Medical Treatment of Benign Thyroid Nodules: Have We Defined a Benefit?

Thyroid nodules, detected by physical examination, are present in 4% to 7% of the U.S. population [1, 2]. This figure represents only the tip of the iceberg because ultrasonography done in patients without clinically apparent thyroid disease and autopsy studies show that thyroid nodules are present in 30% to 50% of adult thyroid glands [3]. The chance that a nodule detected by physical examination is malignant is less than 10%; most studies show a prevalence of approximately 4% [4, 5]. Fine-needle aspiration biopsy of thyroid nodules has emerged as the most important diagnostic study to perform to distinguish malignant from benign thyroid nodules. Because at least 90% of thyroid nodules are benign, physicians and patients are presented with the interesting problem of how to manage benign nodules. The magnitude of the problem is illustrated by considering that as many as 10 to 20 million persons in the United States have a benign and clinically apparent thyroid nodule. Surgical excision of all such nodules is clearly not acceptable to patients, physicians, or the health care industry: This practice could consume in excess of $100 billion annually. A more popular option has been medical therapy, consisting of oral thyroxine therapy to suppress pituitary secretion of thyroid-stimulating hormone, thereby removing an important growth factor for thyroid follicle cells. Such therapy is relatively inexpensive: One year of thyroxine therapy costs $50 to $100. However, even this conservative form of therapy would cost $1 to $2 billion annually. A third option is to do nothing except examine the patient annually and determine whether the clinical characteristics of the nodule have changed.

The critical issue is …