Restoration of Radioiodine Uptake in Thyroid Carcinoma: A Clinical Trial

OBJECTIVES: I. Determine the ability of azacitidine to restore iodine uptake by dedifferentiated thyroid cancer, enabling detection and treatment with iodine I 131 in patients with metastatic follicular or papillary thyroid cancer. II. Evaluate different doses and schedules of azacitidine administration to determine an optimally effective combination for restoration of iodine I 131 uptake with acceptable toxicity in this patient population. III. Determine the efficacy of azacitidine plus iodine I 131 in this patient population. OUTLINE: This is a dose escalation study of azacitidine. Patients undergo a control phase consisting of oral liothyronine sodium twice daily on weeks 1-4 and a low iodine diet on weeks 4-7. At week 6, patients receive a scan dose of iodine I 131 followed by whole body scanning over 5 days. Beginning at week 7, patients undergo a treatment phase consisting of oral liothyronine sodium twice daily for 3 weeks, azacitidine subcutaneously daily for 10 or 20 days (weeks 7-11) and a low iodine diet on weeks 8-11. During week 11, patients undergo additional whole body scanning over 5 days followed by a therapeutic dose of iodine I 131. Patients achieving successful therapy receive 5 additional doses of azacitidine. Cohorts of 4 patients receive escalating doses of azacitidine until demonstrable radioiodine uptake is seen or the maximum tolerated dose (MTD) is determined. The MTD is defined as the dose preceding that at which 2 of 8 patients experience dose limiting toxicity. Patients are followed weekly for 8 weeks. PROJECTED ACCRUAL: A total of 38 patients will be accrued for this study.