THYROXINE SUPPRESSIVE THERAPY IN PATIENTS WITH NODULAR THYROID-DISEASE

Purpose: To review evidence about thyroxine suppressive therapy in pat ients with thyroid nodules, including the clinical importance and natu ral history of nodules and the effects and potential side effects of t hyroxine therapy. Data Sources: English-language articles published fr om 1986 to December 1996 were identified through searches of the MEDLI NE database, selected bibliographies, and personal files. Data Extract ion: Randomized, controlled trials and nonrandomized trials of thyroxi ne suppressive therapy for solitary and predominantly solid thyroid no dules were reviewed. In most studies, nodule cytology was evaluated by fine-needle aspiration biopsy. Therapy was considered suppressive if suppression was documented by thyroid-stimulating hormone-releasing ho rmone tests or sensitive thyroid-stimulating hormone assays. Response was defined as a decrease of 50% or more in nodule size or volume; mos t recent studies measured nodule size by ultrasonography. Data Synthes is: The evidence suggests that thyroxine suppressive therapy fails to shrink most nodules: Only 10% to 20% of nodules responded to this trea tment. Fine-needle aspiration biopsy is more reliable in distinguishin g benign from malignant nodules. Recent studies suggest that spontaneo us decrease in size with complete disappearance of thyroid nodules is not uncommon. No data show that thyroxine therapy arrests further grow th in most existing nodules or prevents the emergence of new nodules. Postoperative thyroxine therapy does not seem to prevent recurrence of thyroid nodules except in patients with a history of radiation therap y. Potential adverse effects of long-term suppressive therapy include osteoporosis and heart disease. Conclusions: Patients with cytological ly benign nodules are best followed without thyroxine treatment. Most benign nodules remain stable in size and remain benign when monitored for a long time. For nodules that increase in size, biopsy should be d one again or surgery should be performed.