Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically confirmed* anaplastic or poorly differentiated variant thyroid cancer,
including 1 of the following:

- Recurrent/regionally advanced disease no longer amenable to definitive curative
surgery or radiotherapy

- Untreated metastatic disease NOTE: *If original/diagnostic tumor blocks are
unavailable, tumor must be accessible for pretreatment core needle biopsy

- Must have relapsed or progressed during or after prior combined modality therapy
(e.g., systemic chemotherapy and radiotherapy) for regionally advanced (but not
metastatic) disease

- Measurable or evaluable disease

- Patent trachea and airway by screening direct and indirect laryngoscopy* NOTE: *For
patients with bulky thyroid/neck masses and/or suspected airway obstruction

- No active brain metastases, as evidenced by any of the following:

- Symptomatic involvement

- Cerebral edema by CT scan or MRI

- Radiographic evidence of progression since definitive therapy

- Continued requirement for corticosteroids

PATIENT CHARACTERISTICS:

Age

- 18 and over

Performance status

- ECOG 0-2

Life expectancy

- At least 12 weeks

Hematopoietic

- Absolute granulocyte count at least 1,500/mm^3

- Platelet count at least 75,000/mm^3

- Hemoglobin at least 8.5 g/dL

Hepatic

- Bilirubin no greater than 1.5 times upper limit of normal (ULN)

- ALT and AST no greater than 3.5 times ULN

Renal

- Creatinine no greater than 1.5 times ULN

Cardiovascular

- LVEF at least 50% by MUGA

- EKG normal

- No evidence of prior myocardial infarction (e.g., significant Q waves), QTc
greater than 450 msec, or other clinically significant abnormalities

- No history of angina (even if controlled by medication)

- No congestive heart failure

- No uncontrolled atrial arrhythmias

- No clinically significant arrhythmias, including any of the following:

- Conduction abnormalities

- Nodal junctional arrhythmias and dysrhythmias

- Sinus bradycardia or tachycardia

- Supraventricular arrhythmias

- Atrial fibrillation or flutter

- Syncope or vasovagal episodes

- No significant heart wall abnormality or heart muscle damage by MUGA

- No uncontrolled hypertension (blood pressure consistently greater than 150 mm Hg
systolic and 100 mm Hg diastolic regardless of medication)

- Patients with previous hypertension are allowed provided there is clinical
documentation of controlled blood pressure for 2 months prior to study
enrollment

- No symptomatic peripheral vascular disease

- No symptomatic cerebrovascular disease

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception

- No grade 2 or greater preexisting motor or sensory peripheral neuropathy

- No uncontrolled hypokalemia or hypomagnesemia

- No concurrent serious infection

- No other nonmalignant medical illness that is uncontrolled or whose control may be
jeopardized by study therapy

- No psychiatric disorders or other conditions that would preclude study compliance

PRIOR CONCURRENT THERAPY:

Biologic therapy

- No concurrent biologic therapy

- No concurrent immunotherapy

- No concurrent prophylactic colony-stimulating factors (e.g., filgrastim [G-CSF] or
sargramostim [GM-CSF])

Chemotherapy

- See Disease Characteristics

- At least 3 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin)

- No other concurrent chemotherapy

Endocrine therapy

- See Disease Characteristics

- No concurrent hormonal therapy, except any of the following:

- Gonadotropin-releasing hormone agonists for hormone-refractory prostate cancer

- Hormone replacement therapy

- Oral contraceptives

- Megestrol for anorexia/cachexia

Radiotherapy

- See Disease Characteristics

- More than 4 weeks since prior radiotherapy with progressive disease beyond radiation
ports

- No prior radiotherapy to more than 30% of the bone marrow

- No concurrent radiotherapy

Surgery

- See Disease Characteristics

- More than 4 weeks since prior major surgery

Other

- At least 6 weeks since other prior therapy associated with delayed toxicity

- No prior therapy for metastatic disease

- No concurrent medication(s) known to prolong the QTc interval, unless medication(s)
can be held for at least 72 hours before, during, and for at least 6 hours after
study drug administration

- No other concurrent investigational therapy

- No other concurrent antineoplastic or cytotoxic therapy