11. Treatment repeats every 21 days for at least 4 courses in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed periodically.

Inclusion Criteria:

• The Eastern Cooperative Oncology Group (ECOG) 0-2 OR Karnofsky 60-100%
• Platelet count >= 100,000/mm^3
• Absolute neutrophil count >= 1,500/mm^3
• White Blood Count (WBC) >= 3,000/mm^3
• Aspartate aminotransferase (AST) and Alanine aminotransferase (ALT) =< 2.5 times upper limit of normal
• Bilirubin normal
• No symptomatic congestive heart failure
• Creatinine normal OR creatinine clearance >= 60 mL/min
• No unstable angina pectoris
• No cardiac arrhythmia
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No other malignancy within the past 5 years except basal cell skin cancer or carcinoma in situ of the cervix
• No ongoing or active infection
• No psychiatric illness or social situation that would preclude study compliance
• No other uncontrolled illness
• At least 4 weeks since prior chemotherapy
• No more than 2 prior chemotherapy regimens
• At least 6 months since prior external beam radiotherapy for locoregional disease in the thyroid bed or to the cervical or upper mediastinal lymph nodes (dose =< 6,000 cGy)
• At least 6 months since prior radioiodine therapy
• No prior external radiotherapy to the measured tumor
• Prior thyroidectomy allowed
• No concurrent combination antiretroviral therapy for HIV-positive patients
• No other concurrent investigational agents
• No other concurrent anticancer therapy
• Unresponsive to prior radioiodine therapy
• Histologically confirmed differentiated thyroid cancer-papillary or follicular type, including, but not limited to, any of the following variants: hurthle cell (oxyphilic), insular, columnar cell, tall cell
• Metastatic disease
• At least 1 unidimensionally measurable lesion >= 20 mm by conventional techniques OR >= 10 mm by spiral CT scan
• No prior radiotherapy to the only measurable lesion
• No radioiodine uptake in the measured metastatic tumor by radioiodine scan (Note: Must have had >= 1 radioiodine scan since the last radioiodine treatment)
• No known brain metastases